The respiratory system in connective tissue disorders.

The connective tissue disorders (also called collagen vascular diseases) represent an heterogeneous group of immunologically mediated inflammatory disorders with a large variety of affected organs besides the lungs. The respiratory system may be involved in all its components: airways, vessels, parenchyma, pleura, respiratory muscles, etc. The frequency, clinical presentation, prognosis and response to therapy vary, depending on the pattern of involvement as well as on the underlying connective tissue disorders. The subject of this review is to describe the most frequent type of lung disorders observed in patients with connective tissue disease (CTD). We will focus on the most frequent CTD: systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's syndrome, dermatopolymyositis and mixed CTD.