Conversion of ciclosporin A to tacrolimus in kidney transplant recipients with chronic allograft nephropathy.

BACKGROUND Tacrolimus and ciclosporin might have different effects on intra-renal fibrosis and allograft function in chronic allograft nephropathy (CAN). It is difficult to predict the response to calcineurin inhibitor minimization in patients with CAN. METHODS This prospective randomized study compared ciclosporin A (CsA)-to-tacrolimus conversion (group A, target tacrolimus trough level 6-8 ng/ml) vs CsA minimization (group B, target CsA trough level 80-100 ng/ml) with regard to efficacy and safety in patients with CAN and deteriorating allograft function. The primary efficacy endpoint was improvement in the slope of inverse serum creatinine (1/SCr) vs time plot. RESULTS There were 34 evaluable patients (n=16 in group A; n=18 in group B), with similar baseline characteristics. Both groups reached target drug levels after a 3-month run-in period. Over the ensuing 12 months, nine (56.3%) subjects in group A and 10 (55.6%) in group B reached the primary end point (P=0.968). Both groups showed considerable improvement in the slope of 1/SCr vs time plot. There was no significant difference in the slope between groups before and after intervention. Graft survival was 87% in group A and 100% in group B (P=0.121). Acute rejection was encountered in two group A subjects. There was no significant change or difference in blood glucose, lipids, and blood pressure between groups. CONCLUSION Our results suggest that in patients with CAN and deteriorating allograft function, CsA-to-tacrolimus conversion or CsA minimization achieved comparable efficacies in retarding the decline of graft function. Such contention may be biased by the low patient number. Further studies with a larger cohort are needed for validation.