Serum Epithelial Biomarkers and Oxidative Stress Indicators in Acute Bronchiolitis: Association with Disease Severity and Recurrent Wheezing.

Background

Acute bronchiolitis is one of the most common lower respiratory tract infections in early childhood and is frequently associated with recurrent wheezing and later development of asthma. Identifying biomarkers related to airway epithelial injury and disease severity may improve risk stratification. Materials and

Methods

A total of 155 children aged 1-36 months who presented with their first episode of wheezing were enrolled. Clinical data and bronchiolitis symptom scores were recorded at admission. Serum levels of CC16, surfactant protein-D (SP-D), YKL-40, and isoprostane were measured. Patients were followed for one year to assess recurrence of wheezing.

Results

According to symptom scores, 81 patients had mild and 74 had moderate bronchiolitis; no severe cases were observed. The distribution of bronchiolitis severity differed significantly between recurrent and non-recurrent wheezing groups. Serum YKL-40 levels were significantly correlated with disease severity (p < 0.05), and the effect size analysis indicated a moderate effect. SP-D levels showed a non-significant trend with severity (p = 0.17). No significant associations were observed for CC16 or isoprostane.

Conclusions

Serum YKL-40 may be a potential biomarker reflecting disease severity in children with acute bronchiolitis. Further longitudinal studies are needed to evaluate the prognostic value of epithelial injury markers for recurrent wheezing and asthma development.