P054 Comparison of anti-angiotensin II type 1 receptor antibody response in desensitization versus natural history of transplant candidates

Aim We have previously reported that more than half of HLA-sensitized renal transplant candidates also exhibit anti-angiotensin II type 1 receptor antibody (AT1R-Ab). AT1R-Ab has been associated with antibody-mediated rejection and worse allograft survival. The aim of the present study was to prospectively compare the natural evolution of AT1R-Ab levels with response to desensitization therapy. Methods Ninety-three patients receiving desensitization therapy (VDS group, N  = 23) or without desensitization therapy (non-VDS group, N  = 70) had AT1R-Ab levels determined ELISA (U/mL after 1:50 dilution), before and after desensitization (VDS group) or before and after transplantation (non-VDS group). Results Initial AT1R-Ab levels were higher in VDS (17.64 ± 10.62 U/mL) then in non-VDS group (13.01 ± 9.14 U/mL, p p  = 0.0003), when compared to non-VDS group (13.01 ± 9.14 U/mL before transplantation versus 11.94 ± 9.79 U/mL after transplantation, p  = 0.13 – see figure). AT1R-Ab levels were more elevated in Caucasians then in African-Americans both before (20.7 ± 14.9 versus 12.3 ± 3.7 U/mL, p  = 0.1), and after desensitization (14.7 ± 15.9 versus 5,2 ± 2.9 U/mL, p  = 0.1). Conclusions More than half of HLA-sensitized candidates exhibit AT1R-Ab. This initial desensitization experience consistently provided substantial reductions of AT1R-Ab levels in an unselected, highly sensitized kidney transplant candidate population, reduction that is more pronounced that post-transplant natural antibody dynamics. Download high-res image (104KB) Download full-size image