Impact of Blood Donation on Immune Function and Donor Health Recovery

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Maima This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6189603/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Blood donation could potentially affect immune function and donor health. Most studies have centered on hematological alterations after donation; however, studies on various immune parameters and recovery dynamics are sparse. Objective This study aims to investigate the immune function, donor health, and recovery dynamics after blood donation. Methods Healthy adult blood donors (n = 108) were recruited and evaluated at four time points: baseline (pre-donation), immediately after donation, 1-week post-donation, and 4-weeks post-donation. Blood samples were collected to study white blood cell (WBC) count, lymphocyte subtypes (CD4 + T-cells, CD8 + T-cells, B-cells), and Ig levels (IgG, IgA, IgM) in serum. Donors filled out a self-report questionnaire regarding post-donation symptoms, including fatigue, dizziness, and lightheadedness. The assessment involved statistical analyses using paired t-test, repeated measures ANOVA, and linear regression. Results Blood donation resulted in immediate post-donation decreases in WBC count, lymphocyte subtypes, and immunoglobulin levels, with restoration to pre-donation levels by 4 weeks. The largest decrease was seen in CD4 + T-cells and IgG levels. Post-donation symptoms of fatigue and dizziness were frequently reported immediately post-donation, though most had recovered by 1 week. Recovery was prolonged in older and frequent donors; however, the difference was not statistically significant. Conclusion Temporary immune suppression occurs following blood donation, but recovery to baseline is typically achieved within 4 weeks. Post-donation symptoms, while common, tend to be mild and transient. Consequently, blood donation appears to be generally safe for most healthy individuals, with some delayed recovery observed among older and frequent donors. Health sciences/Health care Health sciences/Medical research Blood donation Immune system function Post-donation recovery White blood cells (WBC) Lymphocyte subtypes Immunoglobulins Donor health symptoms Fatigue Dizziness Lightheadedness Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Blood donation is crucial to all healthcare systems around the world, and donated blood is utilized for many medical procedures, such as surgical interventions, traumatic interventions, cancer interventions, and chronic condition interventions, like anemia ( 1 ). Blood donation must be safe not only for the recipient but also for the donor. Blood donation is regarded as healthy in most instances; however, researchers are now more interested in how it may affect donor health, particularly with respect to immune function and recovery after a donation. There have been previous studies that have concentrated much on the various physiological changes following blood donation, involving transient immune alterations while the post-donation donor's body compensates for the loss in blood volume and cellular componentsity ( 1 ). The other paramount issue in blood donation relates to its effect on the immune system of the person giving the blood. The immune system is extremely central to all mechanisms defending the host against infectious organisms and foreign invaders. Short-term reductions in immune cells and immunoglobulins occur with the donation of blood, corresponding to the loss of blood volume as well as cellular components; however, studies suggest that these effects are typically transient and recovery occurs in full within a few weeks ( 2 ). This still raises the inquiry of whether such short-lived immune alterations would have any consequences in the donor's vulnerability to infections in the contexts of health. Previous studies have identified several parameters involved in the immune recovery after a blood donation, such as white blood cell (WBC) counts, lymphocyte subtypes (i.e., CD4 + T-cells, CD8 + T-cells, B-cells), and immunoglobulins (IgG, IgA, IgM). Studies have consistently documented an immediate decline in all these immune markers after blood donation, with recovery in most cases occurring anywhere between 1 and 4 weeks post-donation ( 3 ). Also, health symptoms reported by blood donors have been investigated, including fatigue, dizziness, and lightheadedness. Although mild and transient, these symptoms have also raised concerns relating to the well-being of donors during recovery ( 4 ). Given continuing discussions surrounding donor safety and immune health, this study intends to investigate the possible effects of blood donation on immune functioning and post-donation recovery using an array of immune markers, including WBC counts, lymphocyte subtypes, and serum immunoglobulin levels, as well as related self-reported health symptoms. The outcome will contribute to the understanding of blood donation in relation to immune functioning and donor health to ensure that the donation procedure is safe and sustainable. Methods Study Design and Population This longitudinal study targeted the impact of blood donation on immune system function, donor health, and post-donation recovery. Healthy adult blood donors aged between 18 and 60 years who had no chronic medical conditions or history of immunodeficiency disorders were recruited from a local blood donation center. In addition, the inclusion criteria were such that healthy volunteers within the stated age range were eligible. Exclusion conditions were: any recent acute illness, pregnancy, or blood donation in the preceding 3 months. Data were collected at a baseline, post-donation, one week after donation, and four weeks after donation. Blood samples were drawn at every time point to analyze immune system status, and participants completed self-report measures for post-donation symptoms such as fatigue, dizziness, and lightheadedness. Blood Sample Collection and Laboratory Analysis For hematology and immunophenotyping analysis, 5 mL of peripheral venous blood was taken from each participant in EDTA-coated vacutainer tubes (BD Vacutainer® K2EDTA) at all time points: baseline, immediately post-donation, one-week post-donation, and four weeks post-donation. For immunoglobulin quantification, plain serum-separating tubes were used. Using the Sysmex XN-1000 automated hematology analyzer (Sysmex Corporation, Kobe, Japan), the white blood cell (WBC) count and hemoglobin levels were determined. Flow cytometry for lymphocyte subtyping was conducted, using the BD FACSCanto™ II flow cytometer (BD Biosciences, San Jose, USA). Fluorescent-labeled monoclonal antibodies to CD4 (clone RPA-T4), CD8 (clone RPA-T8), and CD19 (clone HIB19) all were obtained from BD Biosciences. Isotype-matched controls were used to confirm specificity. Compensation and gate setting were performed using FlowJo software (version 10). Quantitative ELISAs were performed on serum immunoglobulins (IgG, IgA, IgM) with the use of commercial kits (Thermo Fisher Scientific, USA) following manufacturer's protocols. All kits had inter-assay and intra-assay coefficients of variation of less than 10%. Laboratory assays were performed in duplicate for all analyses to guarantee reproducibility. A detailed questionnaire was used to assess post-donation symptoms (fatigue, dizziness, lightheadedness) Statistical Analysis Descriptive statistics (mean ± standard deviation) were used for summarizing demographic characteristics (age, gender, frequency of donation) and the immune parameters at each time point. Paired t-tests were used in table 2 to test pre- and post-donation values for WBC count, lymphocyte, immunoglobulin, and hemoglobin levels. This paired test would inform almost all immediate changes that have occurred to immune parameters after blood donation. Repeated measures ANOVA was used to determine time variations of immune function (WBC count, lymphocyte subtypes, IgG, IgA, and IgM levels) between the four points in time. Such ANOVA indicated significant time variations in the recovery of immunity after donation. Bonferroni-corrected pairwise post-hoc tests were conducted after repeated measures ANOVA to assess specific time points at which significant changes were noted (i.e., baseline vs. post-donation, baseline vs. 1-week, and so on). Linear regression models were used to explore the relationship between donor characteristics (age, gender, frequency of donation) and recovery of immune markers. These models examined how these characteristics impacted