Breast cancer chemotherapy induces the release of cell-free DNA, a novel procoagulant stimulus

DNA liquid biopsy-based prediction of cancer-associated venous thromboembolism

Cancer-associated venous thromboembolism (VTE) is a major source of oncologic cost, morbidity and mortality. Identifying high-risk patients for prophylactic anticoagulation is challenging and adds to clinician burden. Circulating tumor DNA (ctDNA) sequencing assays ('liquid biopsies') are widely implemented, but their utility for VTE prognostication is unknown. Here we analyzed three plasma sequencing cohorts: a pan-cancer discovery cohort of 4,141 patients with non-small cell lung cancer (NSCLC) or breast, pancreatic and other cancers; a prospective validation cohort consisting of 1,426 patients with the same cancer types; and an international generalizability cohort of 463 patients with advanced NSCLC. ctDNA detection was associated with VTE independent of clinical and radiographic features. A machine learning model trained on liquid biopsy data outperformed previous risk scores (discovery, validation and generalizability c-indices 0.74, 0.73 and 0.67, respectively, versus 0.57, 0.61 and 0.54 for the Khorana score). In real-world data, anticoagulation was associated with lower VTE rates if ctDNA was detected (n = 2,522, adjusted hazard ratio (HR) = 0.50, 95% confidence interval (CI): 0.30-0.81); ctDNA- patients (n = 1,619) did not benefit from anticoagulation (adjusted HR = 0.89, 95% CI: 0.40-2.0). These results provide preliminary evidence that liquid biopsies may improve VTE risk stratification in addition to clinical parameters. Interventional, randomized prospective studies are needed to confirm the clinical utility of liquid biopsies for guiding anticoagulation in patients with cancer.

Effects of chemotherapy treatment with doxorubicin on right ventricular function in dogs

Left ventricular dysfunction in dogs after the administration of doxorubicin (DOX) has been extensively examined. However, the effects of DOX on right ventricular (RV) function remain unknown. Therefore, the present study investigated whether the chemotherapy treatment with DOX decreases RV function. Twelve dogs (five with multicentric lymphoma, four with hemangiosarcoma, two with thyroid cancer, and one with lung adenocarcinoma) that received at least two doses of DOX were prospectively enrolled. Echocardiography and the measurement of troponin I were performed prior to each administration of DOX and approximately one month after the last administration. Right ventricular function was assessed by the RV fractional area change and RV Tei index. Two (n=4), three (n=3), four (n=3), and five (n=2) doses of DOX were administered. While no significant differences were observed in the RV fractional area change, the RV Tei index was significantly impaired after two doses of DOX. Troponin I level significantly increased after four doses. Cumulative doses of DOX correlated with the RV Tei index (r=0.77, P<0.001). The present results demonstrated that the chemotherapy treatment with DOX decreased RV function in a dose-dependent manner in dogs.

Neutrophil extracellular traps in cancer

Neutrophil extracellular traps (NETs), which consist of chromatin DNA studded with granule proteins, are released by neutrophils in response to both infectious and sterile inflammation. Beyond the canonical role in defense against pathogens, the extrusion of NETs also contributes to the initiation, metastasis, and therapeutic response of malignant diseases. Recently, NETs have been implicated in the development and therapeutic responses of various types of tumors. Although extensive work regarding inflammation in tumors has been reported, a comprehensive summary of how these web-like extracellular structures initiate and propagate tumor progression under the specific microenvironment is lacking. In this review, we demonstrate the initiators and related signaling pathways that trigger NETs formation in cancers. Additionally, this review will outline the current molecular mechanisms and regulatory networks of NETs during dormant cancer cells awakening, circulating tumor cells (CTCs) extravasation, and metastatic recurrence of cancer. This is followed by a perspective on the current and potential clinical potential of NETs as therapeutic targets in the treatment of both local and metastatic disease, including the improvement of the efficacy of existing therapies.

