Antielastases of the human alveolar structures. Implications for the protease-antiprotease theory of emphysema Academic Article uri icon


MeSH Major

  • Lung
  • Pancreatic Elastase
  • Pulmonary Emphysema
  • alpha 1-Antitrypsin Deficiency


  • The current concepts of the pathogenesis of emphysema hold that progressive, chronic destruction of the alveolar structures occurs because there was in imbalance between the proteases and antiproteases in the lower respiratory tract. In this context, proteases, particularly neutrophil elastase, work unimpeded to destroy the alveolar structures. This concept has evolved from consideration of patients with alpha 1-antitrypsin deficiency, who have decreased levels of serum alpha 1-antitrypsin and who have progressive panacinar emphysema. To directly assess the antiprotease side of this equation, the lower respiratory tract of non-smoking individuals with normal serum antiproteases and individuals with PiZ homozygous alpha 1-antitrypsin deficiency underwent bronchoalveolar lavage to evaluate the antiprotease screen of their lower respiratory tract. These studies demonstrated that: (a) alpha 1-antitrypsin is the major antielastase of the normal human lower respiratory tract; (b) alpha 2-macroglobulin, a large serum antielastase, and the bronchial mucous inhibitor, an antielastase of the central airways, do not contribute to the antielastase protection of the human alveolar structures; (c) individuals with PiZ alpha 1-antitrypsin deficiency have little or no alpha 1-antitrypsin in their lower respiratory tract and have no alternative antiprotease protection against neutrophil elastase; and (d) the lack of antiprotease protection of the lower respiratory tract of PiZ individuals is a chronic process, suggesting their vulnerability to neutrophil elastase is always present.

publication date

  • December 14, 1981



  • Academic Article



  • eng

PubMed Central ID

  • PMC370876

PubMed ID

  • 6169740

Additional Document Info

start page

  • 889

end page

  • 98


  • 68


  • 4