EBV Infection as a Risk Factor for SLE Development in Adult Sudanese Patients: A Case‒Control Study

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A. Mohamed, Abdelrahim O. Mohamed, Alnour Alagib This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3807852/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 To evaluate Epstein–Barr virus (EBV) infection as a risk factor for the development of systemic lupus erythematosus (SLE) in Sudanese patients. This was a case‒control study. Forty-two SLE patients and forty-one age- and sex-matched controls were included. Demographic, clinical and laboratory data were collected. Venous blood samples were drawn, and EBV-viral capsid antigen (EBV-VCA) IgG titre levels were quantified. Demographic, clinical and laboratory data were compared between the two groups by either Student’s t test or the Mann‒Whitney U test for continuous data or by χ² analysis for categorical data. P values < 0.05 were considered to indicate statistical significance. Results The SLE patients in the present study had a low mean Hb concentration (11.5 ± 1.7 gm/dL) and a low RBC count (4.1 ± 0.73). Almost all patients (41, 97.6%) and controls (40, 97.6%) were positive for VCA-IgG (P = 0.99). The titre levels of VCA-IgG between the two groups were similar (153.8 ± 58.2 RU/ml for patients, 156.6 ± 64.1 RU/ml for control groups; p = 0.83). The mean EBV-VCA-IgG levels were similar between the positive and negative anti-dsDNA patients, with a p value of 0.98. The mean VCA-IgG titre was also similar between anti-Sm-positive and anti-Sm-negative patients (p = 0.22). Conclusions No association was found between EBV infection and SLE development in adult Sudanese patients. A larger sample size and younger population are recommended to elucidate any associations between EBV and SLE. Autoantibodies Epstein–Barr viral capsid antigen Epstein–Barr virus infections Systemic lupus erythematosus Figures Figure 1 Figure 2 Figure 3 BACKGROUND Systemic lupus erythematosus (SLE) is a rare multisystem autoimmune disease characterized by a history of worsening disease activity and intermittent flares. It mainly presents in women (90% of cases) of childbearing age. The incidence of SLE varies worldwide according to age, sex and ethnicity. The highest estimates were found in North America (241/100 000 people, 95% CI: 130, 352), while the incidence in Africa was 0.3/100 000 person-years ( 1 ). SLE is a complex multifactorial disease that is caused by genetic, immunological, hormonal and environmental etiological factors. The environmental risk factors for SLE include ultraviolet light, some drugs and chemicals. Bacterial and viral infections are major risk factors for the development of SLE, and Epstein–Barr virus (EBV) is of particular interest. EBV has been associated with multiple autoimmune diseases, specifically SLE, as evidenced by the presence of defective EBV-specific T cells, increased viral loads, increased expression of lytic cycle proteins and high levels of antibodies against EBV in multiple autoimmune diseases. These findings suggest reactivation of the infection in these diseases ( 2 – 4 ). Reactivation from latent infection might contribute to the flares observed in autoimmune diseases. The mechanisms by which EBV causes autoimmunity include several processes, e.g., direct infection and activation of B lymphocytes resulting in antibody production, expression of immune-modulating proteins ( 5 ), suppression of apoptosis in infected lymphocytes ( 6 ), activation of autoreactive T lymphocytes induced by inflammation and ultimately through molecular mimicry between viral antigens and autoantigens, resulting in cross-reactivity followed by epitope spreading ( 7 ). It has been reported that the viral antigen Epstein–Barr nuclear antigen EBNA1 has homology with several proteins (e.g., 50 kDa Ro, the Sm protein and spliceosomes) that cause an autoimmune humoral response. This molecular mimicry may play an essential role in the induction of the autoantibodies observed in SLE( 8 ). A systemic review and meta-analysis showed that the seroprevalence of antiviral capsid antigen (VCA) IgG was greater in SLE patients than in controls (OR 2.08, 95% CI 1.15–3.76; p=0.007). Similar results were found for anti-early antigen-diffuse (EA)/D IgG (OR 4.5, 955 CI 3-11.6, p < 0.00001) but not for anti-EBNA 1 (OR 1.45, 955 CI 0.7–2.98, p = 0.32)( 9 ). The elevated titre of these antibodies suggested reactivation of EBV in epithelial cells or reinfection of epithelial cells after reactivation of the B cells, indicating a lack of control of latent infection. Another study by Li et al. in Taiwan reported higher IgA anti-EBV EBNA1 (31.2% vs 4.1%, P < 10 − 7 ) and IgG anti-EBV DNase antibody (53.8% vs 12.2%, p < 10 − 7 ) levels in SLE patients than in controls( 10 ). In addition, a greater prevalence of EBV-EA/D antibodies was found in SLE patients than in controls in both Turkish ( 11 ) and Colombian populations( 12 ). The incidence and prevalence of SLE are highest among people of black ethnicity( 1 ). Additionally, SLE is known to have a more severe course and worse outcomes in populations of African origin ( 13 , 14 ). Studies have shown that African American SLE patients have higher frequencies of autoantibodies against anti-dsDNA, chromatin, ribosomal P, SSA/Ro60 and Sm protein than European Americans living in the same area ( 15 ). EBV is ubiquitous in the adult population worldwide, but African children are known to be infected early in life, as most of them are seroconverted at the age of 2 years, while in developed countries, primary infection is delayed until young adult life ( 16 ). A study examining the association between EBV and SLE with respect to race revealed that African SLE patients had a greater EBV-IgG seroprevalence than white patients did; this difference has been attributed to the fact that the African population has a greater incidence of infection and likelihood of encountering the virus( 17 ). Many studies have been performed to investigate the clinical course and immunological profile of Sudanese patients with SLE ( 18 ). Sudanese SLE patients were younger and had shorter disease durations than Caucasian Sweden patients were (33.0 vs 47.7 years; P < 0.0001), possibly indicating limited survival. Interestingly, the same study compared the immunological profiles of Sudanese SLE patients and Caucasian Sweden patients and reported a greater frequency of anti-Sm antibodies in the Sudanese population ( 19 ). Instead of the previous studies performed to study SLE in the African population, data are still lacking. The diverse environmental risk, genetic admixture and difficulty in tracing individuals in the African population contribute to the difficulty in studying SLE in this population. To the best of our knowledge, no previous research has been performed to study the association between SLE and EBV in the Sudanese population. The results of this study could explain the higher antibody titres and the more severe course observed in Sudanese and African populations in general. New and emergent treatments for the EBV load and the course of latent EBV infection are interesting possible treatments for SLE. The aim of this study was to evaluate EBV infection as a risk factor for the development of SLE in adult Sudanese patients. This was assessed by comparing the anti-VCA IgG antibody titre and seroconversion between Sudanese SLE patients and control individuals. MATERIALS AND METHODS This was a case‒control noninterventional hospital-based study that was conducted between July 2021 and February 2022. The study was conducted at the Rheumatology Clinic of Omdurman Military Hospital, Omdurman, Sudan. Forty-two SLE patients who fulfilled the classification criteria established by the European League Against Rheumatism/American College of Rheumatology 2019 (EULAR/ACR) ( 20 ) were recruited from the clinic. The exclusion criteria were SLE patients with other connective tissue diseases and SLE patients with symptoms suggestive of EBV infection, e.g., fever, sore throat or body aches. Forty-one age- and sex-matched controls were included in the study. The controls were healthy individuals without a history of any chronic disease. Patients were recruited from the Omdurman Military Hospital, and most of them were relatives of patients attending the clinics in the hospital. The patients and controls were consulted about their will and approval to participate in the study, and written consent was obtained. DATA COLLECTION METHODS AND TOOLS A structured interview questionnaire was used to collect social, demographic and clinical data from the participants. Trained qualified medical personnel interviewed the participants using the questionnaire. Then, full history and examination (skin, cardiopulmonary, renal, neurological) were done to fulfil the ACR criteria. Past laboratory