ABSTRACT Introduction: Data on the prevalence of clinically significant antigens (Rh, Kell, Kidd, Duffy, MNSs, Lewis, P and Lutheran) among the Indian donor population is sparse. Objective: This prospective study was aimed at determining the prevalence of 21 clinically significant antigens for the first time in the South Indian donor population. Method: A total of 672 regular O group blood donors were enrolled for Rh (C, c, E, e) and Kell (K) antigens typing. Of these, 188 donors were typed for other clinically significant antigens (k, Kpa, Kpb, Jka, Jkb, Fya, Fyb, M, N, S, s, P1, Lea, Leb, Lua and Lub). Results: Antigen frequencies were expressed in percentages. In our study, R1R1 and rr were the most common phenotypes among D+ and D− donors, respectively. Among the Rh antigens, the e antigen was expressed by 97.5% and 100% of D+ and D− donors, respectively. The K antigen was found in only 0.15% of donors. In the Duffy and Kidd blood group system, Fy (a+b+) and Jk (a+b+) were the most frequent phenotypes, respectively. In the MNSs blood group system, M+N+ and S−s+ were the most common phenotypes reported. The Le (a−b+) was found to be the phenotype with the highest prevalence in the Lewis blood group system. The Lu (a−b+) was the only phenotype found in the Lutheran blood group system. Conclusion: Knowledge regarding the prevalence of antigens in a given population is essential in developing cost-effective in-house panels and a rare donor registry comprising donors typed negative for a high-frequency antigen or a combination of common multiple antigens.

Abstract Introduction Lewis antibodies have been thought to play a small role in clinical transfusion practice, but recent reports suggest that they have gained more importance in the context of transfusion and transplantation. Data regarding the prevalence of Lewis antibodies and their clinical significance in the Indian context is very limited. Hence, this study was aimed at analyzing the serological characteristics and clinical significance of Lewis antibodies encountered in our patient and donor populations. Methods The retrospective data analyzed the records of red cell antibody screening results and the additional serological evaluation performed on the donor and patient samples included in the study. Results A total of 26 study subjects were noted to have Lewis antibodies (including 6 healthy donors and 20 patients). Of them, 13 individuals had anti-Leb, 10 had anti-Lea and the remaining three had an anti-Lea/Leb mixture. IgG Lewis antibodies were detected in 7 individuals. All cases of IgM Lewis antibodies detected were reacting at 37°C. Two patients were suspected of having hemolytic transfusion reactions due to Lewis antibodies. Antigen-negative cross-match compatible units were provided for transfusion in the recipients. Conclusion Lewis antibodies of the IgM class reacting at 37°C should be regarded as clinically important. The present study findings urge that the lab personnel look for the thermal amplitude of Lewis antibodies, irrespective of the fact that the antibody class and antigen-negative crossmatch compatible units should be provided to avoid hemolytic transfusion reactions.