Comparative study of serum inflammatory mediators and immunoglobulin levels in children with severe asthma infected by viruses versus bacteria.

BACKGROUND

By tracking fluctuations in inflammatory mediators and immunoglobulins (Igs) in bacterialversus viral-induced severe asthma (SA) cases, this research seeks to identify microbial-specific immune characteristics to guide individualized treatment.

METHODS

This analysis included 100 children hospitalized between March 2023 and April 2025 for severe acute SA exacerbations with confirmed single-pathogen infections (50 viral vs. 50 bacterial). Serum samples collected preand post-treatment were analyzed for inflammatory mediators (Th1/Th2/Th17 cytokines and TNF-a) and Ig profiles (total IgE and IgG subclasses). Comparative analysis was performed to identify intergroup differences.

RESULTS

At baseline, the viral group showed higher Th1/Th17 co-activation responses, whereas the bacterial group had elevated Th2 cytokines/TNF-a (P < 0.05). Therapeutic intervention reduced all cytokine subsets, though Th1/Th17 co-activation suppression was more marked in the viral group (P< 0.05), and Th2 decay lagged in the bacterial group. Besides, viral cases had elevated IgG1/IgG3; bacterial cases showed higher IgG2 (P< 0.05). After treatment, the levels of IgG1 and IgG3 in the virus group continued to increase, but IgG2 did not change.

CONCLUSIONS

Viral SA infections predominantly trigger Th1/Th17 co-activation-mediated inflammation and higher IgG1/IgG3. In contrast, bacterial infections favor a Th2-dominant profile with IgG2 elevation, resulting in slower inflammation resolution.