COVID-19, Asthma, and Inhaled Corticosteroids: Another Beneficial Effect of Inhaled Corticosteroids?

Maes et al discuss the study by Peters and colleagues which provides important insights in the complex interplay between asthma, ICS, SARS-CoV-2 infection and COVID-19. The authors hypothesized that differences in the expression of ACE2 (angiotensin-converting enzyme 2) and TMPRSS2 (transmembrane protease serine 2) may modulate the individual susceptibility to and clinical course of SARS-CoV-2 infection and thus identify asthma subgroups at risk for COVID-19 morbidity. Whereas the spike protein of SARS-CoV-2 binds to ACE2 as receptor during viral attachment to host cells, viral entry is also facilitated by priming of the spike protein by the membrane-bound protease TMPRSS2.