RA is associated with endothelial cell dysfunction (ECD) and increased cardiovascular mortality and morbidity. Circulating endothelial cells (CECs) are a novel marker of severe endothelial damage. We hypothesized altered CECs in patients with RA compared with community controls (CCs) and hospital controls (HCs, with diabetes and hypertension) correlate with established plasma markers of inflammation and of ECD.
CECs (CD146-immunobeads), von Willebrand factor, soluble E-selectin, soluble intercellular adhesion molecule-1, soluble vascular endothelial adhesion molecule-1 (sVCAM, all ELISA) and C-reactive protein (CRP, immunonephelometry) were measured in 57 patients with RA, 45 CC and 23 HC patients.
CECs in RA [median/interquartile range 8 (5-13.5) cells/ml] were elevated compared with either CC [4 (2-8.5) cells/ml] or HC [4 (1-8) cells/ml] (both P < 0.001). Levels of CECs did not correlate with other markers of ECD or of inflammation but did correlate inversely with sVCAM.
Evidence of endothelial damage in the form of mildly increased numbers of CECs is present in RA and is independent of plasma markers of inflammation and of ECD.