[Discrepant results of ABO type of red cells and serum in a patient with acute myelogenous leukemia].

A 42-year-old woman was admitted to our hospital with acute myelogenous leukemia. We conducted blood-type examination, and her serum showed strong agglutination with all B cells but questionable agglutination with A1 cells, which became stronger with incubation. We considered her blood type as O, but her previously assessed blood type was A. After receiving one cycle of induction therapy, she achieved complete remission and blood group A antigen was proven on her red blood cells. Anti-A1 in her serum disappeared after induction therapy. We should be aware that blood group antigens are not entirely independent of the environment and are occasionally modified by disease.