The presence of Sjögren's syndrome is a major determinant of the pattern of interstitial lung disease in scleroderma and other connective tissue diseases.

A number of patients with scleroderma, Sjögren's syndrome and other connective tissue diseases (CTD) were assessed to ascertain the prevalence of respiratory abnormalities as defined by bronchoalveolar lavage (BAL), standard respiratory function studies and gallium scan of the lung, and the relationship of these abnormalities to the presence or absence of dyspnea. These results suggest that respiratory symptoms are very common in CTD and in scleroderma, particularly if Sjögren's syndrome is also present. Our findings also suggest the presence of 2 patterns of interstitial lung involvement in scleroderma. In scleroderma alone this appears to be characterized by the presence of increased neutrophil proportions in the BAL, decreased DLCO, and no increase in gallium uptake within the lung. Where scleroderma is associated with Sjögren's syndrome, there is an increase in the proportion of lymphocytes in the BAL and respiratory symptoms are very prominent, the latter associated with an increase in gallium uptake within the lung. This suggests that Sjögren's is a major determinant of the pattern of interstitial lung disease seen in CTD.