Quantification of hepatitis C virus in viremic blood donors in Iran: Need to reinforce post-donation follow up.

INTRODUCTION: Hepatitis C virus (HCV) infection is a public health problem and a major cause of chronic liver disease around the world. The main route of HCV transmission is contact with small quantities of infectious blood. Knowledge of the distribution of HCV viral load is essential to control HCV infection. This study aimed to investigate the HCV viral load distribution among Iranian blood donors. MATERIALS AND METHODS: This cross-sectional study was conducted on 160 HCV confirmed blood donors with detectable HCV RNA who referred to blood transfusion centers for post-donation counseling all over the country. HCV RNA was quantified using an in-house one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) kit. Statistical analysis was performed in STATA version 13. RESULTS: The mean age of the participants was 37.66 years. Out of 160 subjects, 156 (97.5 %) were male. The median viral load of the subjects was 7.7 × 104 (range: 2.28 × 10 3-3.42 × 107 IU/mL). Out of 160 blood donors, 70 (43.75 %, 95 % CI 0.36-0.51) had a viral load ≤5 × 104 IU/mL, and 90 (56.25 %, 95 % CI: 0.49-0.64) had a viral load >5 × 104 IU/mL. DISCUSSION: The distribution of HCV viral load among viremic blood donors emphasizes on the role of post-donation follow up in identification of blood donors potentially need for HCV anti-viral therapies.

Blood supply sufficiency and safety management in Iran during the COVID-19 outbreak.

BACKGROUND: COVID-19 first appeared in Iran on 19 February 2020, and then spread rapidly over the country. In this article, we review the action plan of the Iranian Blood Transfusion Organization with respect to this disease. METHOD AND MATERIALS: We collected data on blood donations and RBC inventory for the first 8 weeks of the outbreak. We also evaluated the trend of blood donations and RBC inventory and compared them with the data of the past year. We include a summary of actions taken by the National Committee on Management of COVID-19 outbreak. RESULTS: Blood donations decreased from 33 275 to 23 465 units during the first 2 weeks of the outbreak with a corresponding decrease in the RBC inventory. But after that, donations gradually increased from 23 465 to 29 665 units. RBC inventory levels improved at the same time. Then, the Iranian New Year's holiday resulted in another downward trend. After the holiday, blood donations revived, along with the RBC inventory. DISCUSSION: Although it appears that this virus cannot be transmitted through transfusion, changes in lifestyle had a significant impact on reducing blood supply. Following implemented measures, we saw an upward trend in blood donations and an adequate supply of RBC units in blood centres, helped by a reduction in demand by hospitals. Blood centres need to be more prepared to manage future viral disasters, especially in case of transfusion-transmissible infections.

Analysis of blood donors' characteristics and deferrals related to COVID-19 in Iran.

BACKGROUND: With the outbreak of the coronavirus disease in 2019, called COVID-19, Iranian Blood Transfusion Organization (IBTO) implemented the new deferrals. This study analyzed the COVID-19 deferrals of blood volunteers and compared the demographics, deferrals, and the donor status during the COVID-19 outbreak in 2019. STUDY DESIGN AND METHODS: Data were collected from the integrated blood donor database between Feb-Apr 2019 and 2020. Deferral reasons of COVID-19 were categorized as: those who have symptoms or live with a symptomatic family member, have direct exposure with a confirmed case, have travelled from the outbreak affected areas, and have fully recovered from confirmed COVID-19. The z-test analysis was used, and 95 % confidence intervals were calculated to compare the sample proportions. RESULTS: The blood donations dropped to 26.09 % in 2020. The percent change of first-time blood donors, female donors, and donors within the age group of 45-54 years old was significantly greater in 2020 than the same time frame in 2019 (p < 0.05). The results showed that 0.58 % of volunteers were deferred from blood donation to avoid transmission of SARS-CoV-2. The rate of COVID-19 deferrals in all types except travelling to affected areas has increased in the second 30-day of the study (p < 0.05). CONCLUSION: The blood shortage that occurred during the COVID-19 outbreak was not due to increased deferral for COVID-19, but it was mostly due to a decrease in the number of volunteers who referred to BTCs.

miRNA96 expression level within red blood cells is probably associated with RSL indicators during the storage of red blood cell units.