immune recovery rates. Multivariate Analysis of Covariance (MANCOVA) tested the effect of donor characteristics (age, gender, frequency of donation) on immune recovery and protected against confounding variables such as baseline health status. This analysis was designed for simultaneous consideration of multiple confounders. Spearman’s rank correlation was applied to determine the extent of association between self-reported health symptoms (fatigue, dizziness, and lightheadedness) and immune recovery (WBC count, lymphocyte subtypes, and IgG levels). This analysis established whether any of the symptoms were associated with slower immune recovery. Kaplan-Meier survival analysis was done to assess recovery time for immune function following blood donation. This provided a graphic representation of the immunity recovery timeline for WBC count, lymphocyte subtypes, and immunoglobulin levels. All statistical analyses were carried out in SPSS version 25 (SPSS Inc., Chicago, IL). The level of significance set for all analyses was p < 0.05. Bonferroni corrections were applied for multiple comparisons whenever required. Ethics approval and consent to participate Ethical approval waiver was granted by the IRB of Kisii Teaching and Reporting Hospital. The study observed ethics according to Helsinki declaration and all participants signed voluntary written informed consent form before enrollment. Confidentiality regarding participants was maintained throughout the study; all the data were anonymized and stored securely. Additionally, the participants were informed that they would withdraw from the study without penalty at any time. Results This study assessed the impact of blood donation on immune system function in 108 blood donors, measuring white blood cell (WBC) count, lymphocyte subtypes, and serum immunoglobulin levels at baseline, immediately post-donation, 1-week post-donation, and 4-weeks post-donation. Demographic Characteristics of Study Participants The sample comprised 108 participants, with a nearly equal gender distribution and a wide age range. Table 1, figure 1, figure 2 and figure 3 presents the demographic characteristics of the participants. Table 1 : Demographic Characteristics of Study Participants Characteristic Frequency (%) Gender Male 55 (50.9%) Female 53 (49.1%) Age Group 18-30 years 40 (37.0%) 31-40 years 30 (27.8%) 41-50 years 20 (18.5%) 51+ years 18 (16.7%) Frequency of Donation First-time donors 50 (46.3%) Frequent donors (≥3 times/year) 58 (53.7%) White Blood Cell (WBC) Count The WBC count significantly decreased immediately post-donation, followed by partial recovery within 1-week, and full recovery by 4-weeks post-donation. These findings are summarized in Table 2 and figure 1. Table 2 : White Blood Cell Count Before and After Blood Donation Time Point Mean WBC Count (x10³/µL) p-value Baseline 6.8 ± 1.2 - Immediate Post-Donation 5.2 ± 1.0 <0.001 1-Week Post-Donation 6.0 ± 1.1 <0.01 4-Weeks Post-Donation 6.7 ± 1.3 NS NS = Not Significant Lymphocyte Subtypes A significant decrease in CD4+ T-cells was observed immediately post-donation. This decrease was more pronounced compared to CD8+ T-cells and B-cells, but all lymphocyte subtypes returned to baseline levels by 1-week post-donation. The changes in lymphocyte subtypes are detailed in Table 3 Table 3 : Lymphocyte Subtypes Before and After Blood Donation Lymphocyte Subtype Baseline (%) Post-Donation (%) 1-Week (%) 4-Weeks (%) p-value CD4+ T-cells 37 ± 4 29 ± 5 36 ± 3 37 ± 4 <0.01 CD8+ T-cells 22 ± 3 19 ± 4 21 ± 3 22 ± 2 <0.05 B-cells 30 ± 5 26 ± 5 28 ± 4 30 ± 4 <0.05 Serum Immunoglobulin Levels (IgG, IgA, IgM) Serum levels of immunoglobulins (IgG, IgA, IgM) were significantly reduced immediately post-donation but returned to baseline by 4-weeks post-donation. These findings are summarized in Table 4 and figure 2 . Table 4 : Serum Immunoglobulin Levels Before and After Blood Donation Immunoglobulin Baseline (mg/mL) Post-Donation (mg/mL) 1-Week (mg/mL) 4-Weeks (mg/mL) p-value IgG 11.5 ± 1.2 9.8 ± 1.3 10.6 ± 1.1 11.3 ± 1.2 <0.05 IgA 1.2 ± 0.2 0.9 ± 0.2 1.1 ± 0.1 1.2 ± 0.2 <0.05 IgM 1.0 ± 0.1 0.7 ± 0.1 0.9 ± 0.1 1.0 ± 0.1 <0.05 Self-Reported Health Symptoms Approximately 30% of donors reported mild symptoms, such as fatigue, dizziness, and lightheadedness, immediately post-donation. These symptoms largely resolved by 1-week post-donation, with only 10% of participants reporting any symptoms at that time. These findings are summarized in Table 5 and figure 3 . Table 5 : Self-Reported Health Symptoms Post-Donation Symptom Immediately Post-Donation 1-Week Post-Donation 4-Weeks Post-Donation Fatigue 18% 5% 0% Dizziness 12% 3% 0% Lightheadedness 10% 2% 0% Hemoglobin Levels Hemoglobin levels significantly decreased immediately post-donation but returned to baseline levels by 4-weeks post-donation. These results are shown in Table 6 and figure 4 . Table 6 : Hemoglobin Levels Before and After Blood Donation Time Point Mean Hemoglobin (g/dL) p-value Baseline 14.2 ± 1.3 - Immediate Post-Donation 12.4 ± 1.0 <0.001 1-Week Post-Donation 13.2 ± 1.1 <0.01 4-Weeks Post-Donation 14.1 ± 1.2 NS NS = Not Significant Correlations Between Immune Recovery and Donor Characteristics Age and Immune Recovery: Older donors (aged 50 years and above) exhibited slower recovery of CD4+ T-cells and IgG levels compared to younger donors (18-35 years). Frequency of Donation: Frequent donors (donating more than three times per year) showed a slightly slower immune recovery rate compared to first-time donors, though this difference was not statistically significant. Statistical Analysis Data were analyzed using paired t-tests to compare pre- and post-donation immune parameters. Linear regression models were applied to assess the influence of donor characteristics on immune recovery rates, and multivariate analysis was conducted to control for potential confounding factors such as baseline health status and pre-existing medical conditions. Repeated Measures Analysis of Variance (ANOVA) Repeated measures ANOVA was used to evaluate changes in immune parameters (WBC count, lymphocyte subtypes, immunoglobulin levels) across multiple time points (baseline, immediately post-donation, 1-week post-donation, 4-weeks post-donation). This approach helps to assess the temporal patterns in immune recovery within participants and identify whether significant changes occur over time. The repeated measures ANOVA indicated significant changes over time for all immune parameters (WBC count, lymphocyte subtypes, IgG, IgA, and IgM levels), with the exception of the CD8+ T-cell and B-cell percentages, which were less sensitive to temporal changes (Table 7). Post-hoc pairwise comparisons revealed that the most significant differences occurred between baseline and immediately post-donation, while the differences between 1-week and 4-weeks post-donation were generally non-significant, indicating full recovery of these immune markers by 4-weeks post-donation, as shown in table 7 and figure 5 Table 7 : Repeated Measures ANOVA Results for Immune Parameters Over Time Immune Parameter F-value p-value WBC Count 35.12 <0.001 CD4+ T-cells 22.14 <0.01 CD8+ T-cells 5.38 <0.05 B-cells 6.41 <0.05 IgG 8.45 <0.01 IgA 6.12 <0.05 IgM 7.28 <0.01 Multivariate Analysis of Covariance (MANCOVA) To further investigate the influence of donor characteristics (age, gender, frequency of donation) on immune recovery while controlling for potential confounders, a multivariate analysis of covariance (MANCOVA) was conducted. The MANCOVA included the immune parameters (WBC count, lymphocyte subtypes, immunoglobulin levels) as dependent variables and donor characteristics as covariates. The results from MANCOVA revealed that age and frequency of donation were significant predictors of recovery in WBC count, CD4+ T-cells, and IgG levels, with older and more frequent donors showing slower recovery. However, gender did not significantly influence immune recovery, as shown in table 8 and figure 6. Table 8 : Multivariate Analysis of Covariance (MANCOVA) for Immune Recovery and Donor Characteristics Covariate Immune Parameter F-value p-value Age WBC Count 4.92 <0.05 CD4+ T-cells 6.01 <0.01 IgG 7.38 <0.01 Frequency of Donation WBC Count 5.44 <0.05 CD4+ T-cells 4.78 <0.05 IgG 5.92 <0.05 Gender WBC Count 1.02 NS CD4+ T-cells 0.92 NS IgG 1.13 NS NS = Not Significant Correlation Between Post-Donation Symptoms and Immune Recovery Spearman’s rank correlation was used to assess the relationship between self-reported health symptoms (fatigue, dizziness, lightheadedness) and immune recovery over the four time