Outcomes of Early Thrombotic Microangiopathy in Renal Transplantation

ABSTRACTBackgroundAlternate complement dysregulation postrenal transplantation can result in thrombotic microangiopathy (TMA). There is a scarcity of data regarding outcomes based on the timing of TMA post‐transplant, coupled with a lack of follow‐up biopsy findings post TMA diagnosis. This study aims to assess allograft and patient outcomes in individuals developing early TMA, defined within 4 months post‐transplantation, and explore any differences in follow‐up surveillance biopsies compared to a non‐TMA group.DesignThis is a single center retrospective study between January 1, 2002 and October 10, 2019. Patients who developed TMA within 4 months post‐transplantation were compared to a propensity matched non‐TMA group.ResultsThirty‐one patients developed TMA within 4 months of renal transplantation. Index TMA biopsy featured noticeable glomerular, and vascular lesions along with acute tubular injury. Four‐month surveillance biopsy showed significant glomerulitis, transplant glomerulopathy and chronic interstitial fibrosis as compared to non‐TMA group. However, at 1 year, these differences were no longer significant. There was no significant difference in patient survival (TMA vs. non‐TMA,p = 0.083); however, death censored graft survival was significantly lower in the TMA group (p < 0.001). TMA patients had a significantly lower estimated glomerular filtration rate at 4 months and at 1 year as compared to the non‐TMA group.ConclusionEarly onset TMA post renal transplant leads to decreased renal function and lower graft survival. Early recognition and prompt treatment may help in reducing the adverse outcomes.