Fibroblast growth-stimulating activity in bronchoalveolar lavage fluid of patients with pulmonary sarcoidosis.

Increased fibroblast growth-stimulating activity (FGA) was found in bronchoalveolar lavage fluid (BALF) from sarcoidosis patients. For evaluation of the significance of FGA in disease activity and the pathophysiology of sarcoidosis, the FGA levels were compared with data on cellular analysis of BALF, serum angiotensin-converting enzyme (S-ACE) activity and chest radiograms. The FGA level was significantly higher in sarcoidosis patients with parenchymal involvement (radiological stages II and III) than in those without parenchymal involvement (radiological stage I). The FGA was positively correlated with albumin and fibronectin concentrations in BALF. However, it was not significantly correlated with the ratio of CD-4 + to CD-8 + T-lymphocytes in BALF or the S-ACE level, which are known to be useful in evaluating the disease activity of sarcoidosis. These results indicate that the diagnostic value of FGA is different from that of the lymphocyte subpopulations in BALF and S-ACE, and is useful in estimating the extent of parenchymal involvement in sarcoidosis.