The Role of Soluble ACE2 as a Prognostic Marker in Severe COVID-19: A Brief Meta-Analysis

Background: The recently emerged novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has posed a serious threat to public health, and there is an urgent need to establish tools that can aid the clinician in the evaluation and management of highrisk patients. This meta-analysis aimed to investigate the potential of sACE2 (soluble angiotensinconverting enzyme 2) as a prognostic biomarker in COVID-19. Methods: A comprehensive search of PubMed/MEDLINE, Cochrane, and Google Scholar, was performed until May 26, 2021. Data extraction and quality assessment of the study were independently conducted by the authors. Finally, 6 studies were included in this meta-analysis. Results: ACE-2 serum or plasma levels were compared between COVID-19 patients and healthy controls. ACE-2 level was not significantly different between severe COVID-19 patients and healthy controls (SMD = 1.2; 95% CI: -1.3-1.5; P = 0.86), severe and non-severe COVID-19 patients (SMD = 0.3; 95% CI: -0.06-0.7; P = 0.1), and severe COVID-19 patients and healthy controls (SMD = 0.6; 95% CI: -1.1-2.3; P = 0.5). Conclusions:We cautiously propose that circulating levels of ACE2 cannot be used as a biomarker to assess disease severity in COVID-19 patients.