D1.86 - Age-Related Features of Sensitization to Timothy Grass in Children According to Component-Resolved Diagnostics

Allergy to pollen is a global health problem with a significant impact on human health and the socio-economic sphere, leading to substantial costs for both patients and healthcare systems. The prevalence of pollinosis has been increasing worldwide, including in Uzbekistan.

In order to determine IgE sensitization to timothy grass components, positive results of molecular allergy diagnostics were analyzed in 427 children with respiratory symptoms identified through questionnaire screening (adapted ISAAC questionnaire) and clinically confirmed.

Allergological examination was performed using the ALEX1 chip (Allergy Explorer 1, Macro-Array Diagnostics GmbH, Austria), a research-based multiplex testing platform that allows detection of sensitization to 160 allergen extracts and 122 allergenic components.

The gender distribution of the studied children was as follows: 250 boys (58.5%) and 177 girls (41.5%). Sensitization to timothy grass allergens was detected in 174 children (40.7%). Overall, sensitization to timothy grass extract (Phl p) was observed in 18.7% of children, whereas specific IgE to major allergenic components was detected in 30.4% for Phl p 1 and 10.5% for Phl p 5. Sensitization to minor components was found in 1.9% for Phl p 7 and 16.4% for Phl p 12.

According to the degree of sensitization (sIgE ≥ 0.3 kUA/L) to Phl p 1 (n = 130), the following distribution was observed:0.3–1 kUA/L — 11.5%;1–5 kUA/L — 28.5%;5–15 kUA/L — 28.5%;

15 kUA/L — 31.5%.

For Phl p 5 (n = 45), the majority of children demonstrated a very high level of sensitization, with sIgE values >15 kUA/L observed in 68.9% of cases.

To assess age-related differences in the severity of sensitization, data from three age groups were analyzed: 4–8 years, 9–12 years, and 13–18 years. The analysis demonstrated a direct association between increasing age and higher levels of sensitization. The proportion of children with sIgE >15 kUA/L to Phl p 1 was 25%, 24%, and 43.8%, respectively, while for Phl p 5 it was 50%, 62.5%, and 80.9%.

The results indicate age-related progression of sensitization severity and molecular spreading. Initiation of allergen-specific immunotherapy (AIT) at an early age appears advisable, as avoidance of pollen exposure is not feasible due to the widespread distribution of grasses and the prolonged grass pollen season.