[Lower airway abnormalities in patients with allergic rhinitis]

Area of Science:

• Respiratory Medicine
• Allergology
• Immunology

Background:

• Allergic rhinitis (AR) is a common condition, but its impact on the lower airways in patients without a concurrent asthma diagnosis is not fully understood.
• Investigating lower airway abnormalities in AR patients is crucial for a comprehensive understanding of respiratory health.

Purpose of the Study:

• To characterize lower airway abnormalities in allergic rhinitis patients who do not have asthma.
• To compare respiratory parameters between AR patients and healthy individuals.

Main Methods:

• Recruited 377 AR patients and 264 healthy subjects for a study conducted between June 2008 and December 2012.
• Utilized medical history, nasal examination, skin prick tests, blood tests, induced sputum analysis, fractional exhaled nitric oxide (FeNO) measurement, and bronchial challenge tests.

Main Results:

• AR patients exhibited significantly higher rates of positive bronchial provocation tests, elevated FeNO, sputum eosinophilia, peripheral blood eosinophilia, and increased serum total IgE compared to controls (P<0.01).
• Patients with AR showed lower FEV1/FVC%, MMEFpred%, MEF75pred%, and MEF25pred% (P<0.05) compared to healthy controls.
• FeNO, sputum eosinophil percentage, and peripheral blood eosinophil percentage were significantly correlated (P<0.01).

Conclusions:

• Allergic rhinitis without asthma is associated with lower airway inflammation, small airway impairment, and bronchial hyperreactivity.
• These characteristics observed in AR patients resemble those found in asthma, suggesting a potential continuum or shared pathophysiology.
• Further research into the lower airway manifestations of AR is warranted.