Impact of Corticosteroid-Free Regimen on Interstitial Fibrosis Following Kidney Transplantation.

Introduction: In kidney transplantation, concerns remain about whether corticosteroids (CS) avoidance could favor interstitial fibrosis (IF) and its progression. We conducted a multicenter randomized noninferiority clinical trial to evaluate the histopathological progression of IF using an innovative automated method in patients receiving CS or not. Methods: Low immunological risk recipients of a kidney allograft for whom an analyzable biopsy was available at implantation were randomly assigned to receive a CS-free regimen (CS-) or a standard CS tapering regimen (CS+). All patients received induction therapy with basiliximab, and conventional maintenance therapy. The primary outcome was the difference in the percentage change of IF between the baseline and the 1-year protocol biopsy with a prespecified 10% noninferiority margin. Results: A total of 108 patients were analyzed in the full analysis set (FAS) population as follows: 52 patients in the CS+ group and 56 patients in the CS- group. Complete avoidance of CS was reached in 36 (64%) CS- patients (per-protocol [PP] population). In the FAS population, the mean percentage of IF at implantation was 19.5% ± 7.9% in the CS- group ( Conclusion: Progression of IF during the first year following kidney transplantation was not inferior among patients without CS compared with patients with CS.