Pretransplant angiotensin II type 1-receptor antibodies point to an increase in renal graft sub-intimal fibrosis in living- donor kidney transplant recipients

Abstract The association between anti-AT1Rabs and microvascular injury observed in antibody-mediated rejection has been described in kidney graft Biopsies (KGBx). Methods We herein describe the histopathologic findings of KGBx performed during the first year of transplantation (Tx) in 134 patients tested for pre-Tx anti-AT1Rabs in cryopreserved sera (04/2009 to 09/2013). Protocol KGBx before implantation (time-zero), 1 year after Tx and for cause KGBx were included. 21/134 Tx patients were anti-AT1Rab positive (≥17 U/mL); 7/21 experienced acute rejection. For comparison a control group with anti-AT1Rabs n  = 16) and without ( n  = 31) acute rejection was included. Results Preimplantation KGBx showed no differences in inflammatory and chronic findings, nor in subintimal fibrosis (25 vs 12.8%, p  = .42) between patients with anti-AT1Rabs ≥17 U/mL and those with vs. 27.6%, p  = .049) and extension (15.7 vs. 5.3, p  = .015) in anti-AT1Rabs ≥17 U/mL compared to anti-AT1Rabs p  = .012) and more importantly anti-AT1Rabs ≥ 30 U/mL (β12.1, 3.1 to 20.9, p Conclusion Our study findings have shown that anti-AT1Rab values ≥17 U/mL are significantly associated to sub-intimal fibrosis and a greater percentage of vessel occlusion in kidney graft biopsies obtained during the first year posttransplant, particularly in coexistence with inflammation and de novo DSA.