Acute rejection characteristics from a prospective, randomized, double-blind, placebo-controlled multicenter trial of early corticosteroid withdrawal.

Background: This report characterizes acute rejection and rejection outcomes in subjects randomized to continuous corticosteroid therapy (CCS) or early corticosteroid withdrawal (CSWD; 7 days after transplantation) in the Astellas Blinded CSWD Trial.

Methods: The Astellas Blinded CSWD Trial was a 5-year, prospective, multicenter, randomized, double-blind trial of early CCS withdrawal in 386 kidney transplant recipients (195 CCS and 191 CSWD). Tacrolimus and mycophenolate mofetil were required as well as either rabbit antithymocyte globulin or interleukin-2 receptor antibody induction. Biopsy-confirmed acute rejection (BCAR) was grade 1A or higher by Banff criteria. This report also provides borderline changes (BL) that did not meet Banff grade 1A included with BCAR (BCAR+BL).

Results: BCAR+BL was 25 (12.8%) in CCS group and 42 (22.0%) in CSWD group (P=0.022). Early BCAR+BL (first 90 days after transplantation) was less frequent in CCS (n=5 [2.6%]) than in CSWD (n=22 [11.5%]; P<0.001). Among non-African-American subjects, early BCAR+BL occurred more often in CSWD (n=20 [12.7%]) versus CCS (n=2 [1.3%]; P<0.001). Late acute rejection (>2 years) occurred more often in African-American subjects in CCS (n=5 [13.9%]) than in CSWD (n=0; P=0.056). Risk factors were CSWD (hazard ratio [HR], 4.72; P<0.002) and human leukocyte antigen mismatch (HR, 1.48; P<0.005) for early BCAR+BL and CSWD (HR, 1.9; P<0.02), human leukocyte antigen mismatch (HR, 1.2; P<0.01), and age (HR, 0.97; P<0.002) for 5-year rejection. The HR for graft loss associated with BCAR+BL was 8.8.

Conclusions: BCAR+BL may occur more frequently during the early period after transplantation under an early CSWD regimen with tacrolimus plus induction compared with CCS, particularly among non-African-Americans.