Interstitial lung disease in primary Sjögren syndrome. 
Primary Sjögren syndrome (pSS) has been associated with various histologic patterns of interstitial lung disease (ILD).  We retrospectively identified 18 patients with pSS and suspected ILD who underwent lung biopsies (14 surgical biopsies and 9 bronchoscopic biopsies) at our institution during a 13-year period from 1992 through 2004.  Histopathologic findings were analyzed and correlated with radiologic features and outcome.  Median age was 62 years (range, 34 to 78 years), and 15 patients (83%) were women.  Most patients presented with dyspnea and cough.  Chest radiographs demonstrated bilateral infiltrates, and high-resolution CT revealed abnormalities of various types including ground-glass, consolidation, reticular, and nodular opacities.  The major histopathologic patterns included nonspecific interstitial pneumonia (NSIP) [five patients], organizing pneumonia (OP) [four patients], usual interstitial pneumonia (UIP) [three patients], lymphocytic interstitial pneumonia (three patients), primary pulmonary lymphoma (two patients), and diffuse interstitial amyloidosis (one patient).  In four patients (three with OP and one with amyloidosis), the diagnosis was established on transbronchial biopsy results.  Treatment commonly included prednisone with or without another immunosuppressive agent.  During the follow-up period (median, 38 months), most patients improved or remained stable except three patients with UIP, one patient with NSIP, and one patient with amyloidosis.  Seven patients (39%) died, including three deaths from acute exacerbation of interstitial pneumonia.  A variety of histologic patterns can be seen in patients with pSS-associated ILD.  Those with UIP tended to have progression of lung disease.  Death from acute exacerbation of interstitial pneumonia may occur in patients with pSS-associated ILD.