A Prospective Study of Acute Clinical and Subclinical Rejection in a Rapid Steroid Withdrawal Protocol.

Abstract

Purpose: To estimate the incidence and risk factors for acute clinical rejection (CR) and subclinical rejection (SCR) and evaluate response to therapy. Methods: We prospectively followed all adults who underwent kidney transplantation between 1/1/2013 - 9/30/2013 at our center. All received thymoglobulin(94%) or simulect(6%) induction, CNI/MPA maintenance therapy and rapid steroid withdrawal by day 7. Protocol biopsy was performed at 3 months post transplant. Five pts expired within 3 months of transplant and were excluded. Remaining 138 were divided into 4 groups. Gr I (N=15) had SCR on protocol biopsy and received therapy. Gr II (N=62) no rejection. Gr III (n=16) had acute CR on indication biopsy. Gr IV (n=45) did not undergo biopsy. Banff classification was followed for biopsy grading. Steroids and/or thymoglobulin were used for acute T-cell rejection and PP/IVIG for acute AMR. Recipient demographics, transplant and post-transplant variables, serum creatinine (1, 3 and 6 months) were compared using t-test and chi-square test. Results: The incidence of SCR was 16%(15/93) and CR was 11.6%(16/138). The distribution of variables are as shown.Table: No Caption available.No statistical difference was noted for all variables among the groups. Creatinine was higher in patients with CR at the time of the biopsy. There was a trend towards decline in creatinine from 1 to 6 months in Gr 1 and 3 (p = NS). Conclusion: This prospective study revealed the incidence of acute CR to be 11.6% and SCR to be 16% with mainly thymoglobulin induction and CNI/MPA based maintenance therapy with rapid steroid withdrawal. This immunosuppressive regimen was associated with high incidence of combined CR and SCR (at 3 months post-transplant). Protocol biopsy helps identify early acute rejection and optimize therapy to stabilize short-term renal function. Longer follow up with larger cohort size is required to estimate long-term outcome.