CONCENTRATION OF SOLUBLE VASCULAR CELL-ADHESION MOLECULE-1 (VCAM-1) CORRELATED WITH EXPRESSION OF VCAM-1 MESSENGER-RNA IN THE HUMAN ATHEROSCLEROTIC AORTA

Background: Adherence of circulating monocytes and lymphocytes to arte rial endothelium is detectable early in experimental and human atheros clerotic plaque formation. The purpose of the present study was to ass ess vascular cell adhesion molecule-1 (VCAM-1) mRNA expression and the properties of soluble VCAM-1 in patients with atherosclerotic aortic disease. Methods: Thirteen patients with aortic disease (mean age 64 y ears) and 40 healthy volunteers (mean age 32 years) were included in t he study. We investigated the expression of VCAM-1 mRNA in eight human aortic specimens obtained during surgery. Of these, two showed no evi dence of atherosclerotic plaque formation [aortic dissection (n=1) and annuloaortic ectasia (n=1)], whereas six had demonstrable complex ath erosclerotic formation [abdominal aneurysm (n=5) and aortic dissection (n=1)]. The RNase protection assay was performed using an alpha(32)P- labeled 121 base pair VCAM-1 cRNA probe. We also measured concentratio ns of the soluble VCAM-1 using two-site enzyme immunoassays in 40 heal thy volunteers and in 13 patients with abdominal and thoracic aortic a neurysms. Results: In human samples, VCAM-1 mRNA expression was found to be higher in the six patients with complex atherosclerotic formatio n [optical density (OD), 0.71+/-0.14] than in the two patients with no evidence of atherosclerotic plaque formation (OD, 0.53 and 0.49). The concentration of serum soluble VCAM-1 was higher (850+/-298 ng/ml) in patients with aortic or thoracic disease than in the healthy voluntee rs (494+/-94 ng/ml). In addition, there was a relationship between VCA M-1 mRNA expression and the concentration of soluble VCAM-1 (y = 2088x -554, r(2) = 0.73). Conclusion: VCAM-1 expression is higher in the hum an aorta in patients with atheromatous changes. Furthermore, concentra tions of soluble VCAM-1 may provide important information about endoth elial activation or in-vivo damage.