Factors influencing glomerular filtration rate in renal transplantation after cyclosporine withdrawal using sirolimus-based therapy: a multivariate analysis of results at five years

Changes in calculated glomerular filtration rate (GFR) from baseline to five yr were analyzed in relation to risk factors among renal transplant recipients. At three months after transplantation (baseline), 430 eligible patients receiving sirolimus (SRL), cyclosporine (CsA), and steroids (ST) were randomly assigned (1:1) to continue SRL-CsA-ST or have CsA withdrawn and SRL trough levels increased (SRL-ST group). For each risk factor, changes from baseline were compared within each treatment using a t-test and between treatments using ANCOVA. Univariate then multivariate robust linear regression analyses were also performed. In the SRL-ST group, changes from baseline were not significantly different for any risk factor. With the exception of cold ischemia time >24 h, GFR values declined significantly for all risk factors in SRL-CsA-ST patients. For all risk factors, except second transplant or cold ischemia time >24 h, renal function was significantly different between groups. By order of significance in the multivariate analysis, treatment (p < 0.001), donor age (p < 0.001), proteinuria (p < 0.001), and biopsy-confirmed rejection (p = 0.010) were significant predictors of GFR change from baseline. In conclusion, patients with risk factors for reduced renal function benefit from SRL maintenance therapy without CsA vs. those remaining on CsA.