Investigation of Fibronectin in Biopsied Bronchial Tissues

In Bronchial Asthma and the other Bronchopulmonary Diseases

Abstract

The observation of fibronectin in the basement membranes of bronchial mucosa in 43 specimens biopsied bronchoscopically from patients with bronchial asthma (18 cases), chronic bronchitis (4 cases), lung cancer (11 cases), lung tuberculosis (one case), lung fibrosis (2 cases) and control subjects (7 cases) was done by the direct immunofluorescence staining method.
The results were as follows.
1) Fibronectin staining was observed in the bronchial basement membranes of twelve of the 18 patients with bronchial asthma and of two of the four patients with chronic bronchitis, but only two of the 14 patients with other bronchopulmonary diseases and the seven control subjects.
2) In bronchial asthma, there was no correlation of clinical type (atopic, infectious, and mixed) and fibronectin staining in the bronchial basement membranes.
3) Fibronectin staining in the bronchial basement membrane was observed in nine of the 13 cases whose biopsied bronchial tissues showed the thickening of basement membrane, but in only two of the 17 cases whose bronchial tissues showed no thickening of basement membranes.
4) Fibronectin staining in the bronchial basement membrane was observed in ten of the 15 cases whose biopsied bronchial specimens revealed fibrinogen staining in the basement membrane, but in five of the 26 cases whose bronchial specimens revealed no fibrinogen staining.
From these results it was suggested that increase in fibronectin in the bronchial basement membranes correlated to thickening of the basement membranes and deposition of fibrin, and that fibronectin in the bronchial basement membranes may be involved in repeated destruction and repair of bronchial mucous tissues.