[Clinical analysis of 9 patients with transplant-related thrombotic microangiopathy]

Objective: To analyze the clinical features, efficacy and outcomes in patients with transplantation associated thrombotic microangiopathy (TA-TMA). Methods: The clinical data of 9 patients who developed TA-TMA after allogeneic hematopoietic stem cell transplantation (allo-HSCT) were retrospectively analyzed from January 2011 to August 2018 in Affiliated Tumor Hospital of Zhengzhou University. Results: There were 6 male and 3 female patiens with a median age of 31 (12-38) years. The median time from transplantation to TA-TMA was 76 (24-155) days. The baseline blood and biochemical parameters at diagnosis of TA-TMA included median hemoglobin (Hb) 66 (58-77) g/L,platelet (PLT) count 22 (4-38) × 10(9)/L,serum lactic dehydrogenase (LDH) 655 (305-4 238) U/L,blood urine nitrogen (BUN) level 15.9 (4.8-26.2) mmol/L,blood creatinine (Cr) level 118 (24-380) μmol/L. The proportion of median peripheral blood schistocytes was 2.6%(1.2%-9%). All patients had positive urinary occult blood tests,and urinary protein was seen in 4 patients. Three patients had mental symptoms. Coombs tests were all negative. The main treatments of TA-TMA composed of reduction and withdrawal of calcineurin inhibitor,steroids and plasma exchange. Response was seen in 4 patients. Patients who did not response to the treatment had a higher proportion of schistocytes,more severe acute graft-versus-host disease (aGVHD),more elevated serum LDH and other transplant-related complications. Conclusions: TA-TMA after allo-HSCT is a serious complication with high mortality rate. The proportion of schistocytes in peripheral blood, serum LDH level and comorbidities are prognostic factors of clinical outcome.