[Electron microscopic studies on pathogenesis of idiopathic pulmonary fibrosis].
OBJECTIVE
To observe ultrastructural changes and study the pathogenesis of idiopathic pulmonary fibrosis.


METHODS
The clinical manifestations in 9 patients with idiopathic pulmonary fibrosis were selected. Transbronchial lung biopsy materials were obtained for light microscopic and electron microscopic examination.


RESULTS
The major morphologic changes were as follows: histologically, alveolar inflammation and interstitial fibrosis were observed. electron microscopic findings were: 1. alveolar type I cells were degenerated, broken-down and desquamated, endothelial cells were swelled, with inter cellular tight junction shortened, alveolar type II cells hyperplastic, basement membrane thinned and deformed; 2. alveolar macrophages and interstitial macrophages were hyperplastic; 3. mast cells were infiltrated and degranulated; 4. electron-dense deposits were present at alveolar wall; 5. myofibroblasts, fibroblasts, collagen and basement membrane like material were hyperplastic.


CONCLUSIONS
Electron microscopic observations show that the alveolar epithelial cells, endothelial cells and basement membrane are all injured, interstitial macrophages hyperplasia, mast cells infiltration and degranulation, electron-dense deposits at alveolar wall are present. These morphologic changes provide basis for formation of idiopathic pulmonary fibrosis.
Tang
X
X
Department of Electron Microscopy, The First Hospital, Beijing Medical University, Beijing 100034.
He
B
B
Li
G
G
Zhang
H
H
Chai
L
L
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008168:Lung / Q000648:ultrastructure*; D016676:Macrophages, Alveolar / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000209:etiology / Q000473:pathology*