Clinical and subclinical alveolitis in collagen vascular diseases: contribution of alpha 2-macroglobulin levels in BAL fluid.

The probability that patients with collagen vascular diseases (CVD) will develop fibrosis is unpredictable. Since changes in bronchoalveolar lavage (BAL) cell data can be observed in CVD patients without evidence of lung involvement, we investigated whether the study of soluble components in BAL could help to distinguish CVD patients with lung involvement (n = 15) from those without pulmonary disease (n = 37). Our results demonstrate that the alveolitis observed in patients with overt lung involvement is associated with an increase of BAL alpha 2-macroglobulin (alpha 2-MA). In contrast, the BAL alpha 2-MA levels were found to be normal in CVD patients without evidence of pulmonary disease as well as in CVD patients with overt lung involvement treated with steroids. This was observed even in the presence of high neutrophil or lymphocyte counts in BAL. In conclusion, when neutrophils or lymphocytes accumulate in the lungs of CVD patients without evidence of lung damage, in the majority of patients this cell accumulation is not associated with an increase of BAL soluble components.