Impact of Hematopoietic Stem Cell Transplantation-Associated Thrombotic Microangiopathy on Renal Failures Requiring Dialysis in Adult Patients ≥ 40 Years

Introduction: Allogeneic hematopoietic cell transplantation (allo-HSCT)-associated thrombotic microangiopathy (TA-TMA) and pre-transplant renal dysfunction are recognized risk factors for mortality after allo-HSCT. Utilizing the data from the Center for International Blood and Marrow Transplant Research (CIBMTR), we investigated the association between onset of TA-TMA and pre-HSCT renal dysfunction on renal failure requiring dialysis (RFD). Methods: We evaluated TA-TMA as a time-dependent covariate in a multivariate Cox regression model for RFD in Allo-HSCT recipients aged ≥ 40 years between 2008 and 2016. Pre-HSCT patients were divided into two groups, estimated GFR (eGFR) < 60 mL/min/1.73 m2 group and eGFR ≥ 60 mL/min/1.73 m2. Cumulative hazards of RFD in patients with and without onset of TA-TMA were estimated. Results: TA-TMA was significantly associated with increased risk (6.6-fold compared to No TA-TMA) for RFD, the highest of all the significant risk factors. The estimated cumulative hazard for patients with TA-TMA in the two pre-HSCT renal function groups was significantly elevated when compared to similar patients with no TA-TMA (80% vs. 12% for eGFR < 60 mL/min and 50% vs. 5% for eGFR ≥ 60 mL/min group, respectively) at 12 months post-HSCT. Conclusions: Our results demonstrate that the adjusted HR of renal failure requiring dialysis and cumulative hazard was much higher in patients with onset of TA-TMA, especially among patients with pre-existing renal dysfunction, underscoring the importance of early recognition and risk-adapted management.