ABO blood grouping discrepancies in the donor population

Abstract

Background and ObjectivesABO discrepancies occur when the reactions in forward grouping are not corroborative to those in the reverse grouping due to weak subgroups of A and/or B, missing or weak ABO antibodies or unexpected alloantibodies. We aimed to determine the prevalence of ABO discrepancies in our donor population and to know the causes by using a standard classification.Materials and MethodsIt was a retrospective study on donor samples. For all the discrepant samples, the ABO and RhD grouping was repeated using tube technique. Adsorption–elution testing was done for detecting weak subgroups of A and B. Antibody screen (3‐cell) and identification (11‐cell) were done by gel technique (Bio‐Rad, Switzerland).ResultsWe detected 93 (0·064%) ABO discrepancies out of the total 144279 donor samples tested. The ABO discrepancies were due to weak anti‐B antibody (33/93; 35·5%), weak anti‐A antibody and weak subgroups of A (24 each; 25·8% each) and weak subgroups of B (5/93; 5·4%). Agglutination with O cells was observed in 7 (7·5%) samples at room temperature testing. The alloantibodies identified in these samples were anti‐M (5) and anti‐Lea in (1), while the remaining 1 sample was of ‘Bombay’ (Oh) phenotype. The autologous control was negative for all the samples.ConclusionThe prevalence of ABO discrepancies in our donor population is 0·064%.