Frequency and distribution of a2 and a2b subgroups among blood donors at mgm kamothe blood bank, navi mumbai

Background: Group A individuals are further subdivided into A1, A2 and other rare types like A3, A intermediate (int.), Ax, Am, Aend, Ay, Ael, etc. Subgroups of A can result in discrepancy in ABO blood typing. The occurrence of weak variants due to heterogeneity of the A and B alleles poses a challenge for immunohaematology practice. Materials and Methods: A retrospective study of 2.5 years from January 2013 to July 2015 carried out at the Department of Immunohaematology & Blood Transfusion of MGM Hospital, Kamothe, Navi Mumbai. Data has been collected from blood bank donor grouping records. All blood samples processed during period of observation were included in the study. Results: Blood group records of 9,539 whole blood donors were analysed. It was found that out of total 9,539 donors 3,986 (41.78%) belonged to A1 subgroup and 68 (0.71%) belonged to A2 subgroup. 672 (7.04%) belonged to A1B subgroup and 72 (0.76%) belonged to A2B subgroup. Conclusion: Identification & recording of subgroups is important. Weak subgroups of A antigen red cells may be mistyped as group O or B which might led to transfusion reactions in a few cases.