Y. Fukuda et al., SIGNIFICANCE OF EARLY INTRAALVEOLAR FIBROTIC LESIONS AND INTEGRIN EXPRESSION IN LUNG-BIOPSY SPECIMENS FROM PATIENTS WITH IDIOPATHIC PULMONARY FIBROSIS, Human pathology, 26(1), 1995, pp. 53-61
To study the pulmonary structural remodeling in idiopathic pulmonary f
ibrosis (IPF), ultrastructural, immunohistochemical, and light microsc
opic molphometric observations were made on 11 pulmonary biopsy specim
ens from patients with IPF. The morphometric study was done using sequ
entially cut tissue sections stained for keratin-alcian blue periodic
acid-Schiff (PAS), fibronectin, and type IV collagen-alcian blue PAS.
Most of the early fibrotic lesions, which were alcian blue- and fibron
ectin-positive, were intra-alveolar in location. Intra-alveolar fibros
is is considered to be essential for the fusion of alveolar walls in I
PF. A strong reaction for integrin alpha 5 beta 1 and vinculin was fou
nd in epithelial cells and mesenchymal cells in areas of intra-alveola
r fibrosis. These finding show that these cells are active in adhesion
to fibronectin in areas of early intra-alveolar fibrosis. Some of the
epithelial cells, including cytoplasmic hyaline-laden cells, showed e
vidence of inadequate adhesion to the extracellular matrix, and this m
ay constitute one of the mechanisms of progression of fibrosis in IPF.
HUM PATHOL 26:53-61. Copyright (C) 1995 by W.B. Saunders Company