Neutrophil extracellular traps mediate neuro-immunothrombosis

Neutrophil extracellular traps are primarily composed of DNA and histones and are released by neutrophils to promote inflammation and thrombosis when stimulated by various inflammatory reactions. Neutrophil extracellular trap formation occurs through lytic and non-lytic pathways that can be further classified by formation mechanisms. Histones, von Willebrand factor, fibrin, and many other factors participate in the interplay between inflammation and thrombosis. Neuro-immunothrombosis summarizes the intricate interplay between inflammation and thrombosis during neural development and the pathogenesis of neurological diseases, providing cutting-edge insights into post-neurotrauma thrombotic events. The blood-brain barrier defends the brain and spinal cord against external assaults, and neutrophil extracellular trap involvement in blood-brain barrier disruption and immunothrombosis contributes substantially to secondary injuries in neurological diseases. Further research is needed to understand how neutrophil extracellular traps promote blood-brain barrier disruption and immunothrombosis, but recent studies have demonstrated that neutrophil extracellular traps play a crucial role in immunothrombosis, and identified modulators of neuro-immunothrombosis. However, these neurological diseases occur in blood vessels, and the mechanisms are unclear by which neutrophil extracellular traps penetrate the blood-brain barrier to participate in immunothrombosis in traumatic brain injury. This review discusses the role of neutrophil extracellular traps in neuro-immunothrombosis and explores potential therapeutic interventions to modulate neutrophil extracellular traps that may reduce immunothrombosis and improve traumatic brain injury outcomes.

In response to bacteria, neutrophils release extracellular vesicles capable of initiating thrombin generation through DNA-dependent and independent pathways

Neutrophils release extracellular vesicles (EVs) and some subsets of neutrophil-derived EVs are procoagulant. In response to S. aureus, neutrophils produce EVs that associate electrostatically with neutrophil extracellular traps (NETs). DNA in NETs is procoagulant, but whether neutrophil EVs produced during bacterial challenge have similar activity is unknown. Given that EV activity is agonist- and cell-type dependent and coagulation contributes to sepsis, we hypothesized that sepsis-causing bacteria increase production of neutrophil-derived EVs, as well as EV-associated DNA, and intact EVs and DNA cause coagulation. We recovered EVs from neutrophils challenged with S. aureus (SA), S. epidermidis (SE), E. coli (EC), and P. aeruginosa (PA), and measured associated DNA and procoagulant activity. EVs from SA-challenged neutrophils (SA-EVs), which were previously characterized, displayed dose-dependent procoagulant activity as measured by thrombin generation (TG) in platelet-poor plasma. EV lysis and DNase treatment reduced TG by 90% and 37%, respectively. SE, EC, and PA also increased EV production and EV-associated extracellular DNA, and these EVs were also procoagulant. Compared to spontaneously released EVs, which demonstrated some ability to amplify Factor XII-dependent coagulation in the presence of an activator, only EVs produced in response to bacteria could initiate the pathway. SA-EVs and SE-EVs had more surface-associated DNA than EC-EVs and PA-EVs, and SA-EVs and SE-EVs contributed to initiation and amplification of TG in a DNA-dependent manner. However, DNA on EC- or PA-EVs played no role, suggesting that neutrophils release procoagulant EVs which can activate the coagulation cascade through both DNA-dependent and independent mechanisms.

Cell-free DNA in plasma and ascites as a biomarker of bevacizumab response- a translational research sub-study of the REZOLVE (ANZGOG-1101) clinical trial

OBJECTIVE

To investigate cell-free DNA (cfDNA) in plasma and ascites and its association with clinical outcomes (paracentesis-free interval, overall survival) and CA125 level in participants with advanced ovarian cancer, treated with palliative intraperitoneal bevacizumab to delay re-accumulation of ascites.

METHODS

cfDNA was extracted from 0.3 to 1 mL samples from 20/24 participants of the REZOLVE trial. Standard and methylation-specific PCRs were performed to measure 3 biomarkers: total cfDNA (Alu), tumour-derived cfDNA (ctDNA, methylated IFFO1 promoter) and endothelium-derived cfDNA (ec-cfDNA, unmethylated CDH5 promoter). Values were correlated to clinical outcomes.

RESULTS

cfDNA was detected in all samples, with higher yield in ascites (mean 669 ng/mL) than plasma (mean 75 ng/mL, p < 0.0001). Ascites had a higher ctDNA proportion than plasma (74 % vs. 20 %, p < 0.0001) and plasma had a higher ec-cfDNA proportion than ascites (24 % vs. 16 %, p < 0.002). High ctDNA proportion (>75 %) in ascites was associated with a significantly shorter paracentesis-free interval (median interval 47.5 versus 84 days, hazard ratio (HR) 2.21, 95 % confidence interval (CI) 0.85 to 5.73, p = 0.039) and ctDNA presence in plasma was unfavourable for survival (median survival 56 versus 242 days, HR 3.21, 95 % CI 1.15 to 9.00, p = 0.008). A significant positive correlation was observed between ctDNA proportion in plasma and CA125 level (p = 0.012). No significant difference in total cfDNA, ctDNA nor ec-cfDNA was observed between participants who were responders versus non-responders.

