Effectiveness of Intravenous Immunoglobulin Plus Plasmapheresis on Antibody-mediated Rejection or Thrombotic Microangiopathy in Iranian Kidney Transplant Recipient

BACKGROUND: Antibody mediated rejection (AMR) and thrombotic microangiopathy (TMA) after kidney transplantation are difficult to differentiate most of the times and both play important roles in kidney allograft loss. Common treatment strategies of these two conditions include plasmapheresis, intravenous immunoglobulin (IVIG) and rituximab. OBJECTIVES: This study was designed to assess the efficacy of routine treatment of AMR/TMA in Iranian kidney transplant recipients, which comprises of plasmapheresis and IVIG. PATIENTS AND METHODS: This one-year cross-sectional study was performed in the Kidney Transplantation Ward of Imam-Khomeini Hospital Complex, Tehran, Iran. All kidney transplant recipients who were administered plasmapheresis and IVIG to treat definite or suggested AMR or TMA were assessed clinically and also evaluated on laboratory data. RESULTS: During 2014, we encountered five patients with suspicious AMR or TMA at our kidney transplant center. Renal biopsy was performed for two of them, suggesting AMR for one patient and TMA for another patient. All patients were treated with plasmapheresis plus IVIG. In this center, as a routine practice, the cumulative dose of 2 g/kg of IVIG was divided to 300 - 400 mg/kg after each plasmapheresis. Only one out of the five patients showed response, albeit not completely. CONCLUSIONS: Due to daily plasmapheresis within the first several days after AMR or TMA, administering high amounts of the cumulative dose of IVIG after plasmapheresis may result in high amounts of IVIG withdrawal by plasmapheresis and response failure. Our suggestion is to reduce the IVIG dose after each plasmapheresis to 100 mg/kg (i.e. replacement dose) to reach a cumulative dose of 2 g/Kg. If plasmapheresis treatment is initiated sooner than the completion of the IVIG cumulative dose of 2 g/kg, the remaining dose can be administered during one injection.