Serum ACE as a prognostic biomarker in COVID‐19: a case series

We have earlier proposed that serum ACE (s-ACE) could be used as a biomarker for severity in COVID-19 due to an assumed inverse relationship between ACE and ACE2. High s-ACE could indicate lower ACE2 activity and therefore more widespread and severe SARS-CoV-2 infection, owing to virally mediated downregulation of ACE2 (1). Dysregulation of the renin–angiotensin–aldosterone system (RAAS) is found in comorbidities known as risk factors for...