Pulmonary involvement in Sjögren syndrome.

Sjögren syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic inflammation of exocrine glands and a variety of extraglandular sites. Lung involvement as defined by symptoms and either pulmonary function testing or radiographic abnormalities occurs in approximately 10 to 20% of patients. Subclinical lung disease is even more frequent and often includes evidence of small airways disease and airway inflammation. In general, patients will have evidence of both airway and interstitial lung disease by radiographs and pathology. Bronchiolitis and bronchiectasis are the most common airway manifestations while the interstitial pathologies associated with SS include nonspecific interstitial pneumonitis, usual interstitial pneumonitis, and lymphocytic interstitial pneumonitis. Patients with SS are also at an increased risk of lymphoma. A protean of other lung abnormalities including amyloidosis, granulomatous lung disease, pseudolymphoma, pulmonary hypertension, and pleural disease have been described.