BACKGROUND AND OBJECTIVES: Many biochemical and hematological changes occur during the storage of RBC units. Collectively, these changes are known as RSLs. Previous studies found miRNA96 as non-coding RNA that its expression level changed during RBC storage. However, its correlation with mechanical and biochemical RSL indicators is not yet determined. Therefore, this study aimed to assess possible correlations between miRNA96a and some RSLs indicators to clarify its biomarker capability for evaluating the storage quality of RBC units. MATERIALS AND METHODS: Samples were collected from ten leuko-reduced RBC units on days 0, 14, 28, and 42 of storage. miRNA96 gene expression level and RSLs indicators including hemolysis, mechanical fragility index (MFI), total antioxidant capacity (TAC), lipid peroxidation (TBARs), thiol groups, and RBC indices were measured on the days mentioned above. RESULTS: Significant correlations were found between the changes in miRNA96 expression level and the levels of hemolysis, TAC, TBARs, and MFI indices (p values < 0.05). The donors were classified into the high risk group and low risk group, according to four important characteristics and lifestyle habits (smoking, physical activity, age, and BMI). The high risk group had a significantly lower rate of hemolysis, free hemoglobin, MFI, TAC, and a higher rate of lipid peroxidation compared to low risk group (p values < 0.05). CONCLUSION: The finding suggested that upregulation of miRNA96 could prevent hemolysis of RBCs, despite the accumulation of oxidative injuries in them. The miRNA96 expression level was probably a potential predictor for mechanical and biochemical RSL indicators.

COVID-19 related callback in blood donors; Outcomes in blood donors and patients.

Call back as a procedure to report post donation symptoms or illness by donors has been established since 2009 in Iranian Blood Transfusion Organization (IBTO). During the first phase of COVID-19 outbreak, all blood donors were requested to report any respiratory infection symptoms after donation. The study investigated the callback data of COVID-19 in Tehran Blood Center during the first 3 months of the outbreak in Iran. The purpose of this study was to estimate the frequency of post donation COVID-19 related call back reports and determine its implications for blood donors and patients. A telephone interview was conducted with donors who had reported COVID-19 symptoms. Some questions were asked to evaluate donor's health at the time of blood donation. The donors categorized into three groups: laboratory-confirmed, suspected, and COVID-19 irrelevant based on their answers. In cases that the blood component obtained from a laboratory-confirmed donor had been released, the hospital was notified and asked to follow up the recipient for COVID-19. The results showed 30 donors (0.08 %) had callback related to COVID-19 and 76.63 % of the obtained component was disposed. The results also showed that only one donor had a laboratory-confirmed result with the RBC unit processed from her whole blood released for transfusion. The RBC unit recipient did not show any signs or symptoms of infection during a 46-day follow-up. Concluded that callback system was effective to remove most of the components obtained from the donors who reported to be COVID-19 suspected or confirmed. Moreover, the result did not support virus transmission through blood transfusion.

Prevalence of Hepatitis B Virus Infection Among Voluntary Blood Donors from the Northeastern Region of Iran: Genotyping, Viral Load Characterization and Drug Resistance Prediction.

