Endothelial functions in Behçet's disease.

Behçet's disease (BD) is a systemic vasculitis, capable of involving all types of vessels. Endothelial dysfunction (ED) has been previously documented in BD. The aim of the study was to see whether ED was more prominent in Behçet's patients with vascular involvement (VI) than in those without. The study population consisted of 65 patients with BD, 27 of whom had VI, and 30 healthy controls. High-resolution ultrasound was used to measure endothelium-dependent vasodilatation (EDVD) of brachial artery. Overall, regardless of VI, EDVD was significantly impaired in patients with BD compared with controls (11.4 +/- 6.3 vs 20.4 +/- 9.1%,P = 0.001); however, EDVD was similar in BD patients with and without VI (9.7 +/- 6.3% vs 12.6 +/- 6.1%, P = 0.07). Patients with BD had significantly-higher plasma homocysteine levels than controls (13 +/- 6 micromol/L vs 9 +/- 3 micromol/L, P = 0.001). Plasma homocysteine levels were significantly higher in the subgroup with VI than in those without (15 +/- 7 micromol/L vs 12 +/- 4 micromol/L, P = 0.03); however, we found no positive/significant correlation between plasma homocysteine levels and EDVD. ED is a constant feature of BD, regardless of VI. Etiology of ED in BD is probably multifactorial, including high homocysteine levels. As both ED and elevated homocysteine levels may represent an early atherosclerotic process, a more structured approach to risk factor assessment is needed in BD.