Liquid biopsy as a tool for predicts of severe COVID-19 and hospitalised community-acquired pneumonia.

Cell-free DNA (cfDNA) is released into the circulation after apoptosis, necrosis, and active secretion from cells. In a healthy individual, cfDNA is present in small amounts, has a short half-life, and is predominantly derived from circulating hematopoietic cells. The composition and quantity of cfDNA dramatically changes during pathological conditions. Indeed, several studies reported elevated cfDNA concentration as a potential noninvasive biomarker in many diseases. AIM: The aim of the study was evaluation of the circulating cell-free DNA in patients with severe Covid-19 in comparison with patients with hospitalised community-acquired pneumonia (with and without hyperglycemia and type 2 diabetes mellitus) to determine the specificity, sensitivity and cutoff value of cfDNA for each nosology. MATERIALS AND METHODS: The studies were carried out on the basis of city and regional hospitals in the Luhansk region between 2015 to 2021. Were examined in the study 28 patients with a positive diagnosis of COVID-19 according to PCR analysis (14 women and 14 men), 60 patients with community- acquired pneumonia (CAP) (30 women and 30 men), 101 patients with community-acquired pneumonia and hyperglicemia (CAP+HH) (44 women and 57 men), 70 patients with type 2 diabetes mellitus (T2DM) (37 women and 33 men), 42 patients with community-acquired pneumonia in combination with type 2 diabetes mellitus (CAP+T2DM) (27 women and 15 men). The control group consisted of 81 healthy volunteer donor (46 women and 35 men). DNA fragmentation was measured with the diphenylamine assay. Statistical and graphical analyses were done using Statistica 7.0 StatSoft software and using GraphPad Prism version 9.0 (GraphPad Software, La Jolla, CA, USA) software. RESULTS: We found 3-4-fold higher concentration of serum cfDNA levels in COVID-19 patients (womens and mens) compared with healthy controls. Similarly, the levels of cfDNA were 1,5- to 2-fold higher in pneumoniawomens and pneumonia-mens, pneumonia+hyperglycemia-womens and pneumonia+hyperglycemia-mens pneumonia+Type2 Diabetes-womens and pneumonia+Type2 Diabetes-mens, compared with healthy controls. Our results indicate cfDNA profiles on admission can discriminate between patients with COVID-19 and community-acquired pneumonia at risk of severe disease and death with better performance than previously reported inflammatory markers. CONCLUSIONS: Circulating cell-free nucleic acids (cfDNA) are novel potential biomarkers of COVID-19 and community-acquired pneumonia identified. Our study is one of the first to analyze cfDNA level (the cutoff value of cfDNA concentration) for prediction of COVID-19 and community-acquired pneumonia (with and without complications and comorbidity diseases).

Remote monitoring using donor-derived, cell-free DNA after kidney transplantation during the coronavirus disease 2019 pandemic.

BACKGROUND: Donor-derived, cell-free DNA (dd-cfDNA) level correlates with allograft injury with clinical validity and utility for quiescence and active acute rejection (AR) in kidney transplant recipients. We analyzed trends in dd-cfDNA level immediately preceding and during the coronavirus disease 2019 (COVID-19) pandemic with implemented "shelter in place" and a tele-health strategy with remote home phlebotomy to limit COVID-19 exposure. METHODS: During COVID-19 in the United States (US), we surveyed weekly (January 6, 2020-May 25, 2020) metrics for dd-cfDNA corresponding to both a low risk for active rejection (dd-cfDNA < 0.5%) and cohorts with indeterminate levels of 0.5% to 1.0% and > 1.0%. During the study timeframe, over 11,000 patient samples (67%) from 150 kidney transplantation centers were transitioned from standard facility-based to remote phlebotomy. RESULTS: The proportion of dd-cfDNA samples, analyzed in 21 weekly aggregated cohorts by risk-stratification category, was unchanged during the COVID-19 escalation in the US. Linearized slopes for numbers of samples corresponding to indeterminate risk for AR cohorts of > 1.0% and 0.5% to 1.0% were -0.31 and -0.12, respectively; indicating that prevalence of these "at risk for AR cohorts" decreased during remote surveillance. Approximately 73% of samples corresponded to low risk of AR (dd-cfDNA < 0.5%), while an additional 15% of samples had dd-cfDNA level ≤ 1.0%. CONCLUSION: The combination of remote home phlebotomy including dd-cfDNA analysis and a tele-health program offer a new paradigm that may substantially improve patient compliance and assuage anxiety regarding the state of kidney allograft health during the COVID-19 pandemic. Further prospective multi-center studies with robust outcomes data are warranted.

Cell-free nucleic acid patterns in disease prediction and monitoring-hype or hope?

Interest in the use of cell-free nucleic acids (CFNAs) as clinical non-invasive biomarker panels for prediction and prevention of multiple diseases has greatly increased over the last decade. Indeed, circulating CFNAs are attributable to many physiological and pathological processes such as imbalanced stress conditions, physical activities, extensive apoptosis of different origin, systemic hypoxic-ischemic events and tumour progression, amongst others. This article highlights the involvement of circulating CFNAs in local and systemic processes dealing with the question, whether specific patterns of CFNAs in blood, their detection, quantity and quality (such as their methylation status) might be instrumental to predict a disease development/progression and could be further utilised for accompanying diagnostics, targeted prevention, creation of individualised therapy algorithms, therapy monitoring and prognosis. Presented considerations conform with principles of 3P medicine and serve for improving individual outcomes and cost efficacy of medical services provided to the population.