Management of hypersensivity pneumonitis
1 Theramed Medical Center, Spatarul Luca Arbore 16, 500112, Brasov, Romania
2 Faculty of Medicine, Transylvania University Brasov, Department of Allergy and Clinical Immunology, 500112, Brasov, Romania
3 Faculty of Medicine, Transylvania University Brasov, Department of Fundamental and Prophylactic Medical Science, 500112, Brasov, Romania
Clinical and Translational Allergy 2013, 3:5 doi:10.1186/2045-7022-3-5Published: 4 February 2013
Hypersensitivity pneumonitis (HP) is an interstitial lung disease due to a combined type III and IV reaction with a granulomatous inflammation, caused by cytotoxic delayed hypersensitivity lymphocytes, in a Th1/Th17 milieu, chaperoned by a deficient suppressor function of T regulatory cells. Skewing toward a Th2 phenotype is reported for chronic HP. Phenotypic expression and severity depends on environmental and/or host genetic and immune co-factors. The wide spectrum of causative antigens is continuously up-dated with new sources of airborne organic particles and drug-induced HP. The diagnosis requires a detailed history, measurement of environmental exposure, pulmonary function tests, imaging, detection of serum specific antibodies, broncho-alveolar lavage, antigen-induced lymphocyte proliferation, environmental or laboratory-controlled inhalation challenge and lung biopsy. Complete antigen avoidance is the best therapeutic measure, although very difficult to achieve in some cases. Systemic steroids are of value for subacute and chronic forms of HP, but do not influence long term outcome. Manipulation of the immune response in HP holds future promise.