Clinical and Th1/Th2 immune response features of hospitalized children with human rhinovirus infection

Area of Science:

• Pediatric infectious diseases
• Immunology
• Respiratory viral infections

Background:

• Human rhinovirus (HRV) and respiratory syncytial virus (RSV) are common causes of lower respiratory tract infections in children.
• Understanding the distinct clinical and immunological profiles of HRV and RSV infections is crucial for effective management.

Purpose of the Study:

• To compare the clinical characteristics and T-helper 1 (Th1)/Th2 immune profiles of HRV infections with RSV infections in children hospitalized with bronchiolitis and pneumonia.
• To identify differences in clinical presentation, immune responses, and risk factors between HRV and RSV infections.

Main Methods:

• Nasopharyngeal aspirates from 335 children under 14 with bronchiolitis/pneumonia were tested for HRV and other viruses using PCR/RT-PCR.
• Cytokine levels (IFN-γ, IL-2, IL-4, IL-6, IL-10, TNF-α) were measured using multiplex ELISA.
• Clinical data including wheezing, fever, eczema history, and seasonality were analyzed and compared between HRV and RSV groups.

Main Results:

• HRV was detected in 19.7% of cases. HRV-infected children with pneumonia had more wheezing and fever compared to RSV alone. HRV bronchiolitis cases were more common in winter and associated with a history of eczema.
• HRV bronchiolitis showed an increased IL-4/IFN-γ ratio and decreased TNF-α/IL-10 ratio, indicating an imbalanced Th1/Th2 response.
• HRV and RSV infections differed significantly in wheezing, eczema susceptibility, fever, and seasonal patterns.

Conclusions:

• HRV is a major non-RSV pathogen in pediatric bronchiolitis and pneumonia, inducing an imbalanced Th1/Th2 response, particularly in bronchiolitis.
• HRV infections present distinct clinical and epidemiological features compared to RSV, highlighting the need for specific diagnostic and therapeutic considerations.