LOWER AIRWAY RESPONSES TO INFLUENZA-A VIRUS IN HEALTHY ALLERGIC AND NONALLERGIC SUBJECTS

Acute asthma is considered a complication of respiratory viral infecti ons. This investigation assessed the effects of influenza A virus infe ction on both the patency and responsiveness of the lower airways. Sub jects with allergic rhinitis (AR; n = 21) and without AR (non-AR; n = 25) were intranasally inoculated with influenza A virus and monitored for 8 d in a cloistered environment for changes in symptoms, signs, an d airway physiology (pulmonary function, bronchial methacholine provoc ation). All subjects were infected after inoculation. Significant incr eases in nasal symptoms and secretion weights were observed, with peak effects on Days 3 and 4. Cough was a relatively minor symptom, and no ne of the subjects developed wheezing. Likewise, there were no signifi cant changes in the measured functions of the lower airways. No effect s on allergy status were observed. Under these experimental conditions , influenza A virus infection did not produce detectable alterations i n lower airway function in healthy AR and non-AR subjects.