Relationship of plasma cell-free DNA level with mortality and prognosis in patients with Crimean-Congo hemorrhagic fever

Cell free DNA as a new prognostic biomarker for COVID-19, A prospective cohort study

Predicting the need of hospitalization and intensive care in COVID-19 patients has been challenging with current diagnostic tests since the beginning of the pandemic. We aimed to test cell free DNA (cfDNA) as a novel biomarker for COVID-19 disease severity and mortality. cfDNA concentration was quantified by RT-PCR based test. One hundred and sixty-eight patients(85 outpatients, 61 inpatients,22 ICU) included the study. Mean initial plasma cfDNA levels were significantly different (p < 0.01) in outpatients (1.190,66 ng/ml), inpatients (8.258,10 ng/ml) and ICU patients (84.806,87 ng/ml). ROC analysis showed with 95 % specificity that patients with initial cfDNA concentrations ≥6.389 ng/ml need to be hospitalized and those ≥26.104 ng/ml require ICU referral. cfDNA concentration was correlated with neutrophil/lymphocyte ratio, lymphocyte level, CRP, AST, LDH, CK, fibrinogen, ferritin and D-dimer. Plasma cfDNA levels on admission, well correlating with disease severity and mortality in COVID-19 that found as a useful biomarker.

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

Cell-free DNA (cfDNA) in human blood serum, urine, and other body fluids recently became a commonly used diagnostic marker associated with various pathologies. This is because cfDNA enables a much higher sensitivity than standard biochemical parameters. The presence of and/or increased level of cfDNA has been reported for various diseases, including viral infections, including COVID-19. Here, we review cfDNA in general, how it has been identified, where it can derive from, its molecular features, and mechanisms of release and clearance. General suitability of cfDNA for diagnostic questions, possible shortcomings and future directions are discussed, with a special focus on coronavirus infection.

A systems biology approach to better understand human tick-borne diseases

Tick-borne diseases (TBDs) are a growing global health concern. Despite extensive studies, ill-defined tick-associated pathologies remain with unknown aetiologies. Human immunological responses after tick bite, and inter-individual variations of immune-response phenotypes, are not well characterised. Current reductive experimental methodologies limit our understanding of more complex tick-associated illness, which results from the interactions between the host, tick, and microbes. An unbiased, systems-level integration of clinical metadata and biological host data - obtained via transcriptomics, proteomics, and metabolomics - offers to drive the data-informed generation of testable hypotheses in TBDs. Advanced computational tools have rendered meaningful analysis of such large data sets feasible. This review highlights the advantages of integrative system biology approaches as essential for understanding the complex pathobiology of TBDs.

New Perspectives on the Importance of Cell-Free DNA Biology

Body fluids are constantly replenished with a population of genetically diverse cell-free DNA (cfDNA) fragments, representing a vast reservoir of information reflecting real-time changes in the host and metagenome. As many body fluids can be collected non-invasively in a one-off and serial fashion, this reservoir can be tapped to develop assays for the diagnosis, prognosis, and monitoring of wide-ranging pathologies, such as solid tumors, fetal genetic abnormalities, rejected organ transplants, infections, and potentially many others. The translation of cfDNA research into useful clinical tests is gaining momentum, with recent progress being driven by rapidly evolving preanalytical and analytical procedures, integrated bioinformatics, and machine learning algorithms. Yet, despite these spectacular advances, cfDNA remains a very challenging analyte due to its immense heterogeneity and fluctuation in vivo. It is increasingly recognized that high-fidelity reconstruction of the information stored in cfDNA, and in turn the development of tests that are fit for clinical roll-out, requires a much deeper understanding of both the physico-chemical features of cfDNA and the biological, physiological, lifestyle, and environmental factors that modulate it. This is a daunting task, but with significant upsides. In this review we showed how expanded knowledge on cfDNA biology and faithful reverse-engineering of cfDNA samples promises to (i) augment the sensitivity and specificity of existing cfDNA assays; (ii) expand the repertoire of disease-specific cfDNA markers, thereby leading to the development of increasingly powerful assays; (iii) reshape personal molecular medicine; and (iv) have an unprecedented impact on genetics research.

