[Interstitial lung disease in connective tissue diseases].

Interstitial lung disease (ILD) may occur in the connective tissue diseases, with a negative impact on survival. The diagnosis of ILD is established by crackles of the lung bases at auscultation, and high resolution computed tomography of the chest demonstrating diffuse opacities predominating in the bases (ground glass opacities, reticular opacities, honeycombing, and traction bronchiectases). Bronchoalveolar lavage mostly contributes to the differential diagnosis. Video-assisted thorascopic lung biospy is seldom required for clinical management. Clinically significant ILD occurs in 25% of patients with systemic sclerosis, 7-30% in patients with dermatopolymyositis (especially with antisynthetase antibodies including anti-Jo-1 antibodies, often with a subacute onset), and 5% of patients with rheumatoid arthritis. Nonspecific interstitial pneumonia (with fibrosis) is the predominating histopathological pattern in systemic sclerosis and dermatopolymyositis; a pattern of usual interstitial pneumonia is frequent in rheumatoid arthritis (with a clinical and radiological presentation similar to that of idiopathic pulmonary fibrosis). ILD of various presentations may occur in Sjögren syndrome, possibly associated with thin-walled cysts; pulmonary lymphoma must be ruled out. Little information is available regarding treatment of ILD in connective tissue disease. Clinically modest short-term efficacy of cyclophosphamide treatment has been shown in systemic sclerosis, but was not maintained at 2 years.