Comparing the noninfectious adverse effects of two rabbit anti-thymocyte globulin immunosuppression in kidney transplantation: a multicenter, retrospective study.

Background: Rabbit anti-thymocyte globulin (rATG) is widely used for induction immunosuppression in kidney transplantation; however, its administration carries some adverse effects. This study aimed to detect the incidence of thromboembolic events (TEEs) after kidney transplantation and the causality relationship between these events and rATG administration as induction therapy.

Methods: This multicenter retrospective study included 654 kidney recipients from six Iranian centers receiving [Thymoglobulin® (rATG-A) or TGlobulin25™ or (rATG-B)]. Outcomes included TEEs within 30 days post-transplant, hematologic adverse effects, and graft-related outcomes. Risk factors were analyzed using multivariable regression.

Results: TEEs occurred in 4.9% of patients, with no significant difference between rATG-A (4.0%) and rATG-B (5.9%) (p = 0.26). Independent risk factors included peripheral rATG infusion without heparin (p < 0.001), preexisting thromboembolic risk conditions (p < 0.001), cytomegalovirus (CMV) infection (p = 0.01), and recipient age >40 years (p = 0.02). No inter-band difference in thromboembolic risk was observed (odds ratio = 1.63, 95% confidence interval 0.71-3.76). Delayed graft function, rejection, mortality, and nephrectomy rates showed no inter-group differences.

Conclusion: TEEs happened in about 5% of the patients. Peripheral administration of rATG without adding heparin, history of underlying diseases predisposing to TEEs, CMV infection, and recipient age over 40 years were found as risk factors for the occurrence of TEEs.