A Pilot Study Investigating Clinical Responses and Biological Pathways of Azelastine/Fluticasone in Nonallergic Vasomotor Rhinitis before and after Cold Dry Air Provocation.

BACKGROUND

Nonallergic vasomotor rhinitis (NAVMR) has been considered a diagnosis by exclusion due to unknown mechanisms or lack of diagnostic biomarkers.

METHODS

To determine clinical responses and biological pathways in NAVMR subjects challenged to cold dry air (CDA) in an environmental exposure chamber (EEC) pre- and posttreatment with azelastine/fluticasone (AzeFlu), 30 NAVMR subjects, prescreened for CDA-induced symptoms (approx. 14°C, <15% relative humidity, ×1 h) were randomized to treatment with AzeFlu (n = 20) or placebo (n = 10) for 2 weeks. Total nasal symptoms scores, minimum cross-sectional area, cough, and conjunctival redness were recorded at visit 1 (pretreatment) and visit 2 (posttreatment) before, during, and after CDA challenge. At both visits, nasal lavage fluid (NLF) and nasal scrapings (NS) were collected pre- and post-CDA challenge. Substance P, neurokinin-A, and calcitonin gene-related peptide concentrations in NLF were analyzed pre- and postchallenge at each visit. Their relationship with CDA-induced symptoms was determined by statistical analysis. MicroRNA sequencing from NS determined differentially expressed miRNA between the treatment groups post-CDA challenge at each visit.

RESULTS

The minimum cross-sectional area (p < 0.05), cough count (p < 0.05), and substance P (p < 0.01) improved posttreatment with AzeFlu versus placebo. Gene targets for differentially expressed miRNAs at visit 1 were enriched for biological pathways regulating epithelial ciliogenesis and cell integrity that were modified in the AzeFlu-treated group versus placebo posttreatment.

CONCLUSIONS

This study demonstrated the feasibility of an EEC model to investigate CDA-induced clinical responses and pathobiology in NAVMR subjects pre- and posttreatment with AzeFlu. NAVMR disease mechanisms for other nonallergic triggers can be investigated similarly.