Red cell alloimmunization in a transfused patient population: a study from a tertiary care hospital in north India

Red blood cell (RBC) alloimmunization results from genetic disparity of RBC antigens between donor and recipients. There is a paucity of data on the incidence of RBC alloimmunization in transfused recipients from the region studied, as pre-transfusion antibody screening is not routinely performed.

To assess the incidence of RBC alloimmunization in a transfused patient population at a tertiary care hospital in north India.

Antibody screening was carried out in 531 multi-transfused patients prior to crossmatching with a commercially available three-cell panel (Diacell; Diamed AG, Cressier-sur-Morat, Switzerland) by the tube method, using a saline indirect antiglobulin test. Antibody screen-positive samples were analyzed for the specificity of the alloantibody with an 11-cell identification panel (Diapanel; Diamed AG). Antigen-negative crossmatch-compatible blood was transfused if the antibody was clinically significant, whereas for clinically insignificant antibodies, crossmatch-compatible blood at anti-human globulin phase was issued for transfusion.

The overall incidence of RBC alloimmunization in transfused patients was 3.4% (18/531), with anti-c being the most common specificity (38.8%), followed by anti-E (22.2%), anti-M (11.1%), anti-Le(a) (11.1%), anti-D (5.6%), anti-Jk(a) (5.6%) and anti-Le(b) (5.6%). The highest incidence of alloimmunization was observed in gastroenterology patients (4.5%), followed by hematology patients (3.5%). Of the antibodies detected, 16.7% (3/18) were clinically insignificant with Le(a), Le(b) and M specificities.

The majority of alloantibodies detected in the current study were clinically significant. Thus, pre-transfusion antibody screening on patients' samples prior to crossmatching needs to be initiated in India to ensure safe transfusion practice.