Effectiveness of steroid-free immunosuppressive regimens after kidney transplantation: the pioneering experience of a brazilian center.

Introduction: Chronic corticosteroid use, even at low doses, is associated with well-known adverse effects. However, steroid-free regimens after kidney transplantation (KT) have been linked to a higher incidence of acute rejection (AR), limiting their implementation to a few centers worldwide. In this study, we describe the pioneering experience of a Brazilian center that adopted a steroid-free immunosuppressive regimen in 2005 for patients at low to moderate immunological risk.

Methods: This single-center retrospective cohort study includes KT recipients who were submitted to steroid-free regimens between 2012 and 2019. The cohort was followed for three years in a real-world setting.

Results: A total of 562 patients were included, 71.4% male, with a median age of 48.1 years (IQR 35.5-58.6). Most (95.2%) received deceased donor allografts. All patients underwent induction therapy with antithymocyte globulin, and 82.2% received tacrolimus in combination with sirolimus or everolimus as maintenance therapy. After three years, 10.2% experienced treated AR episodes, with biopsy confirmation in 3.2%. Age (HR 0.946, 95% CI 0.923-0.969, p < 0.001) and HLA mismatches (HR 1.312, 95% CI 1.021-1.687, p = 0.034) were risk factors for rejection. Twenty-eight patients (5%) lost their grafts, and 5.7% died. Seventy-one patients (12.6%) required corticosteroid introduction over the years, with a median of 125.5 days (IQR 31.7-409) post-KT. The main reasons were perceived immunosuppressive regimen inefficacy (56.3%) and composition in a low-efficacy immunosuppressive regimen (18.6%).

Conclusion: Steroid-free immunosuppression was effective in low to moderate immunological risk KT recipients over a three-year follow-up period.