Prevalence of red blood cell alloantibodies among blood donors in the French Military Blood Institute: A 10‐year retrospective study

Abstract Background and Objectives Screening for red blood cell alloantibodies (RBC‐Ab) is a critical step in ensuring blood transfusion safety performed by blood donation screening laboratories. We aim to evaluate the prevalence of the RBC‐Ab among healthy blood donors. Materials and Methods Antibody screening of serum of all voluntary blood donors was performed as a routine immune‐haematological procedure by a solid‐phase method on a fully automated immunohaematology analyser. Positive sera were further investigated to identify the specificity of RBC‐Ab by a commercially available red cell panel. Results Between January 2012 and December 2021, a total of 212,218 donations were screened for the presence of RBC‐Ab, 74% from male donors ( n = 157,898) and 26% from female donors ( n = 54,320). Mean age at donation time was 32 ± 12 years. A total of 1007 donations were screened positive (0.47%), and 131 were confirmed positive for alloantibodies in their serum, yielding a prevalence of 0.06% (95% confidence interval: 0.05–0.07). Most frequent alloantibodies identified were of RH blood group system (64%), followed by anti‐MNS (19%), anti‐Kidd and Lewis (6% each) and anti‐KEL (4%). The results showed a statistically higher prevalence of alloantibodies in women than men. Our results showed a lower prevalence as compared to the available data, which might be related to our study population. Conclusion The prevalence of positive antibody screening in healthy donors in this study was found to be 0.47%, while the prevalence of alloantibodies was 0.06%. The most common alloantibodies were anti‐RH1 (25%) and anti‐RH3 (24%).