Effect Of Cigarette Smoking On Nasal Inflammatory Responses After Nasal Allergen Challenge With Dermatophagoides Farinae

Tobacco smoke is generally pro-inflammatory and has been shown to augment Th2 responses that generate allergic inflammation in animal and epidemiologic studies. This pilot study evaluated the effect of smoking on allergen-induced nasal airway inflammation following nasal allergen challenge with Dermatophagoides farinae (Der f). Volunteers with a history of allergic rhinitis and a positive skin prick test to Der f were invited to participate in a screening nasal allergen challenge to demonstrate a clinical response to Der f. Six non-smokers and three smokers underwent a second nasal allergen challenge, during which epithelial lining fluid was collected and assessed for pre- and post-challenge levels of inflammatory mediators using a Mesoscale Human Cytokine 30-Plex Kit. Baseline versus six hours post-allergen challenge cytokine levels were compared by paired t-tests within each cohort. The mean age of subjects was 29.8 years; 4 were female. There were significant increases in pre- and post-allergen challenge levels of nasal IL-5, IL-31, MIP-1a, and MIP-1b among non-smokers (p=0.03 for all cytokines). There were no detectable increases in these inflammatory mediators noted in smokers. There were not sufficient smokers enrolled to allow comparison between the cohorts. In this proof-of-concept study, smokers appeared to have a less robust response to nasal allergen challenge than non-smokers, which may be related to effects on the nasal immune response that need further investigation. The study was greatly limited by challenges in recruiting cigarette smokers that self-identified as having allergic rhinitis, perhaps reflecting changes in perception of nasal symptoms among smokers.