Course of renal allograft function after diagnosis and treatment of post-transplant lymphoproliferative disorders in pediatric kidney transplant recipients.

Abstract

Post-transplant lymphoproliferative disease (PTLD) is a life-threatening complication in renal transplant recipients. Immunomodulatory and chemotherapeutic treatment potentially affect allograft function. The aim of this study was to evaluate graft function of pediatric kidney transplant recipients following diagnosis and standardized treatment of PTLD. Patients were identified from the German Ped-PTLD registry, and data on renal function were retrospectively retrieved from patient charts. For PTLD treatment, immunosuppressive therapy was reduced and all children received rituximab (375mg/m2 ) for up to six doses. Two patients required additional low-dose chemotherapy. Renal allograft function was monitored by consecutive measurements of estimated glomerular filtration rate (eGFR) at defined time points. Follow-up was up to 60months after PTLD. Twenty patients were included in this cohort analysis. Median time from transplantation to PTLD was 2.4years. Histopathology showed monomorphic lesions in 16 and polymorphic in 4 patients. Two patients experienced PTLD relapse after 2 and 14months. Range-based analysis of variance showed stable allograft function in 17 of 20 patients (85%). Mean eGFR increased during early treatment phase. One patient experienced graft rejection 5.3years after diagnosis of PTLD. Another patient developed recurrence of primary renal disease (focal-segmental glomerulosclerosis) and lost his renal allograft 3.8years post-transplant (2.0years after PTLD diagnosis). Treatment of PTLD with rituximab with or without low-dose chemotherapy in combination with reduced immunosuppression, mostly comprising of an mTOR inhibitor-based, calcineurin inhibitor-free regimen, is associated with stable graft function and favorable graft survival in pediatric renal transplant patients.