investigations records (full blood counts, renal profiles, inflammatory marker levels, and antinuclear antibody levels) were recorded. Three cc of blood was withdrawn and collected in heparin tubes. The samples were centrifuged, and the plasma was stored at -20°C until further analysis. All experiments were performed in accordance with relevant guidelines and regulations. QUALITATIVE DETERMINATION OF HUMAN IgG AGAINST EBV- VCA USING ENZYME-LINKED IMMUNOSORBANT ASSAY (ELISA) Anti-VCA IgG antibody titres were quantitatively measured using a Euroimmun (EBV-CA) ELISA Kit (Lubeck, Germany). The procedure was performed using the fully automated EUROIMMUN Analyser 1-2P (Lubeck, Germany). First, the samples were diluted to 1:101 using sample buffer. Then, 100 µl of the 3 calibrator, positive and negative control and diluted samples were transferred to individual microplate wells and incubated for 30 minutes at room temperature. Then, 3 washing steps were performed using 450 µl of washing buffer for each wash. After washing, all the liquid was removed by tapping the plate on absorbent paper. Next, 100 µl of the enzyme conjugate (peroxidase-labelled anti-human IgG) was added to each of the microplate wells, followed by an incubation step for 30 minutes at room temperature. The wells were subsequently emptied and washed as described above. The third and last step involved pipetting 100 µl of chromogen/substrate solution into each of the wells, followed by incubation for 15 minutes. Then, 100 µl of stop solution was added to the wells. Within 30 minutes of adding the stop solution, the color intensity was measured at a wavelength of 450 nm with a reference wavelength between 620 and 650 nm. A standard curve was obtained by point-to-point plotting of the extinction readings measured for the 3 calibration sera against the corresponding units. The titre of the antibodies in the samples was obtained using this calculated curve. DATA MANAGEMENT Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) program, version 26. Continuous data are presented as the mean ± SD for normally distributed data and median with quartiles for nonnormally distributed data. Categorical data are presented as percentages. Continuous data were compared between the patient and control groups by the independent Student’s t test or the Mann‒Whitney U test, while categorical data were compared by the chi-square test. A p value less than 0.05 was considered to indicate statistical significance in this study. RESULTS The study included 42 SLE patients and 41 matched controls. CHARACTERISTICS OF THE SLE PATIENT’S GROUP The SLE patients were from different regions of Sudan. Eight (19%) patients were from Khartoum. The same number (5, 11.9%) were from the White Nile and Al Jazira regions. Four patients (9.5%) were from the River Nile, and the same number was from South Kordofan. Three (7.2%) were originally from northern regions, and the same number was from North Kordofan. Two (4.8%) patients were from West Kordofan, and the same frequency was from Sennar and North Darfur. The lowest frequency, 1 (2.4%), was from the South Darfur, Al Qadarif, Blue Nile and West Darfur regions. No patients were from the Red Sea, East Darfur or Central Darfur. The epidemiological variables of the SLE patients are presented in Table 1. In most of the patients, 41 (97.6%) did not have a first-degree family history of SLE. Only one patient (2.4%) had a sister with SLE. When reviewing the most recent laboratory investigations of the SLE patient group, the following data were found. The mean Hb level was 11.5 ± 1.7 gm/dl, which was below normal. The mean MCV was 82.9 ± 16.3 fL. The mean RBC count was 4.1 ± 0.73 million cells/mcL, which is also below the normal level. The total WBC count was 7.9 ± 3.5 10 9 /L. The mean neutrophil and lymphocyte counts were 5.06 ± 3.1 and 1.98 ± 0.88 10 9 /L, respectively. The platelet count was within the normal range. Her urea and creatinine levels were normal (Table 2). Regarding the immunological workup, only 3 patients had ANA titre results, and all the results were positive. Only 11 of the 42 patients had anti-dsDNA titre data. Five (45.5%) patients had positive ant-dsDNA titre results, and 6 (54.5%) had negative results. Only 8 of the patients had anti-Sm results; most of them (5; 62.5%) had positive anti-Sm results, and 3 (37.5%) had negative results (Table 2). COMPARISON BETWEEN THE GROUP OF SLE PATIENT AND THE CONTROL GROUP The seroconversion of EBV-VCA IgG between the patient and control groups was compared, and it was found that almost all patients (41, 97.6%) and controls (40, 97.6%) were positive for VCA-IgG. The results were similar between the two groups, with a p value of 0.99 and an odds ratio of 1.025 (95% CI = 0.062–16.95). Next, the VCA-IgG titres were compared between the two groups and found to be similar (153.8 ± 58.2 for patients, 156.6 ± 64.1 for control groups; p = 0.83) (Table 3, Fig. 1 ). COMPARING THE EBV-VCA IGG TITERS WITH AUTOANTIBODIES IN SLE GROUP Next, we evaluated VCA-IgG according to the presence of ant-dsDNA and anti-Sm status. The mean EBV-VCA-IgG levels were similar between the positive and negative anti-dsDNA patients, with a p value of 0.98. The mean VCA-IgG titre was also similar between anti-sm-positive and anti-sm-negative patients (p = 0.22; Figs. 2 and 3 ). DISCUSSION This study is the first in Sudan to investigate EBV as a risk factor for the development of SLE in Sudanese patients. The study included 42 patients and 41 controls. First, the origin of the SLE patients was studied. In our study, we found that the highest frequencies were from the central and northern regions, and the lowest numbers were from the eastern and western regions. One previous study examined the ethnic distribution of SLE patients in Sudan and revealed that most of the patients were from Afro-Arabs tribes (94.3%), while fewer were from Nubian ancestry (5.7%), and fewer were from southern and western black tribes ( 21 ). In this study, only one of the 42 patients in the group had a sister with SLE. Epidemiological studies suggest a strong genetic contribution to the etiology of SLE with 66% heritability; i.e., 66% of the variation in the trait is due to genetic factors ( 22 ). Over 40 genes/loci have been identified to be associated with SLE in recent years. Most of these involve HLA and FCγ receptors. The present study reviewed the laboratory investigations of SLE patients and revealed that they had low haemoglobin and RBC levels, which is expected for multiple reasons. Possible causes of anaemia in SLE patients include anaemia caused by chronic disease, the presence of autoantibodies against red blood cells (RBCs), impaired erythropoietin production by impaired kidneys, gastrointestinal blood loss from immunosuppressive drugs and increased red cell destruction from hypersplenism ( 23 ). The immunological workup of the SLE patient group was insufficient, as most of the patients had lost their previous workup. The ANA titre was measured in only 3 patients, and all the patients were positive. Five (45.5%) out of 11 Anti-dsDNA tests were positive, 3 (37.5%) out of 8 Anti-sm tests were positive, 10 (71.4%) out of 14 Anti-Ro tests were positive and 4 (44.4%) out of 9 Anti-la tests were positive in our study. Other autoantibodies that were found with minor frequencies were anti-RNP, anti-nucleosome, anti-histone and anti-Jo antibodies. One study from 4 different centres in Europe reported a prevalence of 31.5% for Anti-Ro, 29.1% for Anti-ds-DNA, 28.1% for Anti-Sm, 24.3% for Anti-RNP, 14% for Anti-La, and 1.3% for Anti-Jo autoantibodies in SLE patients ( 24 ). The prevalence of these autoantibodies in this study was relatively greater than that reported in a previous study, suggesting that the prevalence of these autoantibodies is greater in Africans than in Caucasians, which is controversial among different studies. One study revealed that African American SLE patients had higher autoantibody frequencies for dsDNA, Sm, RNP, Ro, ribosomal P and the Sm/U1RNP complex than European Americans living in the same region ( 15 ). Another study comparing the levels of autoantibodies between Sudanese and Swedish populations has shown that the levels of Anti-Sm, Anti-dsDNA, and Anti-ribosomal P protein are lower among Sudanese patients than among the Swedish population ( 19 ). EBV, which causes latent infection accompanied by periodic reactivation, immortal B lymphocytes and a strong T-cell response, seems to be an excellent candidate cause of autoimmune diseases. The aim of this study was to determine whether EBV infection is a risk factor for developing SLE in Sudanese patients. Most of the studies performed on Sudanese patients have evaluated clinical or laboratory characteristics, but there are no published studies examining the association between EBV and SLE in the Sudanese population. To