Prevalence of Red Blood Cell Alloimmunization in Single and Multiple-Transfused Cancer Patients and its Associated Factors at the Kilimanjaro Christian Medical Centre, Zonal Referral Hospital in Northern Tanzania

Prevalence of Red Blood Cell Alloimmunization in Single and Multiple-Transfused Cancer Patients and its Associated Factors at the Kilimanjaro Christian Medical Centre, Zonal Referral Hospital in Northern Tanzania | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Prevalence of Red Blood Cell Alloimmunization in Single and Multiple-Transfused Cancer Patients and its Associated Factors at the Kilimanjaro Christian Medical Centre, Zonal Referral Hospital in Northern Tanzania Jemrath Bikombo, Paul kosiyo, Boaz Owuor This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9376072/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Background Cancer is the leading cause of death worldwide. Blood transfusions are necessary during cancer management. However, the dependence on blood transfusions in cancer patients predisposes them to red blood cell alloimmunization, leading to complications such as difficulty in finding compatible blood, transfusion delays and haemolytic reactions. In Tanzania, blood banks do not screen for antigens other than A, B and D, which may stimulate alloimmunization. Objectives The present study evaluated the prevalence of red blood cell alloimmunization in single and multiple-transfused cancer patients and its associated factors at Kilimanjaro Christian Medical Centre, zonal referral Hospital in northern Tanzania. Methodology: This cross-sectional study was conducted in northern Tanzania, where a total of 186 transfused cancer patients were recruited through purposive sampling. Blood samples were collected from participants for alloantibody screening and identification. Descriptive statistics was used determine the proportions of the transfused cancer patients. Chi-square test was used to determine differences in proportions. Mann–Whitney U test was used to determine differences in the medians of the continuous variables while multivariable regression was used to determine associations between socio-demographic, clinical factors and red blood cell alloimmunization. Results Red blood cell alloimmunization prevalence was 2.1% and 9.7% among single and multiple-transfused cancer patients, respectively. The overall prevalence among transfused cancer patients was 5.9%. Anti-E 5(33.3%) and anti-Kell 4(26.7%) were the most common alloantibodies, followed by anti-C and anti-Lea 2(13.3%) each and two undetected antibodies. Multiple transfusions significantly increased the odds of alloimmunization (COR = 4.88; p = 0.047); (AOR = 7.32; 95% CI: 1.39–38.65; p = 0.019), whereas higher but nonsignificant odds were observed among patients aged 26–49 and 50–84 years, females, and those with a history of pregnancy (AOR = 4.19; 95% CI: 0.32–54.07; p = 0.272),(AOR = 3.93; 95% CI: 0.36–43.36; p = 0.264), (AOR = 0.50; 95% CI: 0.03–7.70; p = 0.619),(AOR = 2.88; 95% CI: 0.18–44.82; p = 0.449) respectively. No significant associations were found with ABO blood groups. Conclusion Multiple blood transfusions is significantly associated with red blood cell alloimmunization in cancer patients hence regular antibody screening and extended antigen matching should be implemented to improve transfusion safety in Tanzania. Biological sciences/Cancer Health sciences/Diseases Health sciences/Medical research Health sciences/Oncology Red blood cell alloimmunization Multiple blood transfusions Cancer patients Figures Figure 1 Figure 2 Figure 3 Figure 4 Background of the study Cancer is a major global health burden and a leading cause of mortality, with increasing impact in Tanzania ( 1 – 3 ).The treatment and management of cancers include chemotherapy, radiotherapy and surgery( 4 – 6 ). Cancer treatment can lead to side effects such as anaemia, bleeding, and neutropenia, which necessitate multiple blood transfusions for patients( 7 ). This increases the risk of developing red blood cell alloimmunization ( 8 – 10 ). Alloimmunization is an immune reaction against foreign antigens that may occur naturally during pregnancy but is more commonly seen as a complication of repeated blood transfusions in cancer patients.( 11 – 13 ). Red blood cell alloimmunization is the production of alloantibodies against red blood cell nonself antigens( 14 ). There are currently 362 red cell antigens in 45 recognized blood group systems( 15 ). Since routine matching between donors and recipients typically includes only antigens from the ABO system and Rhesus D antigens, patients are frequently exposed to other foreign RBC antigens( 16 ). This leads to the formation of alloantibodies that are clinically significant and capable of causing severe transfusion reactions and haemolytic disease in newborns, complicating future transfusions to obtain compatible blood ( 17 ). Different rates of alloimmunization prevalence in multiple types of transfused cancer patients have been reported in various regions; however, in Tanzania, this remains unknown, especially in northern Tanzania. Existing studies indicate that the distributions of RBC antigens and alloantibodies differ across ethnic groups and human populations; therefore, the results may differ from those of previous studies( 18 ). RBC alloimmunization in repeatedly transfused patients is influenced by number of transfusions, pregnancy history, demographic factors, underlying disease, immune status, therapies, inflammation, and antigen immunogenicity( 18 ). Studies shows that solid cancers carry higher risk of alloimmunization than patients with hematologic malignancies( 19 ). Despite the documented benefits of blood transfusions, RBC alloimmunization has been reported in multiple transfused patients. Blood transfusion safety is a global concern and among the 2030 Sustainable Development Goals set forward by the WHO ( 20 ). Crucial compatibility tests for ensuring safety in blood transfusion include “ABO and RhD grouping for donors and patients, antibody screening, and crossmatching between the patient’s serum and the donor's red blood cells”( 20 ). Alloantibody screening and identification are not commonly performed at transfusion centres in Tanzania, resulting in limited data on RBC alloimmunization. Only two previous studies in Tanzania focused solely on multiple transfused sickle cell disease patients and reported significant findings. To date, no research has investigated RBC alloimmunization in Tanzanian cancer patients. Therefore, this study determined the prevalence, specific alloantibodies and factors associated with RBC alloimmunization in single and multiple transfused cancer patients at KCMC, Zonal Referral Hospital in northern Tanzania. Methods Study Site The study was conducted at the Kilimanjaro Christian Medical Centre (KCMC), a Teaching and Zonal Referral Consultant Hospital situated in Moshi, in the Kilimanjaro region of northern Tanzania from May to December 2025. According to the 2022 census, KCMC serves almost eleven million people in northern Tanzania as a referral hospital( 21 ). The hospital has a well-established cancer care centre that provides clinics, treatment, and follow-up to more than 6000 cancer patients. Study Design This study was a comparative cross-sectional study involving both single and multiple-transfused cancer patients aimed at establishing the prevalence, specific alloantibodies and factors associated with RBC alloimmunization. Study population The study targeted cancer patients (n = 93) with multiple transfusions attending clinics and/or admitted to a cancer care centre. Additional single transfused patients (n = 93) were also recruited for comparison purposes (controls). Inclusion criteria The study included all cancer patients of any age with a history of multiple blood transfusions. A similar proportion of single transfusions was included for comparison purposes. Exclusion criteria The study excluded cancer patients with autoimmune conditions, including idiopathic thrombocytopenia, rheumatoid arthritis, systemic lupus erythematosus and transplant patients, as well as HIV patients. Data collection Recruitment and sample collection The nonprobability purposive sampling method was utilized to obtain the study participants, in which the participant was selected if he or she had been transfused with one or more units of blood during the treatment period until a sample size of 93 for each group was attained. For consenting participants, 4 mL of blood was collected into SST and EDTA tubes, from which serum and EDTA plasma were obtained and stored at 2–6°C or − 20°C. Laboratory procedures Alloantibody screening and identification Alloantibodies in the serum or plasma were screened and identified by the indirect antiglobulin test (IAT) using the tube method. Commercial screening red cells (Maxi-screen Cell3®) and panel cells (Identicell cells10®) expressing Rhesus (C, E, c, e, D), MNS (M, N, S, s), Kell (K, k, Kpa), Lewis (Lea, Leb), Duffy (Fya, Fyb), and Kidd (Jka, Jkb) (procured from Lorne Laboratories UK) antigens were used. The procedure included immediate spinning at room temperature, incubation at 37°C with LISS, and antihuman globulin (AHG) testing after washing. Agglutination was observed macroscopically and microscopically, whereas negative results were confirmed by using IgG-sensitized cells. Data analysis The data were entered into the Statistical Package for Social Sciences (SPSS) version 28. Further analysis was performed in STATA version 19. Descriptive statistics were used to determine the prevalence of alloimmunization among the participants. The chi-square test of independence was used to determine differences in proportions and the associations between alloimmunization and the number of blood transfusions. The Mann–Whitney U test was used to compare the number of units of blood transfused between alloimmunized and non-alloimmunized patients. Binary and multivariable logistic regression was used to find odds for developing alloimmunization while controlling for age, sex and history of pregnancy. A p value ≤ 0.05 was considered statistically significant. Results General, demographic and clinical characteristics of the study participants Multiple transfused (n = 93) and single transfused cancer patients (n = 93) were recruited into the study as participants and controls, respectively. The participants had a mean age of 44 years (SD = 21), with nearly half (47.8%) aged 50–84 years, indicating the dominance of older adults. Males comprised 55.9% and females 44.1%; 64.5% were married. A history of pregnancy was reported by 36.0%, a known sensitizing factor for RBC alloimmunization. Solid tumours accounted for 51.1% of the cases, and haematological malignancies accounted for 48.9% (Table 1 ). Table 1 General, demographic and clinical characteristics of the study participants Variable Frequency n (%) Age 0–25 43 23.1 26–49 54 29 50–84 89 47.8 Gender Male 104 55.9 Female 82 44.1 Mariage status Yes 120 64.5 No 66 35.5 Pregnancy History No 67 36.0 Yes 119 64.0 Cancer type Solid tumor 95 51.1 Hematology 91 48.9 Distribution of hematologic and solid organ malignancies Leukaemia was the most common malignancy (34.4%), followed by lymphoma and prostate cancer (9.7% each) and breast cancer (7.0%). Colon, gastric, and lung cancers were observed at lower frequencies. Overall, haematological cancers predominated (Fig. 1 ). ABO blood group distribution of the study participants Regarding ABO blood group distribution, O-positive was most common (45%), followed by A-positive (27%) and B-positive (21%). AB-positive accounted for 5%, while B-negative and O-negative were rare (1%) each (Fig. 2 ). Distribution of specific red blood cell alloantibodies A total of 13 RBC alloantibodies of known specificity were detected in 9 alloimmunized patients. Two unidentified alloantibodies were also observed. Anti-E was the most common alloantibody with 5 (33.3%), followed by anti-K with 4 (26.7%). Anti-Le and anti-C were 2 (13.3%) each and the remaining 2 (13.3%) could not be determined. Among patients with haematological cancers, the predominant red blood cell alloantibodies identified were anti-E (n = 3), anti-K (n = 3), and anti-Lea (n = 2). In contrast, patients with solid tumours most commonly exhibited anti-C (n = 2), anti-E (n = 2), and anti-K (n = 1). These findings indicate variation in the distribution and frequency of red blood cell alloantibodies between haematological and solid cancers. Most alloimmunized patients 8 (72.7%) developed a single alloantibody specificity, while 3(27.3%) had multiple alloantibodies. Patients with higher transfusion exposure developed clinically significant alloantibodies, predominantly anti‑E and anti‑K, with occasional detection of anti‑C and anti‑Leᵃ. In contrast, individuals with lower transfusion requirements exhibited minimal or no alloantibody formation. Overall, antibodies within the Rhesus and Kell systems were the most identified across cancer types (Fig. 3 ). Differences in the proportions of alloimmunized and non-alloimmunized transfused patients There was no statistically significant association between RBC alloimmunization and demographic or clinical characteristics. Although alloimmunization appeared more frequently among patients aged 50–84 years (54.5%; χ² = 1.321, p = 0.517), females (54.5%; χ² = 0.516, p = 0.540), and those with prior pregnancies (54.5%; χ² = 1.741, p = 0.207), these differences were not significant. Similarly, the rates of cancer type were comparable between solid tumours (54.5%) and haematological malignancies (45.5%; χ² = 0.056, p = 0.530). Marital status showed a trend toward greater alloimmunization among married patients (90.9%) than among unmarried patients (9.1%), but this difference did not reach statistical significance (χ² = 3.557, p = 0.052). Overall, none of the demographic or clinical variables independently predicted RBC alloimmunization. Logistic regression revealed no significant associations between demographic or clinical variables and RBC alloimmunization. Compared with patients aged 0–25 years, those aged 26–49 years (AOR = 4.19; 95% CI: 0.32–54.07; p = 0.272) and 50–84 years (AOR = 3.93; 95% CI: 0.36–43.36; p = 0.264) had higher odds, but these differences were not significant. Female sex (AOR = 0.50; 95% CI: 0.03–7.70; p = 0.619), pregnancy history (AOR = 2.88; 95% CI: 0.18–44.82; p = 0.449), and cancer type (AOR = 0.84; 95% CI: 0.21–3.80; p = 0.812) also showed no independent associations (Table 2 , Table 3 ). Table 2 Differences in the proportions of alloimmunized and non-alloimmunized transfused patients Variable RBC alloimmunization Negative n (%) Positive n (%) Chi-square P value Age 1.321 0.517 0–25 42(24.0) 1(9.1) 26–49 50(28.6) 4(36.4) 50–84 83(47.4) 6(54.5) Gender 0.516 0.540 Male 99(56.6) 5(45.5) Female 76(43.4) 6(54.5) Mariage status 3.557 0.052 Yes 110(62.9) 10(90.9) No 65(37.1) 1(9.1) Pregnancy History 1.741 0.207 No 114(65.1) 5(45.5) Yes 61(43.9) 6(54.5) Cancer type 0.056 0.530 Solid tumor 89(50.9) 6(54.5) Hematology 86(49.1) 5(45.5) Differences in proportions between RBC alloimmunized patients and no alloimmunized patients were determined via the chi-square test of independence. A p value ≤ 0.05 was considered statistically significant. Table 3 Associations between demographic and clinical factors and red blood cell alloimmunization. Variable COR (95%CI) P value AOR (95%CI) P value Age 0–25 1 1 26–49 3.36(0.36–31.23) 0.287 4.19(0.32–54.07) 0.272 50–84 3.04(0.35–26.04) 0.311 3.93(0.36–43.36) 0.264 Gender Male 1 1 Female 1.56(0.46–5.32) 0.474 0.50(0.03–7.70) 0.619 Pregnancy No 1 1 Yes 2.24(0.66–7.65) 0.197 2.88(0.18–44.82) 0.449 Cancer type Solid tumor 1 1 Hematology 0.86(0.25–2.93) 0.813 0.84(0.21–3.80) 0.812 Univariate and multivariate logistic regression were performed to assess factors associated with red blood cell alloimmunization, and crude and adjusted odds ratios (95% CI) were calculated with reference categories of age 0–25 years, male sex, no pregnancy history, and solid tumours. Prevalence of red blood cell alloimmunization in multiple-transfused cancer patients A total of 11 (5.9%) patients developed alloantibodies, and 175 (94.1%) tested negative for alloantibodies. Alloimmunization was more common in patients with multiple transfusions (9.7%, 9/93) than in those with a single transfusion (2.1%, 2/93(Fig. 4 ). The association between the number of transfusions and RBC alloimmunization in multiple-transfused cancer patients The current study revealed that patients who developed alloantibodies required significantly more transfusions than those who did not develop alloantibodies (mean 129.4 vs. 91.2 units; Mann‒Whitney U test, Z = − 2.44, p = 0.015). The majority of alloimmunized patients had multiple transfusions (81.8%) rather than single transfusions (18.2%), %), a difference that was statistically significant (χ² = 4.735, p = 0.030). Multiple transfusions were associated with markedly increased odds of alloimmunization (COR = 4.88; p = 0.047), and after adjusting for confounders, multiple transfusions remained an independent predictor, with patients receiving multiple transfusions showing more than sevenfold higher odds of alloimmunization (AOR = 7.32; 95% CI: 1.39–38.65; p = 0.019) (Table 4 ). Table 4 Association between the number of transfusions and RBC alloimmunization Number of transfusions RBC Alloimmunization Mann‒Whitney U test, Z Negative n (%) Positive n (%) χ 2 p value COR (95% Cl) P value Single 91(52.0) 2(18.2) 1 Multiple 84(48.0) 9(81.8) 4.735 0.030 4.88(1.02–23.21) 0.047 Z= -2.44, P = 0.015 The data are summarized as frequencies and percentages [n (%)]. Group comparisons were conducted by the chi-square test and the Mann–Whitney U test, as appropriate. Crude odds ratios (CORs) with corresponding 95% confidence intervals (CIs) are provided. The Association between the ABO blood groups and RBC alloimmunization Blood group was not associated with RBC alloimmunization. Most non-alloimmunized patients were O (46.3%) or A (28%), while alloimmunized patients had a more even distribution: O (36.4%), B (36.4%), A (18.2%), AB (9.1%). The association was not statistically significant (p = 0.555). RBC alloimmunization did not differ by blood group. Most non-alloimmunized patients were O (46.3%) or A (28%), while alloimmunized patients were distributed as O (36.4%), B (36.4%), A (18.2%), and AB (9.1%) (χ² = 2.087, p = 0.555). Patients with blood groups A, B, or AB had higher odds than those with group O, but this difference was not statistically significant. After adjustment for potential confounders, ABO blood group showed no significant association with RBC alloimmunization. Using blood group O as the reference, the adjusted odds ratios were: A (AOR = 0.91; 95% CI: 0.15–5.55; p = 0.917), B (AOR = 4.06; 95% CI: 0.83–19.91; p = 0.084), and AB (AOR = 2.38; 95% CI: 0.21–26.93; p = 0.483). None of these estimates reached statistical significance (Table 5 ). Table 5 The Association between the ABO blood groups and RBC alloimmunization Variable RBC alloimmunization Negative n (%) Positive n (%) Chi-square P value Blood group 2.087 0.555 A 49 ( 28 ) 2 (18.2) B 36 (20.6) 4 (36.4) AB 9 (5.1) 1 (9.1) O 81(46.3) 4(36.4) COR (95%CI) P-value AOR (95%CI) P-value Blood group O 1 1 A 0.83(0.15–4.68) 0.830 0.91(0.15–5.55) 0.917 B 2.25(053 − 9.50) 0.27 4.06(0.83–19.91) 0.084 AB 2.25(0.23–22.37) 0.489 2.38(0.21–26.93) 0.483 Distribution of RBC alloimmunization by ABO blood group and the Chi-square test, corresponding crude (COR) and adjusted (AOR) logistic regression analyses assessing the association between blood group and alloimmunization OR = Crude Odds Ratio; AOR = Adjusted Odds Ratio; CI = Confidence Interval. Blood group O was used as the reference category (OR = 1). Odds ratios were obtained using logistic regression analysis. P values < 0 .05 were considered statistically significant. Discussion Alloimmunization occurs when an external antigen is introduced into an immunocompetent host that lacks the antigen and triggers an immune response. Due to variations in genetics between recipients and donors of blood, alloimmunization with red blood cell antigens is one of the recognized risks of blood transfusion alloimmunization and has also been linked to pregnancy( 22 , 23 ). Age, sex, underlying disease, and the quantity and frequency of transfusions can all affect alloimmunization ( 13 , 24 ). In the present study, the prevalence of RBC alloimmunization was 2.1% among single-transfused patients and 9.7% among multiple-transfused patients, yielding an overall prevalence of 5.9%, indicating that only a small proportion developed alloantibodies to transfused blood. Onoriode et al. (2022) reported a higher incidence of alloimmunization (13.3%) than 9.7% reported in our study among multiple transfused patients, a difference that may be attributed to variations in patient characteristics, transfusion burden, and antibody detection methods( 14 ). Similarly, Hand et al. (2020) reported a prevalence of 7.5%, close to our findings, supporting evidence that patients receiving multiple transfusions, especially those with haematological cancers, have an increased risk of alloantibody development( 25 ). A study at Moi Referral and Teaching Hospital reported an alloimmunization prevalence of 6.2%, lower than the 9.7% in the present study, whereas a cross-sectional study in Malaysia reported 5.3%( 12 , 18 ). The consistency across these studies suggests that our findings are representative of cancer patient populations managed under comparable transfusion practices. Compared with our findings, Mangwana 2019 reported a markedly lower alloimmunization prevalence of 0.3%, likely reflecting a cohort predominantly composed of solid tumor patients who typically receive fewer transfusions. ( 26 ). Unni et al. (2024) and Moussa et al. (2023) reported lower rates (1% and 1.3%) than those reported in this study( 8 , 27 ). Furthermore, the absence of alloimmunization reported in a study in Uganda highlights the wide variability across studies, potentially explained by smaller sample sizes, lower transfusion intensity, or methodological differences in antibody detection( 28 ). Studies from Tanzania reported alloimmunization prevalence rates of 4.1% and 8.5% among multiply transfused patients with sickle cell disease, which are comparable to those reported in the present cohort of cancer patients( 29 , 30 ). This similarity points to a broader trend in transfusion-dependent populations, indicating that alloantibody formation is not disease-specific but is largely driven by cumulative transfusion exposure. The consistency of findings across different clinical groups reinforces alloimmunization as a predictable and clinically significant consequence of repeated transfusion, highlighting the need for routine monitoring and preventive measures. By placing the current cancer cohort within the wider body of evidence from sickle cell disease, this study emphasizes the importance of harmonized transfusion practices and strengthened immunopharmacological surveillance across diverse patient populations. The predominance of anti‑E in our cohort aligns with multiple studies reporting similar patterns. The study in Nigeria found anti‑E to be the most frequent alloantibody, representing nearly half of all cases among multi‑transfused patients, while Handa et al. , 2020 in India reported it as the leading antibody in oncology patients, with prevalence ranging from 30–40%( 14 , 25 ). Moussa et al. (2023) also identified anti‑E as the most common alloantibody in solid tumor patients, despite a low overall alloimmunization rate of 1.3%( 8 ).This pattern reflects the strong immunogenicity of Rh antigens, especially E and C, where donor and recipient mismatches often trigger alloantibodies, and populations with diverse Rh profiles are particularly prone to anti‑E. Anti‑K was the second most common alloantibody in our study (27.3%), reflecting the high immunogenicity of the Kell system despite its relatively low prevalence in donors. Similar patterns have been reported by in cancer patients( 25 ). Clinically, anti‑K is important as it can lead to haemolytic transfusion reactions and haemolytic disease of the foetus and newborn. The current findings differ from a study in Iran that found anti‑Kell to be the most common alloantibody, where anti‑K accounted for the