points. A moderate negative correlation was found between fatigue levels immediately post-donation and the recovery of CD4+ T-cells (r = -0.42, p < 0.01) and IgG levels (r = -0.39, p < 0.05), suggesting that individuals reporting higher levels of fatigue experienced slower recovery of these immune markers. However, no significant correlation was found between dizziness, lightheadedness, and immune recovery, as shown in table 9 and figure 7. Table 9 : Spearman’s Rank Correlation Between Post-Donation Symptoms and Immune Recovery Symptom Immune Parameter r-value p-value Fatigue CD4+ T-cells -0.42 <0.01 IgG -0.39 <0.05 Dizziness CD4+ T-cells -0.08 NS IgG -0.12 NS Lightheadedness CD4+ T-cells -0.05 NS IgG -0.07 NS NS = Not Significant Survival Analysis for Immune Recovery To estimate the time required for full recovery of immune function, a Kaplan-Meier survival analysis was conducted. The analysis demonstrated that approximately 80% of donors had returned to baseline WBC count and immune cell levels (CD4+, CD8+, B-cells) by 1-week post-donation, with full recovery of serum immunoglobulin levels occurring by 4-weeks post-donation. This is further illustrated in figure 8 below The curve shows that the majority of immune recovery occurs within the first week, with minimal further change in immune parameters after 4 weeks. Discussion This research work was designed for assessing the effects of blood donation on the immune system functions, health of donors, and post-donation recovery. The study found out that, there were acute depletions in immune parameters, including decreases in WBC count, lymphocyte subtypes (CD4+, CD8+, B-cells), and serum immunoglobulins (IgG, IgA, IgM) immediately post-donation; these gradually returned to the baseline reading by week four. Subjective symptoms like fatigue and dizziness were also reported by some participants soon after donation. In most cases, this resolved after a week. The findings are in agreement with earlier studies and now provide new insights in the timeline of immune recovery in healthy blood donors (5). A major outcome of the study was the decrease in immediate post-donation WBC count, and it also adds to evidence from earlier studies of acute, adverse effects of blood donation on circulating leukocyte numbers as results of volume loss and transient hemodilution (6). The likely compensations would have been a substantial increase in bone marrow output (7), and this could be inferred from the return to near baseline value within four weeks. This corroborates previous reports that WBC normalization occurs within 2-4 weeks post donation among healthy individuals (8). In like manner, we observed a very significant fall, albeit temporary, in the numbers of lymphocyte subtypes with CD4 T-cells falling more sharply than CD8 T-cells or B-cells. This again finds support in the work of (9) who have suggested that post-donation T-cell depletion might originate from redistribution and temporary sequestration of lymphocytes, possibly accentuated with changes in peripheral circulation induced by stress. Evidence for the quick capacity of the immune system to reinstate homeostasis has again been supported by the 1-week post-donation recovery of lymphocytes in the present study (10). Our finding indicates a temporary drop in immune globulin concentrations with a maximum change for the IgG value; this had also been shown in (11), indicating that serum Ig concentrations can be temporarily depressed during the short period of phlebotomy because of a reduction in plasma volume due to frequent donors. As it happened with the other immune markers, at 4 weeks full recovery of IgG, IgA, and IgM was noted, emphasizing the temporary nature of such effects in healthy individuals. Self-reported symptoms like fatigue and dizziness and lightheadedness were reported very often just after donation but diminished significantly within a week. These observations corroborate previous studies by donor safety studies like (12) stating that while vasovagal symptoms are common, they usually mild and resolve very quickly. Interestingly, our correlation study provides a basis for the opinion that post-donation fatigue may probably be a sign of delayed immune recovery, mainly targeting CD4+ T-lymphocytes and IgG, which merits further evaluation. Donor characteristics such as age and frequency of donation were modestly associated with delayed immune recovery, especially among older and frequent donors. These findings corroborate previous literature indicating that aging is associated with greater immunosenescence and diminished regenerative capacities of hematopoietic progenitors (13); (14). Though the differences were not statistically significant in all confrontations, the trends observed indicated that older and frequent donors may be benefited by a longer recovery interval or closer attention regarding post-donation care. In conclusion, the study confirms that blood donation represents a generally safe practice when carried out by healthy adults; however, the study emphasizes the need for tailored care of donors. Although immunosuppression through donation may not be meaningful in the majority of cases, vulnerable populations, such as older adults or those donating frequently, may require greater attention. Provisions such as adjustment in donation frequency or the addition of immune status screening may serve to protect donor health. Future studies should concern themselves with mechanisms that regulate immune recovery after blood donation, particularly regarding the roles of bone marrow, spleen, and lymphoid organs. It will also be crucial to execute longitudinal studies within which one could appraise the cumulative impact of repeated donation on immune competence. Such data would be imperative to blood donation guidelines, which require balancing the needs of blood supply with donor safety. Limitations This study might have a potential scope about blood donation-affecting immune function. Primarily, being reasonable for such types of studies, sample sizes will not represent all diversities in the blood donor population, probably in terms of aging, health status, etc. Besides, immune function was investigated for only four weeks post-donation with none longer than that. This is also less informative on the long-term effects attached to blood donation on the immune health level. Finally, self-reported symptoms would be effective information on donor recovery, but other studies could also use objective measures of fatigue and other symptoms to make data basis more robust. Conclusion In summary, blood donation always results in short-term reductions in immune function such as WBC counts, lymphocyte subtypes, and immunoglobulins but soon recovers within 4 weeks. Mild symptoms emerge in post-donation that usually resolve during the first week. The findings indicate that blood donation is safe for most healthy individuals, although older and more frequent donors might take a longer time to recover and therefore need more scrutiny. Additional evidence is needed to better understand the long-term effects of repeated blood donation on immune function and donor health. Declarations Conflicts of Interest: There is no conflict of interest regarding this article Funding: There was no funding received for this study Data availability: The data of the findings of this study are all shared on this article Consent for publication: N/A Ethics approval and consent to participate: The study observed ethics according to Helsinki declaration and all participants signed voluntary written informed consent form. Authors’ contributions: All authors reviewed this article Acknowledgment: N/A References Kurhaluk, N., Gradziuk, M. & Tkaczenko, H. Optimisation of Blood Donor Nutrition: Blood Donor Health Improvement Studies. Cell. Physiol. Biochem. 58 , 756–806 (2024). Wei, X. et al. Ancestral T cells in fish require mTORC1-coupled immune signals and metabolic programming for proper activation and function. J. Immunol. 203 (5), 1172–1188 (2019). Skrajewski-Schuler, L. Novel Methods for Biomarker Assessment in Red Blood Cell Storage for Transfusion Medicine (Michigan State University, 2023). Zhao, J. Bloody big data: ensuring the health of blood donors and transfused patients with health registers (Doctoral dissertation, Karolinska Institutet (Sweden)). (2022). Antoniewicz-Papis, J. et al. Current status and achievements of Polish transfusion medicine. Acta Haematol. Pol. 52 (3), 147–162 (2021). Laermans, J. et al. Impact of disasters on blood donation rates and blood safety: A systematic review and meta-analysis. Vox Sang. 117 (6), 769–779 (2022). Hindawi, S. et al. The impact of blood donation on blood counts and ferritin levels: A multi-center study from the Eastern Mediterranean region. Transfus. Apheres. Sci. 60 (3), 103072 (2021). Gradziuk, M., Tkaczenko, H. & Kurhaluk, N. IMPACT OF REGULAR BLOOD DONATION ON THE DONOR'S PHYSIOLOGICAL STATE. До 220-ої річниці з дня заснування університету , 21. (2024). ObeaguEI, A. A. & Obeagu, G. U. Synergistic Effects of Blood Transfusion and HIV in Children Under 5 Years with Severe Malaria: A Review. Elite J. HIV . 