MO012IS IT SAFE TO USE INTERLEUKIN-2 RECEPTOR ANTAGONIST INDUCTION THERAPY IN 2DR MISMATCH RENAL TRANSPLANTS IN TACROLIMUS ERA?

Abstract Background and Aims 2DR HLA mismatch indicates high immunological risk renal transplant. Induction therapy with rabbit Anti-thymocyte Globulin (r-ATG) and IL-2 Receptor Antagonist (IL-2RA) resulted in marked reduction of acute allograft rejection rate and improved graft survival. However, the outcomes in 2DR (HLA-DR) mismatched renal transplant recipients (RTRs) in the era tacrolimus-mycophenolate mofetil maintenance immunosuppression remains understudied. Method Using data from the United States organ procurement and transplantation network, all 2 DR mismatched RTRs with panel reactive antibodies <20% maintained on tacrolimus and mycophenolate mofetil immunotherapy between 2000 and 2017 were retrospectively reviewed. Data including age, sex, gender, ethnicity, functional status, diabetes, body mass index, cold ischemia time, number of previous transplants, panel reactive antibodies, donor type, donor age, HLA-mismatches, number of acute rejection episodes, induction therapies, maintenance immunotherapy, recipients and graft survival were collected. Based on induction therapies administered, RTRs were divided into 2 groups: (r-ATG) and IL-2RA groups. Poisson regression analysis was used to assess effect of induction therapies on acute rejection episodes. Cox hazard regression analysis was used to assess effect of different induction therapies on patient and graft survival Results 3379 patients received IL2-RA while 3677 patients received ATG for induction. There were no significant differences between both groups in terms of acute rejection episodes (95% CI ranges from 0.95 to 1.068, P=0.805), graft survival (95% CI: 0.91 - 1.06, P=0.712), or patient survival (95% CI: -0.949 - 1.12, P=0.43) . Conclusion This study revealed no significant difference in acute rejection episodes, patient or graft survival when utilizing ATG vs IL-2RA in 2DR HLA mismatched renal transplant recipients with PRA<20%, in the tacrolimus-based maintenance immunosuppression era. Therefore, IL2-RA is a safe induction therapy in this group of patients and non-inferior to –ATG induction therapy.