Lattimore, ShereneSkill, Nicholas J.Maluccio, Mary A.Elliott, HollyDobben, ElizabethShafuddin, AsifGoggins, William C.2020-01-072020-01-072019-09-27Lattimore, S., Skill, N. J., Maluccio, M. A., Elliott, H., Dobben, E., Shafuddin, A., & Goggins, W. C. (2019). Antithymocyte Globulin Antibody Titer Congruent With Kidney Transplantation: Analysis of Incidence, Outcomes, Cost, and Alternative Targets. Transplantation direct, 5(10), e493. doi:10.1097/TXD.0000000000000933https://hdl.handle.net/1805/21766Rabbit antithymocyte globulin (rATG) use for immunosuppression induction is widespread but is contraindicated by the presence of anti-rATG antibodies. This study reports the incidence of positive anti-rATG antibody titers in patients before and after renal transplant and evaluates associated outcomes and costs. In addition, it will correlate CD40L and interleukin (IL)-21 with anti-rATG antibody titers. Methods: Clinical and billing records from the Indiana University Transplant Laboratory were reviewed for positive versus negative anti-rATG antibody titers, graft survival, and 7-day readmission costs between 2004 and 2018. Serum from patients with positive and negative rATG antibody titers were quantitated for CD40L and IL-21 by enzyme-linked immunosorbent assay. Results: On average, between 2004 and May 2018, 163 kidney transplants per year were performed. Anti-rATG antibody titers were ordered for 17 patients/year, of which 18.2% were positive at 1:100 titer either pre- or post-transplant. Time to graft loss correlated with a positive rATG titer at time of readmission. Moreover, second kidney transplant increased the anti-rATG positive rate. A weak correlation was observed between anti-rATG titer and recipient age. Seven-day readmission treatment costs were significantly lower in patients with positive anti-rATG titer. IL-21 and CD40L were significantly greater in patients with positive anti-rATG titers after transplant when compared with negative anti rATG patients. Conclusions: Positive anti-rATG antibody titer is associated with a significant negative impact on outcomes. Monitoring of anti-rATG antibody titer is recommended to optimize treatment options in patients, especially in the setting of second transplants. Elucidation of the mechanisms associated with positive anti-rATG antibody is required. IL-21 and CD40L are potential targets for future study.en-USRabbit antithymocyte globulin (rATG)Immunosuppression inductionAnti-rATG antibodiesRenal transplantArticle