Predictive Value of dsDNA and Nucleosomes as Neutrophil Extracellular Traps-Related Biomarkers for COVID-19 in Older Patients.

Background: Previous studies have demonstrated that neutrophil extracellular traps (NETs) are crucial in infectious diseases. This study aims to evaluate the clinical value of NET-related biomarkers in identifying the risk of COVID-19 and diagnosing the disease.

Methods: This study involved 32 patients who tested positive for COVID-19 via polymerase chain reaction (PCR) between April and August 2023. During the same period, 30 healthy volunteers were enrolled as a control group. The principal biomarkers related to NETs are citrullinated histone H3 (CitH3), double-stranded DNA (dsDNA), myeloperoxidase-DNA complex (MPO-DNA), and Nucleosome. Elevated levels in two or more of these biomarkers indicate raised NET concentrations. Multivariable logistic regression analysis was employed to assess whether NET-related biomarkers were the independent risk factor of COVID-19. The diagnostic value of NET-related biomarkers in COVID-19 was further evaluated using receiver operating characteristic (ROC) curve analysis. Statistical procedures were executed in SPSS software (version 24.0, USA).

Results: Compared with the control group, patients infected with COVID-19 had higher levels of dsDNA and nucleosomes (P < 0.001). Correlation analysis revealed a positive correlation between dsDNA levels and neutrophil count (r = 0.309, P = 0.015) as well as between nucleosome levels and neutrophil count (r = 0.446, P < 0.001). Further analysis showed that dsDNA and nucleosomes were independent risk factors for COVID-19 infection. ROC curve analysis showed that dsDNA area under the curve (AUC) = 0.777, 95% confidence interval (CI), 0.661-0.893, P < 0.001, and nucleosomes (AUC = 0.884, 95% CI, 0.778-0.991, P < 0.001) had well diagnostic value in the diagnosing COVID-19 infection.

Conclusion: NET-related biomarkers, dsDNA and nucleosomes, were independent risk factors of COVID-19 infection and potentially useful biomarkers in diagnosing COVID-19 infection in older patients.