largest share of identified antibodies( 31 ). Anti-C alloantibodies were identified in 18.2% of patients, reinforcing the high immunogenicity of the Rh system, consistent with findings by Unni et al . (2024) and Moussa et al. (2023)( 8 , 27 ). Anti-Lea was found in 18.2% of patients. While it rarely causes serious transfusion reactions, recognizing Anti-Lea is important because it can appear naturally, even without prior transfusion, and may affect interpretation of blood compatibility tests Two patients had unidentified antibodies, reflecting detection limits in resource‑constrained settings, consistent with a study by Onoriode et al. (2022) where in one subject with a single antibody, specificity could not be determined. Variability has been noted elsewhere; D et al. (2023) reported no alloimmunization, likely reflecting methodological constraints rather than true absence ( 28 ). The current study revealed no significant association between age and alloimmunization, although patients aged 26–49 and 50–84 years had higher odds of alloimmunization than those aged 0–25 years did. This study, in accordance with reports by Wanik et al. , revealed no significant association with the risk of alloimmunization( 18 ). However, a study by Wapukha et al. revealed a significant association between age and association and that older age groups had higher alloimmunization rates, likely due to repeated transfusions over time, resulting in greater exposure to foreign antigens( 12 ). There was no statistically significant association between sex and the risk of alloimmunization in this study, although females had slightly greater odds than males did. This study is consistent with a previous report by Wanik et al. However, studies performed in Kenya and the USA have shown that females are more at risk of alloimmunization than males are( 12 , 16 ). Participants with a prior history of pregnancy had greater odds of red cell alloimmunization than did those without such a history, although the association was not statistically significant. This finding is biologically plausible, as pregnancy exposes mothers to fetal red cell antigens that may stimulate antibody production, which is consistent with previous reports( 32 ). Comparable findings have been reported in transfusion studies, where pregnancy history was examined as a potential risk factor, but no statistically significant association with alloimmunization was demonstrated( 33 ). No significant association was observed between cancer type and red cell alloimmunization, with comparable rates in solid tumours and haematological malignancies. Several studies have suggested that patients with solid tumours may have an increased risk of developing red cell alloantibodies( 34 ), whereas others have reported high rates of haematological malignancies( 35 ). Despite the expectation that frequent transfusions in patients with haematological cancers might increase antigen exposure, our data did not reveal a meaningful difference between the groups. This lack of association may reflect the limited sample size or comparable transfusion practices across cancer types, highlighting the need for larger studies to clarify the influence of cancer type on alloimmunization risk. In the Current study, ABO blood groups were not significantly associated with RBC alloimmunization. While groups O and A predominated among non-alloimmunized patients, alloimmunized individuals were more evenly distributed across all blood groups. No significant associations were found and while groups B and AB had higher odds compared with group O. This aligns with Onoriode et al and Wanik et al . findings, which showed no significant link between alloimmunization and ABO or Rh (D) blood groups( 14 , 18 ).Wanik et al. also reported that blood group A is an independent risk factor for RBC alloimmunization in solid cancer patients, with 7.45 times higher odds than non-A patients. A study of repeatedly transfused leukaemia patients in Northern Sudan found alloimmunization was most frequent in blood group O and A positive individuals, with a significant link to blood group type( 36 ). The variation in findings across studies highlights the need for further research on the association between ABO blood groups and alloimmunization, as current evidence remains limited. In the present study, multiple transfusions were significantly associated with an elevated risk of RBC alloimmunization among transfused patients. Our findings align with reports indicating that the likelihood of alloimmunization increases with the number of RBC units transfused ( 18 , 29 , 37 , 38 ). Pessoni et al. ( 2018) reported that alloimmunization is correlated with both the number of transfused units and the number of transfusion episodes( 39 ). A retrospective study in Saudi Arabia revealed that repeated blood transfusions significantly increased the risk of alloimmunization, leading to recommendations for extended antigen typing in chronically transfused patients( 40 ). The findings of the present study contradict those of other studies, which revealed no significant association between the number of transfusions and alloimmunization( 14 , 41 , 42 ). A study from Sudan revealed no significant link between the number of transfusion units and the development of alloantibodies, indicating that individual factors such as genetic makeup, immune response, and inflammatory status may influence the risk of alloimmunization( 20 ). These differences may reflect variations in transfusion frequency, testing practices, antibody types, and the use of extended RBC phenotyping across centres. Limitations of the Study This study has limitations, despite the important findings. First, the antibody screening and identification methods may miss very low-titre alloantibodies, which could lead to an underestimation of the prevalence of alloimmunization. In addition, cancer treatment regimens may suppress the immune system, which could reduce antibody production and result in the detection of some alloantibodies. Conclusions Red blood cell alloimmunization was observed in 5.9% of transfused patients, with a higher prevalence among multiple transfused compared to single transfused patients, underscoring the role of cumulative antigen exposure in antibody development. Although higher rates were noted in older patients and females with a history of pregnancy, these associations were not statistically significant. The findings identify multiple transfusions as the principal driver for alloimmunization and highlight the need for extended antigen and alloantibody matching in patients requiring frequency transfusion support. Recommendations Multiple-transfused cancer patients should be periodically screened for alloimmunization in transfusion facilities for better selection of compatible blood and components to prevent transfusion complications. Abbreviations AHG; Antihuman Globulin, CCC; Cancer Care Center, EDTA; Ethylene Diamine Tetra Acetic Acid, HIV; Human Immunodeficiency Virus, ISBT; International Society of Blood Transfusion, KCMC; Kilimanjaro Christian Medical Center, LISS; Low Ionic Strength Solution; RBC; Red Blood Cells, SPSS; Statistical Package for Social Sciences, SST; Serum Separator Tube, WHO; World Health Organization Declarations Ethics approval and consent to participate Ethical approval was obtained from the Maseno University Scientific Ethical Review Committee (MUSERC, approval number MUSERC/01464/25) in Kenya and the KCMC University CRERC (PG197/2025) in Tanzania, granted a research ethical clearance certificate to conduct the study. Informed consent was obtained from the participants before inclusion in the study. The participants were informed of the purpose of the study and its benefits. Written informed consent was obtained from the study participants, and their participation was voluntary. In cases where minors were involved, the parent’s or guardian’s permission was sought. The participants were informed about their rights and how their data would be used to ensure transparency and trust. The confidentiality of the participants was observed, including their samples and their data. All the data collected from the participants were kept confidential, with access restricted to authorized personnel. All hard copy information was secured and stored in a lockable cabinet to maintain privacy and comply with ethical standards and regulations. The study adhered to the ethical standards in accordance with the World Medical Association’s Declaration of Helsinki 2024. Consent for publication Not applicable. Competing interests The authors declare that no competing interests exist. Author details 1 Department of Biomedical Science and Technology, School of Public Health Maseno University, Private Bag, Maseno Kenya. 2 Department of Medical Laboratory Sciences, School of Medicine, Maseno University, Private Bag, Maseno Kenya. 3 Department of Health Laboratory Sciences, School of Medicine, KCMC University, Moshi, Tanzania. Funding None. Author Contribution Jemrath Bikombo (JB), Paul Kosiyo (PK), and Boaz Owuor (BO) supervised the overall study. JB prepared the manuscript. All authors critically reviewed the final version of the manuscript and approved it for submission **.** Acknowledgement We sincerely thank the leaders of Kilimanjaro Christian Medical Centre (KCMC) and the KCMC Cancer Care Center for granting permission to conduct this study. We are deeply grateful to all the study participants whose involvement made this research possible. We also extend our appreciation to the laboratory staff for their dedication, cooperation, and hard work during the collection and analysis of the clinical samples. Data Availability The data supporting the results of this study are not publicly accessible because of their sensitive nature. However, they can be obtained from the corresponding author upon reasonable request. References Bray, F. et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J. Clin. 74 (3), 229–263. 10.3322/caac.21834 (2024). WHO. Global cancer burden growing, amidst mounting need for services. Saudi Med. J. 45 (3), 326–327 (2024). PubMed PMID: 38438207. WHO. WHO applauds new Lancet Report on Cancer in sub-Saharan Africa. WHOReginal Off Afr. 2022;(September):4. CDC. Cancer Survivors [Internet]. 2024 [cited 2024 Sep 18]. Cancer Treatments. Available from: https://www.cdc.gov/cancer-survivors/patients/treatments.html Miller, K. D. et al. Cancer treatment and survivorship statistics, 2022. CA Cancer J. Clin. 72 (5), 409–436. 10.3322/caac.21731 (2022). Treatment For Cancer. | Cancer Treatment Options | American Cancer Society [Internet]. [cited 2024 Sep 18]. Available from: https://www.cancer.org/cancer/managing-cancer/treatment-types.html Bozzini, C. et al. Anemia in patients receiving anticancer treatments: focus on novel therapeutic approaches. Front. Oncol. 14 , 1380358. 10.3389/fonc.2024.1380358 (2024). PubMed PMID: 38628673; PubMed Central PMCID: PMC11018927. Moussa, A. Y., Ibrahim, R. H. & Alshemali, S. A. Prevalence of alloimmunization against red blood cell antigens among oncology patients: A tertiary center experience in Syria. Asian J. Transfus. Sci. 1–5. 10.4103/ajts.ajts (2023). Sharma, A., Jasrotia, S. & Kumar, A. Effects of Chemotherapy on the Immune System: Implications for Cancer Treatment and Patient Outcomes. Naunyn Schmiedebergs Arch. Pharmacol. 397 (5), 2551–2566. 10.1007/s00210-023-02781-2 (2024). Types of Cancer Treatment - NCI [cgvMiniLanding] [Internet]. 2017 [cited 2024 Sep 18]. Located at: nciglobal, ncienterprise. Available from: https://www.cancer.gov/about-cancer/treatment/types Thakral, B., Saluja, K., Sharma, R. R. & Marwaha, N. Red cell alloimmunization in a transfused patient population: a study from a tertiary care hospital in Red cell alloimmunization in a transfused patient population : a study from a tertiary care hospital in north India. Hematology 8454 10.1179/102453308X343419 (2013). Wapukha, Z. B., Wanjau, T. W., Emonyi, W. I. & Marabi, P. M. Risk Factors for Red Blood Cell Alloimmunization in Multi-Transfused Oncology Patients at Moi Teaching and Referral Hospital, Kenya. Afr. J. Health Sci. 36 (3), 326–336 (2023). Arthur, C. M. & Stowell, S. R. The Development and Consequences of Red Blood Cell Alloimmunization. Annu. Rev. Pathol. Mech. Dis. 18 (1), 537–564. 