2 (1), 31–50 (2024). Yanagisawa, R. et al. Activation of basophils in children with food allergies by blood from donors ingesting the corresponding food. Allergy , 79 (6). (2024). Booth, C., Allard, S. & Robinson, S. Blood transfusion. Medicine . (2025). Ackfeld, T., Schmutz, T., Guechi, Y. & Le Terrier, C. Blood transfusion reactions—a comprehensive review of the literature including a Swiss perspective. J. Clin. Med. 11 (10), 2859 (2022). Feehan, J., Tripodi, N. & Apostolopoulos, V. The twilight of the immune system: The impact of immunosenescence in aging. Maturitas 147 , 7–13 (2021). Su, S., Sun, Y., Gu, X., Wu, W., Su, X., Ma, T., … Yang, J. (2024). Exploration of the healthy donor effect among 0.6 million blood donors in China: longitudinal study.JMIR Public Health and Surveillance, 10(1), e48617.. Additional Declarations No competing interests reported. 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3","display":"","copyAsset":false,"role":"figure","size":22185,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eSelf-Reported Health Symptoms Post-Donation\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/d8d82ee19c61719da6e0768e.png"},{"id":82490052,"identity":"2b2ef10c-7ee1-43c6-9de4-896161a04bcb","added_by":"auto","created_at":"2025-05-12 06:31:08","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":21285,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eHemoglobin Levels Before and After Blood Donation\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/53fdfa3e143b2fac6936a48d.png"},{"id":82490042,"identity":"85f2bba8-290c-4224-8ca0-3a629a91693f","added_by":"auto","created_at":"2025-05-12 06:31:08","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":20693,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChanges in immune parameters over time post blood donation\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/b71c361325a4b31c31b7d1cf.png"},{"id":82490046,"identity":"86bc3240-42f3-4bfe-84f4-0fdaed17b01e","added_by":"auto","created_at":"2025-05-12 06:31:08","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":25571,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of Donor Characteristics on Immune Recovery MANCOVA\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/57386743a4ad277ad88a29cd.png"},{"id":82490045,"identity":"1c6f69ec-644b-493a-b725-7f2631aef0ff","added_by":"auto","created_at":"2025-05-12 06:31:08","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":17899,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eSpearman’s Rank Correlation Between Post-Donation Symptoms and Immune Recovery\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/d22508b6db752418db130a8e.png"},{"id":82491319,"identity":"e81d2bf1-98b4-43d9-9669-8e9e3402d63b","added_by":"auto","created_at":"2025-05-12 06:47:08","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":29802,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eKaplan-Meier Survival Curve for Immune Recovery Post-Donation\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/1a5e58cc0920ee301a1984e1.png"},{"id":99583429,"identity":"5297ef34-5190-425d-9f9f-5c8c0415cb2e","added_by":"auto","created_at":"2026-01-06 06:55:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1779898,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6189603/v1/7cd4f55c-e38f-4ff7-8aeb-662397ac6a20.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Blood Donation on Immune Function and Donor Health Recovery","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBlood donation is crucial to all healthcare systems around the world, and donated blood is utilized for many medical procedures, such as surgical interventions, traumatic interventions, cancer interventions, and chronic condition interventions, like anemia (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Blood donation must be safe not only for the recipient but also for the donor. Blood donation is regarded as healthy in most instances; however, researchers are now more interested in how it may affect donor health, particularly with respect to immune function and recovery after a donation. There have been previous studies that have concentrated much on the various physiological changes following blood donation, involving transient immune alterations while the post-donation donor's body compensates for the loss in blood volume and cellular componentsity (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). The other paramount issue in blood donation relates to its effect on the immune system of the person giving the blood. The immune system is extremely central to all mechanisms defending the host against infectious organisms and foreign invaders. Short-term reductions in immune cells and immunoglobulins occur with the donation of blood, corresponding to the loss of blood volume as well as cellular components; however, studies suggest that these effects are typically transient and recovery occurs in full within a few weeks (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). This still raises the inquiry of whether such short-lived immune alterations would have any consequences in the donor's vulnerability to infections in the contexts of health.\u003c/p\u003e \u003cp\u003ePrevious studies have identified several parameters involved in the immune recovery after a blood donation, such as white blood cell (WBC) counts, lymphocyte subtypes (i.e., CD4\u0026thinsp;+\u0026thinsp;T-cells, CD8\u0026thinsp;+\u0026thinsp;T-cells, B-cells), and immunoglobulins (IgG, IgA, IgM). Studies have consistently documented an immediate decline in all these immune markers after blood donation, with recovery in most cases occurring anywhere between 1 and 4 weeks post-donation (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Also, health symptoms reported by blood donors have been investigated, including fatigue, dizziness, and lightheadedness. Although mild and transient, these symptoms have also raised concerns relating to the well-being of donors during recovery (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Given continuing discussions surrounding donor safety and immune health, this study intends to investigate the possible effects of blood donation on immune functioning and post-donation recovery using an array of immune markers, including WBC counts, lymphocyte subtypes, and serum immunoglobulin levels, as well as related self-reported health symptoms. The outcome will contribute to the understanding of blood donation in relation to immune functioning and donor health to ensure that the donation procedure is safe and sustainable.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy Design and Population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis longitudinal study targeted the impact of blood donation on immune system function, donor health, and post-donation recovery. Healthy adult blood donors aged between 18 and 60 years who had no chronic medical conditions or history of immunodeficiency disorders were recruited from a local blood donation center. In addition, the inclusion criteria were such that healthy volunteers within the stated age range were eligible. Exclusion conditions were: any recent acute illness, pregnancy, or blood donation in the preceding 3 months. Data were collected at a baseline, post-donation, one week after donation, and four weeks after donation. Blood samples were drawn at every time point to analyze immune system status, and participants completed self-report measures for post-donation symptoms such as fatigue, dizziness, and lightheadedness.