Inflammatory And Allergenic Aspects Of Common Indoor Molds

Common indoor and foodborne fungi are known to produce hundreds of allergens and mycotoxins which can cause allergenic and toxic reactions (1, 2). The most studied indoor molds include Alternaria and various Aspergillus species such as Aspergillus fumigatus. Numerous studies have linked exposure to total airborne molds, and exposure to Aspergillus and Alternaria, to respiratory diseases like asthma and rhinitis.

Other common indoor molds such as Penicillium and Cladosporium have also been linked to asthma and allergic diseases. A Belgian study recently studied the allergic and inflammatory effects of common indoor molds including Alternaria alternata, Penicilllium chrysogenum, Aspergillus fumigatus and versicolor, and Cladosporium cladosporoides and sphaerospermum. All of these species were able to stimulate production of inflammatory cytokines such as tumor necrosis factor, and interleukins IL-1α and IL-1β and IL-6 in mouse bone marrow derived dendritic cells (BMDCs).

All species but Aspergillus veriscolor were able to significantly stimulate production of IgE (the antibody involved in immediate allergic reactions) in mice exposed to mold spores in the lungs. Spores from all 6 species were able significantly increase many inflammatory cytokines in mouse lungs including IL-4, IL-5, IL-13, CCL-11 and CCL-24.

Blood from 32 asthmatic humans were also tested for significant IgE levels for 10 common molds. Higher mold IgE levels have been associated with higher asthma risk. The percentages of asthmatics with IgE sensitization to the following molds are as follows: Alternaria alternata 40%, Aspergillus fumigatus 40%, Aspergillus versicolor 9%, Aspergillus niger 16%, Aspergillus flavus 9%, Cladosporium herbareum 30%, Cladosporium sphaerospermum 20%, Cladosporium cladosporodies 9%, Penicillium chrysogenum 19%, and Penicillium brevicompactum 16%.

References / Sources

1. Vincent M, Percier P, De Prins S, Huygen K, Potemberg G, Muraille E, et al. Investigation of inflammatory and allergic responses to common mold species: Results from in vitro experiments, from a mouse model of asthma, and from a group of asthmatic patients. Indoor air. 2017.

2. Brase S, Encinas A, Keck J, Nising CF. Chemistry and biology of mycotoxins and related fungal metabolites. Chem Rev. 2009;109(9):3903-90.