Soluble endothelial protein C receptor levels in Behçet patients with and without ocular involvement

The protein C system is an important natural anticoagulant mechanism. Endothelial cell-activated protein C receptor (EPCR), which was discovered at the surface of endothelial cells, binds protein C and enhances its activation. The soluble form of EPCR (sEPCR) has been detected in plasma. Behçet's disease is a chronic inflammatory disorder affecting multiple organs. Arterial and venous thrombosis is a common clinical manifestation of Behçet's disease and the pathogenic mechanism of thrombotic tendency in the disease is not well known. The aim of this study is to determine sEPCR concentrations in Behçet patients with and without ocular involvement as well as to investigate the association between sEPCR levels and clinical manifestations of Behçet's disease.

Sixty patients with Behçet's disease and 67 healthy control subjects were included in this study. A complete ophthalmic examination was performed by ophthalmologists with an interest in Behçet's disease. Sixty patients with Behçet's disease were divided into two groups. Group 1 consisted of 30 patients with ocular involvement and Group 2 consisted of 30 patients without ocular involvement. Soluble EPCR levels were determined in plasma by using sEPCR Asserachrom enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer's instructions. Differences of the mean sEPCR levels between groups were evaluated using Mann-Whitney U-test. Pearson's correlation analysis was used for evaluating the correlation between sEPCR levels and age, gender, duration of the disease as well as different clinical manifestations of Behçet's disease.

Age and gender ratio were not different between patients and controls. Plasma sEPCR concentrations were significantly higher in patients with Behçet's disease than those in controls (p<0.05). There was no statistically significant difference in serum sEPCR levels between the patients with versus the ones without ocular involvement. There were no statistically significant correlations between sEPCR levels and age, gender, duration of the disease or clinical manifestations.

Our data suggests a possible role of soluble EPCR in the pathogenesis of Behçet's disease. Further studies by possible mutations and polymorphisms in EPCR gene in patients with Behçet's disease would be useful to bring to light the pathogenic mechanism of ocular and systemic vascular complications of the disease.