Antithymocyte globulin dosing effects on biopsy-proven acute rejection and infection risk.

Background: Antithymocyte globulin (rATG) is a polyclonal antibody commonly used as induction therapy in kidney transplantation to reduce risk of allograft rejection. Currently there is no consensus on the optimal dosing. rATG is not FDA approved for induction therapy, so no dosing recommendations are provided by the manufacturer. Current kidney transplant guidelines do not provide dosing recommendations. The objective of this study was to evaluate effects of different cumulative doses of rATG on rejections and infection rates.

Material And Methods: This was a retrospective, single-center chart review that included 142 renal transplant patients from January 2007 to October 2012 who received either 3 or 5 doses of rATG.

Results: The primary outcome of biopsy-proven acute rejection (BPAR) was not significantly different between the 3-dose and 5-dose groups, (6.1% versus 7.4%, p=NS). No significant difference was seen between the 3-dose and 5-dose groups in regards to bacterial infections (33.9% versus 40.7%, p>0.05) or BK viremia (24.3% versus 18.5%, p>0.05). However, in regards to CMV viremia there was a significantly higher incidence in the 5-dose group (37% versus 15.7%, p=0.47).

Conclusions: Five doses of rATG versus 3 doses did not provide any additional benefit in preventing BPAR.