Antibodies to Endothelial Cells in Borderline Hypertension

Abstract

Background —Antibodies to endothelial cells (aECs) and to cardiolipin (aCLs) are implicated in autoimmune diseases like systemic lupus erythematosus vasculitis. β 2 -Glycoprotein 1 (β2GP1) is a cofactor for aCLs. The present study investigated the possible role of aECs, aCLs, and aβ2GP1 in borderline hypertension. Methods and Results —Seventy-three men with borderline hypertension (BHT) and 73 age-matched normotensive (NT) men (diastolic blood pressure, 85 to 94 and <80 mm Hg, respectively) were recruited from a population screening program. Antibody levels were determined by ELISA. Presence of carotid atherosclerosis was determined by B-mode ultrasonography, and 29 individuals had atherosclerotic plaques. BHT men had significantly higher aEC and aβ2GP1 levels of IgG class than NT control subjects ( P =0.029 and P =0.0001, respectively). aEC levels of IgM class were higher in BHT ( P =0.012), but not aβ2GP1 levels. There was no correlation between aCL levels and BHT. Individuals with atherosclerotic plaques had significantly higher aEC levels of both IgG ( P =0.042) and IgM subclasses ( P =0.018) than those without plaques, but no difference was found in aCL and aβ2GP1 levels. Endothelin and aECs of IgM class were significantly associated. Conclusions —We demonstrate the first evidence of a significant elevation of aEC and aβ2GP1 levels in borderline hypertension. These findings provide a new link between hypertension and atherosclerosis and indicate that humoral immune reactions to the endothelium may play an important role in both conditions.