Low levels of endothelial progenitor cells correlate with disease duration and activity in patients with Behçet's disease

We tested whether Behçet's disease (BD) is characterized by alterations of circulating endothelial progenitor cells (EPCs),which are involved in vascular homeostasis and repair.We enrolled 30 BD patients and 27 matched healthy controls. EPCs were defined and measured by flow cytometry according to the expression of CD34, CD133 and KDR.We show that BD patients had significantly lower levels of CD34+KDR+ and CD34+CD133+KDR+ EPCs than controls. We found significant negative correlations between EPC phenotypes and BD duration, while there were positive correlations between CD34+KDR+ EPCs and both BD activity scores and C-reactive protein. The lower EPC levels with increasing disease duration was shown in univariate analysis and in multivariable analysis adjusted for possible confounders.This is the first report that BD is associated with progressive EPC decline. Reduction of EPCs may represent a mechanism of induction and/or progression of vascular injury in these patients.