BACKGROUND: Blood donor selection, along with laboratory screening of the HBV, plays a pivotal role in providing safe blood products. This study was aimed to evaluate the prevalence, genotype, and drug resistance prediction of HBV among Iranian blood donors. METHODS: This cross-sectional study was conducted on 47,506 blood donors referring to Golestan Blood Center from March 21, 2018, to March 20, 2019. Siemens Enzyngnost HBsAg6, INNO-LiPA Genotyping kits, and Nest-PCR were used for HBV screening, genotyping, and amplification of the polymerase gene, respectively. An online tool at hbv.geno2pheno.org and real-time PCR method were also utilized for drug resistance prediction and viral load measurement respectively. RESULTS: It was found that from among 47,506 donors, 47 (0.09%) were confirmed to be HBV positive subjects. About 0.94% of first-time blood donors (46 out of 4, 872) and 0.008% of repeated blood donors (1 out of 12,125) were found to be positive for HBV. First-time blood donors were also 8.6 times more likely to have a hepatitis B virus infection (odds ratio: 9.6; 95% confidence interval, 6.2 - 14.7). Seven donors had genotype D as predominant and one case had a mixed infection with genotypes A and D. Furthermore, the most predicted mutation in the polymerase gene was m204V, causing resistance to telbivudine and lamivudine. CONCLUSIONS: The results showed that the risk of HBV transmission is higher among first-time blood donors. Therefore, it is recommended that predonation laboratory screening in first-time blood donors be conducted to improve the safety of the donated blood in the studied region.

Effective ways to retain first-time blood donors: a field-trial study.

BACKGROUND: Regular blood donors are the cornerstone of blood safety. Understanding the donors' behavior to donate blood improves blood donor retention programs. The purpose of this study is to evaluate the return rate of first-time blood donors following different interventions to identify effective ways to retain first-time donors. STUDY DESIGN AND METHODS: The study was conducted on 1356 first-time blood donors at four main blood centers in Iran. The donors were randomly assigned based on different interventions (phone calls, educational letter, emotional letter, incentive, motivational meeting, and no intervention) to six groups. The return rate of donors was defined as a second attempt to donate within 6 months after the first donation. Return rate and 95% confidence intervals (CIs) were calculated and compared among different groups. RESULTS: A total of 394 (29%) donors returned within 6 months for a second donation (95% CI, 0.26-0.31). The return rate in the emotional letter group, educational letter, phone reminder, incentives, motivational meeting, and control groups was 36% (95% CI, 0.31-0.42), 33.2% (95% CI, 0.27-0.38), 31.5% (95% CI, 0.25-0.37), 30% (95% CI, 0.22-0.38), 22% (95% CI, 0.17-0.27) and 22.1% (95% CI, 0.17-0.27), respectively. CONCLUSIONS: This study provides evidence supporting the fact that more first-time blood donors can be motivated to donate again by implementing targeted interventions. It demonstrates that emotional letters, educational letters, and phone reminders were effective in improving the return rate of first-time donors.

Association of HCV genotype with viral load among Iranian blood donors: a penalized logistic regression.

Background: Hepatitis C virus (HCV) is a blood born virus and the leading cause of advanced hepatitis disease. HCV genotype 3a is predominant among Iranian blood donors. The aim of this study was to evaluate the relationship between HCV genotype and HCV viral load. Methods: In this analytical cross-sectional study 106 anti-HCV positive and HCV RNA positive blood donors referred to Iranian blood centers across the county were entered. HCV viral loads were determined by an in-house one step Taq Man Real-Time RT-PCR assay. Penalized logistic regression was performed for data analysis. STATA software version 13 was used for statistical analysis. Results: The mean age was 37.94 ± 9.04 years ranged from 19 to 58 years. Male gender included 104 (98.1%) of subjects. 31, 10 and 65 subjects were infected with genotypes1a, 1b, and 3a, respectively. The mean viral load was 1.44 × 106 ± 4.5× 105 IU/ml. HCV viral load was not significantly different among subjects infected with HCV genotypes 1, 1.49 × 10 6 ± 4.57 × 10 6 IU/ml compare to genotype 3, 1.40 × 10 6 ± 5.58 4.58 × 106 IU/ml (p=0.93). Conclusion: Although not significant, the frequency of subjects with high viral load (> 800,000 IU/ml) was higher in subjects infected with genotype 3 than those of genotype 1. No associations were found between demographic characteristics and HCV genotype. Although the study was unable to find any association between HCV genotype and HCV viral load/ HCV viral load group, it highlighted the role of high viral load in the high circulation of HCV genotype 3a among Iranian blood donors.

