PT  - JOURNAL ARTICLE
AU  - Whetstone, C
AU  - Ranjbar, M
AU  - Alsaji, N
AU  - Al-Sajee, D
AU  - Wiltshire, L
AU  - Wattie, J
AU  - O'Byrne, P
AU  - Cusack, R
AU  - Sehmi, R
AU  - Gauvreau, G
TI  - Reduced ACE2 and TMPRSS2 immunopositive bronchial cells in asthmatics after inhaled allergen challenge
AID  - 10.1183/13993003.congress-2022.4057
DP  - 2022 Sep 04
TA  - European Respiratory Journal
PG  - 4057
VI  - 60
IP  - suppl 66
4099  - http://erj.ersjournals.com/content/60/suppl_66/4057.short
4100  - http://erj.ersjournals.com/content/60/suppl_66/4057.full
SO  - Eur Respir J2022 Sep 04; 60
AB  - Rationale: The incidence of SARS-CoV-2 infection and the impact of corticosteroid treatment in patients with symptomatic airway disease has been a concern. We examined airway expression of SARS-CoV-2 receptors following allergen challenge and steroid intervention in asthmatic patients.Methods: From steroid-naïve mild allergic asthmatic (AA n=23) we collected endobronchial biopsies pre and 24hr post allergen inhalation challenge (AIC). In a subset of AA with allergic rhinitis (AR n=8) we collected inferior nasal turbinate biopsies pre and 24hr post-nasal allergen challenges (NAC) after placebo treatment or after 21 days of 22 mg BID triamcinolone nasal spray. FEV1 and PNIF expressed as % fall from baseline quantified the early (ER, 0-2h) and late (LR, 3-7h) airway responses post challenge. Epithelium and laminae propria were immunostained for ACE2 and TMPRSS2 and expressed as # cells/mm2.Results: AIC reduced FEV1 (31% ER, 19% LR) and the number of bronchial cells immunopositive for ACE2, TMPRSS2 and double positive for ACE2/TMPRSS2 (P=0.0002, P=0.04, P=0.02, respectively). The PNIF reduction by NAC (69% ER, 49% LR) was attenuated by triamcinolone (31% ER, 18% LR), but without changes in ACE2 or TMPRSS2 in nasal tissue after NAC or steroid treatment (all P>0.05). In the nasal tissue, significantly fewer cells expressed ACE2 compared to bronchi (P=0.007).Conclusion: ACE2 and TMPRSS2 expression in bronchial tissue is reduced in the T2 microenvironment post allergen challenge, however it is unknown if this protects lower airways from SARS-CoV-2 infection. Low expression of ACE2 and TMPRSS2 in nasal tissue made it difficult to determine the effects of NAC or steroid.FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 4057.This article was presented at the 2022 ERS International Congress, in session “-”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).