Conversion to combined therapy with sirolimus and mycophenolate mofetil improved renal function in stable renal transplant recipients

Background/Purpose: Information is needed on renal function improvement after late elimination of calcineurin inhibitors (CNIs) and conversion to combined therapy of sirolimus (SRL) and mycophenolate mofetil (MMF) in Asian renal transplant recipients. Methods: A single-arm prospective study was undertaken to assess the outcome of stable Taiwanese renal transplant recipients who had CNI withdrawn and received combined SRL and MMF therapy. The primary endpoints were acute rejection and renal function. The secondary endpoints were graft and patient survival, side effects and infectious complications. Therapeutic drug monitoring of SRL and MMF was conducted during the study period. Results: Thirty patients were recruited at 9-72 (31.7 +/- 18.6) months post-transplantation. The graft and patient survival rates were both 100% at 12 months, though one of the 30 patients (3.33%, 1/30) had biopsy-proven acute rejection. On paired t test, the estimated glomerular filtration rates (GFR) from 4 to 12 months were significantly higher than the baseline GFR. The average trough level of SRL was 7.38 +/- 3.74 ng/mL at 12 months and the average abbreviated area under the concentration curve of mycophenolic acid was 64.86 +/- 36.62 mg/L center dot hour at an average MMF dose of 1.56 +/- 0.45 g/day. However, two patients (6.67%, 2/30) had tuberculosis (TB) reactivation at 3 and 4 months, respectively, after the combined SRL and MMF therapy. Conclusion: Conversion to combined SRL and MMF therapy improved renal function in stable renal transplant recipients, though the risk of TB reactivation should be kept in mind when the combined therapy is employed in the Asian countries with a high prevalence of TB.