- Multisystem inflammatory syndrome in children and adolescents temporally related to COVID-19
WHO has developed a preliminary case definition and case report form for multisystem inflammatory disorder in children and adolescents. The preliminary case definition reflects the clinical and laboratory features observed in children reported to date and serves to identify suspected or confirmed cases both for the purpose of providing treatment and for provisional reporting and surveillance. The case definition will be revised as more data become available.
- Cigarette smoke exposure and inflammatory signaling increase the expression of the SARS-CoV-2 receptor ACE2 in the respiratory tract
Cigarette smoke causes a dose-dependent upregulation of Angiotensin Converting Enzyme 2 (ACE2), the SARS-CoV-2 receptor, in rodent and human lungs. Using single-cell sequencing data, authors show that ACE2 is expressed in a subset of secretory cells in the respiratory tract. Chronic smoke exposure triggers the expansion of this cell population and a concomitant increase in ACE2 expression. In contrast, quitting smoking decreases the abundance of these secretory cells and reduces ACE2 levels. These results may partially explain why smokers are particularly susceptible to severe SARS-CoV-2 infections.