Biomarkers in COVID-19: how to stratify the Adverse Outcomes in Hospitalized COVID-19 Patients

Background and aimCOVID-19 has heterogeneous clinical manifestations and may evolve in a severe interstitialpneumonia and ARDS with adverse prognosis. Reliable biomarkers allowing early patientsstratification according to the expected disease evolution are still warranted. Growth arrest specific 6(Gas6), together to its receptors named TAM, that are Tyro-3, Axl and Mer and other molecules suchas OPN and CGRP are involved in immune homeostasis, fibrosis, and thrombosis regulation and allof them are promising candidate biomarkers in COVID-19.Materials and MethodsBetween January and May 2021 (Italian third pandemic wave), 139 consecutive SARS-CoV-2positive patients were enrolled in a prospective observational study aimed to evaluate if all theprevious mentioned biomarkers could early predict disease evolution either towards a negative (deathor ICU admission need) or positive (discharge and/or clinical resolution within the first 14 days ofhospitalization) outcome. Plasmatic levels of these molecules were measured by ELISA assays at thetime of hospital admission and after 7 and 14 days of hospitalization.ResultsWe observed that higher plasma biomarker concentrations at hospital admission correlate with aworsening in clinical conditions. At multivariate analysis with correction for demographic andCOVID-19 severity variables (NEWS2 and PiO2/FiO2), some of these biomarkers in different timepoint predicted an adverse prognosis.ConclusionTaken together, these results support the hypothesis that a dysregulation in immune response couldplay a key role in COVID-19 clinical evolution. Gas6 and the TAM receptors, OPN, CGRP and theother biomarkers showing a promising role as a prognostic laboratory parameter useful in drivingclinical decisions according to the expected disease severity and evolution.