Architectural remodelling in acute and chronic interstitial lung disease: fibrosis or fibroelastosis?
OBJECTIVE
Pulmonary fibrosis in acute and chronic lung disease has been much investigated, but little attention has been directed at the elastic tissue in these situations. Our aim was to verify whether elastic deposition accompanies collagen deposition in the repairing process of acute and chronic lung injury.


RESULTS
We measured, by image analysis, the content of fibres of the collagenous and elastic systems of the alveolar septum in histological slides sampled from autopsied lungs, using the picrosirius-polarization method and Weigert's resorcin-fuchsin stain, respectively. Five groups were studied: I, 10 normal patients; II, 10 patients with cardiogenic pulmonary oedema; III, 23 adult respiratory distress syndrome (ARDS) patients in the early phase; IV, 14 ARDS patients in the late fibroproliferative phase; and V, 10 idiopathic pulmonary fibrosis patients. The first two groups were used as controls. The content of fibres of the collagenous and elastic systems was significantly increased in groups IV and V as compared to the other groups.


CONCLUSIONS
Our results indicate that deposition of elastic system fibres is present in the fibroproliferative phase of ARDS and in usual interstitial pneumonia and suggest that this event may contribute to the alveolar mechanical dysfunction and remodelling that occur in acute and chronic interstitial lung disease.
Negri
E M
EM
Department of Pathology, Clinical Hospital, The University of São Paulo School of Medicine, Brazil. enegri@ibm.net
Montes
G S
GS
Saldiva
P H
PH
Capelozzi
V L
VL
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003094:Collagen / Q000378:metabolism; D004547:Elastic Tissue / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017563:Lung Diseases, Interstitial / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D011654:Pulmonary Edema / Q000378:metabolism / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000378:metabolism / Q000473:pathology*; D012128:Respiratory Distress Syndrome / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies
D003094:Collagen