Importance of endothelial dysfunction biomarkers in patients with Crimean-Congo hemorrhagic fever

The pathogenesis of the Crimean-Congo hemorrhagic fever (CCHF) and the cause of the hemorrhage are not yet fully understood. However, the endothelium plays a key role in the pathogenesis. The purpose of this study was to investigate endothelial dysfunction markers (asymmetrical dimethyl arginine [ADMA], endothelin 1[ET-1], thrombomodulin [TM], von Willebrand factor [vWf], and intercellular adhesion molecule [ICAM-1]) in serum in patients with CCHF and their associations with hemorrhage. Seventy-three patients with CCHF were included in the study. All patients' endothelial dysfunction markers were studied using routine biochemical and hematological tests. The data obtained were then subjected to statistical analysis. Statistically significant differences were determined between the patients and healthy control groups at time of presentation to hospital in terms of ADMA (P < 0.001), ET-1 (P < 0.001), TM (P = 0.039), vWf (P < 0.001), and ICAM-1 (P < 0.001) levels. Only the differences in TM and vWf were significant between the hemorrhagic and non-hemorrhagic groups (P < 0.05). Both serum ADMA and TM levels were significantly higher in the hemorrhage and non-hemorrhage CCHF groups on the 5th day compared to the 1st day (P < 0.05). Levels of endothelial dysfunction markers in CCHF vary in proportion to the damage occurring in the endothelium. ADMA and TM levels were lower in periods with mild endothelial injury. They were increased in line with severity endothelial injury. They may be an early marker in showing hemorrhage. Elevation in ADMA levels and low nitric oxide levels lead to endothelial injury and hemorrhage. Soluble TM that entered the circulation in line with the increased endothelial injury in hemorrhagic patients has been compromised the coagulation cascade.

Prognostic factors, pathophysiology and novel biomarkers in Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a geographically widespread tick-borne zoonosis. The clinical spectrum of the illness varies from mild infection to severe disease and death. In severe cases, hemorrhagic manifestations develop, with fatality rates of 4-20%, depending on the geographic region and quality of the health care. Although vast majority of the CCHF cases were reported from Turkey, mortality rate is lower than the other regions, which is 5% on average. Prediction of the clinical course of the disease enables appropriate management planning by the physician and prompt transportation, if needed, of the patient to a tertiary care hospital for an intensive therapy. Thus, predicting the outcome of the disease may avert potential mortality. There are numerous studies investigating the prognostic factors of CCHF in the literature. Majority of them were reported from Turkey and included investigations on clinical and biochemical parameters, severity scoring systems and some novel biomarkers. Somnolence, bleeding, thrombocytopenia, elevated liver enzymes and prolonged bleeding times are the most frequently reported prognostic factors to predict the clinical course of the disease earlier. High viral load seems to be the strongest predictor to make a clinical decision about the patient outcome. The severity scoring systems based on clinically important mortality-related parameters are especially useful for clinicians working in the field to predict the course of the disease and to decide which patient should be referred to a tertiary care hospital for intensive care. In the light of the pathophysiological characteristics of CCHF, some new biomarkers of prognosis including cytokines, soluble adhesion molecules, genetic polymorphisms and coagulopathy parameters were also investigated. However most of these tests are not available to clinicians and they were obtained mostly for research purposes. In spite of the various studies about prognostic factors, they have several inherent limitations, including large variability in the results and confusing data that are not useful for clinicians in routine practice. In this paper, the results of diverse studies of the prediction of the prognosis in CCHF based on epidemiological, clinical and laboratory findings of the disease were summarized and suggestions for future studies are provided.

Current situation of Crimean-Congo hemorrhagic fever in Southeastern Europe and neighboring countries: a public health risk for the European Union?

Crimean-Congo hemorrhagic fever (CCHF) is the most widespread tick-borne viral infection of humans, occurring across western China through southern Asia, Middle East, and Southeastern Europe (SEE) and in the most of African countries. CCHF virus is maintained through vertical and horizontal transmission in several genera of ticks, mainly in Hyalomma, which spreads the virus to a variety of wild and domestic mammals, which develop a transient viremia without signs of illness. Human infections occur through tick bite or exposure to the blood or other body fluids of an infected animal or of a CCHF patient. In SEE the number of clinical cases of CCHF as well as the areal of the infected ticks continuously rapidly increased after 2000. The aim of this study was to present actual situation of CCHF in SEE. Sources of information include published literature and personal unpublished data.

CONCLUSIONS

Based on: 1. Hyaloma's presence in Western EU countries, 2. Changes in climatic conditions and 3. Absence of an active vaccination against CCHF, it can be expected that this disease will continue to present real threat for human health in SEE and Southwestern Europe (SWE).