Incidence of clinically significant antibodies in patients and healthy blood donors: a prospective cross-sectional study from a tertiary healthcare center in India.

INTRODUCTION Since there is scarce data available on incidence and type of irregular antibodies in patients and donors in India, a study was undertaken to find the incidence of irregular antibodies in patients and irregular antibodies and a positive Direct Antiglobulin Test (DAT) in blood donors. MATERIALS AND METHODS Antibody screening was performed using commercial pooled "O" cells and three-cell panel for donors and patients respectively and an 11-cell panel for identification using Column Agglutination Technology (CAT) with Low-Ionic-Strength Saline-Indirect Antiglobulin Test (LISS-IAT) technique (Ortho Clinical Diagnostics, Johnson & Johnson, USA). The cassettes used were Anti-human Globulin (AHG) type. DAT on donors was also performed using the AHG cassettes. RESULTS Cumulative incidence of irregular antibodies amongst patients (n=32,560) and donors (n=31,367) were 0.12-0.009%, respectively. In patients, the commonest antibodies were from Rh system with anti-D being the most common antibody type (14/40; 35%) while in donors it was the MNS system with anti M (2/3) being the most common. Incidence of a positive DAT amongst the healthy blood donors was 0.04% (n=13/32,560). DISCUSSION Incidence of irregular antibodies in patients at 0.12% was slightly lower than published reports and could be because of the fact that the patient population studied comprised largely of surgical patients many of whom have never received blood transfusion. This data could also be more representative since the number of patients studied was much higher as compared to the previous Indian studies (32,560 vs. 531-2026). The report on incidence of irregular antibodies and DAT (0.009-0.04%) in blood donors was first such attempt in India.