Survival Analysis of Transplant-Associated Thrombotic Microangiopathy Under Different Diagnostic Criteria and Efficacy of Plasma Exchange

BACKGROUND: Transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication of hematopoietic stem cell transplantation (HSCT). The efficacy and survival of plasma exchange (PE) for TA-TM have not been fully clarified. In addition, there is a lack of consensus on diagnostic criteria for TA-TMA. MATERIAL/METHODS: We retrospectively analyzed 32 patients diagnosed with TA-TMA by different diagnostic criteria from January 2018 to February 2022 at the First Medical Center of the PLA General Hospital. RESULTS: (1) The patients with TA-TMA treated with PE in this study had a remission rate of 42.8%, a 100-day OS of 47.6%, and a 6-month OS of 38.1%. The only factor affecting the response to PE treatment was the number of PE sessions (P=0.047). (2) III–IV aGVHD prior to TA-TMA diagnosis (P=0.002), renal or neurological dysfunction (P=0.021), and the time to onset of TA-TMA (P=0.002) were independent risk factors for overall survival with TA-TMA. (3) Probable TA-TMA had the highest survival rate, but the Jodele criteria are expected to diagnose earlier and provide the greatest benefit to patients. CONCLUSIONS: PE can temporarily alleviate TA-TMA patients’ clinical symptoms and laboratory indicators. It does not, however, significantly increase overall survival. In addition, probable TA-TMA improved survival prognosis through early detection of patients with TA-TMA. There is a need for further large prospective trials to identify the population more suitable for PE treatment of TA-TMA and more valid diagnostic criteria.