A quantitative study of collagen and elastin content in human lung tissue has been made in relation to a morphometric measure of airspace size. The subjects included non-smokers, smokers with and without macroscopic emphysema and three subjects with alpha 1-protease inhibitor (α1-Pi) deficiency. Airspace size was determined morphometrically as Alveolar Wall surface area per Unit Volume of lung (AWUV). The results were as follows: 1. There were no significant differences in AWUV, collagen content or elastin content between the upper and lower lobes with a single lung from both a non-smoker and a smoker without macroscopic emphysema. 2. Analysis of 102 samples from 9 smokers' lungs with no signs of macroscopic emphysema showed significant negative correlations between AWUV and collagen content and between AWUV and elastin content such that as the surface area of alveolar wall per unit volume decreased there was an increase in both the collagen and elastin content of the remaining alveolar tissue. 3. In tissue samples from 14 non-smokers there was no significant correlation between age and collagen content or between AWUV and collagen content. 4. Samples taken from smokers' lungs where either macroscopic centriacinar emphysema or panacinar emphysema or a mixture of centriacinar and panacinar emphysema were present were found to have a significantly higher collagen content than samples from non-smokers. 5. Tissue samples from the lungs of three α1-Pi deficient subjects had a significantly higher collagen content than samples from a non-smoker. In view of these findings the definition of emphysema, which states that no obvious fibrosis is present, may have to be revised.
|Fiaux, Gerald W.
|University of Edinburgh
|Electronic Thesis or Dissertation
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