Risk factor analysis of hepatitis C virus seropositivity in Iranian blood donors: a case-control study.

BACKGROUND: Due to blood screening and blood donor selection, the prevalence of hepatitis C virus (HCV) is expected to be lower among blood donors compared to the general population. The effective control of blood-transmitted infectious diseases should be one of the goals of public health. Thus, this case-control study was conducted to evaluate the risk factors of HCV in a representative sample of blood donors in Iran. STUDY DESIGN AND METHODS: A case-control study was conducted on HCV-negative and on serologically confirmed HCV-positive donors across the country from 2009 to 2013. Univariate logistic regression, multiple logistic regression, and subgroup analyses were performed to assess the risk factors in first-time blood donors (FTs) and repeat blood donors (RDs) independently. RESULTS: A total of 970 cases and 1542 controls were selected from the cohort of Iranian blood donors registered in the Iran Blood Transfusion Organization. Intravenous (IV) drug abuse (ORFT , 6.42; 95% CI, 3.34-12.34; and ORRD , 27.62; 95% CI, 12.58-60.62), living with an IV drug abuser (ORFT , 3.47; 95% CI, 1.26-9.55; and ORRD , 6.95; 95% CI, 1.54-31.34), prison history (ORFT , 2.4; 95% CI, 1.48-3.88; and ORRD , 2.42; 95% CI, 1.38-4.27), sharing personal razors (ORFT , 2.00; 95% CI, 1.01-3.96; and ORRD , 5.62; 95% CI, 2.65-11.89), and medical exposure (ORFT , 1.97; 95% CI, 1.15-3.37; and ORRD , 2.19; 95% CI, 1.27-3.76) were significant independent risk factors in both types of blood donation. CONCLUSION: The findings of this analytic study on HCV exposure in Iranian blood donors conforms to those of international studies. Behavioral and medical factors should be examined in the donor health screening process.

Blood collection, components preparation and distribution in Iran, 2008-2012.

BACKGROUND: The information about the dynamics of blood collection, components preparation and distribution in Iran was measured and compared during 2008-2012. STUDY DESIGNS AND METHODS: The survey instruments were based on collecting data from all 220 blood collections and blood processing centers over the country, registering them in the validated data base and reporting them to headquarter of Iranian Blood Transfusion Organization. RESULTS: Total blood collection increased during this period, and in 2012 represented a 12.6 percent increase compared to that in 2008. On average, red blood cells, fresh frozen plasma and platelet concentrate were prepared from 95.5 ± 2.4, 81 ± 3.8 and 47 ± 8.8 percent of all whole blood collection. From 2008 to 2011, the distribution of whole blood and fresh frozen plasma revealed different patterns. For whole blood, declines were noted, while for fresh frozen plasma increases were reported. In addition the distribution of red blood cells and platelet concentrate did not change considerably. Also between 2008 and 2012, the mean percentage of outdated and discarded units was 3.6 ± 1 and 5.2 ± 4.6. CONCLUSION: This study as a first national survey provides comprehensive information about the blood supply, components preparation and distribution, and helps to define strategy for the future.

The return rate of deferred blood donors in Iran.

