Complement inhibition with eculizumab for thrombotic microangiopathy rescues a living-donor kidney transplant in a patient with antiphospholipid antibody syndrome

Antiphospholipid antibody syndrome (APS) is an enigmatic heterogeneous disorder despite several revelations in its pathobiology. Renal transplantation in patients with APS has been notoriously difficult due to the high risk of development of thrombotic microangiopathy (TMA), which is often refractory to conventional treatment modalities such as aggressive anticoagulation and plasmapheresis. We describe a case of a 58-year-old male with secondary APS undergoing living unrelated renal transplantation for end-stage renal disease from lupus nephritis. Shortly after transplantation, he developed graft dysfunction from APS related TMA that was refractory to systemic anticoagulation and plasmapheresis. After becoming hemodialysis dependent, the patient was started on eculizumab, a humanized monoclonal antibody against complement factor 5, as salvage therapy. We show that this intervention successfully rescued his renal allograft and that the patient has remained dialysis free for over 20 months. Our experience adds to the limited body of literature suggesting the role of complement inhibition in facilitating renal transplantation in patients with APS spectrum of disorders, thus adding a new tool to the therapeutic armamentarium for this difficult disease. The optimal treatment schedule and long term safety data for eculizumab in complement mediated TMA is still unclear. The search for an optimal biomarker to help guide treatment duration is an area of active research.