Persistent Neutropenia after ABOi Kidney Transplantation: A Case Report

Post-transplant neutropenia (PTN) is frequently reported in the first-year after transplantation. Although prevalence and clinical consequences are widely described, there are no guidelines to manage diagnosis and treatment. We report here a case of persistent PTN occurred in a patient undergoing a kidney transplant from an AB0-incompatible living donor. The desensitization protocol consisted of Rituximab administration and immunoadsorption while the pre-transplant protocol, which was initiated 14 days before the transplant, included Tacrolimus, Mofetil Mycophenolate (MMF), antimicrobial and antiviral prophylaxis. Induction therapy consisted of anti-thymocyte globulins and steroids, while maintenance after transplantation consisted of steroid, tacrolimus and MMF. When the first occurrence of leukopenia was observed six weeks after the transplant, firstly antimicrobial/antiviral prophylaxis was stopped and later also MMF treatment was interrupted but severe neutropenia relapsed after MMF resuming treatment. Immunological and virological causes were excluded. The patient was treated with Filgrastim. Bone marrow biopsy, which was performed to exclude a hematological cause of severe persistent neutropenia, revealed a bone marrow hypoplasia with neutrophils maturation interrupted at the early stages. This case highlights the need to establish diagnostic and therapeutic guidelines for PTN which take in consideration all the therapeutic steps including the pre-transplant phase in particular in the context of AB0i where immunosuppression is more consistent