ABSTRACT
Objective and design: Several proteases have drawn attention as potential targets to control the SARS-CoV-2 infection (COVID-19), thus circulating enzymatic activity and RAS regulation in severe hospitalized patients still remain to be determined. Material or subjects: 164 patients with COVID-19-like symptoms were grouped according to the severity of symptoms (COVID-19 negative, mild, moderate and severe). Methods: Patients were subjected to biochemical analyzes and to enzymatic activities of ACE2, ACE, DPPIV, PREP and CAT L, evaluated in serum samples. One-way ANOVA and multivariate logistic regression analysis were used. Statistical significance was accepted at p<0.05. Results: We show a correlation among comorbidities, elevated C-reactive protein (CRP) levels and disease severity. Additionally, concomitant high levels of D-dimer and CRP could be as prognostic for severe conditions. Assays of enzymatic activities revealed that, according to disease severity, both ACE2 and CAT L were statistically increased, while ACE, DPPIV and PREP activities were significantly reduced. Notably, analysis of ACE2/ACE ratio suggest a possible imbalance of Ang II/Ang1-7 ratio in severe patients. Conclusion: Our findings reveal the correlation between protease activity and the severity of COVID-19, in addition to highlighting the imbalance of ACE2/ACE ratio, predicting RAS dysregulation, closely related with a poor outcome of disease.