Practical Use of Acoustic Rhinometry for Quantitative Assessment of Nasal Obstruction in an Allergic Model Using Macaque Monkeys

Nasal obstruction, a primary symptom of allergic rhinitis, results in breathing difficulties and decreases quality of life in patients. Quantitative methods are required for diagnosis of nasal obstruction to accurately assess drug efficacy, not only in patients but also in animal models. Acoustic rhinometry is a non-invasive technique to measure nasal airway patency using acoustic reflections. To date, little information on its application in non-human primates (NHP) has been accumulated. Macaque monkeys are a practical NHP model because of their high similarity with humans in their biomedical nature, including genomic and immunologic events and morphology. We established an allergic rhinitis model of cynomolgusmacaque ( Macaca fascicularis ) sensitized with Japanese cedar pollen and applied acoustic rhinometry to measure nasal congestion. The extent of nasal congestion followed by allergen challenge was successfully quantified as the minimal cross-sectional area (MCA) of the nasal passage for the first time in an NHP allergic model. We also applied this acoustic technique to evaluate the efficacy of an antihistamine drug, fexofenadine. The acoustic assessment achieved quantitative evaluation of the efficacy of fexofenadine on nasal congestion in a macaque allergic model.