study this association, we compared the seropositivity of EBV-VCA IgG and the plasma titre between 42 SLE patients and age- and sex-matched controls. We found that both groups had similar percentages of positive cells (97.6%), and the titre levels were similar between the two groups. A meta-analysis of the frequency of SLE in EBV-infected individuals vs noninfected individuals revealed a greater frequency of SLE among EBV-infected individuals ( 25 ). Another systemic review and meta-analysis included 25 case‒control studies and revealed a greater EBV-VCA-IgG seroprevalence among SLE patients than among controls (OD 2.08, 95% CI 1.15- 3; p = 0.007)( 9 ). These results support but do not demonstrate a causal link between EBV infection and SLE, as autoimmunity causes a state of immune dysregulation that could lead to an increased risk of EBV infection. One of the suggested explanations for the association between EBV and SLE is molecular mimicry. The Sm spliceosome protein is a common target for autoantibody formation in SLE, and anti-Sm antibodies are found in 10–30% of SLE patients. The Sm protein was found to be structurally similar and to antigenically cross-react with a peptide region in EBV nuclear antigen 1, and immunization with that peptide induced lupus humeral autoimmunity ( 26 ). To study the possibility of other hidden molecular mimics, we investigated VCA-IgG titres among patients with positive anti-dsDNA or Anti-Sm antibodies, but the titres were similar between positive and negative patients. This study has several limitations. First, because of the small sample size, especially given the high seropositivity of EBV among adults (> 90%), a larger sample size or younger population would be more relevant for determining significant differences between patients and control individuals. Another limitation is the deficient immunological workup of the patient group. CONCLUSIONS In conclusion, in this study, no association was found between EBV infection and SLE development in adult Sudanese patients, as both the patient and control groups had similar VCA-IgG titres. Similarly, the VCA-IgG titres were similar between SLE patients with positive and negative Anti-dsDNA and Anti-Sm antibodies. A larger sample size and younger population are recommended to elucidate any association between EBV and SLE. LIST OF ABBREVIATIONS EBV: Epstein‒Barr virus, EBNA1: Epstein‒Barr nuclear antigen, EULAR/ACR: European League Against Rheumatism/American College of Rheumatology 2019, VCA: viral capsid antigen, SLE: systemic lupus erythematosus DECLARATIONS ETHICS APPROVAL AND CONSENT TO PARTICIPATE This study was ethically approved by the Ethical Committee of the Research Unit, EDC- Sudanese Medical Specialization Board. Hospital permission was obtained to invite participants to the study. The study was also ethically approved by the Ethical Committee of the Federal Ministry of Health. Oral and written informed consent was obtained from each participant in this study. The data collected in this study were kept confidential. CONSENT FOR PUBLICATION Not Applicable AVALBILITY OF DATA AND MATERIALS The dataset generated and analysed during the current study is available in the Figshare repository, [https://doi.org/10.6084/m9.figshare.24903312.v2] COMPETING INTERESTS The authors declare that they have no competing interests. FUNDING Not Applicable. AUTHORS' CONTRIBUTIONS S.G., H.K.M. and A.A. designed the study. A.A. provided participants from his clinic. S.G. collected the data. S.G., H.K.M. and A.O.M. analysed the data and interpreted the results. SG. wrote the first draft. H.K.M., A.O.M. and A.A. revised and edited the manuscript. ACKNOWLEDGEMENTS We would like to acknowledge the help and support of the workers of the Alrayan Laboratory, Dr. Khalifa, Ms. Razaz and Ms. Einas, who helped us accomplish the laboratory work. We would also like to thank the medical laboratory staff in the central laboratory of Military Hospital, especially Mr. Mohamed Ahmed, for his help during sample preparation and storage. 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Gender (Number, percentage) Male Female 2 (4.8%) 40 (95.2%) Age (mean ± SD) 42.6±12.7 Origin (Number, Percentage) Khartoum White Nile Al Jazirah River Nile South Kordofan Northern North Kordofan West Kordofan Sennar North Darfur South Darfur Al Qadarif Blue Nile West Darfur East Darfur Central Darfur Red Sea Kassala 8 (19 %) 5 (11.9%) 5 (11.9%) 4 (9.5%) 4 (9.5%) 3 (7.1%) 3 (7.1%) 2 (4.8%) 2 (4.8%) 2 ( 4.8%) 1 (2.4%) 1 (2.4%) 1 (2.4%) 1 ( 2.4 %) 0 (0%) 0 (0 %) 0 (0%) 0(0%) Family History (Number, Percentage) No Yes 41 (97.6 %) 1 (2.4%) Table 2 . Laboratory variables among the SLE patient s’ group. Hb (mean ± SD) (n=36) 11.5 ± 1.7 RBCs (mean ± SD) (n=31) 4.1 ± 0.73 MCV (mean ± SD) (n=31) 82.9 ± 16.3 WBCs (mean ± SD) (n=34) 7.9 ± 3.5 Neutrophils count (mean ± SD) (n=31) 5.06 ± 3.1 Lymphocytes count (mean ± SD) (n=31) 1.98 ± 0.88 Platelets count (mean ± SD) (n=34) 292 ± 95.9 Urea (mean ± SD) (n=28) 32.5 ± 33.8 Creatinine (mean ± SD) (n=34) 0.92 ± 0.99 Anti dsDNA (n=11) Positive (number, percentage ) Negative (number percentage) 5 (45.5%) 6 (54.5%) Anti Sm (n=8) Positive (number, percentage ) Negative (number percentage) 3 ( 37.5%) 5 (62.5%) Anti RO (n=14) Positive (number, percentage ) Negative (number percentage) 10 (71.4%) 4 (28.6%) Anti La (n=9) Positive (number, percentage ) Negative (number percentage) 4(44.4%) 5 (55.6%) Other positive Autoantibodies Anti RNP Anti histone Anti nucleosome Anti Jo 3 2 3 1 ESR (mean ± SD) (n=13) 55.5 ± 36.8 Table 3 . Comparison of the epidemiological and EBV-VCA IgG titres between the patient and control groups SLE patient’s group N=42 Control group N=41 P value Age (median 25 th -75 th centiles ) 43(43.6-48.5) 39(30.5-45) 0.14 Gender (number, percentage) Female Male 40 (95.2%) 2 (4.8%) 40 (97.6%) 1(2.4%) 0.57 Seroconversion of EBV-VCA IgG (number, percentage) Positive Negative 41 (97.6%) 1(2.4%) 40 (97.6%) 1 (2.4%) 0.99 OD = 1.025 (CI 95% 0.062-16.95) EBV-VCA IgG titer (mean ± SD) 153.8± 58.2 156.6± 64.1 0.83 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-3807852","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":264551631,"identity":"4194f2be-72bb-4fb3-b98d-46a5cd826d8e","order_by":0,"name":"Sahar Gamil","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYDCCA0DM2ABmJj4GU8zMDURrSTZmYDAAamEkXgubNFgLAwEtfLcPMH/4ucMun4H/wLPqgoo/0fztQC0/Krbh1CJ5LoFNsvdMsmWDRELa7RlnDHJnHGZsYOw5cxunFoMzDGwMvG3MBgwSDGm3edsMchuAWpgZ2/BqYf74t63eAOiwtGKQlvlEaGGQ5m07DPR2QhozSMsGQlokgQ6Tlm07DnRYQrI0zxnj3I1ALQfx+YUP5LC3bdVAh51J/MxTIZc77/zhgw9+VODWwsDA/wFM2R/gSYCLHcCjHhmwE6twFIyCUTAKRhoAAIzDVM6BmDHYAAAAAElFTkSuQmCC","orcid":"","institution":"Prince Sattam bin Abdelaziz University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Sahar","middleName":"","lastName":"Gamil","suffix":""},{"id":264551632,"identity":"ce777271-4644-4cd2-9b69-aee5fff3547a","order_by":1,"name":"Hala K. A. Mohamed","email":"","orcid":"","institution":"African International University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Hala","middleName":"K. A.","lastName":"Mohamed","suffix":""},{"id":264551633,"identity":"7df39d3a-d8f4-44a7-a67e-08434637389b","order_by":2,"name":"Abdelrahim O. Mohamed","email":"","orcid":"","institution":"University of Khartoum","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Abdelrahim","middleName":"O.","lastName":"Mohamed","suffix":""},{"id":264551634,"identity":"400d49fc-bee0-426d-b452-3a3b973d57c4","order_by":3,"name":"Alnour Alagib","email":"","orcid":"","institution":"Military Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Alnour","middleName":"","lastName":"Alagib","suffix":""}],"badges":[],"createdAt":"2023-12-26 11:29:55","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3807852/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3807852/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":49092491,"identity":"dd7f6b5e-bcfb-4349-bf59-b9636ad1e309","added_by":"auto","created_at":"2024-01-03 02:04:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":171786,"visible":true,"origin":"","legend":"\u003cp\u003eSimple scatterplot comparing EBV-VCA IgG titres between the SLE and control groups\u003c/p\u003e","description":"","filename":"Figure.1.png","url":"https://assets-eu.researchsquare.com/files/rs-3807852/v1/10fa26614dd6298c938f39cb.png"},{"id":49093245,"identity":"bf3ec40f-322c-4659-8de4-f260823091b1","added_by":"auto","created_at":"2024-01-03 02:12:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":14741,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of EBV-VCA-IgG titres between anti-dsDNA-positive and -negative patients.\u003c/p\u003e","description":"","filename":"Figure.2.png","url":"https://assets-eu.researchsquare.com/files/rs-3807852/v1/06c4a168dd2505a8fa638a71.png"},{"id":49092490,"identity":"62ee2f44-1308-4d8c-a339-2435c53ee074","added_by":"auto","created_at":"2024-01-03 02:04:47","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":13454,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of EBV-VCA-IgG titres between anti-Sm-positive and -negative patients.