Severe hemolysis due to passenger lymphocyte syndrome after hematopoietic stem cell transplantation from an HLA-matched related donor

A 61-year-old white man (group A, Rh-positive) was allotransplanted for acute myelogenous leukemia from his HLA-matched related sister (group O, Rh-positive) in 2 separate infusions. Three days after the second graft infusion, the patient's front blood type converted to O Rh-positive, with a negative direct antiglobulin test and elevated anti-A1 titer. Severe hemolysis developed, and the patient expired 14 days posttransplantation.