Asthma and prognosis of coronavirus disease 2019

It is well-known that asthma patients show compromised production of antiviral interferons and lower expression of ACE-2, most likely owing to ACE-2 expression is inversely correlated with type 2 (Th2: T helper 2) cytokine levels of asthmatics. However, COVID-19 patients with poor outcomes show early vigorous type I interferon expression. This does not match with the pathophysiology of worse COVID-19 disease development in asthma patients. Actually, why asthma might protect against poor outcomes in COVID-19 is explained in detail in recent reviews. Some new data even show decreased mortality in asthma patients. There were no flawless data that asthma patients are at a greater risk of becoming severely ill with SARS-CoV-2 infection, although current reports from the United States and the United Kingdom indicate that asthma is much more common in children and adults with COVID-19 than was formerly described from Asia as well as from central Europe.