D1.165 - Asthma Predisposition and miRNA Expression in Children with Recurrent Infections

Asthma is a chronic inflammatory disorder of the airways. Primary immunodeficiencies also contribute substantially to childhood morbidity. This study aimed to assess asthma predisposition and potential immunodeficiency background in children with recurrent infections, and to evaluate the role of selected miRNAs in these conditions.

Thirty children aged 1–18 years with recurrent infections and 30 healthy controls admitted to Gaziantep University Children’s Hospital between November 2024 and November 2025 were enrolled. Four serum miRNAs (miRNA-146a, -155, -365, -375) were normalized. Demographic, clinical and laboratory parameters were prospectively recorded

Elevated IgE levels (66.6%) were significantly more frequent in the patient group. Post-bronchodilator FEV1 change and R5-R20 indices on IOS were also significantly increased, indicating small airway involvement. Primary immunodeficiency history (16.6%), wheezing (20%), hospitalization (36.6%) and PICU admission (23.3%) were more common in patients. Wheezing correlated with eosinophilia, and nocturnal dry cough correlated with inhalant allergen sensitization. Frequent hospitalizations were associated with age-adjusted decreases in lymphocyte and CD19 counts. Breastfeeding for <6 months and family history of suspected primary immunodeficiency were associated with reduced CD3/8 and CD16/56 levels. Prematurity and PICU admission correlated with short stature; IgG levels were significantly reduced in preterm children, and CD3/4 and CD19 levels were reduced for age in those with PICU history. miRNA-155 expression was significantly upregulated in the patient group. Increased miRNA-365 expression was observed in patients with obstructive spirometry and elevated IgE. miRNA-375 expression increased in those with age-adjusted low CD3/8 levels. miRNA-375 and miRNA-155 were increased in children with rhinitis and/or eczema, while miRNA-146a was elevated in those with recurrent skin infections.

Although the sample size does not permit a definitive conclusion regarding asthma predisposition in children with recurrent infections, notable clinical and laboratory associations were identified. The observed miRNA expression patterns suggest potential diagnostic or monitoring biomarkers. Comprehensive evaluation and further biomarker-focused research in recurrently infected children are warranted.