Allergic rhinitis, like asthma, is an inflammatory disease affecting a large proportion of the population globally. It specifically affects the nose and some of the physiological manifestations of the disease classically include itching, sneezing, rhinorrhea, as well as nasal obstruction. These symptoms can be of variable intensity and duration and occur in an intermittent or persistent manner. Allergic rhinitis can have a considerable impact on the patient’s quality of life. Nasal obstruction, which is most frequently reported, can significantly impair the patients’ normal breathing.
MEASURING UPPER AIRWAY RESISTANCE
In preclinical models of allergic rhinitis, the flexiVent has been successfully used to directly measure changes in the resistance of the upper airways. Using a retrograde cannulation of the trachea, the approach offers the same reproducibility and accuracy as in the assessment of the lower airways. In addition, a specialized configuration of the system conveniently allows the assessment of both airway segments (e.g. upper and lower airway) in the same subject.
- Characterization of nasal obstruction in the allergic guinea pig using the forced oscillation method. – McLeod et al. J Pharmacol Toxicol Methods, 48: 153, 2002.
- Physiologic assessment of allergic rhinitis in mice: Role of the high-affinity IgE receptor (FcɛRI) – Miyahara et al. J All Clin Immunol., 116: 1020, 2005.
- Contribution of allergen-specific and nonspecific nasal responses to early-phase and late-phase nasal responses. – Miyahara et al. J All Clin Immunol., 121: 718, 2008.
TARGETED ALLERGEN DELIVERY
In experimental research, animal models of allergic rhinitis have been reported in the literature. A challenge often associated with their development is to limit the delivery of allergens to the nose. SCIREQ’s inExpose is a compact exposure platform that offers an automated approach to deliver aerosols to conscious subjects. The system is fully computer-controlled and highly modular. It can integrate various particle size generating nebulizers and be configured with a nose-only or whole body exposure tower in order to provide an unparalleled number of reproducible exposure profiles.
TRACKING VENTILATORY PARAMETERS
In allergic rhinitis, upper airways obstruction results mainly from vasodilation, edema, and hyper secretion. When present, it has the potential of directly affecting the subjects’ ability to breathe normally. The plethysmography techniques (e.g. whole body, head-out, double-chamber) can track changes in ventilatory parameters in conscious animals and offer a non-invasive physiological assessment of allergic rhinitis models. Sneezes can also be detected with whole body plethysmography and can be quantified by integrating a microphone into the chamber.