© 2020 Verduci Editore s.r.l. All rights reserved.OBJECTIVE: The pathogenesis of primary hypertension (HT) is still not completely clear, although autoimmunity has been implicated in recent years. Carbonic anhydrase (CA) is an enzyme involved in a number of important metabolic processes. CA I and II autoantibodies have been linked to various autoimmune diseases. However, CA I and II autoantibody levels in primary HT have not been previously investigated. The purpose of this study was, therefore, to investigate levels of CA I and II autoantibodies in primary HT. PATIENTS AND METHODS: Fifty-six patients newly diagnosed with primary HT and 33 healthy individuals were included in the study. Twenty- four-hour ambulatory blood pressure monitoring was performed following office controls. Blood specimens were collected under appropriate conditions for CA I and II autoantibody level investigation and biochemical tests. Urine sodium and protein excretion were measured after 24 h. Demographic and biochemical parameters and CA I and II autoantibody levels were then compared between the patient and healthy groups. RESULTS: CA II autoantibody and uric acid levels were significantly higher in the hypertensive group than in the control group (p=0.005, and p<0.001, respectively). CA II autoantibody (exp ß: 79.06 CI: 4.44-1407.02) (p=0.003) and uric acid elevation (exp ß: 2.10 CI: 1.31- 3.34) (p=0.002) were identified as independent predictors of HT development at logistic regression analysis. CONCLUSIONS: CA II autoantibody levels were higher in hypertensive patients, and this elevation is an independent predictor of HT development.