The risk of acute rejection and the influence of induction agents in lower‐risk African American kidney transplant recipients receiving modern immunosuppression

Abstract

While kidney transplant recipients of African American (AA) descent are frequently considered at increased risk of acute rejection, the value of induction therapy is not defined in settings of lower immunologic risk and modern immunosuppression. Using the Scientific Registry of Transplant Recipients database, we identified 23,244 primary kidney transplant recipients with panel-reactive antibody (PRA) = 0% treated with TAC/MPA and prednisone from 2000 to 2008. We compared acute rejection, graft survival (GS), and patient survival rates among AA and non-AA and further stratified by induction therapy (none, IL2ra, or rATG). One-yr acute rejection was higher in AA than in non-AA overall (14.5% vs. 9.9%, hazard ratio [HR] for acute rejection [AR] 1.43, p < 0.0001) and was higher regardless of induction agent use. Induction therapy was associated with a reduction in AR, but no benefit in GS in AA or non-AA. In AA, rATG (adjusted relative risk [RR] 0.81, CI 0.70-0.94) and IL2ra (adjusted RR 0.80, CI 0.68-0.93) were similarly effective in reducing AR rates, but did not reach comparable outcomes as in non-AA. African Americans who are at otherwise lower immunologic risk have a higher risk of rejection despite modern immunosuppression. Depleting or non-depleting induction therapy similarly reduces but does not entirely mitigate this increased risk, with no impact on three-yr GS.