Markers of Endothelial Cell Activation/Injury: CD146 and Thrombomodulin Are Related to Adiponectin in Kidney Allograft Recipients

Abstract

Background: Adiponectin may be used for assessing the risk of coronary artery disease (CAD) and may be related to the development of acute coronary syndrome. Decreased adiponectin has been associated with some risk factors for cardiovascular diseases such as male sex, obesity and diabetes mellitus. Adiponectin has antiatherogenic properties and attenuates endothelial inflammatory responses. CD146, a novel cell adhesion molecule, is localized at the endothelial junction. In kidney allograft recipients, endothelial dysfunction and atherosclerosis are almost universal. The aim of this cross-sectional study was to evaluate possible relations between adiponectin, CD146, and other markers of endothelial cell injury in 82 stable kidney transplant recipients (mean age 45 years, mean time after transplantation 47 months) with and without CAD. Methods: Adiponectin and markers of endothelial injury: CD146, von Willebrand factor, thrombomodulin, ICAM, CD40L, P-selectin and other hemostatic markers were assessed using commercially available kits. Results: Patients with CAD had evidence of more pronounced endothelial dysfunction, procoagulant state and lower adiponectin than patients without CAD. Adiponectin correlated significantly, in univariate analysis, with CD146 (r = 0.29, p = 0.009), thrombomodulin (r = 0.37, p = 0.001), protein Z (r = –0.25, p = 0.03), BMI (r = –0.26, p = 0.047), serum creatinine (r = 0.26, p = 0.02) and urea (r = 0.38, p = 0.001). CD146 correlated significantly with von Willebrand factor (r = 0.33, p = 0.002), thrombomodulin (r = 0.25, p = 0.025), age (r = 0.34, p = 0.001), platelets (r = –0.33, p = 0.002), serum urea (r = 0.24, p = 0.039), cholesterol (r = 0.24, p = 0.046), ICAM (r = 0.23, p = 0.036), protein C activity (r = –0.26, p = 0.019) and tended to correlate with serum creatinine and time after transplantation. In multivariate linear regression, independent predictors of adiponectin were CD146, thrombomodulin and urea, and of CD146 was mainly age of patients. Conclusions: Endothelial dysfunction and procoagulant state are more pronounced in kidney transplant recipients with CAD, particularly in those with lower GFR. In kidney transplant recipients, markers of endothelial cell injury are significantly increased relative to healthy volunteers. Elevation of adiponectin may be a defense mechanism against endothelial damage, reflected by elevated CD146 and thrombomodulin.