Thrombotic thrombocytopenic purpura: a rare late complication of allogeneic bone marrow transplantation.

Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) usually occurs in a setting of systemic infection or graft-versus-host reaction during the first weeks following transplant. We report a case of fatal TTP that developed eight months after allogeneic bone marrow transplantation (BMT) without any evident association with other transplantation-related complications. Conditioning chemotherapy could have induced the disorder by causing damage to the vascular endothelium. The removal of immunosuppression, including cessation of cyclosporin A (CyA), may have precipitated the disease.