BACKGROUND AND OBJECTIVES: The process of selecting blood donors is crucial for keeping the health of donors and ensuring the safety of the blood supply. However, it may create unpleasant feeling in those who are deferred. In this study, we aim to explore the return rates of Iranian deferred donors in comparison with eligible donors. MATERIALS AND METHODS: The study included all whole blood donors referred between March 2017 and March 2018, who experienced temporary deferral for any reason. Donors who successfully donated blood during this period were also part of the study. Participants were followed up until their next donation attempt, spanning 4.8 years after initial inclusion. Then odds of return and median return time for both deferred and eligible donors were calculated. RESULTS: From 993,824 volunteers, 733,153 (73.77%) were eligible and 192,332 (19.35%) temporary deferred. The return rate in the eligible and deferred donors was 74.77% vs. 51.77%, respectively (OR:2.78; 99%CI: 2.71-2.81). Odds of return among deferred regular (OR = 7.02, 99%CI:6.64-7.42), men (OR: 2.57, 99%CI:2.45-2.69), and over 45 years (OR: 1.15, 99% CI: 1.09-1.20), was higher than first-time, women, and younger donors. The median return time for eligible and deferred donors was 315 (99%CI: 313-316) and 1,467(99%CI: 1,412-1,524) days, respectively. CONCLUSION: This study revealed the negative effect of deferral on the return rate, that led to a 23% reduction in the return of deferred donors. Avoiding unnecessary deferral through adherence to the standard operating procedure of donor selection and effective counselling which clarifies the purpose of deferral and encourages them to return after the deferral period ends are recommended.

A change in standard of minimum hemoglobin for male blood donors in Iran.

BACKGROUND: The minimum Hb for blood donation varies from nation to nation. This study assessed the impact of blood donation on donors' iron stores based on different Hb levels. An estimation of drop in the blood collection was made with the new suggested Hb cut-off value. MATERIALS AND METHODS: 2017 male donors were studied. A questionnaire was filled out to gather demographic data, history of donation and risk factors of iron loss. Their blood samples were analyzed for RBC parameters, serum iron, TIBC, and ferritin level. The iron status of all first-time and regular donors was determined for each Hb level. The impact of changing the Hb cut-off value on annual blood collection was assessed. RESULTS: All of the regular donors with Hb levels <13.1g/dL and 75% of those donors with Hb levels of 13.1-13.5 g/dL had abnormal iron stores. Iron deficiency dropped to 35% in donors with Hb levels of 13.5-14 g/dL. It was estimated that increasing the Hb cut-off from 12.5 g/dL to 13 g/dL or to 13.5 g/dL would cause a drop of 0.82% and 2.77% in the annual blood collection, respectively. DISCUSSION: A modification in the minimum Hb level for blood donation is necessary when Hb is used as the single criterion for screening donors. Increasing the minimum Hb level will lead to an increase in donor deferral; therefore a comprehensive donor retention program will be needed.

The impact of pre-donation viral markers screening of new blood donors on blood safety.

BACKGROUND: The risk of transfusion-transmissible infections (TTIs) remains a concern in transfusion medicine. Since the rate of infection among first-time blood donors is higher than repeated donors, strategies to enhance blood safety can focus on new donors. The aim of the study was to investigate the effect of pre-donation viral screening of new donors on blood safety. METHODS AND MATERIALS: The pre-donation screening of new donors was implemented in the Kurdistan blood center. In this program, new donors who met the blood donation criteria were informed about the program and only a blood sample was donated for HBs Ag, HCV Ab, and HIV Ab testing. New donors with negative results were invited to donate blood after 12 weeks. A unit of blood was collected from eligible returned donors. Laboratory tests were performed again using the same methods. Finally, the prevalence of confirmed positive TTI results among donated blood in Kurdistan blood center was compared before and after the establishment of program. RESULTS: During the study, 4,434 new donors were screened for viral markers. A total of 41 new donors (0.92%, 95% CI, 0.007-0.13) had repeatedly reactive results and infection was confirmed in blood sample of 24 donors (0.54%, 95% CI, 0.003-0.008). Overall, 56% of new donors returned for blood donation. Prevalence of confirmed TTIs markers in collected blood units was 0.27% and 0 before and after implementing program, respectively. CONCLUSIONS: This study indicated that Pre-donation screening can reduce the risk of TTI transmission by identifying infected donors at the pre-donation phase.

Estimate of anti-SARS-CoV-2 spike IgG antibodies prevalence among Iranian population based on blood donations: A serial cross-sectional study during the third wave of the pandemic.

