Conversion from azathioprine to mycophenolate mofetil followed by calcineurin inhibitor minimization or elimination in patients with chronic allograft dysfunction

The purpose of this study was to evaluate the effects of the conversion from azathioprine (AZA) to mycophenolate mofetil (MMF) followed by calcineurin inhibitor (CNI) elimination or minimization in patients with progressive chronic allograft dysfunction (CAD). METHODS: Between November 6, 1999 and February 12, 2003, 169 patients receiving CNI/AZA/prednisone (153 CsA; 14 tacrolimus) were included in this study. Demographics, immunosuppression, graft function, hematology, and biochemistry were obtained before (-6, -3, and -1 month) and 1, 3, 6, 9 and 12 months after and at last follow-up visit after conversion. RESULTS: Mean age was 34 +/- 12 years, 66% males, 51% Caucasian, and 72% living allograft recipients. Mean follow-up times before and after conversion were 32.4 and 19.4 months; 10 patients completed 3 years of follow-up. CNI elimination was performed in 39% and minimization in 61% of patients. Overall there was significantly improved graft function at 1 year after conversion (2.6 +/- 1.0 vs 2.1 +/- 0.6 mg/dL, P = .038). The slopes of the regression lines of 1/Cr vs time were significantly improved from preconversion to after conversion (-0.026 vs +0.007 mg(-1)/dL per day(-1), P = .001). There was a significant decrease in mean systolic (141 +/- 21 vs 135 +/- 22 mm Hg, P = .015) and diastolic (89 +/- 15 vs 84 +/- 14 mm Hg, P = .005) blood pressure values at 1 year. There were four episodes of acute rejection (Banff IA) treated with steroids. Three years after conversion, patient and graft survivals were 95% and 79%, respectively. One patient developed posttransplant lymphoproliferative disease. CONCLUSION: Among patients with CAD, conversion from AZA to MMF followed by CNI minimization or elimination was a safe and effective strategy to preserve or improve graft function.