Von Willebrand factor, endothelial damage and ocular disease

Plasma von Willebrand factor (vWF), a marker for vascular damage, was measured in patients with giant cell arteritis (GCA), central retinal vein occlusion (CRVO), and active intraocular inflammation (AII), vWF was highest in GCA (median 3.52 kIU/L) relative to age matched controls (1.08 kIU/L, p<0.0001), with elevated levels in 75% of patients, the highest values found at disease presentation. Longitudinal measurements showed prolonged elevation of vWF, and increased levels were also found in 50% of patients with clinically inactive disease. In CRVO, raised levels were found in 53% of patients (median 2.32 kIU/L, p = 0.0002), but could not differentiate between an ischaemic and non-ischaemic sub-group. There was no statistical difference between those patients with and without systemic disease. Although vWF was raised in 34% of patients with AII (median 1.26 kIU/L, p = 0.0114), it was not different in uveitis (median 1.26 kIU/L), as compared to retinal vasculitis (median 1.58 kIU/L) or in those patients with and without systemic disease. vWF did not correlate with C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) in any of the groups studied. It appears a sensitive test for detecting vascular damage in GCA and may have a role in monitoring the disease where either a prolonged elevation or alteration of vWF levels may be of importance, particularly if ESR and CRP levels are normal. vWF measurement may be limited to more widespread vascular disease, such as in GCA as it was unable to differentiate between different types of CRVO or AII.