10.1146/annurev-pathol-042320-110411 (2023). Onoriode, O., Benedict, N. & Ebose, E. Frequency, pattern and risk factors for red blood cell alloimmunization in multiply transfused cancer patients in a Nigerian Tertiary Healthcare facility in Nigeria. J. Blood Disord Transfus. 13 , 485 (2022). Red Cell Immunogenetics and Blood Group Terminology | ISBT Working Party | The International Society of Blood. Transfusion (ISBT) [Internet]. [cited 2024 Sep 5]. Available from: https://www.isbtweb.org/isbt-working-parties/rcibgt.html Karafin, M. S. et al. Risk factors for red blood cell alloimmunization in the Recipient Epidemiology and Donor Evaluation Study (REDS - III) database. Br. J. Haematol. 181 (5), 672–681. 10.1111/bjh.15182 (2018). Tormey, C. A. & Hendrickson, J. E. Transfusion-related red blood cell alloantibodies: induction and consequences. Blood 133 (17), 1821–1830. 10.1182/blood-2018-08-833962 (2019). Wanik, C. F. C. et al. Associated Factors of Red Blood Cell Alloimmunization among Solid Cancer Patients in Teaching Hospital in Malaysia. Bangladesh J. Med. Sci. 22 (2), 379–384. 10.3329/bjms.v22i2.64999 (2023). Evers, D. et al. Treatments for hematologic malignancies in contrast to those for solid cancers are associated with reduced red cell alloimmunization. Haematologica 102 (1), 52–59. 10.3324/haematol.2016.152074 (2017). Elkobani, H., Elbager, S. & Bayoumi, M. A. RBC Alloimmunization in Sudanese Multi-transfused Patients. J. Biosci. Appl. Res. 6 (1), 30–37. 10.21608/jbaar.2020.115765 (2020). report7.pdf [Internet]. [cited 2024 Dec 10]. Available from: https://sensa.nbs.go.tz/publication/report7.pdf Gothwa, M. et al. Red cell alloimmunization in pregnancy: a study from a premier tertiary care centre of Western India. Obstet. Gynecol. Sci. 66 (2), 84–93. 10.5468/ogs.22190 (2023). White, J. et al. Guideline for blood grouping and red cell antibody testing in pregnancy. Transfus. Med. 26 (4), 246–263. 10.1111/tme.12299 (2016). Almorish, M. A. W., Al-absi, B., Elkhalifa, A. M. E., Alhamidi, A. H. & Abdelrahman, M. Red blood cell alloimmunization in blood transfusion-dependent β thalassemia major patients in Sana’a City-Yemen. Sci. Rep. 14 (1), 1005. 10.1038/s41598-024-51561-2 (2024). Handa, A., Kukar, N., Maharishi, R. N., Syal, N. & Arora, H. Analysis of red cell alloimmunization in multi transfused patients at a Tertiary care teaching hospital. J. Fam Med. Prim. Care . 9 (6), 2907. 10.4103/jfmpc.jfmpc_351_20 (2020). Mangwana, S., Kacker, A. & Simon, N. Red Cell Alloimmunization in Multi-Transfused, Oncology Patients: Risks and Management. Glob J. Transfus. Med. 4 (1), 74. 10.4103/GJTM.GJTM_11_19 (2019). Unni, H., RED CELL ALLOIMMUNIZATION IN MULTI TRANSFUSED, D. M. & ONCOLOGY PATIENTS IN A TERTIARY CARE HOSPITAL. INDIAN J. Appl. Res. ;78–80. doi: 10.36106/ijar/3702879 (2024). Martin, D. O. C. W. S. A., Noah, N., Nancy, K. & Harriet, H. Frequency of red blood cell allo-immunization in patients undergoing blood transfusion at the Uganda Cancer Institute. Afr. Health Sci. 23 (4), 4. 10.4314/ahs.v23i4.39 (2023). Meda, E. et al. Red Blood Cell Alloimmunization in Sickle Cell Disease Patients in Tanzania. East. Afr. J. Public. Health . 11 (2), 775–780 (2014). PubMed PMID: 28979065; PubMed Central PMCID: PMC5624511. Tebuka, E., Charles, M. & Bhuko, J. O. Prevalence and risk factors for red blood cell alloimmunisation among sickle cell patients in Mwanza City, Tanzania. Afr. J. Lab. Med. 9 (1), 823. 10.4102/ajlm.v9i1 (2020). 823 PubMed PMID: 33102164; PubMed Central PMCID: PMC7564817. Foomani, F. M. et al. Frequency of Kell and Rh alloantibodies in Iranian Thalassemia Patients in Khorasan Razavi Province, Iran. Int. J. Hematol-Oncol Stem Cell. Res. 2023 Jan 16 . 10.18502/ijhoscr.v17i1.11707 Manduzio, P. et al. Alloimmunization in Pregnancy: A Practical Guide for Transfusion Medicine. Hemato 7 (1), 4. 10.3390/hemato7010004 (2026). Taremwa, I. M. et al. Red blood cell alloantibodies in transfused patients with haematological malignancies at Mbarara Regional Referral Hospital and the Uganda Cancer Institute: Prevalence, specificities and associated factors. Vox Sang. ;vox.70198. (2026). 10.1111/vox.70198 Arora, K. et al. Cancer type predicts alloimmunization following RhD-incompatible RBC transfusions. Transfus. (Paris) . 57 (4), 952–958. 10.1111/trf.13999 (2017). Asare, M., Hendrickson, J. E. & Tormey, C. A. Determination of Red Blood Cell Alloimmunization Rates in Transfused Patients with Hematologic and Oncologic Malignancies. Blood 128 (22), 1463–1463. 10.1182/blood.V128.22.1463.1463 (2016). Abdalkream Jawish, T. A. et al. Red Cell Alloimmunization in Repeatedly Transfused Sudanese Patients with leukemia in Northern Sudan. Asian Pac. J. Cancer Prev. APJCP . 24 (1), 21–24 (2023). .21 PubMed PMID: 36708548; PubMed Central PMCID: PMC10152849. Orhan, M., Adigül, M., Altindiş, M. & Köroğlu, M. Major and minor subgroup profile of blood in patients receiving multiple transfusions and donors. Asian J. Transfus. Sci. 16 (2), 219. 10.4103/ajts.ajts_17_21 (2022). Papay, P. et al. High Risk of Transfusion-induced Alloimmunization of Patients with Inflammatory Bowel Disease. Am J Med. ;125(7): 717.e1-717.e8. (2012). 10.1016/j.amjmed.2011.11.028 Pessoni, L. L., Ferreira, M. A. & Silva, J. C. R. da, Alcântara KC de. Red blood cell alloimmunization among hospitalized patients: transfusion reactions and low alloantibody identification rate. Hematol Transfus Cell Ther. ;40(4):326–31. (2018). 10.1016/j.htct.2018.04.001 Salman, A. et al. Wala Andejani. Impact of Extended Red Blood Cell Antigen Typing on Alloimmunization in Multi-Transfused Patients: A Retrospective Study [Internet]. Jan 9. (2025). 10.5281/ZENODO.15222887 Rofinda, Z. D., Darwin, E., Nasrul, E. & Wahid, I. Erythrocyte Antibody Due to Alloimmunization in Repeated Transfusion: A Meta-Analysis. Open. Access. Maced J. Med. Sci. 10 (F), 257–262. 10.3889/oamjms.2022.9035 (2022). Zalpuri, S. et al. Red-blood‐cell alloimmunization and number of red‐blood‐cell transfusions. Vox Sang . 102 (2), 144–149. 10.1111/j.1423-0410.2011.01517.x (2012). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 04 May, 2026 Reviews received at journal 01 May, 2026 Reviews received at journal 22 Apr, 2026 Reviewers agreed at journal 22 Apr, 2026 Reviewers agreed at journal 19 Apr, 2026 Reviewers agreed at journal 17 Apr, 2026 Reviewers invited by journal 17 Apr, 2026 Editor invited by journal 14 Apr, 2026 Editor assigned by journal 11 Apr, 2026 Submission checks completed at journal 11 Apr, 2026 First submitted to journal 10 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9376072","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":627774105,"identity":"783c83da-c639-4f32-a7f6-4e37caf4cd0e","order_by":0,"name":"Jemrath 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University","correspondingAuthor":false,"prefix":"","firstName":"Paul","middleName":"","lastName":"kosiyo","suffix":""},{"id":627774107,"identity":"a996459f-e9eb-49a9-8a09-859744c0447b","order_by":2,"name":"Boaz Owuor","email":"","orcid":"","institution":"Maseno University","correspondingAuthor":false,"prefix":"","firstName":"Boaz","middleName":"","lastName":"Owuor","suffix":""}],"badges":[],"createdAt":"2026-04-10 07:38:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9376072/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9376072/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107692253,"identity":"f7cbfb49-cec8-4f48-a755-ae07dcd9ef49","added_by":"auto","created_at":"2026-04-24 06:21:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":68753,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of cancer types\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9376072/v1/6075627ac9cd1a2bdf169f93.png"},{"id":107707103,"identity":"ba8b0752-9886-4261-a0c5-7f08b6965ecf","added_by":"auto","created_at":"2026-04-24 09:19:31","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":134997,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of blood groups of the study participants\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9376072/v1/be820b68da5e87814604e470.png"},{"id":107692255,"identity":"c0649549-6a84-4086-9794-dccc4faf92c8","added_by":"auto","created_at":"2026-04-24 06:21:46","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":13513,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of specific red blood cell alloantibodies\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9376072/v1/71e1728ee6c94d1f8f3d114c.png"},{"id":107692256,"identity":"d0316c19-44ca-493f-8b31-f08d49143a0b","added_by":"auto","created_at":"2026-04-24 06:21:46","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":36639,"visible":true,"origin":"","legend":"\u003cp\u003ePrevalence of red blood cell alloimmunization in single and multiple-transfused cancer patients\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-9376072/v1/a3c4b4f3ce6a94126c303d67.png"},{"id":107710364,"identity":"bb551d36-b889-40b4-bbeb-461e8f3ecb38","added_by":"auto","created_at":"2026-04-24 09:40:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":675653,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9376072/v1/eeb20cf1-5391-4229-9c61-5bb83442026d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Prevalence of Red Blood Cell Alloimmunization in Single and Multiple-Transfused Cancer Patients and its Associated Factors at the Kilimanjaro Christian Medical Centre, Zonal Referral Hospital in Northern Tanzania","fulltext":[{"header":"Background of the study","content":"\u003cp\u003eCancer is a major global health burden and a leading cause of mortality, with increasing impact in Tanzania (\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).The treatment and management of cancers include chemotherapy, radiotherapy and surgery(\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Cancer treatment can lead to side effects such as anaemia, bleeding, and neutropenia, which necessitate multiple blood transfusions for patients(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). This increases the risk of developing red blood cell alloimmunization (\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAlloimmunization is an immune reaction against foreign antigens that may occur naturally during pregnancy but is more commonly seen as a complication of repeated blood transfusions in cancer patients.(\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Red blood cell alloimmunization is the production of alloantibodies against red blood cell nonself antigens(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). There are currently 362 red cell antigens in 45 recognized blood group systems(\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Since routine matching between donors and recipients typically includes only antigens from the ABO system and Rhesus D antigens, patients are frequently exposed to other foreign RBC antigens(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). This leads to the formation of alloantibodies that are clinically significant and capable of causing severe transfusion reactions and haemolytic disease in newborns, complicating future transfusions to obtain compatible blood (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDifferent rates of alloimmunization prevalence in multiple types of transfused cancer patients have been reported in various regions; however, in Tanzania, this remains unknown, especially in northern Tanzania. Existing studies indicate that the distributions of RBC antigens and alloantibodies differ across ethnic groups and human populations; therefore, the results may differ from those of previous studies(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRBC alloimmunization in repeatedly transfused patients is influenced by number of transfusions, pregnancy history, demographic factors, underlying disease, immune status, therapies, inflammation, and antigen immunogenicity(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). Studies shows that solid cancers carry higher risk of alloimmunization than patients with hematologic malignancies(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Despite the documented benefits of blood transfusions, RBC alloimmunization has been reported in multiple transfused patients. Blood transfusion safety is a global concern and among the 2030 Sustainable Development Goals set forward by the WHO (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Crucial compatibility tests for ensuring safety in blood transfusion include \u0026ldquo;ABO and RhD grouping for donors and patients, antibody screening, and crossmatching between the patient\u0026rsquo;s serum and the donor's red blood cells\u0026rdquo;(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Alloantibody screening and identification are not commonly performed at transfusion centres in Tanzania, resulting in limited data on RBC alloimmunization. Only two previous studies in Tanzania focused solely on multiple transfused sickle cell disease patients and reported significant findings. To date, no research has investigated RBC alloimmunization in Tanzanian cancer patients. Therefore, this study determined the prevalence, specific alloantibodies and factors associated with RBC alloimmunization in single and multiple transfused cancer patients at KCMC, Zonal Referral Hospital in northern Tanzania.