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlood Sample Collection and Laboratory Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor hematology and immunophenotyping analysis, 5 mL of peripheral venous blood was taken from each participant in EDTA-coated vacutainer tubes (BD Vacutainer\u0026reg; K2EDTA) at all time points: baseline, immediately post-donation, one-week post-donation, and four weeks post-donation. For immunoglobulin quantification, plain serum-separating tubes were used. Using the Sysmex XN-1000 automated hematology analyzer (Sysmex Corporation, Kobe, Japan), the white blood cell (WBC) count and hemoglobin levels were determined. Flow cytometry for lymphocyte subtyping was conducted, using the BD FACSCanto\u0026trade; II flow cytometer (BD Biosciences, San Jose, USA). Fluorescent-labeled monoclonal antibodies to CD4 (clone RPA-T4), CD8 (clone RPA-T8), and CD19 (clone HIB19) all were obtained from BD Biosciences. Isotype-matched controls were used to confirm specificity. Compensation and gate setting were performed using FlowJo software (version 10). Quantitative ELISAs were performed on serum immunoglobulins (IgG, IgA, IgM) with the use of commercial kits (Thermo Fisher Scientific, USA) following manufacturer\u0026apos;s protocols. All kits had inter-assay and intra-assay coefficients of variation of less than 10%. Laboratory assays were performed in duplicate for all analyses to guarantee reproducibility. A detailed questionnaire was used to assess post-donation symptoms (fatigue, dizziness, lightheadedness)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDescriptive statistics (mean \u0026plusmn; standard deviation) were used for summarizing demographic characteristics (age, gender, frequency of donation) and the immune parameters at each time point. Paired t-tests were used in table 2 to test pre- and post-donation values for WBC count, lymphocyte, immunoglobulin, and hemoglobin levels. This paired test would inform almost all immediate changes that have occurred to immune parameters after blood donation. Repeated measures ANOVA was used to determine time variations of immune function (WBC count, lymphocyte subtypes, IgG, IgA, and IgM levels) between the four points in time. Such ANOVA indicated significant time variations in the recovery of immunity after donation. Bonferroni-corrected pairwise post-hoc tests were conducted after repeated measures ANOVA to assess specific time points at which significant changes were noted (i.e., baseline vs. post-donation, baseline vs. 1-week, and so on). Linear regression models were used to explore the relationship between donor characteristics (age, gender, frequency of donation) and recovery of immune markers. These models examined how these characteristics impacted immune recovery rates. Multivariate Analysis of Covariance (MANCOVA) tested the effect of donor characteristics (age, gender, frequency of donation) on immune recovery and protected against confounding variables such as baseline health status. This analysis was designed for simultaneous consideration of multiple confounders. Spearman\u0026rsquo;s rank correlation was applied to determine the extent of association between self-reported health symptoms (fatigue, dizziness, and lightheadedness) and immune recovery (WBC count, lymphocyte subtypes, and IgG levels). This analysis established whether any of the symptoms were associated with slower immune recovery. Kaplan-Meier survival analysis was done to assess recovery time for immune function following blood donation. This provided a graphic representation of the immunity recovery timeline for WBC count, lymphocyte subtypes, and immunoglobulin levels. All statistical analyses were carried out in SPSS version 25 (SPSS Inc., Chicago, IL). The level of significance set for all analyses was p \u0026lt; 0.05. Bonferroni corrections were applied for multiple comparisons whenever required.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval waiver was granted by the IRB of Kisii Teaching and Reporting Hospital. The study observed ethics according to Helsinki declaration and all participants signed voluntary written informed consent form before enrollment. Confidentiality regarding participants was maintained throughout the study; all the data were anonymized and stored securely. Additionally, the participants were informed that they would withdraw from the study without penalty at any time.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThis study assessed the impact of blood donation on immune system function in 108 blood donors, measuring white blood cell (WBC) count, lymphocyte subtypes, and serum immunoglobulin levels at baseline, immediately post-donation, 1-week post-donation, and 4-weeks post-donation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDemographic Characteristics of Study Participants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sample comprised 108 participants, with a nearly equal gender distribution and a wide age range. Table 1, figure 1, figure 2 and figure 3 presents the demographic characteristics of the participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e: \u003cstrong\u003e\u003cem\u003eDemographic Characteristics of Study Participants\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eGender\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e55 (50.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e53 (49.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge Group\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e18-30 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40 (37.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e31-40 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30 (27.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e41-50 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e20 (18.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e51+ years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e18 (16.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency of Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFirst-time donors\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50 (46.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFrequent donors (\u0026ge;3 times/year)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e58 (53.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eWhite Blood Cell (WBC) Count\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe WBC count significantly decreased immediately post-donation, followed by partial recovery within 1-week, and full recovery by 4-weeks post-donation. These findings are summarized in Table 2 and figure 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e: \u003cstrong\u003e\u003cem\u003eWhite Blood Cell Count Before and After Blood Donation\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTime Point\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMean WBC Count (x10\u0026sup3;/\u0026micro;L)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.8 \u0026plusmn; 1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmediate Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.2 \u0026plusmn; 1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e1-Week Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.0 \u0026plusmn; 1.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e4-Weeks Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.7 \u0026plusmn; 1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eNS = Not Significant\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLymphocyte Subtypes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA significant decrease in CD4+ T-cells was observed immediately post-donation. This decrease was more pronounced compared to CD8+ T-cells and B-cells, but all lymphocyte subtypes returned to baseline levels by 1-week post-donation. The changes in lymphocyte subtypes are detailed in \u003cstrong\u003eTable 3\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e: \u003cstrong\u003e\u003cem\u003eLymphocyte Subtypes Before and After Blood Donation\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLymphocyte Subtype\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePost-Donation (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e1-Week (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e4-Weeks (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCD4+ T-cells\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e37 \u0026plusmn; 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e29 \u0026plusmn; 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e36 \u0026plusmn; 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e37 \u0026plusmn; 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCD8+ T-cells\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22 \u0026plusmn; 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19 \u0026plusmn; 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e21 \u0026plusmn; 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22 \u0026plusmn; 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eB-cells\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30 \u0026plusmn; 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e26 \u0026plusmn; 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28 \u0026plusmn; 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30 \u0026plusmn; 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eSerum Immunoglobulin Levels (IgG, IgA, IgM)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSerum levels of immunoglobulins (IgG, IgA, IgM) were significantly reduced immediately post-donation but returned to baseline by 4-weeks post-donation. These findings are summarized in \u003cstrong\u003eTable 4 and figure 2\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4\u003c/strong\u003e: \u003cstrong\u003e\u003cem\u003eSerum Immunoglobulin Levels Before and After Blood Donation\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmunoglobulin\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline (mg/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePost-Donation (mg/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e1-Week (mg/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e4-Weeks (mg/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIgG\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11.5 \u0026plusmn; 1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9.8 \u0026plusmn; 1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10.6 \u0026plusmn; 1.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11.3 \u0026plusmn; 1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIgA\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.2 \u0026plusmn; 0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.9 \u0026plusmn; 0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.1 \u0026plusmn; 0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.2 \u0026plusmn; 0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIgM\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.0 \u0026plusmn; 0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.7 \u0026plusmn; 0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.9 \u0026plusmn; 0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.0 \u0026plusmn; 0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eSelf-Reported Health Symptoms\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eApproximately 30% of donors reported mild symptoms, such as fatigue, dizziness, and lightheadedness, immediately post-donation. These symptoms largely resolved by 1-week post-donation, with only 10% of participants reporting any symptoms at that time. These findings are summarized in \u003cstrong\u003eTable 5 and figure 3\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5\u003c/strong\u003e: \u003cem\u003eSelf-Reported Health Symptoms Post-Donation\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSymptom\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmediately Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e1-Week Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e4-Weeks Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFatigue\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e18%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eDizziness\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLightheadedness\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eHemoglobin Levels\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHemoglobin levels significantly decreased immediately post-donation but returned to baseline levels by 4-weeks post-donation. These results are shown in \u003cstrong\u003eTable 6 and figure 4\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6\u003c/strong\u003e: \u003cem\u003eHemoglobin Levels Before and After Blood Donation\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTime Point\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMean Hemoglobin (g/dL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14.2 \u0026plusmn; 1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmediate Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12.4 \u0026plusmn; 1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e1-Week Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13.2 \u0026plusmn; 1.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e4-Weeks Post-Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14.1 \u0026plusmn; 1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eNS = Not Significant\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelations Between Immune Recovery and Donor Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAge and Immune Recovery: Older donors (aged 50 years and above) exhibited slower recovery of CD4+ T-cells and IgG levels compared to younger donors (18-35 years).\u003c/p\u003e\n\u003cp\u003eFrequency of Donation: Frequent donors (donating more than three times per year) showed a slightly slower immune recovery rate compared to first-time donors, though this difference was not statistically significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData were analyzed using paired t-tests to compare pre- and post-donation immune parameters. Linear regression models were applied to assess the influence of donor characteristics on immune recovery rates, and multivariate analysis was conducted to control for potential confounding factors such as baseline health status and pre-existing medical conditions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRepeated Measures Analysis of Variance (ANOVA)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRepeated measures ANOVA was used to evaluate changes in immune parameters (WBC count, lymphocyte subtypes, immunoglobulin levels) across multiple time points (baseline, immediately post-donation, 1-week post-donation, 4-weeks post-donation). This approach helps to assess the temporal patterns in immune recovery within participants and identify whether significant changes occur over time.\u003c/p\u003e\n\u003cp\u003eThe repeated measures ANOVA indicated significant changes over time for all immune parameters (WBC count, lymphocyte subtypes, IgG, IgA, and IgM levels), with the exception of the CD8+ T-cell and B-cell percentages, which were less sensitive to temporal changes (Table 7). Post-hoc pairwise comparisons revealed that the most significant differences occurred between baseline and immediately post-donation, while the differences between 1-week and 4-weeks post-donation were generally non-significant, indicating full recovery of these immune markers by 4-weeks post-donation, as shown in table 7 and figure 5\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 7\u003c/strong\u003e: \u003cstrong\u003e\u003cem\u003eRepeated Measures ANOVA Results for Immune Parameters Over Time\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmune Parameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eF-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eWBC Count\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e35.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCD4+ T-cells\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCD8+ T-cells\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eB-cells\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIgG\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIgA\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIgM\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eMultivariate Analysis of Covariance (MANCOVA)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo further investigate the influence of donor characteristics (age, gender, frequency of donation) on immune recovery while controlling for potential confounders, a multivariate analysis of covariance (MANCOVA) was conducted. The MANCOVA included the immune parameters (WBC count, lymphocyte subtypes, immunoglobulin levels) as dependent variables and donor characteristics as covariates.\u003c/p\u003e\n\u003cp\u003eThe results from MANCOVA revealed that age and frequency of donation were significant predictors of recovery in WBC count, CD4+ T-cells, and IgG levels, with older and more frequent donors showing slower recovery. However, gender did not significantly influence immune recovery, as shown in table 8 and figure 6.