title: Pathogenesis of hypersensitivity pneumonitis.
abstract: OBJECTIVE
  Hypersensitivity pneumonitis is a group of immunologically mediated diseases caused by an abnormal response to a wide variety of inhaled antigens. Its pathogenesis is complex and involves many immunological concepts. This review discusses recent advances in our understanding of the pathogenesis of hypersensitivity pneumonitis.
  
  
  RESULTS
  Over the last 3 years, several studies on the pathogenesis of hypersensitivity pneumonitis have been published. New antigens have been identified. We now have a better understanding of the role of inflammatory cells and mediators, and promoting and protective factors have been suggested.
  
  
  CONCLUSIONS
  Most of the mechanisms involved in the pathogenesis of hypersensitivity pneumonitis remain incompletely understood. Current and future findings will not only help our understanding of the disease and its prevention, but also improve its treatment.
authors.affiliation: Institute of Cardiology and Pneumology Research Centre, Laval University, Laval Hospital, Quebec, Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Girard
authors.forename: Evelyne
authors.initials: E
authors.lastname: Israël-Assayag
authors.forename: Yvon
authors.initials: Y
authors.lastname: Cormier
mesh_terms: D000542:Alveolitis, Extrinsic Allergic / Q000209:etiology* / Q000276:immunology / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D018925:Chemokines / Q000502:physiology; D016207:Cytokines / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism; D005609:Free Radicals / Q000009:adverse effects; D020022:Genetic Predisposition to Disease; D006801:Humans; D012907:Smoking / Q000009:adverse effects
chemical_list: D018925:Chemokines; D016207:Cytokines; D005609:Free Radicals