\u003c/p\u003e","description":"","filename":"Figure.3.png","url":"https://assets-eu.researchsquare.com/files/rs-3807852/v1/610a2a0ea5ab15365f693123.png"},{"id":54300684,"identity":"e58210c7-60a0-4c0f-9074-ae741313b602","added_by":"auto","created_at":"2024-04-08 14:26:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":540551,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3807852/v1/00d6a5bb-5384-4faa-9e30-70ae1f2998d1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"EBV Infection as a Risk Factor for SLE Development in Adult Sudanese Patients: A Case‒Control Study","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eSystemic lupus erythematosus (SLE) is a rare multisystem autoimmune disease characterized by a history of worsening disease activity and intermittent flares. It mainly presents in women (90% of cases) of childbearing age. The incidence of SLE varies worldwide according to age, sex and ethnicity. The highest estimates were found in North America (241/100 000 people, 95% CI: 130, 352), while the incidence in Africa was 0.3/100 000 person-years (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSLE is a complex multifactorial disease that is caused by genetic, immunological, hormonal and environmental etiological factors. The environmental risk factors for SLE include ultraviolet light, some drugs and chemicals. Bacterial and viral infections are major risk factors for the development of SLE, and Epstein\u0026ndash;Barr virus (EBV) is of particular interest. EBV has been associated with multiple autoimmune diseases, specifically SLE, as evidenced by the presence of defective EBV-specific T cells, increased viral loads, increased expression of lytic cycle proteins and high levels of antibodies against EBV in multiple autoimmune diseases. These findings suggest reactivation of the infection in these diseases (\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Reactivation from latent infection might contribute to the flares observed in autoimmune diseases.\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003eThe mechanisms by which EBV causes autoimmunity include several processes, e.g., direct infection and activation of B lymphocytes resulting in antibody production, expression of immune-modulating proteins (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e), suppression of apoptosis in infected lymphocytes (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e), activation of autoreactive T lymphocytes induced by inflammation and ultimately through molecular mimicry between viral antigens and autoantigens, resulting in cross-reactivity followed by epitope spreading (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). It has been reported that the viral antigen Epstein\u0026ndash;Barr nuclear antigen EBNA1 has homology with several proteins (e.g., 50 kDa Ro, the Sm protein and spliceosomes) that cause an autoimmune humoral response. This molecular mimicry may play an essential role in the induction of the autoantibodies observed in SLE(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eA systemic review and meta-analysis showed that the seroprevalence of antiviral capsid antigen (VCA) IgG was greater in SLE patients than in controls (OR 2.08, 95% CI 1.15\u0026ndash;3.76; p=0.007). Similar results were found for anti-early antigen-diffuse (EA)/D IgG (OR 4.5, 955 CI 3-11.6, p\u0026thinsp;\u0026lt;\u0026thinsp;0.00001) but not for anti-EBNA 1 (OR 1.45, 955 CI 0.7\u0026ndash;2.98, p\u0026thinsp;=\u0026thinsp;0.32)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). The elevated titre of these antibodies suggested reactivation of EBV in epithelial cells or reinfection of epithelial cells after reactivation of the B cells, indicating a lack of control of latent infection. Another study by Li et al. in Taiwan reported higher IgA anti-EBV EBNA1 (31.2% vs 4.1%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e) and IgG anti-EBV DNase antibody (53.8% vs 12.2%, p\u0026thinsp;\u0026lt;\u0026thinsp;10\u003csup\u003e\u0026minus;\u0026thinsp;7\u003c/sup\u003e) levels in SLE patients than in controls(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). In addition, a greater prevalence of EBV-EA/D antibodies was found in SLE patients than in controls in both Turkish (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e) and Colombian populations(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe incidence and prevalence of SLE are highest among people of black ethnicity(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Additionally, SLE is known to have a more severe course and worse outcomes in populations of African origin (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Studies have shown that African American SLE patients have higher frequencies of autoantibodies against anti-dsDNA, chromatin, ribosomal P, SSA/Ro60 and Sm protein than European Americans living in the same area (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). EBV is ubiquitous in the adult population worldwide, but African children are known to be infected early in life, as most of them are seroconverted at the age of 2 years, while in developed countries, primary infection is delayed until young adult life (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). A study examining the association between EBV and SLE with respect to race revealed that African SLE patients had a greater EBV-IgG seroprevalence than white patients did; this difference has been attributed to the fact that the African population has a greater incidence of infection and likelihood of encountering the virus(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMany studies have been performed to investigate the clinical course and immunological profile of Sudanese patients with SLE (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). Sudanese SLE patients were younger and had shorter disease durations than Caucasian Sweden patients were (33.0 vs 47.7 years; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), possibly indicating limited survival. Interestingly, the same study compared the immunological profiles of Sudanese SLE patients and Caucasian Sweden patients and reported a greater frequency of anti-Sm antibodies in the Sudanese population (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eInstead of the previous studies performed to study SLE in the African population, data are still lacking. The diverse environmental risk, genetic admixture and difficulty in tracing individuals in the African population contribute to the difficulty in studying SLE in this population. To the best of our knowledge, no previous research has been performed to study the association between SLE and EBV in the Sudanese population. The results of this study could explain the higher antibody titres and the more severe course observed in Sudanese and African populations in general. New and emergent treatments for the EBV load and the course of latent EBV infection are interesting possible treatments for SLE.\u003c/p\u003e \u003cp\u003eThe aim of this study was to evaluate EBV infection as a risk factor for the development of SLE in adult Sudanese patients. This was assessed by comparing the anti-VCA IgG antibody titre and seroconversion between Sudanese SLE patients and control individuals.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003eThis was a case‒control noninterventional hospital-based study that was conducted between July 2021 and February 2022. The study was conducted at the Rheumatology Clinic of Omdurman Military Hospital, Omdurman, Sudan. Forty-two SLE patients who fulfilled the classification criteria established by the European League Against Rheumatism/American College of Rheumatology 2019 (EULAR/ACR) (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) were recruited from the clinic. The exclusion criteria were SLE patients with other connective tissue diseases and SLE patients with symptoms suggestive of EBV infection, e.g., fever, sore throat or body aches. Forty-one age- and sex-matched controls were included in the study. The controls were healthy individuals without a history of any chronic disease. Patients were recruited from the Omdurman Military Hospital, and most of them were relatives of patients attending the clinics in the hospital. The patients and controls were consulted about their will and approval to participate in the study, and written consent was obtained.