Routine indirect antiglobulin testing of blood donors-a further step toward blood safety: an experience from a tertiary care center in northern India.

This scientific article emphasizes the importance of a policy for antibody screening of all blood donors as a step to further improve blood safety. We also report the incidence of red blood cell (RBC) alloimmunization in healthy blood donors obtained using a cross-sectional prospective study from September 2017 to January 2019 in the Department of Transfusion Medicine of a tertiary care referral and teaching institute in northern India. The indirect antiglobulin test (IAT) for unexpected RBC antibodies was performed by the conventional tube test with pooled group O RBCs on all donor units irrespective of their D status. Samples with positive IATs were sent to the Immune Hematology Reference Laboratory for further immunohematolo-gy workup, maintaining predefined optimal storage and transport conditions. Of the 10,390 donors studied, 9959 were males and 431 were females. The incidence of unexpected antibodies (antibodies other than those of the ABO blood system) among the blood donors was found to be 0.18 percent (19 of 10,390 with 25 alloantibodies). Of the 19 alloimmunized donors, 16 (84.2%) were male (alloimmunization rate 0.16%, 16 of 9959) and 3 (15.8%) were female (alloimmunization rate 0.69%, 3 of 431) (p = 0.01; chi-square test). In our study, the most frequent alloantibodies identified were of the Lewis blood group system (17 of 25 [68%] in 14 of the 19 alloimmunized donors). The second most common allo-antibodies belonged to the Rh blood group system (4 of 25 [16%] in 3 of the 19 alloimmunized donors), followed by those of the MNS blood group system (3 of 25 [12%] in 2 of 19 alloimmunized donors). Anti-K was found in one donor (1 of 25 [4%]). Based on the results of the study, we recommend that a policy of routinely performing IATs on all donor units, irrespective of their D status, be adopted as an essential component of safe blood transfusion practices.