Presentation and Outcomes of Antibody-Mediated Rejection Associated With Angiotensin II Receptor 1 Antibodies Among Kidney Transplant Recipients

Background. It remains challenging to manage antibody-mediated rejection (ABMR) associated with angiotensin II type 1 receptor antibodies (AT1R-Abs) in kidney transplant recipients and the outcomes are not well defined. We describe the presentation, clinical course, and outcomes of this condition. Methods. This retrospective study included kidney transplant recipients with AT1R-Ab levels >10 units/mL and biopsy-proven ABMR in the absence of significant HLA-donorspecific antibodies at the time of rejection. Results. We identified 13 recipients. Median creatinine (Cr) at rejection was significantly higher (2.05 mg/dL) compared with baseline (1.2 mg/dL), P = .006. After ABMR management, the difference in median Cr was not significant (1.5 mg/dL), P = .152. Median AT1R-Ab level was higher in the pretransplant sample (34.5 units/mL) compared with the level at rejection (19 units/mL) and after rejection treatment (13 units/mL); however, these differences were not significant, P = .129. Eight of the 13 recipients received antibody reduction therapy with plasmapheresis and intravenous immunoglobulin, and 5 of the 13 recipients had other therapies. After rejection management, 6 of the 13 recipients had improvement in Cr to baseline and 7 of the 13 recipients had > 50% reduction in proteinuria. Conclusions. AT1R-Ab-associated ABMR management and outcomes depend on the clinical presentation and may include antibody-reducing therapies among other therapies. Further prospective cohorts will improve recognizing and managing this condition.