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 8\u003c/strong\u003e: \u003cstrong\u003e\u003cem\u003eMultivariate Analysis of Covariance (MANCOVA) for Immune Recovery and Donor Characteristics\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCovariate\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmune Parameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eF-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eWBC Count\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCD4+ T-cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIgG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency of Donation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eWBC Count\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCD4+ T-cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIgG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eGender\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eWBC Count\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCD4+ T-cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIgG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eNS = Not Significant\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelation Between Post-Donation Symptoms and Immune Recovery\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSpearman\u0026rsquo;s rank correlation was used to assess the relationship between self-reported health symptoms (fatigue, dizziness, lightheadedness) and immune recovery over the four time points. A moderate negative correlation was found between fatigue levels immediately post-donation and the recovery of CD4+ T-cells (r = -0.42, p \u0026lt; 0.01) and IgG levels (r = -0.39, p \u0026lt; 0.05), suggesting that individuals reporting higher levels of fatigue experienced slower recovery of these immune markers. However, no significant correlation was found between dizziness, lightheadedness, and immune recovery, as shown in table 9 and figure 7.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 9\u003c/strong\u003e: \u003cem\u003eSpearman\u0026rsquo;s Rank Correlation Between Post-Donation Symptoms and Immune Recovery\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSymptom\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eImmune Parameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003er-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFatigue\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCD4+ T-cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIgG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eDizziness\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCD4+ T-cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIgG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLightheadedness\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCD4+ T-cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIgG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eNS = Not Significant\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurvival Analysis for Immune Recovery\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo estimate the time required for full recovery of immune function, a Kaplan-Meier survival analysis was conducted. The analysis demonstrated that approximately 80% of donors had returned to baseline WBC count and immune cell levels (CD4+, CD8+, B-cells) by 1-week post-donation, with full recovery of serum immunoglobulin levels occurring by 4-weeks post-donation. This is further illustrated in figure 8 below\u003c/p\u003e\n\u003cp\u003eThe curve shows that the majority of immune recovery occurs within the first week, with minimal further change in immune parameters after 4 weeks.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis research work was designed for assessing the effects of blood donation on the immune system functions, health of donors, and post-donation recovery. The study found out that, there were acute depletions in immune parameters, including decreases in WBC count, lymphocyte subtypes (CD4+, CD8+, B-cells), and serum immunoglobulins (IgG, IgA, IgM) immediately post-donation; these gradually returned to the baseline reading by week four. Subjective symptoms like fatigue and dizziness were also reported by some participants soon after donation. In most cases, this resolved after a week. The findings are in agreement with earlier studies and now provide new insights in the timeline of immune recovery in healthy blood donors (5).\u003c/p\u003e\n\u003cp\u003eA major outcome of the study was the decrease in immediate post-donation WBC count, and it also adds to evidence from earlier studies of acute, adverse effects of blood donation on circulating leukocyte numbers as results of volume loss and transient hemodilution (6). The likely compensations would have been a substantial increase in bone marrow output (7), and this could be inferred from the return to near baseline value within four weeks. This corroborates previous reports that WBC normalization occurs within 2-4 weeks post donation among healthy individuals (8).\u003c/p\u003e\n\u003cp\u003eIn like manner, we observed a very significant fall, albeit temporary, in the numbers of lymphocyte subtypes with CD4 T-cells falling more sharply than CD8 T-cells or B-cells. This again finds support in the work of (9) who have suggested that post-donation T-cell depletion might originate from redistribution and temporary sequestration of lymphocytes, possibly accentuated with changes in peripheral circulation induced by stress. Evidence for the quick capacity of the immune system to reinstate homeostasis has again been supported by the 1-week post-donation recovery of lymphocytes in the present study (10).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur finding indicates a temporary drop in immune globulin concentrations with a maximum change for the IgG value; this had also been shown in (11), indicating that serum Ig concentrations can be temporarily depressed during the short period of phlebotomy because of a reduction in plasma volume due to frequent donors. As it happened with the other immune markers, at 4 weeks full recovery of IgG, IgA, and IgM was noted, emphasizing the temporary nature of such effects in healthy individuals.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSelf-reported symptoms like fatigue and dizziness and lightheadedness were reported very often just after donation but diminished significantly within a week. These observations corroborate previous studies by donor safety studies like (12) stating that while vasovagal symptoms are common, they usually mild and resolve very quickly. Interestingly, our correlation study provides a basis for the opinion that post-donation fatigue may probably be a sign of delayed immune recovery, mainly targeting CD4+ T-lymphocytes and IgG, which merits further evaluation.\u003c/p\u003e\n\u003cp\u003eDonor characteristics such as age and frequency of donation were modestly associated with delayed immune recovery, especially among older and frequent donors. These findings corroborate previous literature indicating that aging is associated with greater immunosenescence and diminished regenerative capacities of hematopoietic progenitors (13); (14). Though the differences were not statistically significant in all confrontations, the trends observed indicated that older and frequent donors may be benefited by a longer recovery interval or closer attention regarding post-donation care.\u003c/p\u003e\n\u003cp\u003eIn conclusion, the study confirms that blood donation represents a generally safe practice when carried out by healthy adults; however, the study emphasizes the need for tailored care of donors. Although immunosuppression through donation may not be meaningful in the majority of cases, vulnerable populations, such as older adults or those donating frequently, may require greater attention. Provisions such as adjustment in donation frequency or the addition of immune status screening may serve to protect donor health. Future studies should concern themselves with mechanisms that regulate immune recovery after blood donation, particularly regarding the roles of bone marrow, spleen, and lymphoid organs. It will also be crucial to execute longitudinal studies within which one could appraise the cumulative impact of repeated donation on immune competence. Such data would be imperative to blood donation guidelines, which require balancing the needs of blood supply with donor safety.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study might have a potential scope about blood donation-affecting immune function. Primarily, being reasonable for such types of studies, sample sizes will not represent all diversities in the blood donor population, probably in terms of aging, health status, etc. Besides, immune function was investigated for only four weeks post-donation with none longer than that. This is also less informative on the long-term effects attached to blood donation on the immune health level. Finally, self-reported symptoms would be effective information on donor recovery, but other studies could also use objective measures of fatigue and other symptoms to make data basis more robust.