Influence of Induction Modality on the Outcome of Deceased Donor Kidney Transplant Recipients Discharged on Steroid-free Maintenance Immunosuppression

Background: Over last several years, alemtuzumab induction has been increasingly used in kidney transplantation especially in patients maintained on steroid-free immunosuppression. It is unclear which induction agent is associated with better graft and patient outcomes in these patients.

Methods: Using Organ Procurement and Transplant Network/United Network of Organ Sharing database, graft and patient survivals were compared with multivariate analysis for deceased donor kidney transplant recipients from January 2000 to December 2008 who received induction with rabbit-antithymocyte globulin (r-ATG), alemtuzumab, or an interleukin-2 (IL-2) receptor blocker and were discharged on a calcineurin inhibitor/mycophenolate mofetil/steroid-free immunosuppression.

Results: When compared with r-ATG (n=5348), adjusted graft survival was inferior with alemtuzumab (n=2428, hazards ratio [HR] 1.26, 95% confidence interval [CI] 1.10-1.43, P=0.001) and IL-2 receptor blocker (n=1396, HR 1.19, 95% CI 1.01-1.39, P=0.04) inductions and patient survival was inferior with alemtuzumab (HR 1.29, 95% CI 1.08-1.55, P=0.006). Alemtuzumab induction was associated with higher adjusted graft failure risks in patients with panel reactive antibody more than 20% (HR 1.30, 95% CI 1.01-1.68, P=0.04), recipients of expanded criteria donor kidneys (HR 1.58, 95% CI 1.23-2.02, P<0.001), and kidneys with cold ischemia time more than 24 hr (HR 1.31, 95% CI 1.04-1.65, P=0.02) and higher patient death risks in recipients of expanded criteria donor kidney (HR 1.66, 95% CI 1.20-1.30, P=0.002) and kidneys with cold ischemia time more than 24 hr (HR 1.44, 95% CI 1.04-2.00, P=0.03). Adjusted graft survival rates were similar for different induction agents in the low-immune risk group.

Conclusions: When compared with alemtuzumab and IL-2 receptor blocker, r-ATG induction seems to be associated with superior outcomes in deceased donor kidney transplant recipients maintained on calcineurin inhibitor/mycophenolate mofetil/steroid-free regimen.