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

Introduction. Angiotensin 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. Methods. From 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 prefoimed human leukocyte antigeon (HLA) antibodies were tested with anti-AT1R antibody assay. Forty-two control patients without rejection also were analyzed. Results. The 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. Conclusion. Anti-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.