Vascular Behçet's syndrome: an update.

Behçet's syndrome (BS) is a complex vasculitis, characterised by peculiar histological, pathogenetic and clinical features. Superficial venous thrombosis (SVT) and deep vein thrombosis (DVT) are the most frequent vascular involvements, affecting altogether 15-40% of BS patients. Atypical thrombosis is also an important clinical feature of BS, involving the vascular districts of the inferior and superior vena cava, suprahepatic veins with Budd-Chiari syndrome, portal vein, cerebral sinuses and right ventricle. On the other hand, arterial involvement, although affecting only 3-5% of patients, represents a unique feature of BS, with aneurysms potentially affecting peripheral, visceral and pulmonary arteries. Vascular events in BS are promoted by inflammation, with neutrophils playing a key role in the pathogenesis of thrombotic events; in turn, coagulative components such as fibrinogen, thrombin, factor Xa and factor VIIa amplify the inflammatory cascade. Understanding the contribution of inflammatory and coagulation components in the pathogenesis of BS vascular events is crucial to define the most effective therapeutic strategy. Control of vascular thrombosis is achieved with immunosuppressants drugs rather than anticoagulants. In particular, use of azathioprine and cyclosporine in association with low-dose corticosteroids should be considered in DVT and SVT cases, while treatment with cyclophosphamide together with anti-TNF-α agents can be effectively used in arterial involvement. More recently, the anti-TNF-α drugs have also been reported as a valid alternative for the treatment also of venous events, especially DVT. An exception to the use of anticoagulant in BS could be represented by cerebral veins thrombosis. In this review, we will depict the main characteristics of the vascular involvement in BS, briefly describing histological and pathogenetic features, while focusing on the clinical and therapeutical approaches of the vascular manifestations of BS.