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Site\u003c/h2\u003e \u003cp\u003eThe study was conducted at the Kilimanjaro Christian Medical Centre (KCMC), a Teaching and Zonal Referral Consultant Hospital situated in Moshi, in the Kilimanjaro region of northern Tanzania from May to December 2025. According to the 2022 census, KCMC serves almost eleven million people in northern Tanzania as a referral hospital(\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). The hospital has a well-established cancer care centre that provides clinics, treatment, and follow-up to more than 6000 cancer patients.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eStudy Design\u003c/h3\u003e\n\u003cp\u003eThis study was a comparative cross-sectional study involving both single and multiple-transfused cancer patients aimed at establishing the prevalence, specific alloantibodies and factors associated with RBC alloimmunization.\u003c/p\u003e\n\u003ch3\u003eStudy population\u003c/h3\u003e\n\u003cp\u003eThe study targeted cancer patients (n\u0026thinsp;=\u0026thinsp;93) with multiple transfusions attending clinics and/or admitted to a cancer care centre. Additional single transfused patients (n\u0026thinsp;=\u0026thinsp;93) were also recruited for comparison purposes (controls).\u003c/p\u003e\n\u003ch3\u003eInclusion criteria\u003c/h3\u003e\n\u003cp\u003eThe study included all cancer patients of any age with a history of multiple blood transfusions. A similar proportion of single transfusions was included for comparison purposes.\u003c/p\u003e\n\u003ch3\u003eExclusion criteria\u003c/h3\u003e\n\u003cp\u003eThe study excluded cancer patients with autoimmune conditions, including idiopathic thrombocytopenia, rheumatoid arthritis, systemic lupus erythematosus and transplant patients, as well as HIV patients.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eData collection\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003eRecruitment and sample collection\u003c/h2\u003e \u003cp\u003eThe nonprobability purposive sampling method was utilized to obtain the study participants, in which the participant was selected if he or she had been transfused with one or more units of blood during the treatment period until a sample size of 93 for each group was attained. For consenting participants, 4 mL of blood was collected into SST and EDTA tubes, from which serum and EDTA plasma were obtained and stored at 2\u0026ndash;6\u0026deg;C or \u0026minus;\u0026thinsp;20\u0026deg;C.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003eLaboratory procedures\u003c/h3\u003e\n\u003cp\u003e \u003cstrong\u003eAlloantibody screening and identification\u003c/strong\u003e \u003cp\u003eAlloantibodies in the serum or plasma were screened and identified by the indirect antiglobulin test (IAT) using the tube method. Commercial screening red cells (Maxi-screen Cell3\u0026reg;) and panel cells (Identicell cells10\u0026reg;) expressing Rhesus (C, E, c, e, D), MNS (M, N, S, s), Kell (K, k, Kpa), Lewis (Lea, Leb), Duffy (Fya, Fyb), and Kidd (Jka, Jkb) (procured from Lorne Laboratories UK) antigens were used. The procedure included immediate spinning at room temperature, incubation at 37\u0026deg;C with LISS, and antihuman globulin (AHG) testing after washing. Agglutination was observed macroscopically and microscopically, whereas negative results were confirmed by using IgG-sensitized cells.\u003c/p\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eThe data were entered into the Statistical Package for Social Sciences (SPSS) version 28. Further analysis was performed in STATA version 19. Descriptive statistics were used to determine the prevalence of alloimmunization among the participants. The chi-square test of independence was used to determine differences in proportions and the associations between alloimmunization and the number of blood transfusions. The Mann\u0026ndash;Whitney U test was used to compare the number of units of blood transfused between alloimmunized and non-alloimmunized patients. Binary and multivariable logistic regression was used to find odds for developing alloimmunization while controlling for age, sex and history of pregnancy. A \u003cem\u003ep\u003c/em\u003e value\u0026thinsp;\u0026le;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eGeneral, demographic and clinical characteristics of the study participants\u003c/h2\u003e \u003cp\u003eMultiple transfused (n\u0026thinsp;=\u0026thinsp;93) and single transfused cancer patients (n\u0026thinsp;=\u0026thinsp;93) were recruited into the study as participants and controls, respectively. The participants had a mean age of 44 years (SD\u0026thinsp;=\u0026thinsp;21), with nearly half (47.8%) aged 50\u0026ndash;84 years, indicating the dominance of older adults. Males comprised 55.9% and females 44.1%; 64.5% were married. A history of pregnancy was reported by 36.0%, a known sensitizing factor for RBC alloimmunization. Solid tumours accounted for 51.1% of the cases, and haematological malignancies accounted for 48.9% (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGeneral, demographic and clinical characteristics of the study participants\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFrequency\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003en (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u0026ndash;25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e26\u0026ndash;49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50\u0026ndash;84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e47.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e104\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMariage status\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e120\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e64.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePregnancy History\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e119\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e64.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCancer type\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid tumor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e51.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematology\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eDistribution of hematologic and solid organ malignancies\u003c/h2\u003e \u003cp\u003eLeukaemia was the most common malignancy (34.4%), followed by lymphoma and prostate cancer (9.7% each) and breast cancer (7.0%). Colon, gastric, and lung cancers were observed at lower frequencies. Overall, haematological cancers predominated (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eABO blood group distribution of the study participants\u003c/h2\u003e \u003cp\u003eRegarding ABO blood group distribution, O-positive was most common (45%), followed by A-positive (27%) and B-positive (21%). AB-positive accounted for 5%, while B-negative and O-negative were rare (1%) each (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eDistribution of specific red blood cell alloantibodies\u003c/h2\u003e \u003cp\u003eA total of 13 RBC alloantibodies of known specificity were detected in 9 alloimmunized patients. Two unidentified alloantibodies were also observed. Anti-E was the most common alloantibody with 5 (33.3%), followed by anti-K with 4 (26.7%). Anti-Le and anti-C were 2 (13.3%) each and the remaining 2 (13.3%) could not be determined. Among patients with haematological cancers, the predominant red blood cell alloantibodies identified were anti-E (n\u0026thinsp;=\u0026thinsp;3), anti-K (n\u0026thinsp;=\u0026thinsp;3), and anti-Lea (n\u0026thinsp;=\u0026thinsp;2). In contrast, patients with solid tumours most commonly exhibited anti-C (n\u0026thinsp;=\u0026thinsp;2), anti-E (n\u0026thinsp;=\u0026thinsp;2), and anti-K (n\u0026thinsp;=\u0026thinsp;1). These findings indicate variation in the distribution and frequency of red blood cell alloantibodies between haematological and solid cancers. Most alloimmunized patients 8 (72.7%) developed a single alloantibody specificity, while 3(27.3%) had multiple alloantibodies. Patients with higher transfusion exposure developed clinically significant alloantibodies, predominantly anti‑E and anti‑K, with occasional detection of anti‑C and anti‑Leᵃ. In contrast, individuals with lower transfusion requirements exhibited minimal or no alloantibody formation. Overall, antibodies within the Rhesus and Kell systems were the most identified across cancer types (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eDifferences in the proportions of alloimmunized and non-alloimmunized transfused patients\u003c/h2\u003e \u003cp\u003eThere was no statistically significant association between RBC alloimmunization and demographic or clinical characteristics. Although alloimmunization appeared more frequently among patients aged 50\u0026ndash;84 years (54.5%; χ\u0026sup2; = 1.321, p\u0026thinsp;=\u0026thinsp;0.517), females (54.5%; χ\u0026sup2; = 0.516, p\u0026thinsp;=\u0026thinsp;0.540), and those with prior pregnancies (54.5%; χ\u0026sup2; = 1.741, p\u0026thinsp;=\u0026thinsp;0.207), these differences were not significant. Similarly, the rates of cancer type were comparable between solid tumours (54.5%) and haematological malignancies (45.5%; χ\u0026sup2; = 0.056, p\u0026thinsp;=\u0026thinsp;0.530). Marital status showed a trend toward greater alloimmunization among married patients (90.9%) than among unmarried patients (9.1%), but this difference did not reach statistical significance (χ\u0026sup2; = 3.557, p\u0026thinsp;=\u0026thinsp;0.052). Overall, none of the demographic or clinical variables independently predicted RBC alloimmunization. Logistic regression revealed no significant associations between demographic or clinical variables and RBC alloimmunization. Compared with patients aged 0\u0026ndash;25 years, those aged 26\u0026ndash;49 years (AOR\u0026thinsp;=\u0026thinsp;4.19; 95% CI: 0.32\u0026ndash;54.07; p\u0026thinsp;=\u0026thinsp;0.272) and 50\u0026ndash;84 years (AOR\u0026thinsp;=\u0026thinsp;3.93; 95% CI: 0.36\u0026ndash;43.36; p\u0026thinsp;=\u0026thinsp;0.264) had higher odds, but these differences were not significant. Female sex (AOR\u0026thinsp;=\u0026thinsp;0.50; 95% CI: 0.03\u0026ndash;7.70; p\u0026thinsp;=\u0026thinsp;0.619), pregnancy history (AOR\u0026thinsp;=\u0026thinsp;2.88; 95% CI: 0.18\u0026ndash;44.82; p\u0026thinsp;=\u0026thinsp;0.449), and cancer type (AOR\u0026thinsp;=\u0026thinsp;0.84; 95% CI: 0.21\u0026ndash;3.80; p\u0026thinsp;=\u0026thinsp;0.812) also showed no independent associations (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDifferences in the proportions of alloimmunized and non-alloimmunized transfused patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eRBC alloimmunization\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNegative n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePositive n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChi-square\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.321\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.517\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u0026ndash;25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e42(24.