Micromycetes of indoor environment are the source of allergens

Background. Sensitization to mould reaches 64% in frequency in some regions of the Earth. Data on indoor mycobiota influence on sensitization of patients with genetic predisposition to atopy are fragmentary and conflicting. The aim of this work is to establish a relationship between patient indoor exposure to mould and sensitization to mould allergens in Irkutsk.
Methods. A total of 63 patients with persistent allergic rhinitis (AR), were examined in Irkutsk during 2006-2007. 43 patients had AR and atopic bronchial asthma (BA). Allergological examination included skin pricktests with standard allergen panel and nasal provocation tests. 69 Irkutsk" dwellings of allergic patients sensitive to moulds and non-allergic people were examined. House dust from these 69 dwellings were analyzed for fungi. Results. 76 fungal species from 20 genera were isolated from house dust of Irkutsk. Micromycetes concentration varied from 103 to l06 GFU/g of dust. The most frequent genera were Venicillium (92,8%), Aspergillus (85,5%), Cladosporium (40,6%) and Alternaria (40,6%). Prevalence of positive skin prick-tests and nasal provocation tests was as follows: Cladosporium - 65 and 60%, Venicillium - 60 and 58%, Aspergillus - 39% and 32%, Alternaria - 21 and 9% respectively. Principal-factor analysis revealed a relation between fungal concentration in patients' indoor environment and their sensitization to mould allergens. However a correlation between micromycetes concentration and sensitization to mould is expressed to a variable extent in every particular case. Conclusion. Cladosporium and Venicillium are the most common mould allergens for patients with BA and/or AR in Irkutsk. There is a relation between fungal concentration and sensitization of patients to mould allergens.

mould allergens, sensitization, mould, indoor mycobiota