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eDATA COLLECTION METHODS AND TOOLS\u003c/h2\u003e \u003cp\u003eA structured interview questionnaire was used to collect social, demographic and clinical data from the participants. Trained qualified medical personnel interviewed the participants using the questionnaire. Then, full history and examination (skin, cardiopulmonary, renal, neurological) were done to fulfil the ACR criteria. Past laboratory investigations records (full blood counts, renal profiles, inflammatory marker levels, and antinuclear antibody levels) were recorded.\u003c/p\u003e \u003cp\u003eThree cc of blood was withdrawn and collected in heparin tubes. The samples were centrifuged, and the plasma was stored at -20\u0026deg;C until further analysis. All experiments were performed in accordance with relevant guidelines and regulations.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eQUALITATIVE DETERMINATION OF HUMAN IgG AGAINST EBV- VCA USING ENZYME-LINKED IMMUNOSORBANT ASSAY (ELISA)\u003c/h2\u003e \u003cp\u003eAnti-VCA IgG antibody titres were quantitatively measured using a Euroimmun (EBV-CA) ELISA Kit (Lubeck, Germany). The procedure was performed using the fully automated EUROIMMUN Analyser 1-2P (Lubeck, Germany). First, the samples were diluted to 1:101 using sample buffer. Then, 100 \u0026micro;l of the 3 calibrator, positive and negative control and diluted samples were transferred to individual microplate wells and incubated for 30 minutes at room temperature. Then, 3 washing steps were performed using 450 \u0026micro;l of washing buffer for each wash. After washing, all the liquid was removed by tapping the plate on absorbent paper. Next, 100 \u0026micro;l of the enzyme conjugate (peroxidase-labelled anti-human IgG) was added to each of the microplate wells, followed by an incubation step for 30 minutes at room temperature. The wells were subsequently emptied and washed as described above. The third and last step involved pipetting 100 \u0026micro;l of chromogen/substrate solution into each of the wells, followed by incubation for 15 minutes. Then, 100 \u0026micro;l of stop solution was added to the wells. Within 30 minutes of adding the stop solution, the color intensity was measured at a wavelength of 450 nm with a reference wavelength between 620 and 650 nm. A standard curve was obtained by point-to-point plotting of the extinction readings measured for the 3 calibration sera against the corresponding units. The titre of the antibodies in the samples was obtained using this calculated curve.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eDATA MANAGEMENT\u003c/h2\u003e \u003cp\u003eStatistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) program, version 26. Continuous data are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD for normally distributed data and median with quartiles for nonnormally distributed data. Categorical data are presented as percentages. Continuous data were compared between the patient and control groups by the independent Student\u0026rsquo;s t test or the Mann‒Whitney U test, while categorical data were compared by the chi-square test. A p value less than 0.05 was considered to indicate statistical significance in this study.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eThe study included 42 SLE patients and 41 matched controls.\u003c/p\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n\u003ch2\u003eCHARACTERISTICS OF THE SLE PATIENT\u0026rsquo;S GROUP\u003c/h2\u003e\n\u003cp\u003e\u003cstrong\u003eThe\u003c/strong\u003e SLE patients were from different regions of Sudan. Eight (19%) patients were from Khartoum. The same number (5, 11.9%) were from the White Nile and Al Jazira regions. Four patients (9.5%) were from the River Nile, and the same number was from South Kordofan. Three (7.2%) were originally from northern regions, and the same number was from North Kordofan. Two (4.8%) patients were from West Kordofan, and the same frequency was from Sennar and North Darfur. The lowest frequency, 1 (2.4%), was from the South Darfur, Al Qadarif, Blue Nile and West Darfur regions. No patients were from the Red Sea, East Darfur or Central Darfur.\u003c/p\u003e\n\u003cp\u003eThe epidemiological variables of the SLE patients are presented in Table\u0026nbsp;1.\u003c/p\u003e\n\u003cp\u003eIn most of the patients, 41 (97.6%) did not have a first-degree family history of SLE. Only one patient (2.4%) had a sister with SLE.\u003c/p\u003e\n\u003cp\u003eWhen reviewing the most recent laboratory investigations of the SLE patient group, the following data were found. The mean Hb level was 11.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7 gm/dl, which was below normal. The mean MCV was 82.9\u0026thinsp;\u0026plusmn;\u0026thinsp;16.3 fL. The mean RBC count was 4.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73\u0026nbsp;million cells/mcL, which is also below the normal level. The total WBC count was 7.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5 10\u003csup\u003e9\u003c/sup\u003e/L. The mean neutrophil and lymphocyte counts were 5.06\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1 and 1.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88 10\u003csup\u003e9\u003c/sup\u003e/L, respectively. The platelet count was within the normal range. Her urea and creatinine levels were normal (Table\u0026nbsp;2).\u003c/p\u003e\n\u003cp\u003eRegarding the immunological workup, only 3 patients had ANA titre results, and all the results were positive. Only 11 of the 42 patients had anti-dsDNA titre data. Five (45.5%) patients had positive ant-dsDNA titre results, and 6 (54.5%) had negative results. Only 8 of the patients had anti-Sm results; most of them (5; 62.5%) had positive anti-Sm results, and 3 (37.5%) had negative results (Table\u0026nbsp;2).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n\u003ch2\u003eCOMPARISON BETWEEN THE GROUP OF SLE PATIENT AND THE CONTROL GROUP\u003c/h2\u003e\n\u003cp\u003eThe seroconversion of EBV-VCA IgG between the patient and control groups was compared, and it was found that almost all patients (41, 97.6%) and controls (40, 97.6%) were positive for VCA-IgG. The results were similar between the two groups, with a p value of 0.99 and an odds ratio of 1.025 (95% CI\u0026thinsp;=\u0026thinsp;0.062\u0026ndash;16.95). Next, the VCA-IgG titres were compared between the two groups and found to be similar (153.8\u0026thinsp;\u0026plusmn;\u0026thinsp;58.2 for patients, 156.6\u0026thinsp;\u0026plusmn;\u0026thinsp;64.1 for control groups; p\u0026thinsp;=\u0026thinsp;0.83) (Table\u0026nbsp;3, Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n\u003ch2\u003eCOMPARING THE EBV-VCA IGG TITERS WITH AUTOANTIBODIES IN SLE GROUP\u003c/h2\u003e\n\u003cp\u003eNext, we evaluated VCA-IgG according to the presence of ant-dsDNA and anti-Sm status. The mean EBV-VCA-IgG levels were similar between the positive and negative anti-dsDNA patients, with a p value of 0.98. The mean VCA-IgG titre was also similar between anti-sm-positive and anti-sm-negative patients (p\u0026thinsp;=\u0026thinsp;0.22; Figs.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis study is the first in Sudan to investigate EBV as a risk factor for the development of SLE in Sudanese patients. The study included 42 patients and 41 controls.\u003c/p\u003e \u003cp\u003eFirst, the origin of the SLE patients was studied. In our study, we found that the highest frequencies were from the central and northern regions, and the lowest numbers were from the eastern and western regions. One previous study examined the ethnic distribution of SLE patients in Sudan and revealed that most of the patients were from Afro-Arabs tribes (94.3%), while fewer were from Nubian ancestry (5.7%), and fewer were from southern and western black tribes (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn this study, only one of the 42 patients in the group had a sister with SLE. Epidemiological studies suggest a strong genetic contribution to the etiology of SLE with 66% heritability; i.e., 66% of the variation in the trait is due to genetic factors (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Over 40 genes/loci have been identified to be associated with SLE in recent years. Most of these involve HLA and FCγ receptors.