Cigarette Smoke Inhibits Dynamic Ciliary Beat Frequency in Pediatric Adenoid Explants

Abstract

OBJECTIVE: Environmental tobacco smoke exposure in children increases the incidence of upper respiratory infections, chronic sinusitis, and chronic otitis media. This study investigated the effects of ex vivo and in vitro smoke exposure on dynamic ciliary beat frequency (CBF) in pediatric adenoid explants. STUDY DESIGN: Blinded and controlled prospective study. SETTING: Tertiary care pediatric hospital. SUBJECTS AND METHODS: Fifty-five children undergoing adenoidectomy for obstructive sleep apnea and adenotonsillar hypertrophy were enrolled in this study. Adenoids were surgically removed using currettage. Hair was collected for nicotine analysis. Tissue was sectioned into 1-mm strips and allowed to equilibrate in DMEM/F12 with 2% fetal bovine serum for 24 hours. Cilia-bearing explant tissues were treated with either DMEM/F12 media, 5% cigarette smoke extract (CSE), or 10% CSE for 24 hours. Cilia were then stimulated using either isoproterenol (10(-9) M) or methacholine (10(-6)M), and CBF was serially recorded using the Sisson-Ammons Video Analysis (SAVA) software. RESULTS: Children with hair nicotine levels ≥ 1 ng/mg consistent with secondhand smoke exposure display blunted dynamic CBF response ex vivo. Explants incubated with CSE in vitro demonstrate significant impairment of isoproterenol and methacholine-induced CBF. CONCLUSION: CBF of adenoid explants increases when stimulated with isoproterenol and methacholine. Ex vivo and in vitro smoke exposure blunted ciliostimulation of CBF in adenoid explants. Smoke exposure impairs ciliary function in the pediatric airway and could potentially contribute to disorders such as chronic rhinosinusitis and chronic otitis media.