Allogeneic hematopoietic stem cell transplantation associated thrombotic microangiopathy: 16 cases report and literature review]

To analyze the clinical characteristics, treatment and prognosis of 16 allogeneic hematopoietic stem cell transplantation (allo- HSCT)- associated thrombotic microangiopathy (TA- TMA) patients.The clinical data of 16 TA- TMA cases in 852 patients following allo- HSCT from Jan. 2013 to Jun. 2015 in the First Affiliated Hospital of Soochow University were retrospectively analyzed.Of all the 852 allo-HSCT recipients, 16 patients were diagnosed as TA-TMA and the 1-year cumulative incidence of TA-TMA was (2.3±0.6)%. Among them, there were 9 males and 7 females, the median age was 41-year-old (12-54), and the median times of diagnosis of TA-TMA were 72 (21- 525) days after HSCT. Additionally, the median platelet counts, hemoglobin, percentage of schistocytes and Lactate dehydrogenase (LDH) levels were 20(11-36) ×10(9)/L, 74(56-99) g/L, 3% (2%- 13%) and 762(309-1 049) U/L, respectively. All 16 cases have normal ADAMTS13 level (over 60%), 10 patients had neurologic dysfunction and elevated creatinine were seen in 7. The major treatment of TA-TMA was withdrawn of calcineurin inhibitors, plasma exchange and corticosteroids. Finally, 8 patients achieved response after treatment and the other patients died of poor response. Compared with TA- TMA who achieved remission after therapy, those who got no response after interventions presented acute GVHD and they had higher schistocytes (62.5% cases>5% vs all cases ≤4%), LDH [826 (674-1 310) U/L vs 636 (309- 941) U/L] and serum creatinine levels [127 (70- 215) μmol/L vs 56 (22- 101) μmol/L].TA-TMA was a severe complication after allo-HSCT, it could progress to multi-organ injury and was associated with poor outcome, the therapeutic efficacy depends on disease severity and coexisted complications.