Study subjects and sample collection
Five patients with AERD and another 5 patients with ATA were enrolled at Ajou University Hospital in Suwon, South Korea. Asthma was diagnosed according to the Global Initiative for Asthma guideline (GINA) 2021 by the allergy specialists. AERD was defined by a recurrent clinical history (exacerbation of upper or lower respiratory reactions after ingestion of aspirin/NSAIDs) and/or a positive response to the lysine-aspirin bronchial provocation test (Lys-ASA BPT). The Lys-ASA BPT was performed with increasing doses of Lys-ASA solution up to 300 mg/mL using the method previously reported.9 The positive result of the Lys-ASA BPT was defined when FEV1% was decreased by more than 20% after the challenge. Asthmatics with negative results to the Lys-ASA BPT or denied any changes in upper or lower respiratory tract symptoms after ingestion of aspirin/NSAIDs were defined as ATA. Severe asthma was defined as the international ERS/ATS guidelines.10 Exclusion criteria for enrollment were as follows: 1) asthmatics who had been treated with type 2 biologics, including omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab, within 130 days of enrollment; 2) current smokers or ex-smokers who quit smoking within 30 days of enrollment; and 3) asthmatics who used any of intranasal corticosteroids, intranasal antihistamines, and intranasal anticholinergics within 7 days of enrollment.
Nasal scraping was performed with a pencil-shaped disposable nasal curette (Rhino-probe®, Arlington Scientific, Inc., Springville, UT, USA) for 3 times from the middle portion of the each side of the inferior turbinate after 2 nasal lavages (10-mL saline each) to remove overlying mucus. Peripheral eosinophil counts, sputum eosinophil counts, total immunoglobulin E (IgE), fractional exhaled nitric oxide (FeNO) levels, pulmonary function test results, and atopy status were evaluated at enrollment. All subjects gave written informed consent at the time of enrolment, and the study was approved by the Institutional Review Board of Ajou University Hospital (AJIRB-BMR-SUR-17-182).