CONCLUSION

Sufficient cfDNA was detected in both plasma and ascites to study three biomarkers. These samples can provide useful information and should be considered in the design of future ovarian cancer trials.

The Role of Biomarkers in Diagnosis of Sepsis and Acute Kidney Injury

Sepsis and acute kidney injury (AKI) are two major public health concerns that contribute significantly to illness and death worldwide. Early diagnosis and prompt treatment are essential for achieving the best possible outcomes. To date, there are no specific clinical, imaging, or biochemical indicators available to diagnose sepsis, and diagnosis of AKI based on the KDIGO criterion has limitations. To improve the diagnostic process for sepsis and AKI, it is essential to continually evolve our understanding of these conditions. Delays in diagnosis and appropriate treatment can have serious consequences. Sepsis and AKI often occur together, and patients with kidney dysfunction are more prone to developing sepsis. Therefore, identifying potential biomarkers for both conditions is crucial. In this review, we talk about the main biomarkers that evolve the diagnostic of sepsis and AKI, namely neutrophil gelatinase-associated lipocalin (NGAL), proenkephalin (PENK), and cell-free DNA.

Biomarkers of peripheral blood neutrophil extracellular traps in the diagnosis and progression of malignant tumors

BACKGROUND AND AIMS

The mortality rate associated with malignant tumors remains high and there is a lack of effective diagnostic and tumor progression markers. Neutrophil extracellular traps (NETs) can promote tumor-associated thrombosis, invasive metastasis, and inflammatory responses, but there is a lack of research on the value of measuring NETs in the peripheral blood of patients with malignancies.

METHODS

We included 263 patients with malignancies (55 gliomas, 101 ovarian, 64 colorectal, and 43 lung cancers) and 75 healthy controls in this study. We compared the levels of citrullinated histone H3 (citH3), cell-free DNA (cfDNA), and systemic inflammation-related parameters, including neutrophils, lymphocytes, monocytes, platelets, neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune inflammation index, and systemic inflammation response index. We assessed the value of changes in NETs in peripheral blood to determine the diagnosis, venous thromboembolism, clinical staging, and systemic inflammatory response in patients with malignancy.

RESULTS

The levels of citH3 and cfDNA in peripheral blood can distinguish between healthy controls and tumor patients. The levels of citH3 and cfDNA before clinical intervention did not predict the risk of combined venous thromboembolism in oncology patients in the short-term after clinical intervention. The levels of citH3, cfDNA, and systemic inflammation-related parameters in the peripheral blood of tumor patients increased with the clinical stage. There was a correlation between cfDNA levels in peripheral blood and systemic inflammation-related parameters in tumor patients, and this correlation was more significant in patients with advanced tumors.

CONCLUSIONS

Changes in NETs in the peripheral blood differ between healthy controls and patients with malignant tumors. NETs may be involved in tumor-induced systemic inflammatory responses through interaction with circulating inflammatory cells, thus promoting tumor progression. NETs may be used as markers to assist in the diagnosis and progression of tumor malignancy.

Impaired fibrinolysis and increased clot strength are potential risk factors for thrombosis in lymphoma

