ABO blood group discrepancies among blood donors in Regional Blood Transfusion Centre GTB Hospital, Delhi, India

Abstract

Regional Blood Transfusion Centre (RBTC), GTB Hospital, Delhi is providing safe and quality blood to one third of Delhi population. A discrepancy exists when reactions in forward grouping do not match with reverse grouping or if the previous and current results do not match. To analyze ABO blood group discrepancies in an algorithmic manner, and to access the incidence and causes of ABO discrepancies among blood donors. Retrospective data of blood donors with blood group discrepancies was recorded in Regional Blood Transfusion Centre (East) Delhi, during a period of 3years from January 2010 to May 2013. DiaMed-ID Card Micro Typing System using Gel Cards (Cressier sur Morat, Switzerland) were used for determination of the ABO/Rh blood groups combined with reverse grouping. A detailed serological workup of these cases was studied for recognition and resolution of the blood group discrepancy. Total number of donors during the study period were 104,010 (30,120; 31,117; 32,173 and 10,600 respectively). Blood group discrepancies were found in 51 cases (0.04%). There were 30 (58.8%) cases with low avidity anti-B Antibodies, 10 (19.6%) cases with weaker expression or subgroups of A, 2 (3.9%) cases with weaker expression or subgroups of B, 5(9.8%) cases with unexpected alloantibodies (Anti-N and Anti-M, Anti-Lea) and one(1.9%) case of Bombay blood group. In 3 cases, discrepancy could not be resolved and were referred to reference laboratory for confirmation by molecular analysis. The most frequent cause of discrepancy in forward grouping was found to be weak A or B antigen expressions and in reverse grouping decreased anti-B titers was most common. All discrepancies reported on ABO cell and serum grouping must be investigated further, so that correct blood group is reported, minimizing the chances of transfusion reaction. A note of caution should be mentioned on the blood group card to prevent ABO incompatibility in case of transfusion.