Hypersensitivity pneumonitis.
OBJECTIVE
To bring readers up to date on recent reports, both clinical and basic understanding, on hypersensitivity pneumonitis.


RESULTS
Although many antigens and environmental settings have already been described as sources of this hyperimmune pulmonary disease, the literature continues to bring forth other conditions that can cause hypersensitivity pneumonitis. We also highlight new findings in the diagnosis of hypersensitivity pneumonitis, its histopathology, insight into its potential outcomes, and understanding of its immune mechanisms that could lead to new treatments.


CONCLUSIONS
The review will help clinicians in their diagnostic approach to hypersensitivity pneumonitis and lead them to look for other potential sources of the disease. The findings described will help guide further research on the pathophysiology and seek new treatments for this worldwide orphan disease.
Girard
Mélissa
M
Centre de recherche de l'Institut universitaire de Cardiologie et de Pneumologie de Québec, Quebec City, Quebec, Canada.
Cormier
Yvon
Y
D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D000946:Antigens, Fungal / Q000276:immunology*; D001985:Bronchial Provocation Tests; D003937:Diagnosis, Differential; D004781:Environmental Exposure / Q000009:adverse effects; D005355:Fibrosis; D005658:Fungi / Q000276:immunology*; D006098:Granulocytes / Q000276:immunology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology; D011379:Prognosis; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging / Q000473:pathology*; D013902:Radiography, Thoracic; D013601:T-Lymphocytes / Q000276:immunology*
D000946:Antigens, Fungal