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1(9.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e26\u0026ndash;49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e50(28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4(36.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50\u0026ndash;84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e83(47.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6(54.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.516\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.540\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99(56.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5(45.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e76(43.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6(54.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMariage status\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.557\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.052\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e110(62.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10(90.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e65(37.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1(9.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePregnancy History\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.741\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.207\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e114(65.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5(45.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e61(43.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6(54.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCancer type\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.056\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.530\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid tumor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e89(50.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6(54.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematology\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e86(49.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5(45.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eDifferences in proportions between RBC alloimmunized patients and no alloimmunized patients were determined via the chi-square test of independence. A p value\u0026thinsp;\u0026le;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003eAssociations between demographic and clinical factors and red blood cell alloimmunization.\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCOR (95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAOR (95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u0026ndash;25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e26\u0026ndash;49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.36(0.36\u0026ndash;31.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.19(0.32\u0026ndash;54.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.272\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50\u0026ndash;84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.04(0.35\u0026ndash;26.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.311\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.93(0.36\u0026ndash;43.36)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.264\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.56(0.46\u0026ndash;5.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.474\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.50(0.03\u0026ndash;7.70)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.619\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePregnancy\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.24(0.66\u0026ndash;7.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.197\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.88(0.18\u0026ndash;44.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.449\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCancer type\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSolid tumor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematology\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.86(0.25\u0026ndash;2.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.813\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.84(0.21\u0026ndash;3.80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.812\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eUnivariate and multivariate logistic regression were performed to assess factors associated with red blood cell alloimmunization, and crude and adjusted odds ratios (95% CI) were calculated with reference categories of age 0\u0026ndash;25 years, male sex, no pregnancy history, and solid tumours.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003ePrevalence of red blood cell alloimmunization in multiple-transfused cancer patients\u003c/h2\u003e \u003cp\u003eA total of 11 (5.9%) patients developed alloantibodies, and 175 (94.1%) tested negative for alloantibodies. Alloimmunization was more common in patients with multiple transfusions (9.7%, 9/93) than in those with a single transfusion (2.1%, 2/93(Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eThe association between the number of transfusions and RBC alloimmunization in multiple-transfused cancer patients\u003c/h2\u003e \u003cp\u003eThe current study revealed that patients who developed alloantibodies required significantly more transfusions than those who did not develop alloantibodies (mean 129.4 vs. 91.2 units; Mann‒Whitney U test, Z = \u0026minus;\u0026thinsp;2.44, p\u0026thinsp;=\u0026thinsp;0.015). The majority of alloimmunized patients had multiple transfusions (81.8%) rather than single transfusions (18.2%), %), a difference that was statistically significant (χ\u0026sup2; = 4.735, p\u0026thinsp;=\u0026thinsp;0.030). Multiple transfusions were associated with markedly increased odds of alloimmunization (COR\u0026thinsp;=\u0026thinsp;4.88; p\u0026thinsp;=\u0026thinsp;0.047), and after adjusting for confounders, multiple transfusions remained an independent predictor, with patients receiving multiple transfusions showing more than sevenfold higher odds of alloimmunization (AOR\u0026thinsp;=\u0026thinsp;7.32; 95% CI: 1.39\u0026ndash;38.65; p\u0026thinsp;=\u0026thinsp;0.019) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAssociation between the number of transfusions and RBC alloimmunization\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eNumber of transfusions\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e\u003cem\u003eRBC\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eAlloimmunization\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eMann‒Whitney U test, Z\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eNegative\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003en (%)\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003ePositive\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003en (%)\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eχ\u003c/b\u003e\u003csup\u003e\u003cb\u003e2\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003ep value\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eCOR (95% Cl)\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSingle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e91(52.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2(18.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMultiple\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e84(48.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9(81.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.735\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.030\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.88(1.02\u0026ndash;23.21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.047\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eZ= -2.44,\u003c/p\u003e \u003cp\u003eP\u0026thinsp;=\u0026thinsp;0.015\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe data are summarized as frequencies and percentages [n (%)]. Group comparisons were conducted by the chi-square test and the Mann\u0026ndash;Whitney U test, as appropriate. Crude odds ratios (CORs) with corresponding 95% confidence intervals (CIs) are provided.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003eThe Association between the ABO blood groups and RBC alloimmunization\u003c/h2\u003e \u003cp\u003eBlood group was not associated with RBC alloimmunization. Most non-alloimmunized patients were O (46.3%) or A (28%), while alloimmunized patients had a more even distribution: O (36.4%), B (36.4%), A (18.2%), AB (9.1%). The association was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.555). RBC alloimmunization did not differ by blood group. Most non-alloimmunized patients were O (46.3%) or A (28%), while alloimmunized patients were distributed as O (36.4%), B (36.4%), A (18.2%), and AB (9.1%) (χ\u0026sup2; = 2.087, p\u0026thinsp;=\u0026thinsp;0.555). Patients with blood groups A, B, or AB had higher odds than those with group O, but this difference was not statistically significant. After adjustment for potential confounders, ABO blood group showed no significant association with RBC alloimmunization. Using blood group O as the reference, the adjusted odds ratios were: A (AOR\u0026thinsp;=\u0026thinsp;0.91; 95% CI: 0.15\u0026ndash;5.55; p\u0026thinsp;=\u0026thinsp;0.917), B (AOR\u0026thinsp;=\u0026thinsp;4.06; 95% CI: 0.83\u0026ndash;19.91; p\u0026thinsp;=\u0026thinsp;0.084), and AB (AOR\u0026thinsp;=\u0026thinsp;2.38; 95% CI: 0.21\u0026ndash;26.93; p\u0026thinsp;=\u0026thinsp;0.483). None of these estimates reached statistical significance (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe Association between the ABO blood groups and RBC alloimmunization\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"15\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c15\" colnum=\"15\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"7\" nameend=\"c9\" namest=\"c3\"\u003e \u003cp\u003eRBC alloimmunization\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eNegative n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003ePositive n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e \u003cp\u003eChi-square\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBlood group\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e \u003cp\u003e2.087\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e \u003cp\u003e0.555\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003e49 (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003e2 (18.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003e36 (20.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003e4 (36.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eAB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003e9 (5.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003e1 (9.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003e81(46.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003e4(36.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003e\u003cb\u003eCOR (95%CI)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003e\u003cb\u003eP-value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e \u003cp\u003e\u003cb\u003eAOR (95%CI)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e \u003cp\u003e\u003cb\u003eP-value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBlood group\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c12\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c14\" namest=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c12\" namest=\"c8\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c14\" namest=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e0.83(0.15\u0026ndash;4.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.830\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c12\" namest=\"c8\"\u003e \u003cp\u003e0.91(0.15\u0026ndash;5.