Antiproteases are increased in bronchoalveolar lavage in interstitial lung disease

The present study evaluates different cellular and soluble components in the bronchoalveolar lavage (BAL) from patients with interstitial lung disease. We observed an increased T4/T8 lymphocyte ratio in BAL but not in blood from 24 patients with active pulmonary sarcoidosis compared to sixteen normal individuals and to eleven patients with inactive pulmonary sarcoidosis. Seven patients with hypersensitivity pneumonitis had a normal T4/T8 ratio. In the active sarcoidosis and hypersensitivity pneumonitis groups, alpha 1-Protease Inhibitor (alpha 1 PI) in BAL is significantly higher than in the normal group and a significant correlation between the two antiproteases (alpha 2-macroglobulin and alpha 1 PI) is observed. These data demonstrate that antiprotease levels (alpha 1 PI and alpha 2 M) are increased in the lower respiratory tract of patients with interstitial lung disease and that among cellular and soluble components of BAL, alpha 2 M represents a sensitive marker of the alveolitis.