Analysis of Blood Group Discrepancy in Healthy Blood Donors at a Tertiary Care Referral Hospital from Eastern India: A Retrospective Study.

Objective  ABO typing constitutes cell grouping and serum grouping. The discrepancy may arise in ABO typing due to a mismatch in cell grouping and serum grouping. It may be due to technical errors, missing or weak ABO antibodies (type I), weak ABO subgroups (type II), Rouleaux formation (type III), or other miscellaneous reasons (type IV). This study was carried out to determine the prevalence and cause of ABO blood group discrepancy in donor samples at our center. Methods  A retrospective study of ABO blood group typing of blood donors was conducted at our center. The blood group typing was routinely performed using gel cards and a microcentrifuge system (Tulip Diagnostics(P) Ltd, Goa, India). If any discrepancy in ABO typing was noted, the test was repeated using the conventional tube technique. After sorting clerical/technical error, the causes of discrepancy were analyzed and resolved using anti-A 1 , anti-H, anti-AB, and other immunohematological tests like antibody screening and identification, saliva inhibition test, adsorption-elution studies. Results  A total of 12,715 (98.6% males and 1.4% females) donor samples were tested. The number of ABO discrepancies detected were 15 (0.12%). The discrepancies were characterized as type I (6 cases; 40%), type II (1 case; 6.7%), type III (0 cases; 0%), and type IV (8 cases; 53.3%). Three cases, each of anti-M and anti-Le b , were detected in the study population. A single case of A 3 , a subgroup of A blood group, was found during the study. Conclusion  The prevalence of ABO group discrepancy was 0.12% at our center. Discrepancy arising during ABO typing of blood donor must be resolved before reporting ABO blood group to minimize the recipient's chances of transfusion reaction. The serum grouping is equally crucial as cell grouping for reporting the ABO group of an individual.