D2.67 - Relation betwween IL-6 and asthma in children and adolescent

Asthma is the most common chronic disease in children and adolescents. More than 50% of patients have uncontrolled asthma (UcA), leading to poor quality of life, limitations and comorbidities. Interleukin-6 (IL-6) is a biomarker of systemic inflammation and metabolic dysfunction. Previous studies have suggested an association between elevated IL-6 levels and uncontrolled asthma, particularly in obese asthmatic patients. This study analyzes the clinical evolution of children with asthma and the relationship between IL-6 levels and asthma severity.

We conducted an observational, descriptive, and prospective study in children (aged 4–12 years) from the Severe Asthma Unit of Hospital de Mérida between 2019 and 2022. Children with uncontrolled, moderate or severe asthma were included. Clinical data, lung function, blood eosinophil count, fractional exhaled nitric oxide (FENO), Asthma Control Test (ACT), Mini-Asthma Quality of Life Questionnaire (MiniAQLQ), and IL-6 levels were analyzed over consecutive visits. Additionally, we assessed the relationship between IL-6 levels, overweight status, and asthma severity. Medical records were retrieved from the JARA computer system of the Extremadura Health Service. Serum IL-6 levels were determined using the enzyme-linked immunosorbent assay (ELISA) with the interleukin-6 Quantikine R&D system test.

A total of 59 children with UcA were included (59% boys, 12% overweight, 80% with allergen sensitization and 22% food allergy). At the first visit, 66% had activity limitations, 79% nocturnal symptoms, 33% emergency visits and 5% required hospitalization. The mean FEV₁ (forced expiratory volume in the first second) was 94%, FeNO 23 ppb, blood eosinophil count 1,721/mm³, total IgE 1,049 kU/L, and the mean ACT was 18. Oral corticosteroids (OC) were required in 26% of patients, 40% used rescue medication daily and 5% received biologic therapy. By the third visit, symptoms, limitations, exacerbations, blood eosinophil count, and the use of OC and rescue medication had decreased, while ACT improved. However, no significant changes were observed in serum IL-6 levels. A relationship was noted between higher IL-6 levels and overweight status in asthmatic children.

In our study, children with UcA showed improvement in symptoms, limitations, exacerbations, and T2 asthma biomarkers over time. While IL-6 levels did not change significantly, a trend was observed suggesting an association between elevated IL-6 and higher BMI in children.