Plasma exchange and vincristine in the treatment of hemolytic uremic syndrome/thrombotic thrombocytopenic purpura associated with bone marrow transplantation.

Hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP) is a rare and often fatal complication of bone marrow transplantation (BMT). In this study, we report eight such cases (seven allo and one auto) treated with plasma exchanges (PE), vincristine (six patients), and discontinuation of cyclosporin A (in allo BMT). This complication occurred in 6.3% of 112 allogeneic BMT and in 0.7% of 146 autologous BMT. In seven patients, the BMT preparatory regimens consisted of cyclophosphamide, etoposide, and total-body irradiation (TBI). Among the eight patients with HUS/TTP, one allogeneic BMT patient with reversible renal failure, but without central nervous system (CNS) involvement, or systemic mycotic infection, responded completely and is without evidence of disease for a period of greater than 3.5 years. Three patients showed hematologic improvement, and four did not respond. The median duration of survival was 17 days. Six of the seven deaths occurred in a setting of systemic infection, progressive renal failure, and worsening of graft-versus-host reaction. In spite of hematologic improvement to PE and vincristine, BMT patients in whom HUS/TTP developed usually succumbed to complications.