Background: Rabbit anti-thymocyte globulin (rATG) is a depleting polyclonal antibody often used for induction following kidney transplantation to help prevent acute rejection. The optimal dosage remains unclear, but may depend on recipient risk factors for developing rejection. Known risk factors include PRA ≥20, presence of DSA's, history of previous transplant, African American recipients, & development of DGF or SGF.

The objectives of this study are to determine if low dose thymoglobulin induction (1mg/kg/day x 3 days) in low-risk kidney transplant recipients is a safe, cost-effective, non-inferior approach to conventional thymoglobulin dosing (1mg/kg/day x 5 days) in preventing acute rejection within 3 months after transplant.

Methods: A single center retrospective analysis of 135 low risk adult kidney transplant recipients who received rATG induction between July 1, 2010 – December 31, 2015. Exclusion criteria included those who were ≤ 18 years old, HIV positive, HCV positive, received combined kidney-liver transplant, or whose induction deviated from guidelines, or when outcome information was incomplete, or had risk factors for rejection (African American. DGF, SGF, previous transplant, +DSA, PRA>20%).

Results: Incidences of rejection within 3 months post-transplant were assessed for patients receiving a standard 5mg/kg rATG dose (n=57) compared with those who received a risk stratified 3mg/kg rATG dose (n=78). The groups had similar baseline characteristics, immunologic risk, and indications for rATG induction. The incidence of acute rejection was low and similar between the groups (0% for rATG of standard dose group vs 2.5% for risk-stratified rATG group, p=0.5). Risk stratified rATG dosing was associated with >$187,000 in direct cost savings between 3/2013 – 12/2015. Patient survival & all-cause graft survival did not differ between the groups. Incidences of CMV & BK virus infection & malignancy were also similar between the groups.

Conclusion: Our results suggest dose dependent thymoglobulin induction in risk stratified kidney transplant recipients is not inferior to conventional thymoglobulin dosing in preventing acute rejection within 3 months of transplant. Dose dependent thymoglobulin induction in risk stratified kidney transplant recipients is associated with lower costs, shorter length of hospitalizations, fewer hospital readmissions, & less infection or malignancy complications within 1-year of transplant.

CITATION INFORMATION: Gutman I, Misel M, McKay D, Hemming A, Kerr J, Mekeel K. Evaluation of Dose Dependent Rabbit Anti-Thymocyte Globulin Induction in Risk-Stratified Kidney Transplant Recipients. Am J Transplant. 2016;16 (suppl 3).

« Back to 2016 American Transplant Congress