Thrombotic microangiopathy after kidney transplantation successfully treated with eculizumab: A case report

Abstract

Background: Transplantation-associated thrombotic microangiopathy (TA-TMA) is relatively rare and may cause graft failure. Atypical hemolytic uremic syndrome (aHUS) is caused by dysregulation of the alternative complement pathway, resulting in TMA. Eculizumab, a humanized anti-C5 monoclonal antibody, inhibits terminal membrane-attack complex formation and TMA progression in aHUS. Eculizumab can be successfully used to treat aHUS recurrence after transplantation. Case report: We report the case of a 43-year-old Japanese man who developed TA-TMA and was successfully treated with eculizumab. He was diagnosed with end-stage renal disease with an unknown cause. Thrombocytopenia, hemolytic anemia, elevated lactate dehydrogenase, and graft dysfunction soon developed after kidney transplantation. We diagnosed TA-TMA and administered daily plasma-exchange (PEx) sessions, steroid pulse, intravenous immunoglobulin, an additional rituximab, as well as blood transfusion. The effects of these therapies were limited. Renal allograft biopsy on day 11 revealed TMA and no evidence of rejection. We administered 600 mg eculizumab on days 11 and 18, considering a diagnosis of aHUS. The patient's laboratory test results improved remarkably, and he was discharged on day 36. Genetic testing revealed only a polymorphism on the gene of complement factor H (CHF). Anti-Factor H autoantibody assays were negative. Conclusion: To our knowledge, there are only 3 cases reports on successful use of eculizumab for the treatment of TMA following kidney transplantation. In the case of TA-TMA, the amount and duration of eculizumab administration remains unclear.In our patient, eculizumab was safely and effectively used for TA-TMA. Eculizumab might be beneficial for the treatment of PEx-resistant kidney TA-TMA. Keywords: Transplantation-associated thrombotic microangiopathy (TA-TMA), aHUS, Eculizumab