100228 - Soluble CD25 as a marker of immune activation in pediatric asthma: a prospective case-control study

Asthma is the most prevalent chronic inflammatory airway disease in children and is characterized by persistent immune activation. T lymphocyte activation plays a central role in asthma pathophysiology, contributing to airway inflammation and disease chronicity. Soluble CD25 (sCD25), the circulating form of the interleukin-2 receptor α-chain, is released upon T-cell activation and has been proposed as a biomarker reflecting immune activation in inflammatory and allergic diseases. However, data regarding its clinical relevance in pediatric asthma remain limited.

This prospective observational case-control study included 32 asthmatic children aged 5–15 years and 30 healthy controls. Asthma severity was classified according to Global Initiative for Asthma (GINA) criteria into mild, moderate, and severe forms. Plasma sCD25 levels were quantified by chemiluminescence in all participants. Comparisons were performed between asthmatic children and healthy controls, across asthma severity groups, and according to allergic sensitization status using non-parametric statistical tests.

Plasma sCD25 concentrations were significantly higher in asthmatic children compared with healthy controls (P < 0.001), indicating increased systemic immune activation in pediatric asthma. However, no significant differences in sCD25 levels were observed among the different asthma severity groups. Similarly, sCD25 concentrations did not differ between allergic and non-allergic asthmatic children. Elevated sCD25 levels were detected even in clinically stable patients receiving standard asthma therapy.

Soluble CD25 is significantly increased in pediatric asthma, reflecting persistent immune activation independent of disease severity or allergic sensitization. These findings support the potential role of sCD25 as a biomarker of immune activation in childhood asthma, although its value as a marker of disease severity appears limited.