Plasma auto-antibodies to angiotensin II receptors are correlated with blood pressure and inflammatory factors in hypertension patients

Abstract

Auto-antibodies against to angiotensin II type 1 receptor (AT1R-AA) have been discovered in patients with hypertension and they have a close relationship with inflammatory factors. However, auto-antibodies to angiotensin II type 2 receptor (AT2R-AA) are seldom investigated in hypertension. Subjects ( n = 138) were enrolled and divided into three groups according to their blood pressure levels by using the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) criteria: normotensive (≤120/80 mmHg, n = 31), pre-hypertensive (120–139/80–89 mmHg, n = 39), and hypertensive (≥140/90 mmHg, n = 68) groups. Plasma AT1R-AAs and AT2R-AAs were detected by enzyme-linked immunosorbent assay. Plasma tumour necrosis factor-α (TNF-α), endothelin-1 (ET-1), and angiotensin II (Ang II) were measured by radioimmunity assay. (i) Plasma AT1R-AAs were positively correlated with systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), TNF-α, ET-1, and Ang II. (ii) AT2R-AAs were negatively correlated with SBP, DBP, MAP, TNF-α, ET-1, Ang II, as well as uric acid and serum creatinine. (iii) TNF-α, ET-1, Ang II (all P < 0.01, when compared with the normotensive group), blood uric acid, and serum creatinine (both P < 0.05, when compared with the normotensive group) increased with BP level. (iv) Multiple linear regression analyses showed that age, AT1R-AAs, AT2R-AAs, and ET-1 were independent predictors for SBP. AT1R-AAs, AT2R-AAs, and ET-1 were independent predictors for DBP. AT1R-AAs, AT2R-AAs, ET-1, and Ang II were independent predictors for MAP. Plasma AT1R-AAs and AT2R-AAs play an important role in hypertension progression. AT2R-AAs are inversely related to renal dysfunction.