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

BACKGROUND: 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.

AIM: To analyze ABO blood group discrepancies in an algorithmic manner, and to access the incidence and causes of ABO discrepancies among blood donors.

MATERIAL AND METHODS: 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.

RESULTS: 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.

CONCLUSION: 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.