D1.46 - Molecular patterns of fungal sensitization in patients with asthma and allergic rhinitis: evidence from real-life clinical practice

Fungal allergens represent a clinically relevant yet frequently underrecognized cause of respiratory allergic diseases. Increasing evidence highlights their role in asthma and allergic rhinitis, particularly in relation to disease persistence and severity. Among airborne molds, Alternaria alternata has consistently emerged as a major sensitizing species worldwide. The advent of component-resolved diagnostics has markedly improved the characterization of fungal allergy by enabling precise identification of molecular sensitization patterns beyond extract-based testing. Nevertheless, real-life data on molecular fungal sensitization remain limited, especially from underrepresented regions.

This retrospective observational study included 79 consecutive patients with physician-diagnosed asthma and/or allergic rhinitis. Serum specific IgE levels to twelve fungal molecular components (Alt a 1, Alt a 6, Asp f 1, Asp f 3, Asp f 4, Asp f 6, Cla h, Cla h 8, Mala s 11, Mala s 5, Mala s 6, and Pen ch) were measured using the ALEX² multiplex assay. Sensitization was defined as specific IgE concentrations ≥0.30 kUA/L. Associations between clinical phenotypes and sensitization profiles were assessed using chi-square analysis.

Asthma was diagnosed in 68.4% (54/79) of patients, allergic rhinitis in 67.1% (53/79), and both conditions coexisted in 36.7% (29/79). A statistically significant association between asthma and allergic rhinitis was observed (χ² = 6.41, p = 0.011). Sensitization to at least one fungal molecular component was identified in 46.8% (37/79) of patients. Alt a 1 was the most prevalent allergen, detected in 24.1% (19/79) of the entire cohort and accounting for 51.4% (19/37) of all fungal-sensitized cases. The majority of sensitized individuals demonstrated monosensitization to Alt a 1, while co-sensitization was less common and most frequently involved Mala s 6 and Cla h. Sensitization to other fungal components occurred at comparatively low frequencies and showed no significant association with the coexistence of asthma and allergic rhinitis.

In this real-life clinical cohort, fungal sensitization was frequently observed among patients with respiratory allergic diseases, with Alternaria alternata and its major allergen Alt a 1 representing the dominant molecular pattern. The significant association between asthma and allergic rhinitis supports the concept of a shared airway disease. Component-resolved fungal diagnostics provide clinically meaningful information and may facilitate more accurate phenotypic characterization and individualized management in everyday practice.