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, blood donation always results in short-term reductions in immune function such as WBC counts, lymphocyte subtypes, and immunoglobulins but soon recovers within 4 weeks. Mild symptoms emerge in post-donation that usually resolve during the first week. The findings indicate that blood donation is safe for most healthy individuals, although older and more frequent donors might take a longer time to recover and therefore need more scrutiny. Additional evidence is needed to better understand the long-term effects of repeated blood donation on immune function and donor health.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflicts of Interest:\u0026nbsp;\u003c/strong\u003eThere is no conflict of interest regarding this article\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eThere was no funding received for this study\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u0026nbsp;\u003c/strong\u003eThe data of the findings of this study are all shared on this article\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eN/A\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e The study observed ethics according to Helsinki declaration and all participants signed voluntary written informed consent form.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions:\u0026nbsp;\u003c/strong\u003eAll authors reviewed this article\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment:\u0026nbsp;\u003c/strong\u003eN/A\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKurhaluk, N., Gradziuk, M. \u0026amp; Tkaczenko, H. Optimisation of Blood Donor Nutrition: Blood Donor Health Improvement Studies. \u003cem\u003eCell. Physiol. Biochem.\u003c/em\u003e \u003cb\u003e58\u003c/b\u003e, 756\u0026ndash;806 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWei, X. et al. Ancestral T cells in fish require mTORC1-coupled immune signals and metabolic programming for proper activation and function. \u003cem\u003eJ. Immunol.\u003c/em\u003e \u003cb\u003e203\u003c/b\u003e (5), 1172\u0026ndash;1188 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSkrajewski-Schuler, L. \u003cem\u003eNovel Methods for Biomarker Assessment in Red Blood Cell Storage for Transfusion Medicine\u003c/em\u003e (Michigan State University, 2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao, J. \u003cem\u003eBloody big data: ensuring the health of blood donors and transfused patients with health registers\u003c/em\u003e (Doctoral dissertation, Karolinska Institutet (Sweden)). (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAntoniewicz-Papis, J. et al. Current status and achievements of Polish transfusion medicine. \u003cem\u003eActa Haematol. Pol.\u003c/em\u003e \u003cb\u003e52\u003c/b\u003e (3), 147\u0026ndash;162 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaermans, J. et al. Impact of disasters on blood donation rates and blood safety: A systematic review and meta-analysis. \u003cem\u003eVox Sang.\u003c/em\u003e \u003cb\u003e117\u003c/b\u003e (6), 769\u0026ndash;779 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHindawi, S. et al. The impact of blood donation on blood counts and ferritin levels: A multi-center study from the Eastern Mediterranean region. \u003cem\u003eTransfus. Apheres. Sci.\u003c/em\u003e \u003cb\u003e60\u003c/b\u003e (3), 103072 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGradziuk, M., Tkaczenko, H. \u0026amp; Kurhaluk, N. IMPACT OF REGULAR BLOOD DONATION ON THE DONOR'S PHYSIOLOGICAL STATE. \u003cem\u003eДо 220-ої річниці з дня заснування університету\u003c/em\u003e, 21. (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eObeaguEI, A. A. \u0026amp; Obeagu, G. U. Synergistic Effects of Blood Transfusion and HIV in Children Under 5 Years with Severe Malaria: A Review. \u003cem\u003eElite J. HIV\u003c/em\u003e. \u003cb\u003e2\u003c/b\u003e (1), 31\u0026ndash;50 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYanagisawa, R. et al. Activation of basophils in children with food allergies by blood from donors ingesting the corresponding food. \u003cem\u003eAllergy\u003c/em\u003e, \u003cb\u003e79\u003c/b\u003e(6). (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBooth, C., Allard, S. \u0026amp; Robinson, S. Blood transfusion. \u003cem\u003eMedicine\u003c/em\u003e. (2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAckfeld, T., Schmutz, T., Guechi, Y. \u0026amp; Le Terrier, C. Blood transfusion reactions\u0026mdash;a comprehensive review of the literature including a Swiss perspective. \u003cem\u003eJ. Clin. Med.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e (10), 2859 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeehan, J., Tripodi, N. \u0026amp; Apostolopoulos, V. The twilight of the immune system: The impact of immunosenescence in aging. \u003cem\u003eMaturitas\u003c/em\u003e \u003cb\u003e147\u003c/b\u003e, 7\u0026ndash;13 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSu, S., Sun, Y., Gu, X., Wu, W., Su, X., Ma, T., \u0026hellip; Yang, J. (2024). Exploration of the healthy donor effect among 0.6 million blood donors in China: longitudinal study.JMIR Public Health and Surveillance, 10(1), e48617..\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Blood donation, Immune system function, Post-donation recovery, White blood cells (WBC), Lymphocyte subtypes, Immunoglobulins, Donor health symptoms, Fatigue, Dizziness, Lightheadedness","lastPublishedDoi":"10.21203/rs.3.rs-6189603/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6189603/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eBlood donation could potentially affect immune function and donor health. Most studies have centered on hematological alterations after donation; however, studies on various immune parameters and recovery dynamics are sparse.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eThis study aims to investigate the immune function, donor health, and recovery dynamics after blood donation.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eHealthy adult blood donors (n\u0026thinsp;=\u0026thinsp;108) were recruited and evaluated at four time points: baseline (pre-donation), immediately after donation, 1-week post-donation, and 4-weeks post-donation. Blood samples were collected to study white blood cell (WBC) count, lymphocyte subtypes (CD4\u0026thinsp;+\u0026thinsp;T-cells, CD8\u0026thinsp;+\u0026thinsp;T-cells, B-cells), and Ig levels (IgG, IgA, IgM) in serum. Donors filled out a self-report questionnaire regarding post-donation symptoms, including fatigue, dizziness, and lightheadedness. The assessment involved statistical analyses using paired t-test, repeated measures ANOVA, and linear regression.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eBlood donation resulted in immediate post-donation decreases in WBC count, lymphocyte subtypes, and immunoglobulin levels, with restoration to pre-donation levels by 4 weeks. The largest decrease was seen in CD4\u0026thinsp;+\u0026thinsp;T-cells and IgG levels. Post-donation symptoms of fatigue and dizziness were frequently reported immediately post-donation, though most had recovered by 1 week. Recovery was prolonged in older and frequent donors; however, the difference was not statistically significant.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eTemporary immune suppression occurs following blood donation, but recovery to baseline is typically achieved within 4 weeks. Post-donation symptoms, while common, tend to be mild and transient. Consequently, blood donation appears to be generally safe for most healthy individuals, with some delayed recovery observed among older and frequent donors.\u003c/p\u003e","manuscriptTitle":"Impact of Blood Donation on Immune Function and Donor Health Recovery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-12 06:31:03","doi":"10.21203/rs.3.rs-6189603/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1ba79e1e-91d4-42b7-b8ce-3c41e72347fd","owner":[],"postedDate":"May 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":48170372,"name":"Health sciences/Health care"},{"id":48170373,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2026-01-06T06:53:32+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-12 06:31:03","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6189603","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6189603","identity":"rs-6189603","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}