[Respiratory allergy and the viruses]

Area of Science:

• Pediatric respiratory health
• Immunology of viral infections
• Asthma pathogenesis

Background:

• Viral respiratory tract infections are a leading cause of infant wheezing, affecting 80-85% of school-aged children with wheezing episodes.
• The precise mechanisms by which respiratory viruses exacerbate lower airway inflammation remain unclear, though cytokines are implicated.
• Respiratory epithelial cells are primary sites of viral replication and initial cytokine production during infection.

Purpose of the Study:

• To investigate the influence of viral respiratory tract infections on asthma.
• To evaluate the effects of these infections on airway symptoms, function, and inflammation.
• To explore the role of T cells and cytokines in virus-induced airway inflammation and asthma.

Main Methods:

• Evaluation of airway symptoms, function, and inflammation in relation to viral infections.
• Analysis of cytokine profiles during acute respiratory infections.
• Assessment of T cell responses (Th-1 vs. Th-2) in the context of viral infections and atopy.

Main Results:

• Viral infections are strongly associated with wheezing in infants and children.
• Cytokines likely play a critical role in mediating lower airway inflammation induced by viruses.
• Distinct T cell responses (Th-1 for viral infections, Th-2 for atopy) are involved, with potential implications for asthma development.

Conclusions:

• Viral respiratory infections significantly contribute to wheezing and may influence the development of asthma.
• Virus-specific T lymphocytes may play a role in virus-induced lung disease and asthma.
• Early-life infections can modulate immune responses, impacting the subsequent risk of allergy and asthma.