title: Proteases and lung injury.
abstract: OBJECTIVE
  Acute respiratory distress syndrome (ARDS) represents an inflammatory process that is initiated by diverse systemic and/or pulmonary insults, resulting in a clinical syndrome of severe respiratory distress and refractory hypoxemia. Neutrophils and their cytotoxic products, including oxidants and proteases, such as elastase, have been implicated as playing a key role in the pathophysiology of ARDS. This article reviews some of the physiologic actions of proteases, specifically elastase, the evidence for neutrophil elastase involvement in ARDS, and the potential therapeutic use of neutrophil elastase inhibitors in lung injury.
  
  
  METHODS
  A review of published literature (original articles and reviews) in English from 1965 to 2002.
  
  
  CONCLUSIONS
  Although the data support a key role for neutrophil elastase in the pathogenesis of ARDS, further study is needed to fully define the actions of neutrophil elastase, and how these actions affect host functions, before we can exploit this knowledge for therapeutic benefit.
authors.affiliation: Division of Respiratory Medicine, Department of Paediatrics, Hospital for Sick Children, and Institute of Medical Sciences, Faculty of Medicine, the University of Toronto, Ontario, Canada.
authors.forename: Theo J
authors.initials: TJ
authors.lastname: Moraes
authors.forename: Chung-Wai
authors.initials: CW
authors.lastname: Chow
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Downey
mesh_terms: D006801:Humans; D007249:Inflammation / Q000150:complications; D019272:Leukocyte Elastase / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000502:physiology; D008666:Metalloendopeptidases / Q000378:metabolism / Q000502:physiology; D012128:Respiratory Distress Syndrome / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology
chemical_list: D019272:Leukocyte Elastase; D008666:Metalloendopeptidases