Farmer's lung

Farmer's lung (not to be confused with silo-filler's disease) is a hypersensitivity pneumonitis induced by the inhalation of biologic dusts coming from hay dust or mould spores or other agricultural products.^[1] It results in a type III hypersensitivity inflammatory response and can progress to become a chronic condition which is considered potentially dangerous.^[2] Whilst inhaled allergens often provoke the creation of IgE antibodies that circulate in the bloodstream, these types of immune response are most often initiated by exposure to thermophilic actinomycetes (most commonly Micropolyspora faeni and less commonly Saccharopolyspora rectivirgula), which generates IgG-type antibodies. Following a subsequent exposure, IgG antibodies combine with the inhaled allergen to form immune complexes in the walls of the alveoli in the lungs. This causes fluid, protein and cells to accumulate in the alveolar wall which slows blood-gas interchange and compromises the function of the lung.^[3]

References

1. ^ Enelow, RI (2008). Fishman's Pulmonary Diseases and Disorders (4th ed.). McGraw-Hill. pp. 1161–1172. ISBN 0-07-145739-9. 
2. ^ http://nasdonline.org/document/1663/d001538/farmer-039-s-lung-it-takes-your-breath.html
3. ^ Walport, M (2008). Janeway's immunobiology (7th ed.). Garland Science. pp. 585. ISBN 9780815341451.