[Impaired balance of the lung proteolytic system in patients with pneumoconiosis and chronic dust-induced bronchitis].

The activity of neutrophilic elastase and the level of its major inhibitor--an alpha 1-inhibitor of proteinases were studied to evaluate the protease-antiprotease system in the bronchoalveolar lavage fluid (BALF) of patients with chronic dust-induced bronchitis (CDB) and pneumoconiosis (PC). It was found that CDB, as compared with PC, was characterized by a higher elastase activity in the BALF (70%) and that there were a larger number of patients with elastase activity (40%), which correlated with the detection rate of emphysema. Free elastase activity and relative proteinase alpha 1-inhibitor deficiency suggest that the BALF protease-antiprotease system is impaired in patients with CDB and PC, which is more pronounced in patients with CDB.