Thrombotic microangiopathy in allogeneic stem cell transplantation in childhood.

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.