[Extracellular components of bronchoalveolar lavage fluid (BALF) as a marker of interstitial pulmonary disease activity. I. Protein concentration].

In interstitial pulmonary diseases a passive transudation of protein into an alveolar space takes place as well as local synthesis of protein by cells in alveolar space and protein leaking out of destroyed cells. Concentration of protein in BALF was assessed in 170 patients with interstitial pulmonary diseases and in 18 healthy persons by means of colorimetric method with Coomassie Blue. Patients were divided into 8 groups: active untreated sarcoidosis, inactive untreated sarcoidosis, active sarcoidosis after corticotherapy, inactive sarcoidosis after corticotherapy, avian fanciers' lung in the period of contact with the antigen, avian fanciers' lung after one year's interval in exposure to the antigen, advanced idiopathic pulmonary fibrosis, and moderate idiopathic pulmonary fibrosis. In the group with active forms of diseases the increase of protein concentration in BALF was observed. The increase was statistically significant compared with the results in the control group and in the groups with inactive forms of the diseases. Protein concentration in BALF may play the role as marker of activity in interstitial pulmonary diseases.