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c14\" namest=\"c13\"\u003e \u003cp\u003e0.917\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e2.25(053\u0026thinsp;\u0026minus;\u0026thinsp;9.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c12\" namest=\"c8\"\u003e \u003cp\u003e4.06(0.83\u0026ndash;19.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c14\" namest=\"c13\"\u003e \u003cp\u003e0.084\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eAB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e2.25(0.23\u0026ndash;22.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.489\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c12\" namest=\"c8\"\u003e \u003cp\u003e2.38(0.21\u0026ndash;26.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c14\" namest=\"c13\"\u003e \u003cp\u003e0.483\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c15\" namest=\"c15\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cem\u003eDistribution of RBC alloimmunization by ABO blood group and the Chi-square test, corresponding crude (COR) and adjusted (AOR) logistic regression analyses assessing the association between blood group and alloimmunization OR\u0026thinsp;=\u0026thinsp;Crude Odds Ratio; AOR\u0026thinsp;=\u0026thinsp;Adjusted Odds Ratio; CI\u0026thinsp;=\u0026thinsp;Confidence Interval. Blood group O was used as the reference category (OR\u0026thinsp;=\u0026thinsp;1). Odds ratios were obtained using logistic regression analysis. P values\u0026thinsp;\u0026lt;\u0026thinsp;0 .05 were considered statistically significant.\u003c/em\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eAlloimmunization occurs when an external antigen is introduced into an immunocompetent host that lacks the antigen and triggers an immune response. Due to variations in genetics between recipients and donors of blood, alloimmunization with red blood cell antigens is one of the recognized risks of blood transfusion alloimmunization and has also been linked to pregnancy(\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e). Age, sex, underlying disease, and the quantity and frequency of transfusions can all affect alloimmunization (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the present study, the prevalence of RBC alloimmunization was 2.1% among single-transfused patients and 9.7% among multiple-transfused patients, yielding an overall prevalence of 5.9%, indicating that only a small proportion developed alloantibodies to transfused blood. Onoriode \u003cem\u003eet al.\u003c/em\u003e (2022) reported a higher incidence of alloimmunization (13.3%) than 9.7% reported in our study among multiple transfused patients, a difference that may be attributed to variations in patient characteristics, transfusion burden, and antibody detection methods(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Similarly, Hand \u003cem\u003eet al.\u003c/em\u003e (2020) reported a prevalence of 7.5%, close to our findings, supporting evidence that patients receiving multiple transfusions, especially those with haematological cancers, have an increased risk of alloantibody development(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eA study at Moi Referral and Teaching Hospital reported an alloimmunization prevalence of 6.2%, lower than the 9.7% in the present study, whereas a cross-sectional study in Malaysia reported 5.3%(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). The consistency across these studies suggests that our findings are representative of cancer patient populations managed under comparable transfusion practices. Compared with our findings, Mangwana 2019 reported a markedly lower alloimmunization prevalence of 0.3%, likely reflecting a cohort predominantly composed of solid tumor patients who typically receive fewer transfusions. (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). Unni \u003cem\u003eet al.\u003c/em\u003e (2024) and Moussa \u003cem\u003eet al.\u003c/em\u003e (2023) reported lower rates (1% and 1.3%) than those reported in this study(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). Furthermore, the absence of alloimmunization reported in a study in Uganda highlights the wide variability across studies, potentially explained by smaller sample sizes, lower transfusion intensity, or methodological differences in antibody detection(\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). Studies from Tanzania reported alloimmunization prevalence rates of 4.1% and 8.5% among multiply transfused patients with sickle cell disease, which are comparable to those reported in the present cohort of cancer patients(\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e). This similarity points to a broader trend in transfusion-dependent populations, indicating that alloantibody formation is not disease-specific but is largely driven by cumulative transfusion exposure. The consistency of findings across different clinical groups reinforces alloimmunization as a predictable and clinically significant consequence of repeated transfusion, highlighting the need for routine monitoring and preventive measures. By placing the current cancer cohort within the wider body of evidence from sickle cell disease, this study emphasizes the importance of harmonized transfusion practices and strengthened immunopharmacological surveillance across diverse patient populations.\u003c/p\u003e \u003cp\u003eThe predominance of anti‑E in our cohort aligns with multiple studies reporting similar patterns. The study in Nigeria found anti‑E to be the most frequent alloantibody, representing nearly half of all cases among multi‑transfused patients, while Handa \u003cem\u003eet al.\u003c/em\u003e, 2020 in India reported it as the leading antibody in oncology patients, with prevalence ranging from 30\u0026ndash;40%(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Moussa \u003cem\u003eet al.\u003c/em\u003e (2023) also identified anti‑E as the most common alloantibody in solid tumor patients, despite a low overall alloimmunization rate of 1.3%(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e).This pattern reflects the strong immunogenicity of Rh antigens, especially E and C, where donor and recipient mismatches often trigger alloantibodies, and populations with diverse Rh profiles are particularly prone to anti‑E. Anti‑K was the second most common alloantibody in our study (27.3%), reflecting the high immunogenicity of the Kell system despite its relatively low prevalence in donors. Similar patterns have been reported by in cancer patients(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Clinically, anti‑K is important as it can lead to haemolytic transfusion reactions and haemolytic disease of the foetus and newborn. The current findings differ from a study in Iran that found anti‑Kell to be the most common alloantibody, where anti‑K accounted for the largest share of identified antibodies(\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e). Anti-C alloantibodies were identified in 18.2% of patients, reinforcing the high immunogenicity of the Rh system, consistent with findings by Unni \u003cem\u003eet al\u003c/em\u003e. (2024) and Moussa \u003cem\u003eet al.\u003c/em\u003e (2023)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). Anti-Lea was found in 18.2% of patients. While it rarely causes serious transfusion reactions, recognizing Anti-Lea is important because it can appear naturally, even without prior transfusion, and may affect interpretation of blood compatibility tests Two patients had unidentified antibodies, reflecting detection limits in resource‑constrained settings, consistent with a study by Onoriode \u003cem\u003eet al.\u003c/em\u003e (2022) where in one subject with a single antibody, specificity could not be determined. Variability has been noted elsewhere; D \u003cem\u003eet al.\u003c/em\u003e (2023) reported no alloimmunization, likely reflecting methodological constraints rather than true absence (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe current study revealed no significant association between age and alloimmunization, although patients aged 26\u0026ndash;49 and 50\u0026ndash;84 years had higher odds of alloimmunization than those aged 0\u0026ndash;25 years did. This study, in accordance with reports by Wanik \u003cem\u003eet al.\u003c/em\u003e, revealed no significant association with the risk of alloimmunization(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). However, a study by Wapukha \u003cem\u003eet al.\u003c/em\u003e revealed a significant association between age and association and that older age groups had higher alloimmunization rates, likely due to repeated transfusions over time, resulting in greater exposure to foreign antigens(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThere was no statistically significant association between sex and the risk of alloimmunization in this study, although females had slightly greater odds than males did. This study is consistent with a previous report by Wanik \u003cem\u003eet al.\u003c/em\u003e However, studies performed in Kenya and the USA have shown that females are more at risk of alloimmunization than males are(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eParticipants with a prior history of pregnancy had greater odds of red cell alloimmunization than did those without such a history, although the association was not statistically significant. This finding is biologically plausible, as pregnancy exposes mothers to fetal red cell antigens that may stimulate antibody production, which is consistent with previous reports(\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e). Comparable findings have been reported in transfusion studies, where pregnancy history was examined as a potential risk factor, but no statistically significant association with alloimmunization was demonstrated(\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eNo significant association was observed between cancer type and red cell alloimmunization, with comparable rates in solid tumours and haematological malignancies. Several studies have suggested that patients with solid tumours may have an increased risk of developing red cell alloantibodies(\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e), whereas others have reported high rates of haematological malignancies(\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e). Despite the expectation that frequent transfusions in patients with haematological cancers might increase antigen exposure, our data did not reveal a meaningful difference between the groups. This lack of association may reflect the limited sample size or comparable transfusion practices across cancer types, highlighting the need for larger studies to clarify the influence of cancer type on alloimmunization risk.\u003c/p\u003e \u003cp\u003eIn the Current study, ABO blood groups were not significantly associated with RBC alloimmunization. While groups O and A predominated among non-alloimmunized patients, alloimmunized individuals were more evenly distributed across all blood groups. No significant associations were found and while groups B and AB had higher odds compared with group O. This aligns with Onoriode \u003cem\u003eet al\u003c/em\u003e and Wanik \u003cem\u003eet al\u003c/em\u003e. findings, which showed no significant link between alloimmunization and ABO or Rh (D) blood groups(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).Wanik \u003cem\u003eet al.\u003c/em\u003e also reported that blood group A is an independent risk factor for RBC alloimmunization in solid cancer patients, with 7.45 times higher odds than non-A patients. A study of repeatedly transfused leukaemia patients in Northern Sudan found alloimmunization was most frequent in blood group O and A positive individuals, with a significant link to blood group type(\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e). The variation in findings across studies highlights the need for further research on the association between ABO blood groups and alloimmunization, as current evidence remains limited.