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).