Clinical symptoms and biomarkers of cat allergen-induced allergic rhinitis using the nasal allergen challenge model.

BACKGROUND

The nasal allergen challenge (NAC) of the Allergic Rhinitis-Clinical Investigator Collaborative (AR-CIC) is a validated and reproducible model of allergic rhinitis (AR). To date, only seasonal allergens have been well characterized using this model.

OBJECTIVE

To comprehensively evaluate the symptomatology and pathophysiology of cat allergen-induced AR using the NAC model of the AR-CIC.

METHODS

At least 21 days after the screening visit, participants received the NAC with cat allergen extract. Symptom scores were recorded from baseline to 12 hours and 24 hours after NAC. Blood and nasal samples collected at baseline, 3, 6, and 24 hours were evaluated for cytokine, IgE, and immune cell concentrations. Participants with cat allergy completed a cat exposure and quality-of-life questionnaire at the follow-up visit.

RESULTS

This study included 13 participants with cat allergy and 10 without allergy. After NAC, participants with cat allergy experienced significantly increased total nasal symptom scores from 15 minutes to 4 hours post-exposure, with no differences in safety scores between the groups. Nasal total IgE level increased significantly after NAC. Eosinophil counts increased in the nose, which peaked at 6 hours, but decreased in the blood at 3 and 6 hours. Concentrations of nasal interleukin (IL)-5, IL-33, and CCL4 increased after NAC, whereas those of IL-4 and IL-10 increased in the blood. The participants reported greatest impact to their social activities and general happiness due to their cat allergies. Cat ownership did not appear to affect peak symptom outcomes or baseline characteristics.

CONCLUSION

The NAC of AR-CIC is an effective and safe model for cat allergen-induced AR. It can be used to capture meaningful blood and nasal cellular and immunologic changes over time after intranasal allergen exposure.