\u003c/p\u003e \u003cp\u003eThe present study reviewed the laboratory investigations of SLE patients and revealed that they had low haemoglobin and RBC levels, which is expected for multiple reasons. Possible causes of anaemia in SLE patients include anaemia caused by chronic disease, the presence of autoantibodies against red blood cells (RBCs), impaired erythropoietin production by impaired kidneys, gastrointestinal blood loss from immunosuppressive drugs and increased red cell destruction from hypersplenism (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe immunological workup of the SLE patient group was insufficient, as most of the patients had lost their previous workup. The ANA titre was measured in only 3 patients, and all the patients were positive. Five (45.5%) out of 11 Anti-dsDNA tests were positive, 3 (37.5%) out of 8 Anti-sm tests were positive, 10 (71.4%) out of 14 Anti-Ro tests were positive and 4 (44.4%) out of 9 Anti-la tests were positive in our study. Other autoantibodies that were found with minor frequencies were anti-RNP, anti-nucleosome, anti-histone and anti-Jo antibodies. One study from 4 different centres in Europe reported a prevalence of 31.5% for Anti-Ro, 29.1% for Anti-ds-DNA, 28.1% for Anti-Sm, 24.3% for Anti-RNP, 14% for Anti-La, and 1.3% for Anti-Jo autoantibodies in SLE patients (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). The prevalence of these autoantibodies in this study was relatively greater than that reported in a previous study, suggesting that the prevalence of these autoantibodies is greater in Africans than in Caucasians, which is controversial among different studies. One study revealed that African American SLE patients had higher autoantibody frequencies for dsDNA, Sm, RNP, Ro, ribosomal P and the Sm/U1RNP complex than European Americans living in the same region (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Another study comparing the levels of autoantibodies between Sudanese and Swedish populations has shown that the levels of Anti-Sm, Anti-dsDNA, and Anti-ribosomal P protein are lower among Sudanese patients than among the Swedish population (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eEBV, which causes latent infection accompanied by periodic reactivation, immortal B lymphocytes and a strong T-cell response, seems to be an excellent candidate cause of autoimmune diseases.\u003c/p\u003e \u003cp\u003eThe aim of this study was to determine whether EBV infection is a risk factor for developing SLE in Sudanese patients. Most of the studies performed on Sudanese patients have evaluated clinical or laboratory characteristics, but there are no published studies examining the association between EBV and SLE in the Sudanese population. To study this association, we compared the seropositivity of EBV-VCA IgG and the plasma titre between 42 SLE patients and age- and sex-matched controls. We found that both groups had similar percentages of positive cells (97.6%), and the titre levels were similar between the two groups.\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003eA meta-analysis of the frequency of SLE in EBV-infected individuals vs noninfected individuals revealed a greater frequency of SLE among EBV-infected individuals (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Another systemic review and meta-analysis included 25 case‒control studies and revealed a greater EBV-VCA-IgG seroprevalence among SLE patients than among controls (OD 2.08, 95% CI 1.15- 3; p\u0026thinsp;=\u0026thinsp;0.007)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). These results support but do not demonstrate a causal link between EBV infection and SLE, as autoimmunity causes a state of immune dysregulation that could lead to an increased risk of EBV infection.\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eOne of the suggested explanations for the association between EBV and SLE is molecular mimicry. The Sm spliceosome protein is a common target for autoantibody formation in SLE, and anti-Sm antibodies are found in 10\u0026ndash;30% of SLE patients. The Sm protein was found to be structurally similar and to antigenically cross-react with a peptide region in EBV nuclear antigen 1, and immunization with that peptide induced lupus humeral autoimmunity (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). To study the possibility of other hidden molecular mimics, we investigated VCA-IgG titres among patients with positive anti-dsDNA or Anti-Sm antibodies, but the titres were similar between positive and negative patients.\u003c/p\u003e \u003cp\u003eThis study has several limitations. First, because of the small sample size, especially given the high seropositivity of EBV among adults (\u0026gt;\u0026thinsp;90%), a larger sample size or younger population would be more relevant for determining significant differences between patients and control individuals. Another limitation is the deficient immunological workup of the patient group.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eIn conclusion, in this study, no association was found between EBV infection and SLE development in adult Sudanese patients, as both the patient and control groups had similar VCA-IgG titres. Similarly, the VCA-IgG titres were similar between SLE patients with positive and negative Anti-dsDNA and Anti-Sm antibodies. A larger sample size and younger population are recommended to elucidate any association between EBV and SLE.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"LIST OF ABBREVIATIONS","content":"\u003cp\u003eEBV: Epstein‒Barr virus, EBNA1: Epstein‒Barr nuclear antigen, EULAR/ACR: European League Against Rheumatism/American College of Rheumatology 2019, VCA: viral capsid antigen, SLE: systemic lupus erythematosus\u003c/p\u003e"},{"header":"DECLARATIONS","content":"\u003ch2\u003eETHICS APPROVAL AND CONSENT TO PARTICIPATE\u003c/h2\u003e\n\u003cp\u003eThis study was ethically approved by the Ethical Committee of the Research Unit, EDC- Sudanese Medical Specialization Board. Hospital permission was obtained to invite participants to the study. The study was also ethically approved by the Ethical Committee of the Federal Ministry of Health. Oral and written informed consent was obtained from each participant in this study. The data collected in this study were kept confidential.\u003c/p\u003e\n\u003ch2\u003eCONSENT FOR PUBLICATION\u003c/h2\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003ch2\u003eAVALBILITY OF DATA AND MATERIALS\u003c/h2\u003e\n\u003cp\u003eThe dataset generated and analysed during the current study is available in the Figshare repository, [https://doi.org/10.6084/m9.figshare.24903312.v2]\u003c/p\u003e\n\u003ch2\u003eCOMPETING INTERESTS\u003c/h2\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003ch2\u003eFUNDING\u003c/h2\u003e\n\u003cp\u003eNot Applicable.\u003c/p\u003e\n\u003ch2\u003eAUTHORS\u0026apos; CONTRIBUTIONS\u003c/h2\u003e\n\u003cp\u003eS.G., H.K.M. and A.A. designed the study. A.A. provided participants from his clinic. S.G. collected the data. S.G., H.K.M. and A.O.M. analysed the data and interpreted the results. SG. wrote the first draft. H.K.M., A.O.M. and A.A. revised and edited the manuscript.\u003c/p\u003e\n\u003ch2\u003eACKNOWLEDGEMENTS\u003c/h2\u003e\n\u003cp\u003eWe would like to acknowledge the help and support of the workers of the Alrayan Laboratory, Dr. Khalifa, Ms. Razaz and Ms. Einas, who helped us accomplish the laboratory work. We would also like to thank the medical laboratory staff in the central laboratory of Military Hospital, especially Mr. Mohamed Ahmed, for his help during sample preparation and storage.\u003c/p\u003e"},{"header":"REFERENCES","content":"\u003col\u003e\n\u003cli\u003eRees F, Doherty M, Grainge MJ, Lanyon P, Zhang W. The worldwide incidence and prevalence of systemic lupus erythematosus: a systematic review of epidemiological studies. Rheumatol Oxf Engl. 2017 Nov 1;56(11):1945\u0026ndash;61.\u003c/li\u003e\n\u003cli\u003eKang I, Quan T, Nolasco H, Park SH, Hong MS, Crouch J, et al. Defective control of latent Epstein‒Barr virus infection in systemic lupus erythematosus. J Immunol Baltim Md 1950. 2004 Jan 15;172(2):1287\u0026ndash;94.\u003c/li\u003e\n\u003cli\u003eNewkirk MM, Watanabe Duffy KN, Leclerc J, Lambert N, Shiroky JB. Detection of cytomegalovirus, Epstein‒Barr virus and herpes virus-6 in patients with rheumatoid arthritis with or without Sj\u0026ouml;gren\u0026rsquo;s syndrome. Br J Rheumatol. 1994 Apr;33(4):317\u0026ndash;22.\u003c/li\u003e\n\u003cli\u003eBlaschke S, Schwarz G, Moneke D, Binder L, M\u0026uuml;ller G, Reuss-Borst M. Epstein‒Barr virus infection in peripheral blood mononuclear cells, synovial fluid cells, and synovial membranes of patients with rheumatoid arthritis. J Rheumatol. 2000 Apr;27(4):866\u0026ndash;73.\u003c/li\u003e\n\u003cli\u003eKanegane H, Wakiguchi H, Kanegane C, Kurashige T, Tosato G. Viral interleukin-10 in chronic active Epstein‒Barr virus infection. J Infect Dis. 1997 Jul;176(1):254\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eHenderson S, Huen D, Rowe M, Dawson C, Johnson G, Rickinson A. Epstein‒Barr virus-coded BHRF1 protein, a viral homologue of Bcl-2, protects human B cells from programmed cell death. Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8479\u0026ndash;83.\u003c/li\u003e\n\u003cli\u003eWucherpfennig KW. Mechanisms for the induction of autoimmunity by infectious agents. J Clin Invest. 2001 Oct 15;108(8):1097\u0026ndash;104.\u003c/li\u003e\n\u003cli\u003eMcClain MT, Heinlen LD, Dennis GJ, Roebuck J, Harley JB, James JA. Early events in lupus humoral autoimmunity suggest initiation through molecular mimicry. Nat Med. 2005 Jan;11(1):85\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eHanlon P, Avenell A, Aucott L, Vickers MA. Systematic review and meta-analysis of the sero-epidemiological association between Epstein‒Barr virus and systemic lupus erythematosus. Arthritis Res Ther. 2014 Jan 6;16(1):R3.