Is elevated level of soluble endothelial protein C receptor a new risk factor for retinal vein occlusion?

To evaluate the systemic and thrombophilic risk factors for retinal vein occlusion (RVO) and to determine whether the elevated level of soluble endothelial protein C receptor (sEPCR) is a risk factor for thrombosis.

In this case-control study, 56 patients with central RVO (CRVO), 26 patients with branch RVO (BRVO) and 78 healthy sex- and age-matched subjects were enrolled. Following ophthalmological examination, venous blood was analysed for glucose, lipid profile, lipoprotein (a), homocysteine, activated partial thromboplastin time, fibrinogen, factor VIII, protein C activity, protein S activity, activated protein C resistance, antithrombin III activity, lupus anticoagulant, anti-cardiolipin antibody, anti-phospholipid antibody, sEPCR, factor V Leiden mutation and prothrombin G20210A mutation.

Apart from hypertension, glaucoma, lipoprotein (a), homocysteine and factor VIII, elevated levels of sEPCR were found to be a risk factor for CRVO (odds ratio, 1.02; 95% confidence interval, 1.007-1.028; P = 0.001). Patients with CRVO had significantly higher levels of sEPCR than those with BRVO and controls (respectively, 160.1 +/- 83.8, 116.8 +/- 65.2 and 111.3 +/- 60.5; P = 0.005). Moreover, 39% of patients with CRVO had levels of sEPCR more than 200 ng/mL, and only 5% of controls and 11% of patients with BRVO had similar high levels.

Besides known classical risk factors, elevated levels of sEPCR seem to be an important candidate risk factor for especially CRVO.