A Case of ABO Discrepancy due to Anti-IH / 대한수혈학회지

ABSTRACT

The patient was a 70-year-old woman with hypertension and end stage renal disease, and she presented with left wrist pain due to falling a day before admission. On admission, laboratory testing revealed a hemoglobin level of 6.7 g/dL, and a physician ordered 2 units of packed RBCs. She had never received a RBC transfusion in the past. The ABO grouping showed a discrepancy between the cell type AB and serum type O, and the irregular antibody screening was negative. Crossmatchings with group AB and group O RBCs were incompatible. Anti-I, which is a cold antibody, was inferred because the degree of agglutination was decreased after warming. However, crossmatching with group O RBCs, which are the universal donor blood, was positive and the anti-IH was considered to be the specificity of the irregular antibody. The patient's serum did not react with group O cord (i) blood cells and anti-I was then considered. The genotype of this patient was AB, and it was inferred that the ABO discrepancy was due to anti-IH.