Abstract
This study aimed to investigate the role of the renin-angiotensin system (RAS) in COVID-19, particularly focusing on key components such as ACE, ACE2, and their related peptides, angiotensin-(1-7) and angiotensin-(1-9). Using serum samples from healthy controls and both non-severe and severe COVID-19 patients, ELISA assays revealed no significant differences in these RAS components between the groups. In addition, in vitro studies showed no impact of ACE inhibitors or Angiotensin Receptor Blockers (ARB) on cell viability during SARS-CoV-2 infection. These clinical findings suggest that RAS alterations may not be a major factor in COVID-19 severity and the in vitro data support current guidelines, indicating the safety of continuing ACE inhibitors and ARBs in COVID-19 patients without evidence of increased SARS-CoV-2 infectivity in the presence of these compounds. This study highlights the lack of significant changes in key RAS components during COVID-19 in a clinical cohort and provides critical in vitro evidence supporting the continued use of ACE inhibitors and ARBs in treating patients.