Prevalence of direct antiglobulin test positive in whole blood donors: Study at a tertiary blood center Northern India.

Background: The direct antiglobulin test (DAT) detects red blood cell (RBC) sensitivity to complement or IgG . The clinical disorders of hemolytic disease of the newborn, hemolytic transfusion reaction, and autoimmune and drug-induced hemolytic anemia are some examples of those that can cause coating of RBCs with antibodies or complement autoimmune hemolytic anemia (AIHA). Rarely, DAT is positive in nonimmune-mediated hemolytic anemias as well. Standard donor screening techniques do not require the DAT to be performed.

Aims And Objectives: The aim of the study was to assess the prevalence of DAT positive in healthy blood donors at a tertiary blood center in North India.

Materials And Methods: This 2-year prospective observational study included whole blood donors from January 2020 to December 2022. A total of 152,564 healthy blood donors including 150,246 (98.5%) males and 2318 (1.5%) females were donated at the department of transfusion medicine.

Results: Of a total of 152,564 donors, 150,246 (98.5%) were male, and 2,318 (1.5%) were female. Among the male donors, 11 (0.007%) had a history of blood transfusion and 16 (0.011%) tested DAT positive. Among the female donors, 15 (0.647%) had a history of blood transfusion and none of them tested DAT positive.

Conclusion: We observed low levels of DAT positivity in healthy blood donors. Such donors should be regularly monitored to check for any long-term development of malignancies or clinical or laboratory indications of hemolysis. DAT-positive blood units do not supply the recipient at risk, which may cause negative consequences.