Alternaria alternata as the major fungal allergen: molecular analysis of fungal sensitization patterns

Background. Among the agents causing respiratory and skin pathologies, fungal allergens play a significant role. The epidemiological situation regarding fungal sensitization in Ukraine, specifically in the Vinnytsia region, remains insufficiently studied. Conversely, its characteristics, defined at both the individual and population levels, may contribute to understanding patterns relevant to prevention of fungal allergy. The aim of our study was to evaluate the prevalence and analyze the sensitivity profiles to fungal allergens among residents of the Vinnytsia region. Materials and Methods. We analyzed sensitization profiles to 13 fungal allergens in 2,623 residents of the Vinnytsia region using the ALEX multicomponent test. We considered sIgE levels for major molecules and extracts of Alternaria, Aspergillus, Cladosporium, Malassezia, Penicillium, and Saccharomyces (sensitivity threshold ≥ 0.31 kU/L). We examined the overall prevalence and isolated sensitization cases. Statistical analysis utilized non-parametric methods (Mann–Whitney U-test, χ² with Yates’ correction, p < 0.05) in Statistica 8.0 and MS Excel. Results. The overall prevalence of sensitization to fungal allergens was 9.57 %, and it was 1.85 times more common in children. The leading allergen was Alternaria alternata (Alt a 1), with sensitivity observed in 70.12 % of patients sensitized to fungal components. Among children, 82.93 % were sensitized to Alt a 1 alone. The mediansIgE value for Alt a 1 in children (25.64 kU/L) was significantly higher than in adults (7.87 kU/L) and was the highest among sIgE levels for all fungal components. Aspergillus fumigatus allergens (Asp f 1, Asp f 6) did not show isolated sensitization, which is consistent with their classification as secondary sensitizing agent, although their sIgE levels were substantial. Adults showed more frequent sensitization to Asp f 1 and Asp f 6, while sensitivity to Alt a 1 and Mala s 6 was more prominent in children. Conclusions. The obtained data confirm a high prevalence of fungal sensitization in the Vinnytsia region, particularly hypersensitivity to Alt a 1 among children. The identified age-related and immunological features of allergen sensitivity could contribute to the diagnosis and development of effective, personalized allergen-specific immunotherapy programs.