Frontiers in TransplantationKidney transplantationAnti-Angiotensin Type 1 Receptor Antibodies Associated With Antibody-Mediated Rejection in Patients Without Preformed HLA-Donor-Specific Antibody

•The frequency of increased anti-AT1R was higher in patients with AMR compared with controls (P = .03, OR = 8.0).•It was also higher in patients with AMR+ACR (P = .03, OR = 12.0).•There was no difference in frequencies of elevated anti-AT1R antibody in patients with ACR.

IntroductionAngiotensin II is a peptide hormone involved in the renin-angiotensin system (RAS). Anti-angiotensin receptor 1 (AT1R) antibodies are implicated in stimulating RAS and are suspected to have some adverse impacts on renal transplantation outcome.MethodsFrom November 2009 to February 2012, 37 remaining sera from renal transplantation recipients with biopsy-proven antibody-mediated rejection (AMR) (n = 6), acute cellular rejection (ACR) (n = 23), and AMR + ACR (n = 8) without preformed human leukocyte antigeon (HLA) antibodies were tested with anti-AT1R antibody assay. Forty-two control patients without rejection also were analyzed.ResultsThe frequency of elevated anti-AT1R antibodies was higher in patients with AMR (n = 14) compared to controls (28.6% vs 4.9%, P = .03, OR = 8.0). It was also higher in patients with AMR + ACR (n=8) (37.5% vs 4.9%, P = .03, OR = 12.0). There was no difference in frequencies of elevated anti-AT1R antibody in patients with ACR.ConclusionAnti-AT1R antibodies were suspected to be associated with occurrence of AMR without preformed HLA antibodies in renal transplantation. Further studies in a larger number of patients are needed.