Features of sensitization to molds and its role in development of respiratory allergic diseases

Over recent decades, a steady increase in the number of allergic diseases has been shown. Current evidence demonstrate a close association between their emergence and exposure to fungal allergens. In this regard, the aim of the present study was to identify frequency and structure of sensitization to the most clinically significant molds in the patients with respiratory allergic diseases. In blood serum of 283 patients with allergic rhinitis and bronchial asthma, we determined total IgE and sIgE to the mold allergens: Penicillium notatum, Cladosporium herbarum, Aspergillus fumigatus and Alternaria alternata by the ImmunoCAP method (Phadia, Sweden). Statistical analysis was carried out by nonparametric methods. The total IgE levels (420 (225.5-641) kU/l) were higher (p < 0.05) in patients with sensitization to fungal allergens than in general group (296 (129- 530) kU/l). Multiple sensitization to respiratory allergens was revealed in the patients with allergic rhinitis and bronchial asthma, and sensitization to fungal allergens was associated with increasingly severe manifestations of the disease. In the patients with fungal allergies, sIgE to Alternaria alternata was most often detected (92.5%), with average level of 3.52 (0.635-19.525) kUA/l. Sixteen patients (40%) were sensitized to Aspergillus fumigatus (0.14 (0.06-0.63) kUA/l). In 19 patients (47.5%), we found increased levels of sIgE to Cladosporium herbarum (0.29 (0.045-1.005) kUA/l). Sensitization to Penicillium notatum was detected in 12 patients (30%), the sIgE levels were 0.125 (0.01-0.5) kUA/l. Detection rates in the total group of fungus-allergic patients with respiratory allergies were as follows: Penicillium notatum, 4.2%; Cladosporium herbarum, 6.7%; Aspergillus fumigatus, 5.6%; Alternaria alternata, 13.07%. We found a significant correlation (p < 0.05) between the sIgE contents to different fungal allergens. The levels of IgE antibodies to Alternaria alternata correlated with the levels of sIgE to other fungi (Aspergillus fumigates, r = 0.45; Cladosporium herbarum, r = 0.39; Penicillium notatum, r = 0.39). These findings allow us to suggest that sensitization to Alternaria alternata (13.07%) and Cladosporium herbarum (6.7%) is most common among the patients with allergic rhinitis and bronchial asthma, whereas fungal sensitization aggravates clinical course of these diseases. Determination of sIgE to Alternaria alternata can serve as a marker for the presence of potential cross-sensitization to other fungal allergens, i.e., Aspergillus fumigatus, Cladosporium herbarum, and Penicillium notatum.