Expression of ACE2 in airways: Implication for COVID‐19 risk and disease management in patients with chronic inflammatory respiratory diseases

Abstract

The current outbreak of coronavirus disease 2019 (COVID-19), which was first reported in December 2019, spreads across the globe rapidly and has been declared as pandemic on 11 March 2020 by the World Health Organization. 1-4 COVID-19 is caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and associates with substantial morbidity and mortality. 2-8 As of 19 July 2020, more than 14.0 million cases have been confirmed and over 600,000 deaths. The clinical manifestations of COVID-19 are heterogeneous, ranging from asymptomatic to severe disease and even death. 9,10 Currently, no specific antiviral drug proved by randomized controlled trials or vaccine is available for the prevention and treatment of COVID-19. 8,10,11 A key challenge for clinicians is to identify risk and protective factors for COVID-19 to improve outcomes. A number of epidemiological studies have identified older age, male gender, black and minority ethnicity, and various comorbidities including hypertension,

Impact of SARS-CoV-2 Pandemic on Patients with Primary Immunodeficiency

“…However, our study may strengthen the current understanding of the impact of the pandemic on all subgroups of PID and highlights the requirement of tight measurements in children affected mainly with combined immunodeficiency and immune dysregulation. Of note, several recent studies identified that lymphopenia with prominent decreased T cell (mainly CD8 + cytotoxic T cell) counts are associated with severe COVID-19 condition and mortality [3,[28][29][30][31]. Indeed, lymphopenia seems to correlate with the cytokine profile of the severe patients which resemble our observation in PID patients [30,32].…”

“…ACE2 receptor is ubiquitously expressed on the surfaces of various cell types, including cells of the airway epithelium which is the major site of infection [2]. Besides the ACE2 receptor, SARS-CoV-2 uses the transmembrane serine protease 2 (TMPRSS2), a cellular serine protease, for the host cell entry, which activates the SARS-CoV-2 spike protein by cleaving the Furin site at the S1/S2 subunits [3,4]. Upon entry, the virus can subsequently affect endosomes, and eventually, fuse viral and lysosomal membranes [5].…”

Asthma and allergic diseases are not risk factors for hospitalization in children with coronavirus disease 2019

“…Recently, several studies showed that IL-13 downregulated ACE-2 expression not only in bronchial epithelial cells but also in nasal epithelial cells. 37 Considering the studies done so far, AR does not appear to be a risk factor for COVID-19 either.…”

Diagnostic SARS-CoV-2 Cycle Threshold Value Predicts Disease Severity, Survival, and Six-Month Sequelae in COVID-19 Symptomatic Patients

“…Currently, the emerging evidence is that early Ct values from a nasopharyngeal swab correlate with disease susceptibility (age and comorbidities, such as smoking and hypertension, both associate with potential differential expression of ACE2 receptor [ 41 , 42 ]) and clinical presentations and predict disease severity, survival, and sequelae in symptomatic patients.…”