NON-ALLERGIC RHINITIS STUDY

Abstract

Non-allergic rhinitis (NAR) is characterized by the presence of rhinitis symptoms in the absence of specific IgE-mediated hypersensitivity. The median prevalence of NAR was 16.4% using a symptom-based definition and 31.4% based on serum or skin testing specific for IgE. Despite the lack of allergic sensitization, data show a relationship between NAR and asthma, and evidence that NAR is related to asthma risk. A homodimeric protein secreted by airway non-ciliated Clara cells (CC16) has been identified to have anti-inflammatory properties in the lower respiratory pathway and is being studied for its relationship with asthma. The purpose of this study is to understand how protein content varies in nasal mucous secretions between different 4 different symptom-based phenotypes: allergic rhinitis (AR), NAR, mixed rhinitis (MR), and no rhinitis (NR). Two nasal swabs were collected from subjects (N=72). One nasal swab was stored in a dry 1.5 ml test tube and the other in a 1.5 ml test tube with 500 μl of phosphate buffer solution (PBS). CC16 and total protein content were measured using ELISAs. The sample population resulted in the following phenotypes: 7% AR, 72% MR, 14%NR, and 7% NAR. Descriptive data analysis found many patients who report allergic triggers also report non-allergic triggers. Samples from NAR subjects had a higher ratio of CC16/Total protein concentration compared to the other experimental groups; however, the small sample size resulted in a non-significant statistical comparison. Further investigation will require increasing the sample size and enhancing the clinical data questionnaire to capture symptoms, medication use, and the presence of other airway pathologies to understand how non-allergic triggers can cause rhinitis symptoms despite the absence of an IgE-mediated response.