Thrombosis and bleeding are significant contributors to morbidity and mortality in patients with hematological cancer, and the impact of altered fibrinolysis on bleeding and thrombosis risk is poorly understood. In this prospective cohort study, we investigated the dynamics of fibrinolysis in patients with hematological cancer. Fibrinolysis was investigated before treatment and 3 months after treatment initiation. A dynamic clot formation and lysis assay was performed beyond the measurement of plasminogen activator inhibitor 1, tissue- and urokinase-type plasminogen activators (tPA and uPA), plasmin-antiplasmin complexes (PAP), α-2-antiplasmin activity, and plasminogen activity. Clot initiation, clot propagation, and clot strength were assessed using rotational thromboelastometry. A total of 79 patients were enrolled. Patients with lymphoma displayed impaired fibrinolysis with prolonged 50% clot lysis time compared with healthy controls (P = .048). They also displayed decreased clot strength at follow-up compared with at diagnosis (P = .001). A patient with amyloid light-chain amyloidosis having overt bleeding at diagnosis displayed hyperfibrinolysis, indicated by a reduced 50% clot lysis time, α-2-antiplasmin activity, and plasminogen activity, and elevated tPA and uPA. A patient with acute promyelocytic leukemia also displayed marked hyperfibrinolysis with very high PAP, indicating extreme plasmin generation, and clot formation was not measurable, probably because of the extremely fast fibrinolysis. Fibrinolysis returned to normal after treatment in both patients. In conclusion, patients with lymphoma showed signs of impaired fibrinolysis and increased clot strength, whereas hyperfibrinolysis was seen in patients with acute promyelocytic leukemia and light-chain amyloidosis. Thus, investigating fibrinolysis in patients with hematological cancer could have diagnostic value.

Neutrophil extracellular traps mediate deep vein thrombosis: from mechanism to therapy

Deep venous thrombosis (DVT) is a part of venous thromboembolism (VTE) that clinically manifests as swelling and pain in the lower limbs. The most serious clinical complication of DVT is pulmonary embolism (PE), which has a high mortality rate. To date, its underlying mechanisms are not fully understood, and patients usually present with clinical symptoms only after the formation of the thrombus. Thus, it is essential to understand the underlying mechanisms of deep vein thrombosis for an early diagnosis and treatment of DVT. In recent years, many studies have concluded that Neutrophil Extracellular Traps (NETs) are closely associated with DVT. These are released by neutrophils and, in addition to trapping pathogens, can mediate the formation of deep vein thrombi, thereby blocking blood vessels and leading to the development of disease. Therefore, this paper describes the occurrence and development of NETs and discusses the mechanism of action of NETs on deep vein thrombosis. It aims to provide a direction for improved diagnosis and treatment of deep vein thrombosis in the near future.

Pathophysiology of Disseminated Intravascular Coagulation in Sepsis: A Clinically Focused Overview

Sepsis is a major global health problem that results from a dysregulated and uncontrolled host response to infection, causing organ failure. Despite effective anti-infective therapy and supportive treatments, the mortality rate of sepsis remains high. Approximately 30-80% of patients with sepsis may develop disseminated intravascular coagulation (DIC), which can double the mortality rate. There is currently no definitive treatment approach for sepsis, with etiologic treatment being the cornerstone of therapy for sepsis-associated DIC. Early detection, diagnosis, and treatment are critical factors that impact the prognosis of sepsis-related DIC. Over the past several decades, researchers have made continuous efforts to better understand the mechanisms of DIC in sepsis, as well as improve its quantitative diagnosis and treatment. This article aims to provide a comprehensive overview of the current understanding of sepsis-related DIC, focusing on common causes and diagnoses, with the goal of guiding healthcare providers in the care of patients with sepsis.

Neutrophil-intrinsic TNF receptor signaling orchestrates host defense against Staphylococcus aureus

Staphylococcus aureus is the leading cause of skin and soft tissue infections and is a major health burden due to the emergence of antibiotic-resistant strains. To address the unmet need of alternative treatments to antibiotics, a better understanding of the protective immune mechanisms against S. aureus skin infection is warranted. Here, we report that tumor necrosis factor (TNF) promoted protection against S. aureus in the skin, which was mediated by bone marrow-derived immune cells. Furthermore, neutrophil-intrinsic TNF receptor (TNFR) signaling directed immunity against S. aureus skin infections. Mechanistically, TNFR1 promoted neutrophil recruitment to the skin, whereas TNFR2 prevented systemic bacterial dissemination and directed neutrophil antimicrobial functions. Treatment with a TNFR2 agonist showed therapeutic efficacy against S. aureus and Pseudomonas aeruginosa skin infections, which involved increased neutrophil extracellular trap formation. Our findings revealed nonredundant roles for TNFR1 and TNFR2 in neutrophils for immunity against S. aureus and can be therapeutically targeted for protection against bacterial skin infections.

