Cellular and Connective Tissue Changes in Alveolar Septal Walls in Emphysema

Details

• Personal Author:
  Crapo JD ; Mercer RR ; Russell ML ; Vlahovic G
• Description:
  Emphysema is commonly defined as enlargement of airspaces distal to terminal bronchioles accompanied by destruction of alveolar walls, but without obvious fibrosis. Morphometric techniques were used to correlate changes in components of the alveolar septa surrounding enlarged airspaces in human emphysema with the mean linear intercept (Lm) of those airspaces. Alveolar and capillary surface density decreased with increased Lm, but the ratio of these surface densities to each other remained close to normal for mild to moderate increases in Lm. This suggests that the decreased gas exchange observed in emphysema is initiated by a total loss of septa and not by selective pathological changes of the microvasculature. Increases in septal wall thickness directly correlated with increases in Lm. For the mild to moderate emphysema lesions included in this study, an increase of 100% in Lm correlated with a 130% increase in the relative volume of the alveolar septal interstitium. Significant increases occurred in both elastin (0.14 to 0.56 microm(3)/microm(2) basement membrane [BM]) and collagen (0.49 to 1. 63 microm(3)/microm(2) BM). The increase in elastin and collagen raises the possibility of a remodeling process in the connective matrix in alveolar walls. Whether or not the new connective tissue represents a disordered, nonfunctional regional response needs to be determined. [Description provided by NIOSH]
• Subjects:
  Chronic Disease Lung Lung Diseases Occupational Health Respiratory System Respiratory Tract Diseases Safety
• Keywords:
  Alveolar-cells Chronic-degenerative-diseases Lung-disorders Lung-tissue Pulmonary-system-disorders Respiratory-system-disorders
• ISSN:
  1073-449X
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Colorado ; North Carolina ; OSHA Region 3 ; OSHA Region 4 ; OSHA Region 8 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  160
• Issue:
  6
• NIOSHTIC Number:
  nn:20025375
• Citation:
  Am J Respir Crit Care Med 1999 Dec; 160(6):2086-2092
• Contact Point Address:
  James D. Crapo, M.D., National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206
• Email:
  CRAPOJ@njc.org
• Federal Fiscal Year:
  2000
• Peer Reviewed:
  True
• Source Full Name:
  American Journal of Respiratory and Critical Care Medicine
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1d6e5c46735b7b71479e921811d74f5f6bb8319f8208717f4645e15c4357844f4cd186fbb5d9412ded93f64bce2fe297d3a89648c7ab59671a545703300abdd9
• Download URL:
  https://stacks.cdc.gov/view/cdc/196774/cdc_196774_DS1.pdf
• File Type:
  [PDF - 958.08 KB ]