Clinical and subclinical alveolitis in connective tissue diseases assessed by bronchoalveolar lavage

Subclinical alveolitis, as assessed by bronchoalveolar lavage (BAL) cell analysis,may be present in the lower respiratory tract of a high proportion of symptom-less patients with connective tissue diseases (CTDs) with normal chest roentgenograms. The distribution of BAL cell types, mainly macrophages, lymphocytes, and polymorphonuclear neutrophils, varies according to type of CTD and to the presence of associated interstitial lung disease (ILD). Neverthe-less, subclinical alveolitis can be classified into two major groups: lymphocyte and neutrophil alveolitis. A mixed, lymphocyte and neutrophil alveolitis may be detected as well. Subclinical alveolitis, particularly in systemic sclerosis, frequently is associated with abnormalities of lung parenchyma as assessed by computed tomography (CT) scan, supporting the hypothesis that it may be associated with the development of overt ILD. Close follow-up of these patients is needed to better determine whether subclinical alveolitis precedes ILD and whether early detection of subclinical alveolitis in CTDs may identify those patients who are at risk for the development of ILD in the future.