Introduction: Twice-daily tacrolimus has a well-defined safety and efficacy profile to prevent graft rejection. However, the Symphony study demonstrated that lower exposure to tacrolimus may provide good immunosuppression, improved renal function, and good graft survival. There has been some suggestion that therapeutic doses of cyclosporine compared with twice-daily tacrolimus induce a great reduction in renal hemodynamics. To improve treatment adherence, once-daily tacrolimus was therefore developed. The aim of the present study was to evaluate the effects of conversion from cyclosporine to once-daily tacrolimus at a late post-transplant stage.
Patients and Methods: In this prospective study, 17 recipients who underwent kidney transplants at our institution were receiving cyclosporine. Before conversion, all patients were being treated with cyclosporine, combined with methylprednisolone, plus an antimetabolite or mTOR inhibitor. The patients without acute rejection by graft biopsy were switched from cyclosporine to once-daily tacrolimus on a 50:1 mg basis. At 3 months and at 1 year after conversion, graft biopsies were performed to check for acute rejection and C4d deposition, and graft function was evaluated. We also evaluated the clinical parameters between baseline and at 3 months and 1 year after conversion.
Results: At 3 months and at 1 year after conversion, there were no acute cellular or antibody-mediated rejections in the allograft biopsies. C4d staining patterns showed no diffuse C4d+ staining. Conversion from cyclosporine to once-daily tacrolimus did not induce C4d deposition along the peritubular capillaries in all of the graft biopsies. The mean eGFR value significantly increased at 1 year after conversion compared to baseline.
Conclusions: This study demonstrated that conversion from cyclosporine to one-daily tacrolimus may elicit no acute rejection and no C4d deposition, and that graft function might improve after conversion at a late post-transplant stage.