Immunosuppression Modification by Everolimus With Minimization of Calcineurin Inhibitors Recovers Kidney Graft Function Even in Patients With Very Late Conversion and Also With Poor Graft Function

Abstract

BackgroundAlthough kidney graft survival within 5 years after transplantation is now achieved in >95% of recipients, chronic graft deterioration remains a factor limiting long-term survival. Chronic nephrotoxicity induced by calcineurin inhibitors (CNIs) is one of the major causes of chronic graft injury; thus, minimization of CNIs by administration of everolimus (EVR) is expected to relieve their toxic effects. MethodsFifty-six kidney transplant recipients receiving CNI-based immunosuppression (tacrolimus, n = 34; cyclosporine, n = 22) were analyzed. The average posttransplant period at conversion was 7.4 years and no less than 3 years. Conversion of immunosuppression was accomplished by reducing CNI by 40% in dose and beginning EVR at 1 or 1.5 mg. Changes in graft function were examined, and adverse effects were evaluated. ResultsSignificant improvement in graft function was observed quickly after EVR administration, and it had persisted for 1 year after conversion as a 7% increase in estimated glomerular filtration rate. No obvious acute rejection was observed. Further analyses concerning “timing of EVR conversion” and “graft function at conversion” were performed. Graft function was significantly improved even in patients with late conversion at 2 to 10 years. The estimated glomerular filtration rate was significantly improved even in patients with poor function. ConclusionsWe concluded that this modification to the immunosuppressive regimen, as expected, reduced CNI nephrotoxicity. Our results showed that even patients with very late conversion or poor graft function also benefited from EVR conversion with CNI minimization.