Baseline Plasma Osteopontin Protein Elevation Predicts Adverse Outcomes in Hospitalized COVID-19 Patients.

More than three years have passed since the first case, and COVID-19 is still a health concern, with several open issues such as the lack of reliable predictors of a patient's outcome. Osteopontin (OPN) is involved in inflammatory response to infection and in thrombosis driven by chronic inflammation, thus being a potential biomarker for COVID-19. The aim of the study was to evaluate OPN for predicting negative (death or need of ICU admission) or positive (discharge and/or clinical resolution within the first 14 days of hospitalization) outcome. We enrolled 133 hospitalized, moderate-to-severe COVID-19 patients in a prospective observational study between January and May 2021. Circulating OPN levels were measured by ELISA at admission and at day 7. The results showed a significant correlation between higher plasma concentrations of OPN at hospital admission and a worsening clinical condition. At multivariate analysis, after correction for demographic (age and gender) and variables of disease severity (NEWS2 and PiO2/FiO2), OPN measured at baseline predicted an adverse prognosis with an odds ratio of 1.01 (C.I. 1.0-1.01). At ROC curve analysis, baseline OPN levels higher than 437 ng/mL predicted a severe disease evolution with 53% sensitivity and 83% specificity (area under the curve 0.649, p = 0.011, likelihood ratio of 1.76, (95% confidence interval (CI): 1.35-2.28)). Our data show that OPN levels determined at the admission to hospital wards might represent a promising biomarker for early stratification of patients' COVID-19 severity. Taken together, these results highlight the involvement of OPN in COVID-19 evolution, especially in dysregulated immune response conditions, and the possible use of OPN measurements as a prognostic tool in COVID-19.

Baseline plasma SARS-CoV-2 RNA detection predicts an adverse COVID-19 evolution in moderate to severe hospitalized patients.

BACKGROUND: SARS-CoV-2 is a single-stranded RNA virus, known to be the causative agent of COVID-19. As the resulting disease shows a very heterogeneous range of clinical manifestations, the identification of early biomarkers allowing patients stratification according to the expected disease severity is still an unmet clinical need. METHODS: In this observational prospective cohort study, 137 consecutive patients, testing positive for SARS-CoV-2 infection by nasopharyngeal swab RT-PCR or antigenic test, were enrolled to evaluate their plasma viral load at the time of hospitalization. RESULTS: Even if all of them had a molecular diagnosis of COVID-19, only 29 patients showed a detectable plasma SARSCoV-2 RNAemia. Such viremic patients also showed other clinical and laboratory finding alterations (increased troponin I, IL-6, RDW-CV and creatinine levels along with decreased platelet count and glomerular filtration rate). A plasma detectable RNA viral load predicted in hospital death or ICU admission with an odds ratio of 3.53 (C.I. 1.44-8.64, p=0.0058), while the lack of a detectable viral load was associated with a faster recovery, with an odds ratio of 4.06 (C.I. 1.72-9.59, p=0.0014). These findings were confirmed in multivariate models including age, sex and baseline National Early Warning Score 2 and arterial oxygen tension over inspired oxygen fraction ratio. CONCLUSIONS: Our data thus suggest that plasma viral RNA load at the time of hospital admission could represent a useful independent biomarker allowing early patients' stratification according to the expected disease evolution, and driving clinical decisions tailored on the specific needs of the individual patient.