Thrombin-mediated activation of PAR1 enhances doxorubicin-induced cardiac injury in mice

The chemotherapeutic drug doxorubicin is cardiotoxic and can cause irreversible heart failure. In addition to being cardiotoxic, doxorubicin also induces the activation of coagulation. We determined the effect of thrombin-mediated activation of protease-activated receptor 1 (PAR1) on doxorubicin-induced cardiac injury. Administration of doxorubicin to mice resulted in a significant increase in plasma prothrombin fragment 1+2, thrombin-antithrombin complexes, and extracellular vesicle tissue factor activity. Doxorubicin-treated mice expressing low levels of tissue factor, but not factor XII-deficient mice, had reduced plasma thrombin-antithrombin complexes compared to controls. To evaluate the role of thrombin-mediated activation of PAR1, transgenic mice insensitive to thrombin (Par1R41Q) or activated protein C (Par1R46Q) were subjected to acute and chronic models of doxorubicin-induced cardiac injury and compared with Par1 wild-type (Par1+/+) and PAR1 deficient (Par1-/-) mice. Par1R41Q and Par1-/- mice, but not Par1R46Q mice, demonstrated similar reductions in the cardiac injury marker cardiac troponin I, preserved cardiac function, and reduced cardiac fibrosis compared to Par1+/+ controls after administration of doxorubicin. Furthermore, inhibition of Gαq signaling downstream of PAR1 with the small molecule inhibitor Q94 significantly preserved cardiac function in Par1+/+ mice, but not in Par1R41Q mice subjected to the acute model of cardiac injury when compared to vehicle controls. In addition, mice with PAR1 deleted in either cardiomyocytes or cardiac fibroblasts demonstrated reduced cardiac injury compared to controls. Taken together, these data suggest that thrombin-mediated activation of PAR1 contributes to doxorubicin-induced cardiac injury.

Inhibitors of Polyphosphate and Neutrophil Extracellular Traps

The contact pathway of blood clotting has received intense interest in recent years as studies have linked it to thrombosis, inflammation, and innate immunity. Because the contact pathway plays little to no role in normal hemostasis, it has emerged as a potential target for safer thromboprotection, relative to currently approved antithrombotic drugs which all target the final common pathway of blood clotting. Research since the mid-2000s has identified polyphosphate, DNA, and RNA as important triggers of the contact pathway with roles in thrombosis, although these molecules also modulate blood clotting and inflammation via mechanisms other than the contact pathway of the clotting cascade. The most significant source of extracellular DNA in many disease settings is in the form of neutrophil extracellular traps (NETs), which have been shown to contribute to incidence and severity of thrombosis. This review summarizes known roles of extracellular polyphosphate and nucleic acids in thrombosis, with an emphasis on novel agents under current development that target the prothrombotic activities of polyphosphate and NETs.

NETs-Induced Thrombosis Impacts on Cardiovascular and Chronic Kidney Disease

Arterial and venous thrombosis constitute a major source of morbidity and mortality worldwide. Association between thrombotic complications and cardiovascular and other chronic inflammatory diseases are well described. Inflammation and subsequent initiation of thrombotic events, termed immunothrombosis, also receive growing attention but are still incompletely understood. Nevertheless, the clinical relevance of aberrant immunothrombosis, referred to as thromboinflammation, is evident by an increased risk of thrombosis and cardiovascular events in patients with inflammatory or infectious diseases. Proinflammatory mediators released from platelets, complement activation, and the formation of NETs (neutrophil extracellular traps) initiate and foster immunothrombosis. In this review, we highlight and discuss prominent and emerging interrelationships and functions between NETs and other mediators in immunothrombosis in cardiovascular disease. Also, with patients with chronic kidney disease suffering from increased cardiovascular and thrombotic risk, we summarize current knowledge on neutrophil phenotype, function, and NET formation in chronic kidney disease. In addition, we elaborate on therapeutic targeting of NETs-induced immunothrombosis. A better understanding of the functional relevance of antithrombotic mediators which do not increase bleeding risk may provide opportunities for successful therapeutic interventions to reduce thrombotic risk beyond current treatment options.

How much (evil) intelligence can be encoded by 30 kb?