OBJECTIVES: Iran is one of the countries that have been confronted with the SARS-CoV-2 epidemic since February 2020. This study aimed to determine the levels of specific IgG antibodies against SARS-CoV-2 among healthy blood donors to estimate the burden of the epidemic. MATERIAL AND METHODS: A serial cross-sectional study was conducted on blood donors who referred to 31 main blood donation centers in different provinces during the third weeks of September, October, and November 2020. A questionnaire was filled out to collect socio-demographic characteristics, history of contact with COVID-19 patients, and history of COVID-19. A blood sample was collected from each participant to assess the antibodies against SARS-CoV-2 using the ELISA method. The crude prevalence of anti-SARS-CoV-2 IgG was calculated. Then it was weighted based on the gender and age groups of the general population in each province and adjusted for test sensitivity and specificity. RESULTS: During three time points of the study, 3840, 3697, and 3152 participants enrolled. The seroprevalence of SARS-CoV-2 IgG antibodies was 19.59% (17.18-22.00), 22.67% (20.70-24.65), and 32.63% (29.93-35.33) over the three rounds of the study. We found an association between the seropositivity and the highest educational level; AOR 0.76 (0.63-0.93), history of close contact with COVID-19 patients; AOR 1.69 (1.35-2.11), and history of confirmed SARS-CoV-2 infection; AOR 8.86 (5.38-14.60). CONCLUSION: This study showed that about one-third of the population had been infected with COVID-19. Furthermore, a significant upward trend in seroprevalence was observed. The predisposing factors indicate the importance of public health.

The incidence of hepatitis C in patients with thalassemia after screening in blood transfusion centers: a fourteen-year study.

BACKGROUND: Blood safety is important in all transfusion centers. The aim has always been to try to guarantee the recipient's safety through careful screening and examination of donors' blood samples. In Iran the hepatitis C virus (HCV) screening test became mandatory for blood donations from 1996. We decided to determine the incidence of new cases of HCV in patients with thalassemia, after screening of blood bags was initiated. STUDY DESIGN AND METHODS: The study was done on patients with complete files for anti-HCV test results. Only cases that had a confirmed positive anti-HCV result after a negative result were considered as new cases. The incidence rate was estimated and expressed in person-years (PY). Also, for increased accuracy and comparison of incidence in recent years, the incidence rate was calculated at two 7-year intervals (1996-2002 and 2003-2009). RESULTS: A total of 395 files were studied with a mean age of 27.5 years (SD ± 7.99 years). We had 109 (27.5%) anti-HCV positive, of which 21 (19.2% of positive cases) were exposed after 1996 and considered as new cases. The incidence of HCV cases in 14 years (1996-2009) was 4.2/1000 PY. The incidence in the first 7-year period (1996-2002) was 6.2/1000 PY and 1.3/1000 PY in the second 7-year period (2003-2009). CONCLUSION: The incidence of HCV is on the decline in Iran, both in blood donors and in recipients. We owe this to the improved blood safety in our transfusion center that has taken up better strategies. Even though the residual risk will never reach zero and we may still have new cases of HCV, it will definitely be with a lower rate. The fact that we have had no new cases among our patients with thalassemia since 2005 bears witness to this matter.

The impact of donor selection on blood safety in Iran.

INTRODUCTION: Donor selection is a critical process to identify high risk volunteers and defer them from donating blood. Despite viral screening test on all donated blood, one cannot rely on screening tests alone to ensure a safe blood supply. Monitoring and assessment of the deferral procedure is of utmost importance to balance blood availability and safety. This study compares the prevalence of HIV, HCV, and HBV markers between deferred donors and accepted blood donors in order to evaluate the effectiveness of the current donor selection process in Iran. MATERIALS AND METHODS: This study was carried out on deferred blood donors throughout the country. A blood sample was collected from participants and tested for three viral markers: HbsAg, anti-HCV, and anti-HIV. Repeatedly reactive samples were retested with a confirmatory screening assay. The prevalence of viral markers among deferred donors was compared with national statistical data on blood donors. RESULTS: The prevalence of HIV, Hepatitis B, and Hepatitis C was 120 (CI 95%; 90-150), 1280 (CI 95%; 1170-1390), and 580 (CI 95%; 510-650) in 100,000 deferred donors respectively. A significant increase exists in the prevalence of HBV (1.7 times), HIV (24 times) and HCV (15 times) in deferred donors as compared to accepted blood donors. DISCUSSION: The effectiveness of donor selection in identifying high risk individuals is obvious upon comparing the prevalence of selected viral infections in deferred donors with those accepted for blood donation. This study showed the role and necessity of donor selection criteria.

