Circulating Cell-Free DNA Level in Prediction of COVID-19 Severity and Mortality: Correlation of with Haematology and Serum Biochemical Parameters

Abstract

Lymphocyte dysregulation in coronavirus disease-19 (COVID-19) is a major contributing factor linked to disease severity and mortality. Apoptosis results in the accumulation of cell-free DNA (cfDNA) in circulation. COVID-19 has a heterogeneous clinical course. The role of cfDNA levels was studied to assess the severity and outcome of COVID-19 patients and correlated with other laboratory parameters. The current case series included 100 patients with mild COVID-19 (MCOV-19) and 106 patients with severe COVID-19 (SCOV-19). Plasma cfDNA levels were quantified using SYBR green quantitative real-time PCR through amplification of the β-actin gene. CfDNA level was significantly higher in SCOV-19 at 706.7 ng/ml (522.6–1258) as compared to MCOV-19 at 219.8 ng/ml (167.7–299.6). The cfDNA levels were significantly higher in non-survivor than in survivors ( p = 0.0001). CfDNA showed a significant correlation with NLR, ferritin, LDH, procalcitonin, and IL-6. The diagnostic sensitivity and specificity of cfDNA in the discrimination of SCOV-19 from MCOV-19 were 90.57% & 80%, respectively. CfDNA showed a sensitivity of 94.74% in the differentiation of non-survivors from survivors. CfDNA levels showed a significant positive correlation with other laboratory and inflammatory markers of COVID-19. CfDNA levels, NLR, and other parameters may be used to stratify and monitor COVID-19 patients and predict mortality. CfDNA may be used to predict COVID-19 severity with higher diagnostic sensitivity.

Self-DNA driven inflammation in COVID-19 and after mRNA-based vaccination: lessons for non-COVID-19 pathologies

“…The DAMP most frequently reported for COVID-19 is lactate dehydrogenase, a central enzyme of anaerobic glycolysis that is present in virtually all cells and that, therefore, reliably indicates cell death when occurring at high concentrations in the extracellular space ( 200 – 202 ). Other DAMPs which have been observed at elevated levels in the blood or plasma of patients with severe COVID-19 comprise high-mobility group box protein (HMGB)1 ( 51 , 110 , 111 , 202 – 206 ), S100 proteins ( 108 , 110 , 202 , 207 – 209 ), plasma hyaluronan ( 210 ), extracellular (e)ATP ( 211 , 212 ), the antimicrobial peptide LL-37 ( 213 , 214 ), histones (e.g ( 215 – 217 ), reviewed in ( 218 , 219 ) and circulating self-DNA, including nDNA ( 13 , 20 , 21 , 42 , 46 , 47 ), mtDNA ( 13 , 18 , 21 , 42 , 43 , 48 , 49 ), NET-associated cfDNA ( 201 , 215 , 220 – 222 ), histone-DNA complexes ( 219 ), and cfDNA of non-specified subcellular origin ( 45 , 48 , 50 – 54 ). As recently reviewed for sepsis ( 72 ), most of these studies reported a positive correlation of the plasma levels of at least some of the beforementioned DAMPs with the degree of disease severity (e.g., mild versus severe cases, COVID-19 patients at ICU admission versus healthy controls, ICU-admitted cases with fatal outcomes versus surviving patients, poor oxygenation status, patients with acute respiratory distress syndrome or with multisystem inflammatory syndrome in children, etc.).…”

“…Elevated levels of cf nDNA or mtDNA have been detected in plasma of HIV-1-infected patients ( 87 – 91 ) and of SARS-CoV-2-infected patients ( 19 , 20 , 42 – 44 , 47 , 49 , 52 – 56 , 119 ), as well as in the supernatant of SARS-CoV—infected human airway epithelial cells ( 13 , 18 ).…”

The Diagnostic, Prognostic, and Therapeutic Potential of Cell-Free DNA with a Special Focus on COVID-19 and Other Viral Infections

“…A significant link between antiphospholipid autoantibodies, namely anti-cardiolipin autoantibodies IgG, and serum cfDNA in patients with severe form of COVID-19 was found, that could intensify the thrombo-inflammatory state. Additionally, severely affected patients displayed higher levels of NET biomarker citrullinated histone H3 than mildly affected ones [ 67 ].…”

Evidence for the utility of cfDNA plasma concentrations to predict disease severity in COVID-19: a retrospective pilot study

“…Biomarkers are not only needed for prognosis, but also for predicting response to treatment and thus for improving in the clinical management of patients with COVID-19. Recent studies have linked laboratory measures of hyperinflammation such as macrophage chemoattractant protein 1 (MCP-1), C-reactive protein (CRP) and interleukin-6 (IL-6), ferritin and procalcitonin (PCT) as strong predictors of disease severity in hospitalized patients with COVID-19 ( Broman et al, 2020 ; Jøntvedt Jørgensen et al, 2020 ; Mishra et al, 2022 ). Another promising, non-invasive biomarker of COVID-19 severity from liquid biopsy is cell-free DNA (cfDNA), which is passively released after cell damage and/or actively released from hematopoietic (immune) cells ( Dwivedi et al, 2012 ; Huttunen et al, 2011 ).…”