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Summary Background We have previously reported an experimental infection of young adults with a history of episodic and exclusive viral wheeze (EVW) using human coronavirus, in which 16 of 24 with EVW (15 atopic) and 11 of 19 healthy controls (seven atopic) developed a symptomatic cold with evidence of infection, but only those with EVW developed lower respiratory tract symptoms and increased airway responsiveness. Objective The aim of this study was to compare the EVW and control groups from this study for inflammatory changes occurring in the upper and lower respiratory tracts during the experimental infection, in particular, to determine whether eosinophil‐driven inflammation was associated with EVW. Methods Nasal lavage and induced sputum were collected prior to inoculation (day 0) and 2, 4 and 17 days later. Differential cell counts were performed and supernatant was assayed for IL‐8, IL‐5, IFN‐γ, and eosinophilic cationic protein (ECP). Results There was no difference between the two groups in any measurement at baseline. In both groups, during colds the volume of nasal secretion increased as did leucocyte counts in both upper and lower respiratory tracts. A modest increase in nasal neutrophil count was seen in both EVW and control groups with symptomatic colds on day 2 (median (quartile) difference from baseline 5.4 (0.0, 11.0) and 1.8 (−1.1, 2.2)×104/mL of secretions, respectively). The change in nasal neutrophil counts in all subjects correlated with nasal symptom scores. A significant relative increase in sputum differential neutrophil count was seen on day 4 in the EVW group with a cold but not in controls (mean difference (95% confidence interval) 20.4 (9.6, 31.1)% and 3.1 (−8.2, 14.5)%, respectively, P |
