Plasma homocysteine level and uveitis in Behçet's disease

Behçet's disease is a chronic relapsing systemic vasculitis of unknown origin in which orogenital ulceration, skin lesions and uveitis are prominent features. Patients with BD have been recognized to be at greater risk for vascular diseases such as thrombosis and aneurysms. Uveitis in BD is usually accompanied by retinal vaso-occlusive disease.

To investigate the possible role of hyperhomocysteinemia as a prethrombotic disorder in the development of uveitis.

The study population consisted of 29 patients with BD (13 males and 16 females with a mean age of 32.3 years, range 21-52) and 24 healthy controls. All patients fulfilled the criteria of the International Study Group for BD. The patients were categorized as having active (n = 8) or inactive disease (n = 11) or only uveitis (n = 10). Plasma fasting homocysteine and C-reactive protein levels were studied in all patients and controls. The fasting homocysteine level was significantly higher in patients with only uveitis than in inactive patients and controls (P = 0.029 and P = 0.26 respectively). It was also higher in patients with active disease compared to healthy controls (P = 0.,001). However, no significant difference was found between homocysteine levels of patients with active or inactive disease (P = 0.69). CRP, as a marker of disease activity, was higher in active BD and in patients with only uveitis than in controls (P = 0.01 and P = 0.001 respectively).

Homocysteine may play a role in ocular involvement of BD. Chronic inflammation can induce hyperhomocysteinemia, thereby leading to thrombosis in the retinal vascular bed in a way similar to that recently proposed for the pathogenesis of coronary artery disease.