Biomarkers for activation of the inflammatory and immune systems in the risk of mortality in critically-ill COVID-19 patients

Abstract

<b>Introduction:</b> Soluble urokinase plasminogen activator receptor (suPAR) has been suggested to reflect general activation of the immune system, while presepsin is considered an emerging biomarker of the&nbsp;innate&nbsp;immune response. In the last years, suPAR and presepsin, have been extensively studied as potential diagnostic and prognostic biomarkers in the intensive care unit (ICU). In this study, we investigated whether these infection biomarkers can be used in assessing mortality risk in in critically-ill COVID-19 patients. <b>Methods:</b> Serum suPAR and presepsin levels were measured on ICU admission (&lt; 48-hours) in 66 COVID-19 patients. Receiver operating characteristic (ROC) curves were generated to assess their value. <b>Results:</b> In our cohort, critically-ill non-survivors had considerably higher suPAR and presepsin levels compared to survivors [7.2 (5.4-13.00) vs. 4.2 (3.2-5.4) ng/ml; p&lt; 0.0001) and 7.1 (2.7-23.5) vs. 0.3 (0.1-2.2) ng/ml; p&lt; 0.0001, respectively]. The prognostic values of suPAR and presepsin from the generated ROC curves were 0.84 (95% CI= 0.73-0.94, p&lt;0.0001) and 0.80 (95% CI= 0.68-0.93, p&lt;0.0001), respectively. Moreover, a Kaplan-Meier survival analysis showed that patients who had higher than the cut-off values generated from the corresponding ROC curves, for both biomarkers, exhibited a greater mortality risk than patients with lower values (Log-Rank test, p = 0.017). <b>Conclusions:</b> suPAR and presepsin measured early after ICU admission could be useful in assessing mortality risk in critically-ill COVID-19 patients.