Prevalence of A2 and A2B subgroups and anti-A1 antibody in blood donors at tertiary care center in Bangladesh: A cross sectional study

Context: A2 and A2B are rare phenotypes of ABO blood group system. The presence of anti-A1 in A2 and A2B subgroups may cause hemolytic transfusion reaction if active at 370c. Aim: To assess the prevalence of A2 and A2B subgroups along with anti-A1 in blood donors of Bangladesh. Setting and design: Cross sectional study in a tertiary care hospital, Bangladesh. Subjects and Methods: The study included blood donor samples received at Transfusion Medicine Department. All samples were typed for ABO and RhD grouping using conventional tube technique. Group A and AB were further subtyped using anti-A1 lectin. Detection of anti-A1 antibody for A2 and A2B individuals was done using A1 red cells. Statistical analysis: The data were analyzed and tabulated by using Microsoft Excel and SPSS (version 26). Fisher’s exact test was used for comparing categorical variables. Results: Out of 1,696 healthy blood donors, blood group O was the highest. The overall phenotypic frequency of all blood groups was O>B>A1>A1B>A2B>A2. A antigen (A and AB Blood Group) was present in 610 (36%). Of these, A1 antigen was present in 599 (98.2%) donors and A2 antigen was present in 11 (1.8%) donors. Of 468 donors with blood group A, 466 (99.6%) belonged to A1 and 2 (0.4%) belonged to A2. Out of 142 group AB donors, A1B was found in 133(93.7%) and A 2B in 9 (6.3%). No anti-A1 was detected in A2 and A2B subgroups. Conclusion: Implementation of A1 and A2 grouping can prevent minor incompatibilities, thus ensuring safe blood transfusion. Pulse Vol.16, 2024 P: 10-14