Post transplant thrombotic microangiopathy

Thrombotic microangiopathy (TMA) is an uncommon but serious complication in renal transplant recipients. Posttransplant TMA can either be due the recurrence of the pre-transplant disease or it may occur de-novo. Amongst pre-transplant TMA, majority of the atypical HUS usually lead to renal insufficiency and end-stage kidney disease, while the typical or shiga toxin associated HUS has good prognosis. Post-transplant recurrence is <1% in shiga toxin associated HUS, whereas it is around 80–100% in certain forms of atypical HUS. Due to this high recurrence rates, previously the renal transplant was contraindicated in such patients, however, with better understanding of the pathogenesis of disease and progress in genetic analysis, renal transplant may now be possible in some of these patients. In view of the lack of controlled trials, plasma exchange remains the primary modality of treatment, while further options include isolated kidney transplant, liver transplant, combined liver-kidney transplant, prophylactic and therapeutic eculizumab and judicious use of immunosuppressant. In this review, we have discussed various causes of posttransplant TMA, their pathogenesis, outcomes and different therapeutic options.