Soluble Fas ligand plasma levels are associated with forearm reactive hyperemia in subjects with coronary artery disease: a novel biomarker of endothelial function?

OBJECTIVES: Fas ligand expression by endothelial cells is downregulated under proinflammatory conditions, facilitating the vascular infiltration by circulating cells. We have analyzed whether the forearm vasodilatory response to reactive hyperemia is associated with soluble Fas ligand (sFasL) plasma concentrations in subjects with coronary artery disease (CAD).
METHODS: Forearm blood flow to reactive hyperemia, an indicator of endothelial function, and forearm blood flow to nitroglycerin (endothelial-independent) were measured in 110 subjects with stable CAD. sFasL and C-reactive protein (CRP) concentrations were also determined.
RESULTS: There was a linear trend for the increase of sFasL and forearm reactive hyperemia (p<0.001). In contrast, no association was observed between sFasL and forearm blood flow to nitroglycerine. sFasL was not related with the presence of cardiovascular risk factors. Partial correlation coefficient adjusted by age and gender remained significant between sFasL and forearm blood flow to reactive hyperemia (r=0.35; p<0.001). No association between CRP concentrations and forearm reactive hyperemia, forearm blood flow to nitroglycerin or sFasL plasma concentrations was noted.
CONCLUSIONS: Our results are consistent with the hypothesis that sFasL levels could reflect endothelial function in subjects with CAD and suggest that sFasL plasma concentrations could be a potential biomarker of endothelial function.