\u003c/li\u003e\n\u003cli\u003eLu JJY, Chen DY, Hsieh CW, Lan JL, Lin FJ, Lin SH. Association of Epstein‒Barr virus infection with systemic lupus erythematosus in Taiwan. Lupus. 2007;16(3):168\u0026ndash;75.\u003c/li\u003e\n\u003cli\u003eEsen BA, Yılmaz G, Uzun S, Ozdamar M, Aks\u0026ouml;zek A, Kamalı S, et al. Serologic response to Epstein‒Barr virus antigens in patients with systemic lupus erythematosus: a controlled study. Rheumatol Int. 2012 Jan;32(1):79\u0026ndash;83.\u003c/li\u003e\n\u003cli\u003eBerkun Y, Zandman-Goddard G, Barzilai O, Boaz M, Sherer Y, Larida B, et al. Infectious antibodies in systemic lupus erythematosus patients. Lupus. 2009 Nov;18(13):1129\u0026ndash;35.\u003c/li\u003e\n\u003cli\u003eAlarc\u0026oacute;n GS, McGwin G, Petri M, Ramsey-Goldman R, Fessler BJ, Vil\u0026aacute; LM, et al. Time to renal disease and end-stage renal disease in PROFILE: a multiethnic lupus cohort. PLoS Med. 2006 Oct;3(10):e396.\u003c/li\u003e\n\u003cli\u003eUrowitz MB, Gladman DD, Iba\u0026ntilde;ez D, Fortin PR, Bae SC, Gordon C, et al. Evolution of disease burden over five years in a multicenter inception systemic lupus erythematosus cohort. Arthritis Care Res. 2012 Jan;64(1):132\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eBruner BF, Guthridge JM, Lu R, Vidal G, Kelly JA, Robertson JM, et al. Comparison of autoantibody specificities between traditional and bead-based assays in a large, diverse collection of patients with systemic lupus erythematosus and family members. Arthritis Rheum. 2012 Nov;64(11):3677\u0026ndash;86.\u003c/li\u003e\n\u003cli\u003eBiggar RJ, Henle W, Fleisher G, B\u0026ouml;cker J, Lennette ET, Henle G. Primary Epstein‒Barr virus infections in African infants. I. Decline of maternal antibodies and time of infection. Int J Cancer. 1978 Sep 15;22(3):239\u0026ndash;43.\u003c/li\u003e\n\u003cli\u003eParks CG, Cooper GS, Hudson LL, Dooley MA, Treadwell EL, St Clair EW, et al. Association of Epstein‒Barr virus with systemic lupus erythematosus: effect modification by race, age, and cytotoxic T lymphocyte-associated antigen 4 genotype. Arthritis Rheum. 2005 Apr;52(4):1148\u0026ndash;59.\u003c/li\u003e\n\u003cli\u003eAhmed N, Shigidi M, Al Agib AN, Abdelrahman H, Taha E. Clinical features and antinuclear antibodies profile among adults with systemic lupus erythematosus and lupus nephritis: a cross-sectional study. Pan Afr Med J. 2017 Jun 14;27:114.\u003c/li\u003e\n\u003cli\u003eElbagir S, Elshafie AI, Elagib EM, Mohammed NA, Aledrissy MIE, Sohrabian A, et al. Sudanese and Swedish patients with systemic lupus erythematosus: immunological and clinical comparisons. Rheumatol Oxf Engl. 2020 May 1;59(5):968\u0026ndash;78.\u003c/li\u003e\n\u003cli\u003eAringer M, Costenbader K, Daikh D, Brinks R, Mosca M, Ramsey-Goldman R, et al. 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus. Arthritis Rheumatol Hoboken NJ. 2019 Sep;71(9):1400\u0026ndash;12.\u003c/li\u003e\n\u003cli\u003eBabikir G., Kaballo, Abubakr A., Wahab, Musa M, Nur, et al. Ethnic distribution and clinical features of systemic lupus erythematosus in the Sudan. Sudan Medical Journal. 2009;45(2):49\u0026ndash;56.\u003c/li\u003e\n\u003cli\u003eAlarc\u0026oacute;n-Segovia D, Alarc\u0026oacute;n-Riquelme ME, Cardiel MH, Caeiro F, Massardo L, Villa AR, et al. Familial aggregation of systemic lupus erythematosus, rheumatoid arthritis, and other autoimmune diseases in 1,177 lupus patients from the GLADEL cohort. Arthritis Rheum. 2005 Apr;52(4):1138\u0026ndash;47.\u003c/li\u003e\n\u003cli\u003eLam SK, Quah T. Anemia in systemic lupus erythematosus. J Singapore Paediatr Soc [Internet]. 1990 [cited 2023 Jun 9]; Available from: https://www.semanticscholar.org/paper/Anemia-in-systemic-lupus-erythematosus.-Lam-Quah/2c44d27aa32df4bf170b72a63863a73f3e34ebcf\u003c/li\u003e\n\u003cli\u003eHoffman IEA, Peene I, Meheus L, Huizinga TWJ, Cebecauer L, Isenberg D, et al. Specific antinuclear antibodies are associated with clinical features in systemic lupus erythematosus. Ann Rheum Dis. 2004 Sep;63(9):1155\u0026ndash;8.\u003c/li\u003e\n\u003cli\u003eAscherio A, Munger KL. EBV and Autoimmunity. Curr Top Microbiol Immunol. 2015;390(Pt 1):365\u0026ndash;85.\u003c/li\u003e\n\u003cli\u003eJames JA, Scofield RH, Harley JB. Lupus humoral autoimmunity after short peptide immunization. Ann N Y Acad Sci. 1997 Apr 5;815:124\u0026ndash;7.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e. Epidemiological characteristics of the SLE patients (total number was 42).\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"622\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGender (Number, percentage)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003cp\u003eFemale\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e2 (4.8%)\u003c/p\u003e\n \u003cp\u003e40 (95.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge (mean \u0026plusmn; SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e42.6\u0026plusmn;12.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eOrigin (Number, Percentage)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eKhartoum\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eWhite Nile\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eAl Jazirah\u003c/p\u003e\n \u003cp\u003eRiver Nile\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSouth Kordofan\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eNorthern\u003c/p\u003e\n \u003cp\u003eNorth Kordofan\u003c/p\u003e\n \u003cp\u003eWest Kordofan\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSennar\u003c/p\u003e\n \u003cp\u003eNorth Darfur\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSouth Darfur\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eAl Qadarif\u003c/p\u003e\n \u003cp\u003eBlue Nile\u003c/p\u003e\n \u003cp\u003eWest Darfur\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;East Darfur\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCentral Darfur\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eRed Sea\u003c/p\u003e\n \u003cp\u003eKassala\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e8 (19 %)\u003c/p\u003e\n \u003cp\u003e5 (11.9%)\u003c/p\u003e\n \u003cp\u003e5 (11.9%)\u003c/p\u003e\n \u003cp\u003e4 (9.5%)\u003c/p\u003e\n \u003cp\u003e4 (9.5%)\u003c/p\u003e\n \u003cp\u003e3 (7.1%)\u003c/p\u003e\n \u003cp\u003e3 (7.1%)\u003c/p\u003e\n \u003cp\u003e2 (4.8%)\u003c/p\u003e\n \u003cp\u003e2 (4.8%)\u003c/p\u003e\n \u003cp\u003e2 ( 4.8%)\u003c/p\u003e\n \u003cp\u003e1 (2.4%)\u003c/p\u003e\n \u003cp\u003e1 (2.4%)\u003c/p\u003e\n \u003cp\u003e1 (2.4%)\u003c/p\u003e\n \u003cp\u003e1 ( 2.4 %)\u003c/p\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003cp\u003e0 (0 %)\u003c/p\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003cp\u003e0(0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eFamily History (Number, Percentage)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eNo\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e41 (97.6 %)\u003c/p\u003e\n \u003cp\u003e1 (2.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e Laboratory variables among the SLE \u003cspan dir=\"RTL\"\u003epatient\u003c/span\u003es\u0026rsquo; group.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"622\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eHb (mean \u0026plusmn; SD) (n=36)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e11.5 \u0026plusmn; 1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eRBCs (mean \u0026plusmn; SD) (n=31)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e4.1 \u0026nbsp;\u0026plusmn; 0.73\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMCV (mean \u0026plusmn; SD) (n=31)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e82.9 \u0026plusmn; 16.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eWBCs (mean \u0026plusmn; SD) (n=34)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e7.9 \u0026nbsp; \u0026nbsp; \u0026plusmn; 3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eNeutrophils count (mean \u0026plusmn; SD) (n=31)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e5.06 \u0026plusmn; 3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLymphocytes count (mean \u0026plusmn; SD) (n=31)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e1.98 \u0026plusmn; 0.88\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ePlatelets count (mean \u0026plusmn; SD) (n=34)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e292 \u0026plusmn; 95.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eUrea (mean \u0026plusmn; SD) (n=28)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e32.5 \u0026nbsp;\u0026plusmn; 33.