A intermediate (Aint) subgroup with warm anti-A1 antibody: A case report

Abstract

A intermediate (Aint) subtypes exhibit characteristics intermediate between A1 and A2. Plasma from Aint individuals contains different enzyme, UDP-GalNAc: fucosylgalactoside-a-3-N-acetylgalactosaminyl transferase, which is different from the enzyme in A1 and A2 plasma. We encountered the case of a 54-year-old female (having pneumonia and chronic kidney disease) for pre-transfusion testing. On routine grouping, we encountered group discrepancies. On testing, anti-A gave 4+, anti-B-0, anti-A1 lectin-2+, anti-H lectin, and anti-AB antisera gave 4+ reactions. Reverse grouping gave 4+ with B cells, 2+ at room temperature with A cells, and 4+ and 1+ at 37°C and 4°C. Saliva inhibition studies showed A and H substances. It was typed as an Aint group with warm anti-A1 antibody. It’s the 1st time ever we encountered Aint case with a warm type anti-A1 antibody. Here, O group packed red cells are the suitable blood units to transfuse.