\u003c/p\u003e \u003cp\u003eIn the present study, multiple transfusions were significantly associated with an elevated risk of RBC alloimmunization among transfused patients. Our findings align with reports indicating that the likelihood of alloimmunization increases with the number of RBC units transfused (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e). Pessoni \u003cem\u003eet al. (\u003c/em\u003e2018) reported that alloimmunization is correlated with both the number of transfused units and the number of transfusion episodes(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). A retrospective study in Saudi Arabia revealed that repeated blood transfusions significantly increased the risk of alloimmunization, leading to recommendations for extended antigen typing in chronically transfused patients(\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e). The findings of the present study contradict those of other studies, which revealed no significant association between the number of transfusions and alloimmunization(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). A study from Sudan revealed no significant link between the number of transfusion units and the development of alloantibodies, indicating that individual factors such as genetic makeup, immune response, and inflammatory status may influence the risk of alloimmunization(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). These differences may reflect variations in transfusion frequency, testing practices, antibody types, and the use of extended RBC phenotyping across centres.\u003c/p\u003e \u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003eLimitations of the Study\u003c/h2\u003e \u003cp\u003eThis study has limitations, despite the important findings. First, the antibody screening and identification methods may miss very low-titre alloantibodies, which could lead to an underestimation of the prevalence of alloimmunization. In addition, cancer treatment regimens may suppress the immune system, which could reduce antibody production and result in the detection of some alloantibodies.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eRed blood cell alloimmunization was observed in 5.9% of transfused patients, with a higher prevalence among multiple transfused compared to single transfused patients, underscoring the role of cumulative antigen exposure in antibody development. Although higher rates were noted in older patients and females with a history of pregnancy, these associations were not statistically significant. The findings identify multiple transfusions as the principal driver for alloimmunization and highlight the need for extended antigen and alloantibody matching in patients requiring frequency transfusion support.\u003c/p\u003e \u003cdiv id=\"Sec24\" class=\"Section2\"\u003e \u003ch2\u003eRecommendations\u003c/h2\u003e \u003cp\u003eMultiple-transfused cancer patients should be periodically screened for alloimmunization in transfusion facilities for better selection of compatible blood and components to prevent transfusion complications.\u003c/p\u003e \u003c/div\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAHG; Antihuman Globulin, CCC; Cancer Care Center, EDTA; Ethylene Diamine Tetra Acetic Acid, HIV; Human Immunodeficiency Virus, ISBT; International Society of Blood Transfusion, KCMC; Kilimanjaro Christian Medical Center, LISS; Low Ionic Strength Solution; RBC; Red Blood Cells, SPSS; Statistical Package for Social Sciences, SST; Serum Separator Tube, WHO; World Health Organization\u003c/p\u003e "},{"header":"Declarations","content":" \u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003eEthical approval was obtained from the Maseno University Scientific Ethical Review Committee (MUSERC, approval number MUSERC/01464/25) in Kenya and the KCMC University CRERC (PG197/2025) in Tanzania, granted a research ethical clearance certificate to conduct the study. Informed consent was obtained from the participants before inclusion in the study. The participants were informed of the purpose of the study and its benefits. Written informed consent was obtained from the study participants, and their participation was voluntary. In cases where minors were involved, the parent\u0026rsquo;s or guardian\u0026rsquo;s permission was sought. The participants were informed about their rights and how their data would be used to ensure transparency and trust. The confidentiality of the participants was observed, including their samples and their data. All the data collected from the participants were kept confidential, with access restricted to authorized personnel. All hard copy information was secured and stored in a lockable cabinet to maintain privacy and comply with ethical standards and regulations. The study adhered to the ethical standards in accordance with the World Medical Association\u0026rsquo;s Declaration of Helsinki 2024.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003eNot applicable.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare that no competing interests exist.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eAuthor details\u003c/h2\u003e \u003cp\u003e \u003csup\u003e1\u003c/sup\u003eDepartment of Biomedical Science and Technology, School of Public Health Maseno University, Private Bag, Maseno Kenya. \u003csup\u003e2\u003c/sup\u003eDepartment of Medical Laboratory Sciences, School of Medicine, Maseno University, Private Bag, Maseno Kenya.\u003csup\u003e3\u003c/sup\u003eDepartment of Health Laboratory Sciences, School of Medicine, KCMC University, Moshi, Tanzania.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNone.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eJemrath Bikombo (JB), Paul Kosiyo (PK), and Boaz Owuor (BO) supervised the overall study. JB prepared the manuscript. All authors critically reviewed the final version of the manuscript and approved it for submission **.**\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe sincerely thank the leaders of Kilimanjaro Christian Medical Centre (KCMC) and the KCMC Cancer Care Center for granting permission to conduct this study. We are deeply grateful to all the study participants whose involvement made this research possible. We also extend our appreciation to the laboratory staff for their dedication, cooperation, and hard work during the collection and analysis of the clinical samples.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data supporting the results of this study are not publicly accessible because of their sensitive nature. 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Red-blood‐cell alloimmunization and number of red‐blood‐cell transfusions. \u003cem\u003eVox Sang\u003c/em\u003e. \u003cb\u003e102\u003c/b\u003e (2), 144\u0026ndash;149. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1423-0410.2011.01517.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1423-0410.2011.01517.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2012).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Red blood cell alloimmunization, Multiple blood transfusions, Cancer patients","lastPublishedDoi":"10.21203/rs.3.rs-9376072/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9376072/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eCancer is the leading cause of death worldwide. Blood transfusions are necessary during cancer management. However, the dependence on blood transfusions in cancer patients predisposes them to red blood cell alloimmunization, leading to complications such as difficulty in finding compatible blood, transfusion delays and haemolytic reactions. In Tanzania, blood banks do not screen for antigens other than A, B and D, which may stimulate alloimmunization.\u003c/p\u003e\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eThe present study evaluated the prevalence of red blood cell alloimmunization in single and multiple-transfused cancer patients and its associated factors at Kilimanjaro Christian Medical Centre, zonal referral Hospital in northern Tanzania.\u003c/p\u003e\u003ch2\u003eMethodology:\u003c/h2\u003e \u003cp\u003eThis cross-sectional study was conducted in northern Tanzania, where a total of 186 transfused cancer patients were recruited through purposive sampling. Blood samples were collected from participants for alloantibody screening and identification. Descriptive statistics was used determine the proportions of the transfused cancer patients. Chi-square test was used to determine differences in proportions. Mann\u0026ndash;Whitney U test was used to determine differences in the medians of the continuous variables while multivariable regression was used to determine associations between socio-demographic, clinical factors and red blood cell alloimmunization.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eRed blood cell alloimmunization prevalence was 2.1% and 9.7% among single and multiple-transfused cancer patients, respectively. The overall prevalence among transfused cancer patients was 5.9%. Anti-E 5(33.3%) and anti-Kell 4(26.7%) were the most common alloantibodies, followed by anti-C and anti-Lea 2(13.3%) each and two undetected antibodies. Multiple transfusions significantly increased the odds of alloimmunization (COR\u0026thinsp;=\u0026thinsp;4.88; p\u0026thinsp;=\u0026thinsp;0.047); (AOR\u0026thinsp;=\u0026thinsp;7.32; 95% CI: 1.39\u0026ndash;38.65; p\u0026thinsp;=\u0026thinsp;0.019), whereas higher but nonsignificant odds were observed among patients aged 26\u0026ndash;49 and 50\u0026ndash;84 years, females, and those with a history of pregnancy (AOR\u0026thinsp;=\u0026thinsp;4.19; 95% CI: 0.32\u0026ndash;54.07; p\u0026thinsp;=\u0026thinsp;0.272),(AOR\u0026thinsp;=\u0026thinsp;3.93; 95% CI: 0.36\u0026ndash;43.36; p\u0026thinsp;=\u0026thinsp;0.264), (AOR\u0026thinsp;=\u0026thinsp;0.50; 95% CI: 0.03\u0026ndash;7.70; p\u0026thinsp;=\u0026thinsp;0.619),(AOR\u0026thinsp;=\u0026thinsp;2.88; 95% CI: 0.18\u0026ndash;44.82; p\u0026thinsp;=\u0026thinsp;0.449) respectively. No significant associations were found with ABO blood groups.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eMultiple blood transfusions is significantly associated with red blood cell alloimmunization in cancer patients hence regular antibody screening and extended antigen matching should be implemented to improve transfusion safety in Tanzania.\u003c/p\u003e","manuscriptTitle":"Prevalence of Red Blood Cell Alloimmunization in Single and Multiple-Transfused Cancer Patients and its Associated Factors at the Kilimanjaro Christian Medical Centre, Zonal Referral Hospital in Northern Tanzania","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-24 06:21:35","doi":"10.21203/rs.3.rs-9376072/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-04T19:36:13+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-01T11:02:54+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-22T13:00:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"262473977050365775153374247421218969929","date":"2026-04-22T11:31:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"321356599836233352473782817799125375942","date":"2026-04-19T12:01:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"128216092593397255850889126649042644214","date":"2026-04-17T12:49:41+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-17T11:16:04+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-14T10:47:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-11T14:11:36+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-11T14:11:24+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-04-10T07:33:11+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"36ade6c3-a7ae-4508-9508-c7b5475bd3d8","owner":[],"postedDate":"April 24th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-04T19:36:13+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-01T11:02:54+00:00","index":38,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":66818854,"name":"Biological sciences/Cancer"},{"id":66818855,"name":"Health sciences/Diseases"},{"id":66818856,"name":"Health sciences/Medical research"},{"id":66818857,"name":"Health sciences/Oncology"}],"tags":[],"updatedAt":"2026-05-08T00:53:43+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-24 06:21:35","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9376072","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9376072","identity":"rs-9376072","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}