Risk factors for transplant-associated thrombotic microangiopathy (TA-TMA): a systematic review and meta-analysis

Introduction Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe hematopoietic stem cell transplantation complication with high mortality and a poor patient prognosis. The pathogenesis of TA-TMA is not yet clear. In previous studies, the conclusions of different centers remain controversial. We conducted a systematic review and meta-analysis of nine selected risk factors that might be associated with the onset of TA-TMA.Materials and Methods PubMed databases were searched from their inception up to 15 September 2021, for relevant studies. The articles included unprocessed data related to one or more of the risk factors discussed in this meta-analysis, including recipient gender, donor type, graft source, pretreatment, infection, aGVHD, diagnosis, total body irradiation (TBI), and CMV infection. The outcome is the incidence rate (IR) of TA-TMA.Results and Conclusions According to the sixteen articles included, risk factors included in this Meta-analysis included gender, unrelated donor source (95% CI: 1.29–2.01), graft source from peripheral blood stem cell (PBSC)(95% CI: 0.48–0.97), RIC/NMA, class II–IV aGVHD (95% CI: 2.22–4.78), nonmalignant disease, TBI. However, inconsistent diagnostic criteria for TA-TMA and the limited number of studies have an impact on the results of the study. More prospective cohort studies and More accurate diagnostic criteria are needed.