Fatal coronary artery disease after unrelated donor bone marrow transplantation

Several factors are responsible for the occurrence of cardiac complications after bone marrow transplantation (BMT). These factors include the cardiotoxic effects of radiation therapy, antineoplastic and immunosuppressive drugs, abnormal immunologic reactions associated with graft-vs-host disease, and infectious agents. We report the case of a 45-year-old woman with T-cell prolymphocytic leukemia and no prior risk factors for coronary artery disease in whom sudden cardiac death occurred 2 1/2 years after allogeneic BMT from an unrelated male donor. Autopsy revealed severe 3-vessel coronary disease with grade 4/4 stenosis. This process was primarily nonatherosclerotic, with intimal hyperplasia of undetermined etiology. Furthermore, fluorescence in situ hybridization to identify the donor Y chromosome with simultaneous immunofluorescence labeling of smooth muscle actin suggested the presence of donor cells that transformed into myocytes. Coronary artery disease is an important, albeit rare, complication of BMT. Donor hematopoietic cells may contribute to its pathogenesis.