Exposure, sensitization, and mechanisms of fungus-induced asthma.
Healthy individuals are continuously exposed to fungal biomass, which includes live and dead spores and fungal debris that is entrapped in the airways. In patients with asthma and/or atopy, exposure to fungal biomass might result in age-dependent sensitization and asthmatic reactions. Interaction with Toll-like receptors (TLRs) of the innate immune defense (alveolar macrophages and epithelial cells) and protease-activated receptors (PARs) determine the effectiveness of elimination of fungal material. The association of sensitization to Alternaria with severe asthma is discussed in relation to the age-dependent sensitization, rate of release of allergens from spores, and activity of its proteases. A model is described concerning the influence of polymorphic genes for airway hyperresponsiveness (AHR) and atopy, showing a cumulating influence on susceptibility for allergen-induced asthma, and explaining that fungus-induced airway obstruction is mainly associated with more severe asthma.
Kauffman
Henk F
HF
Department of Allergology, Clinic for Internal Medicine, University Hospital Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands. h.f.kauffman@path.azg.nl
van der Heide
Sicco
S
D000391:Air Microbiology; D001249:Asthma / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D004781:Environmental Exposure / Q000009:adverse effects*; D004847:Epithelial Cells / Q000276:immunology; D020022:Genetic Predisposition to Disease; D006801:Humans; D003904:Mitosporic Fungi / Q000302:isolation & purification*; D020545:Respiratory Mucosa / Q000276:immunology; D013172:Spores, Fungal / Q000302:isolation & purification