Severe thrombotic microangiopathy: an infrequent complication of bone marrow transplantation

Thrombotic microangiopathy (TMA) usually occurs during the first weeks foll owing transplantation in the setting of systemic infections or graft-versus -host reaction. However, some cases without any evidence of other complicat ions or after autologous transplantation have been reported. Transplant-ass ociated TMA (BMT-TMA) incidence ranges from 0% to 74%, possibly due to diff erent diagnostic criteria. The GITMO Group provided the opportunity to retr ospectively study 4334 consecutive Italian patients who received bone marro w transplants (1759 allogeneic and 2575 autologous BMT), during the 1985-19 95 period, The present report focuses on patients with severe TMA requiring specific treatment. We identified nine cases of TMA as a complication of a llogeneic BMT (0.51%), whereas three patients developed the syndrome after ABMT (0.13%); four of the 12 patients were not receiving CsA at the time of TMA onset. Finally, it is noteworthy that TMA occurred in seven patients a s a late complication (up to 90 days after BMT), Despite intensive treatmen t, five of the seven patients with thrombotic thrombocytopenic purpura died . One death was observed among the five cases with hemolytic uremic syndrom e.