Thrombotic Microangiopathies Postrenal Transplantation

Aims: The aim of the study was to describe 12 cases of thrombotic microangiopathy (TMA) postrenal transplantation and study the causes, treatment, and outcomes. Materials and Methods: A retrospective observational study was conducted among renal transplants conducted from 2005 to 2018. Results: Of a total number of 1210 transplants, 12 patients (1%) developed posttransplant thrombotic complications. The mean age of recipients was 36.75 years, and the male-to-female ratio was 9:3. Native kidney diseases included diabetic nephropathy, chronic glomerulonephritis, chronic interstitial nephritis, lupus nephritis, atypical hemolytic uremic syndrome (HUS), and immunoglobulin A nephropathy. Treatment options included plasmapheresis, intravenous immunoglobulin, and everolimus. Seven (58.3%) were associated with an acute rejection, 2 (16.6%) had associated histopathological evidence of calcineurin toxicity, 1 (8.3%) had an unknown etiology, 1 (8.3%) had recurrent HUS in the graft, and 2 (18.2%) patients developed glomerular microthrombi, both of which resolved spontaneously. Graft loss was 50% within the 1st year. Six patients (50%) had a good 1-year graft survival. Two patients succumbed (16.6%). Conclusion: TMA in the posttransplant period may be commonly associated with drug toxicities, antibody-mediated rejection, or recurrent HUS. There is no correlation between drug levels and extent or prognosis of TMA. Empirical plasma exchange may be tried even in cases with no evident cause for TMA. Graft loss is common.