Nasal mucosal brushing as a diagnostic method for allergic rhinitis

Background: Allergen specific immunoglobulin E (spIgE) in the nasal mucosa is a biomarker for local allergic rhinitis. Inferior turbinate tissue biopsy is a sensitive method to detect nasal spIgE but is invasive. Nasal brushing is a relatively noninvasive method to detect nasal spIgE that may be of comparable diagnostic utility. Objective: To assess the performance of nasal brushing to obtain a nasal spIgE sample compared with an inferior turbinate tissue biopsy among patients who underwent turbinate surgery. Methods: A diagnostic cross-sectional study that involved participants who were undergoing turbinate surgery was performed. Nasal brushing, inferior turbinate tissue biopsy, blood collection, and skin-prick test (SPT) were performed perioperatively and tested for house-dust allergens. A receiver operating curve was used to assess the performance of the nasal brushings to obtain nasal spIgE samples compared with the inferior turbinate tissue biopsy. The diagnostic utility of nasal brushings of spIgE compared with serum spIgE testing and SPT was also assessed. Results: A total of 157 patients (41.61 ± 14.83 years; 37.6% women) were included. Nasal brushing was an excellent method to sample for nasal spIgE compared with inferior turbinate tissue biopsy (Area under curve (AUC) 0.87 [95% confidence interval {CI}, 0.81-0.93], p < 0.01). Positive house-dust allergen spIgE results of nasal brushings was defined as > 0.1 kUA/L. Nasal brushings for spIgE sampling was also able to predict the presence of serum spIgE (AUC 0.93 [95% CI, 0.89-0.97], p < 0.01) and SPT (AUC 0.80 [95% CI, 0.72-0.87], p < 0.01). Conclusion: Nasal brushing constituted an easy and relatively noninvasive method to sample nasal epithelium. This sampling technique was comparable with an inferior turbinate tissue biopsy and may be developed as a diagnostic tool for the diagnosis of local allergic rhinitis.