[Pulmonary complications of Behcet's disease and Takayasu's arteritis]

Behçet's disease and Takayasu's arteritis are both forms of large vessel vasculitis involving autoreactive T cells active against HSP 60.

Behçet's disease is more common than Takayasu's arteritis. Pulmonary aneurysms represent the major complication of pulmonary Behçet's disease and have a poor prognosis, being associated with massive haemoptysis. In situ pulmonary artery thrombus can lead to pulmonary infarction. Superior vena cava thrombosis progresses slowly, allowing the development of a prominent collateral circulation. Vascular inflammation can spread to the mediastinum, the pleura and the lungs with diffuse pulmonary haemorrhages, bronchiolitis and organising pneumonia. Electron beam tomodensitometry and MRI are the best diagnostic techniques for assessing pulmonary vascular lesions. In Takayasu's arteritis the pulmonary arteries are less frequently involved than the aorta. Pulmonary hypertension (PHT) and lung infarcts can complicate pulmonary arterial involvement and the association of malaise, fever and weight loss with PHT is characteristic of the disease. The diagnosis is confirmed by imaging means, particularly MRI, demonstrating parietal vascular inflammation.

Treatment of both conditions is based upon steroids and immunosuppression. Endovascular treatment may be used in a complementary way for aneurysms, arterial occlusion, and vena cava obstruction. However, patients often respond poorly to treatment and clinical trials using TNFalpha blockade, interferon alpha and vasodilators are in progress.