Positive anti-SARS-CoV-2 rapid serological test results among asymptomatic blood donors.

OBJECTIVES: The world is fighting with a COVID-19 pandemic, some of the uncertainties have been revealed. To figure out an estimation of asymptomatic patients and seropositive SARS-COV-2 blood donors in Iran, a national survey was conducted to find the prevalence of asymptomatic blood donors with positive SARS-COV-2 IgM/IgG test results at the end of May 2020. MATERIAL AND METHODS: From all 31 provinces, 1339 blood donors were included. At first, data was collected with an interview containing demographic data, risk factors and possible signs and symptoms held for each donor by a trained medical expert. Then, SARS-COV-2 serologic rapid tests were conducted. Subsequently, the test results were observed and recorded; all of their photos were checked by one single expert. We corrected the prevalence rates for sensitivity and weighted them by the last year rate of blood donation of each province. RESULTS: The corrected prevalence rates of positive serological test results for sensitivity in provinces were between zero and 38.24%. The national prevalence was calculated 14.45% after weighting. Out of 161 positive donors, only 43 cases reported related signs or symptoms during the defined period of time, while 118 (73.29%) seropositive cases had not reported any related signs or symptoms. Some signs or symptoms were reported more frequent in the SARS-COV-2 serologic rapid test positives. The highest OR (10.19) was linked to ageusia. CONCLUSIONS: This study has shown the prevalence of seropositive results to be around 14% in target population in which around ¾ had not reported any signs or symptoms.

Red Blood Cell Immunization and Contributing Factors in 685 Thalassemia Patients.

Background: An analysis of red blood cell alloimmunization in patients with thalassemia can help to devise specific strategies to decrease the alloimmunization rate. This study explored the frequency and specificity of alloantibodies and autoantibodies against red blood cell (RBC) antigens in patients with thalassemia referring to the Iranian Blood Transfusion Organization (IBTO) Immunohematology Reference Laboratory (IRL) in Tehran. Materials and Methods: This study first examined the laboratory records of 23,113 patients suffering from different diseases referring to IBTO's IRL for pretransfusion testing in the 2008-2015 period. ABO and Rh(D) typing and antibody screening tests were performed for all 23,113 patient records and 685 (2.97%) beta-thalassemia patients with positive pre-transfusion test results (antibody screening and/or DAT) were selected for further investigation. Results: The antibody screening test was positive in 640 out of 685 thalassemic patients (93.4%). DAT was performed for 529 patients, 226 (33%) of which showed positive results. Meanwhile, 161 out of 685 beta-thalassemia patients (23.5%) had positive auto control test results, reflecting the possible presence of allo- and/or autoantibodies. The most common antigen-specific alloantibodies were directed against K and E RBC antigens with a frequency of 25% (Anti-K) and 11.91% (Anti-E), respectively. The development of two antibodies (double antibodies) in one patient was observed in 80 individuals (11.46%). Conclusion: Age, gender, history of pregnancy, and splenectomy were not contributing factors to the antibody presence in the patient population under study. Extended red blood cell phenotyping should be considered as an essential procedure for expected multi-transfused thalassemia patients before blood transfusion. Considering the high frequency of anti-K and anti-E observed in this study, it is recommended that thalassemia patients in Iran are tested through phenotyping of RBC units for K and E antigens before transfusion.