Anti-angiotensin II type 1 receptor autoantibodies (AT₁R-AAs) in patients with systemic sclerosis: lack of association with disease manifestations

Angiotensin II type 1 receptor autoantibodies (AT₁R-AAs) are known to be associated with malignant hypertension, preeclampsia, and vascular rejection in kidney transplantation. They were also suspected to have pathogenetic role in vasculopathic changes in systemic sclerosis (SSc). Clinical data regarding AT₁R-AAs in SSc are scarce. In this work, we will examine the relationship between serum levels of AT₁R-AAs and disease manifestations. Serum samples from SSc patients and healthy controls were analyzed for AT₁R-AAs by using a commercial ELISA kit. We examined the association of serum levels of AT₁R-AA with disease duration, systolic pulmonary artery pressure (sPAP) measurements, and disease manifestations like cutaneous, lung and esophageal involvements, and the presence of digital ulcers in a cross-sectional manner. There was no statistically significant difference in levels of AT₁R-AAs between SSc (n = 93) patients and healthy controls (n = 66) (p = 0.23). Serum levels of AT₁R-AAs were not correlated with disease duration, sPAP measurements, and showed no association with disease manifestations like lung involvement, esophageal involvement, digital ulcers, and cutaneous fibrosis. In our SSc cohort, AT₁R-AA serum levels were not different from healthy subjects and higher levels were not associated with any disease manifestation neither.