Clinicopathologic evaluation of short-term outcome after early corticosteroid discontinuation in kidney transplantation.

Objectives: Steroids have been a gold-standard drug of immunosuppressive regimens in kidney transplantation. Steroid minimization protocols have been applied to minimize the adverse effects of steroids. We have evaluated the short-term outcomes of our early steroid discontinuation regimen. Methods: A total of 128 recipients who received kidney from ABO-compatible, flow crossmatch-negative living-related donors were included in this study. Immunosuppressive regimens consisted of tacrolimus (TAC), mycophenolate mofetil (MMF), and basiliximab. In a cohort of recipients, designated as a steroid early discontinuation (ESD) group, only three doses of methylprednisolone (MP) were given (500, 250, 125 mg). In the other cohort of recipients, designated as a chronic steroid (CS) group, MP was given chronically, being tapered to 4 mg at one month post-transplant. TAC and mycophenolic acid (MPA) blood levels were monitored. The following data were retrospectively compared between the two groups at 1, 3, 6, 9, 12 months post-transplant: serum creatinine (sCr), urine protein per gCr (uP/Cr), the incidence of biopsy-proven acute rejection (BPAR), graft survival (GS), area-under-the-curve of blood levels of tacrolimus (TAC-AUC(0-12), ng h/mL) and mycophenolic acid (MPA-AUC(0-12), mu g h/mL), MMF dose (mg), the incidence of opportunistic infection, post-transplant diabetes mellitus (PTDM), and histopathologic findings of protocol biopsy according to the Banff '07 classification. Results: sCr and uP/Cr were comparable between the two groups up to 12 months except for sCr at one month (ESD group > CS group). TAC-AUC(0-12) was significantly higher in ESD group at one month but was equivalent thereafter, while the prevalence of biopsy-proven tubulotoxicity was not different. MMF dose was comparable throughout the period between two groups. The incidence of BPAR until 12 months was equivalent. Of note, 60% of BPAR cases in ESD group occurred within one month. Prevalence of opportunistic infection or PTDM was equivalent. Graft survival was 100% in both groups. The following histopathologic scores up to 12 months were also equivalent: t, i, g, v, ci, ct, cg, cv, mm, ah, and ptc. Conclusions: Favorable short-term outcomes were achieved both clinically and histologically using our early steroid discontinuation protocol compared with the conventional protocol with chronic steroid treatment.