Subclinical lung inflammation in primary Sjögren's syndrome. Relationship between bronchoalveolar lavage cellular analysis findings and characteristics of the disease.

To directly evaluate whether a subclinical alveolar inflammation is associated with primary Sjögren's syndrome (SS), we evaluated the distribution of cells obtained by bronchoalveolar lavage (BAL) from the lower respiratory tract in 29 patients who had primary SS, but who were free of clinical pulmonary symptoms and had normal findings on chest roentgenograms. There was no difference in total cell counts of specimens from patients versus those of controls. An abnormal differential cell count was noted in 16 patients (55%). Two patterns of alveolitis were observed: a pure lymphocyte alveolitis (greater than 18% lymphocytes, present in 11 patients) and a neutrophil alveolitis (greater than 4% neutrophils, present in 5 patients). There was associated lymphocytosis in 4 of the patients with neutrophil alveolitis. All patients had normal results on pulmonary function tests. Patients with abnormal BAL findings showed clinical and biologic indexes of more severe disease than did those with normal BAL results, as demonstrated by greater extraglandular extension of the disease, higher mean values of serum gamma globulins and serum beta2-microglobulin, and higher prevalence of rheumatoid factor and of antinuclear antibody. Thus, our data demonstrate that BAL permitted the detection of subclinical inflammatory alveolitis in 55% of our patients with primary SS. A long-term followup is required to determine whether these patients will develop obvious pulmonary involvement.