OBJECTIVES: We define the incidence, risk factors, and mortality rates for the occurrence of thrombotic microangiopathy in 50 children who underwent transplants between January 2006 and June 2008 at 2 Turkish pediatric centers. MATERIALS AND METHODS: The diagnosis of thrombotic microangiopathy was done according to the reports of International Working Group in 2007. RESULTS: Fifty patients (27 male and 23 female; age range, 3 months to 18 years) were included. Patients with malignant and nonmalignant diseases were 13 (26%) and 37 (74%). Myeloablative and nonmyeloablative conditioning regimens were used in 29 (58%) and 21 patients (42%). Bone marrow was used as the source of stem cells in 32 patients (62%) and peripheral blood was used in 18 patients (36%). Thrombotic microangiopathy was seen in 3 of 50 cases (6%). Thrombotic microangiopathy developed in 3 of 18 patients in whom peripheral blood was used as the source of stem cells while none of 32 patients who had bone marrow as the source developed thrombotic microangiopathy (P < .05). CONCLUSIONS: Using peripheral blood as a source of stem cells is a risk factor for development of thrombotic microangiopathy.Wo
