ABSTRACT
Background: Understanding the role of crucial biomolecules and mechanistic pathways supporting coronavirus disease 2019 (COVID-19) pathophysiology is essential to handle the immune dysregulation and complications driven by uncontrolled severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Thus, we evaluated the proteomics, metabolomics and lipidomics plasma profile in a well-characterized cohort of COVID-19 patients ranging from asymptomatic to critical illness. Methods: This multicenter case-control study enrolled 273 adults with SARS-CoV-2 infection, confirmed by Polymerase chain reaction (PCR), who were recruited within the first 21 days of the infection during the first wave (March-May 2020) of COVID-19 pandemic. Participants were categorized into three groups of severity according to the inclusion criteria described in "Diagnosis and Treatment Protocol for COVID-19 Patients" and distributed as mild (n=77), severe (n=134) and critical (n=62). Serum profile of COVID-19 patients was characterized in the acute phase of the infection using a nontargeted multiomics approach. Univariate and multivariate analyses were performed to identify key molecules involved in critical COVID-19 and to evaluate their predictive power as biomarkers of COVID-19 severity. Results: COVID-19 critically ill patients presented a well-differentiated blood pattern for severe disease. The multiomic analysis identified specific alterations in pathways linked to complement and coagulation cascades, platelet activation, cell adhesion, acute inflammation, energy production (Krebs cycle and Warburg effect), amino acid catabolism and lipid transport as hallmarks of critical COVID-19. A new biomarker panel including the combination of selected proteins, metabolites and lipids predicted with high accuracy the most adverse COVID-19 outcomes (AUC: 0.994, 85.9% specificity and 100% sensitivity). Conclusion: The identification of predictive molecules related to critical COVID-19 outcomes provides a valuable tool for the rapid and efficient identification of clinical worsening in the early stage of SARS-CoV-2 infection. The association of a distinctive proteomic, metabolomic and lipidomic fingerprint with COVID-19 severity provides a better understanding of the immunopathogenesis and the host response to SARS-CoV-2 infection which could help in the identification of potential therapeutic targets.