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.