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCreatinine (mean \u0026plusmn; SD) (n=34)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e0.92 \u0026plusmn; 0.99\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnti dsDNA (n=11)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003ePositive (number, percentage )\u003c/p\u003e\n \u003cp\u003eNegative (number percentage)\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e5 (45.5%)\u003c/p\u003e\n \u003cp\u003e6 (54.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnti Sm (n=8)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003ePositive (number, percentage )\u003c/p\u003e\n \u003cp\u003eNegative (number percentage)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e3 ( 37.5%)\u003c/p\u003e\n \u003cp\u003e5 (62.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnti RO (n=14)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003ePositive (number, percentage )\u003c/p\u003e\n \u003cp\u003eNegative (number percentage)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e10 (71.4%)\u003c/p\u003e\n \u003cp\u003e4 (28.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnti La (n=9)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003ePositive (number, percentage )\u003c/p\u003e\n \u003cp\u003eNegative (number percentage)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e4(44.4%)\u003c/p\u003e\n \u003cp\u003e5 (55.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eOther positive Autoantibodies\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eAnti RNP\u003c/p\u003e\n \u003cp\u003eAnti histone\u003c/p\u003e\n \u003cp\u003eAnti nucleosome\u003c/p\u003e\n \u003cp\u003eAnti Jo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eESR \u0026nbsp;(mean \u0026plusmn; SD) (n=13)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003e55.5 \u0026nbsp;\u0026plusmn; 36.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e3\u003c/strong\u003e. Comparison of the epidemiological and EBV-VCA IgG titres between the patient and control groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"37.881219903691814%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.682182985553773%\" valign=\"top\" style=\"width: 18.7874%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSLE\u0026nbsp;patient\u0026rsquo;s\u0026nbsp;group\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eN=42\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.298555377207062%\" valign=\"top\" style=\"width: 14.0707%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eControl\u0026nbsp;group\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eN=41\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.13804173354735%\" valign=\"top\" style=\"width: 29.2239%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP\u0026nbsp;value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"37.881219903691814%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u0026nbsp;(median\u0026nbsp;25\u003csup\u003eth\u003c/sup\u003e -75\u003csup\u003eth\u003c/sup\u003e centiles\u0026nbsp;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.682182985553773%\" valign=\"top\" style=\"width: 18.7874%;\"\u003e\n \u003cp\u003e43(43.6-48.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.298555377207062%\" valign=\"top\" style=\"width: 14.0707%;\"\u003e\n \u003cp\u003e39(30.5-45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.13804173354735%\" valign=\"top\" style=\"width: 29.2239%;\"\u003e\n \u003cp\u003e0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"37.881219903691814%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eGender\u0026nbsp;(number,\u0026nbsp;percentage)\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eFemale\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.682182985553773%\" valign=\"top\" style=\"width: 18.7874%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e40\u0026nbsp;(95.2%)\u003c/p\u003e\n \u003cp\u003e2\u0026nbsp;(4.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.298555377207062%\" valign=\"top\" style=\"width: 14.0707%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e40\u0026nbsp;(97.6%)\u003c/p\u003e\n \u003cp\u003e1(2.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.13804173354735%\" valign=\"top\" style=\"width: 29.2239%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"37.881219903691814%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSeroconversion of EBV-VCA IgG (number, percentage)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003ePositive\u003c/p\u003e\n \u003cp\u003eNegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.682182985553773%\" valign=\"top\" style=\"width: 18.7874%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e41\u0026nbsp;(97.6%)\u003c/p\u003e\n \u003cp\u003e1(2.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.298555377207062%\" valign=\"top\" style=\"width: 14.0707%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e40\u0026nbsp;(97.6%)\u003c/p\u003e\n \u003cp\u003e1\u0026nbsp;(2.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.13804173354735%\" valign=\"top\" style=\"width: 29.2239%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.99\u003c/p\u003e\n \u003cp\u003eOD\u0026nbsp;=\u0026nbsp;1.025\u003c/p\u003e\n \u003cp\u003e(CI\u0026nbsp;95%\u003c/p\u003e\n \u003cp\u003e0.062-16.95)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"37.881219903691814%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eEBV-VCA\u0026nbsp;IgG\u0026nbsp;titer\u0026nbsp;(mean\u0026nbsp;\u0026plusmn;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eSD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.682182985553773%\" valign=\"top\" style=\"width: 18.7874%;\"\u003e\n \u003cp\u003e153.8\u0026plusmn;\u0026nbsp;58.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.298555377207062%\" valign=\"top\" style=\"width: 14.0707%;\"\u003e\n \u003cp\u003e156.6\u0026plusmn;\u0026nbsp;64.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.13804173354735%\" valign=\"top\" style=\"width: 29.2239%;\"\u003e\n \u003cp\u003e0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\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":"Autoantibodies, Epstein–Barr viral capsid antigen, Epstein–Barr virus infections, Systemic lupus erythematosus","lastPublishedDoi":"10.21203/rs.3.rs-3807852/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3807852/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTo evaluate Epstein\u0026ndash;Barr virus (EBV) infection as a risk factor for the development of systemic lupus erythematosus (SLE) in Sudanese patients. This was a case‒control study. Forty-two SLE patients and forty-one age- and sex-matched controls were included. Demographic, clinical and laboratory data were collected. Venous blood samples were drawn, and EBV-viral capsid antigen (EBV-VCA) IgG titre levels were quantified. Demographic, clinical and laboratory data were compared between the two groups by either Student\u0026rsquo;s t test or the Mann‒Whitney U test for continuous data or by χ\u0026sup2; analysis for categorical data. P values\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were considered to indicate statistical significance.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe SLE patients in the present study had a low mean Hb concentration (11.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7 gm/dL) and a low RBC count (4.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73). Almost all patients (41, 97.6%) and controls (40, 97.6%) were positive for VCA-IgG (P\u0026thinsp;=\u0026thinsp;0.99). The titre levels of VCA-IgG between the two groups were similar (153.8\u0026thinsp;\u0026plusmn;\u0026thinsp;58.2 RU/ml for patients, 156.6\u0026thinsp;\u0026plusmn;\u0026thinsp;64.1 RU/ml for control groups; p\u0026thinsp;=\u0026thinsp;0.83). The mean EBV-VCA-IgG levels were similar between the positive and negative anti-dsDNA patients, with a p value of 0.98. The mean VCA-IgG titre was also similar between anti-Sm-positive and anti-Sm-negative patients (p\u0026thinsp;=\u0026thinsp;0.22).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eNo association was found between EBV infection and SLE development in adult Sudanese patients. A larger sample size and younger population are recommended to elucidate any associations between EBV and SLE.\u003c/p\u003e","manuscriptTitle":"EBV Infection as a Risk Factor for SLE Development in Adult Sudanese Patients: A Case‒Control Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-03 02:04:42","doi":"10.21203/rs.3.rs-3807852/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":"aafd28e6-14d9-4906-9f88-1f5a28353dd1","owner":[],"postedDate":"January 3rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-04-08T14:17:57+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-03 02:04:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3807852","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3807852","identity":"rs-3807852","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}