Induction Treatment with Rabbit Antithymocyte Globulin versus Basiliximab in Renal Transplant Recipients with Planned Early Steroid Withdrawal

Study Objective. To compare the safety and efficacy of rabbit antithymocyte globulin (r-ATG) with basiliximab in renal transplant recipients for whom an early steroid withdrawal (ESW) regimen was planned. Design. Single-center, retrospective, cohort study. Setting. Tertiary care medical center, including inpatient hospital stays and outpatient nephrology clinics. Patients. Ninety-nine consecutive adult recipients of living- or deceased-donor renal transplants between January 1, 2004, and December 31, 2007, in whom ESW was planned and who received either r-ATG or basiliximab; patients receiving an extended-criteria kidney donation or a donation after cardiac death were excluded. Measurements and Main Results. All patients received mycophenolate mofetil and tacrolimus as maintenance therapy with planned ESW. Induction therapy was either r-ATG 1.5 mg/kg/day for 4 days (68 patients) or basiliximab 20 mg on postoperative days 0 and 4 (31 patients). The primary composite end point of biopsy-proven acute rejection (BPAR), graft loss, and death occurred in 6 patients (9%) and 9 patients (29%) in the r-ATG and basiliximab groups at 1 year after transplantation, respectively (p=0.01), with rates of 7% (5/68 patients) and 26% (8/31 patients) for BPAR (p=0.02), 0% and 3% (1/31 patients) for graft loss (p=0.31.), and 2% (1/68 patients) and 0% for patient death (p>0.99). Average time to first BPAR was significantly longer in the r-ATG group (mean +/- SD 151.4 +/- 82.9 vs 53.6 +/- 68.4 days, p<0.01). Kidney function at 12 months was similar between the two groups. Conclusion. Rabbit-ATG was associated with a lower frequency and delayed onset of BPAR compared with basiliximab in renal transplant recipients who received an ESW regimen.