Genomes of most RNA viruses are rarely larger than the size of an average human gene (10-15 kb) and still code for a number of biologically active polypeptides that modify the immune system and metabolism of the host organism in an amazingly complex way. Prolonged coevolution developed tricks by which viruses can dodge many protective mechanisms of the host and lead to the formation of molecular mimicry patterns. Some viruses inhibit the interferon response, interfere with the membrane destroying effects of the activated complement cascade. They can replicate in cellular compartments formed by inner membranes of the cell hiding their characteristic features from diverse pattern recognition receptors. In many cases-and in this respect, the new coronavirus is a champion-they can exploit our own defensive mechanisms to cause serious harm, severe symptoms and frequently deadly disease.

Beta 2 glycoprotein I and neutrophil extracellular traps: Potential bridge between innate and adaptive immunity in anti-phospholipid syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by recurrent vascular thrombosis and miscarriages in the absence of known causes. Antibodies against phospholipid-binding proteins (aPL) are pathogenic players in both clotting and pregnancy APS manifestations. There is sound evidence that antibodies specific for beta2 glycoprotein I (β2GPI) trigger thrombotic and pregnancy complications by interacting with the molecule on the membranes of different cell types of the coagulation cascade, and in placenta tissues. In addition to the humoral response against β2GPI, both peripheral and tissue CD4⁺ β2GPI-specific T cells have been reported in primary APS as well as in systemic lupus erythematosus (SLE)-associated APS. While adaptive immunity plays a clear role in APS, it is still debated whether innate immunity is involved as well. Acute systemic inflammation does not seem to be present in the syndrome, however, there is sound evidence that complement activation is crucial in animal models and can be found also in patients. Furthermore, neutrophil extracellular traps (NETs) have been documented in arterial and venous thrombi with different etiology, including clots in APS models. Keeping in mind that β2GPI is a pleiotropic glycoprotein, acting as scavenger molecule for infectious agents and apoptotic/damaged body constituents and that self-molecules externalized through NETs formation may become immunogenic autoantigens, we demonstrated β2GPI on NETs, and its ability to stimulate CD4⁺β2GPI-specific T cells. The aim of this review is to elucidate the role of β2GPI in the cross-talk between the innate and adaptive immunity in APS.

Neutrophil extracellular traps: A novel target for the treatment of stroke

Stroke is a threatening cerebrovascular disease caused by thrombus with high morbidity and mortality rates. Neutrophils are the first to be recruited in the brain after stroke, which aggravate brain injury through multiple mechanisms. Neutrophil extracellular traps (NETs), as a novel regulatory mechanism of neutrophils, can trap bacteria and secret antimicrobial molecules, thereby degrading pathogenic factors and killing bacteria. However, NETs also exacerbate certain non-infectious diseases by activating autoimmune or inflammatory responses. NETs have been found to play important roles in the pathological process of stroke in recent years. In this review, the mechanisms of NETs formation, the physiological roles of NETs, and the dynamic changes of NETs after stroke are summarized. NETs participate in stroke through various mechanisms. NETs promote the coagulation cascade and interact with platelets to induce thrombosis. tPA induces the degranulation of neutrophils to form NETs, leading to hemorrhagic transformation and thrombolytic resistance. NETs aggravate stroke by mediating inflammation, atherosclerosis and vascular injury. In addition, the regulation of NETs in stroke, the potential of NETs as biomarker and the treatment of stroke targeting NETs are discussed. The increasing evidences suggest that NETs may be a potential target for stroke treatment. Inhibition of NETs formation or promotion of NETs degradation plays protective effects in stroke. However, how to avoid the adverse effects of NETs-targeted therapy deserves further study. In summary, this review provides a reference for the pathogenesis, drug targets, biomarkers and drug development of NETs in stroke.

Eating the Enemy: Mycoplasma Strategies to Evade Neutrophil Extracellular Traps (NETs) Promoting Bacterial Nucleotides Uptake and Inflammatory Damage

Neutrophils are effector cells involved in the innate immune response against infection; they kill infectious agents in the intracellular compartment (phagocytosis) or in the extracellular milieu (degranulation). Moreover, neutrophils release neutrophil extracellular traps (NETs), complex structures composed of a scaffold of decondensed DNA associated with histones and antimicrobial compounds; NETs entrap infectious agents, preventing their spread and promoting their clearance. NET formation is triggered by microbial compounds, but many microorganisms have evolved several strategies for NET evasion. In addition, the dysregulated production of NETs is associated with chronic inflammatory diseases. Mycoplasmas are reduced genome bacteria, able to induce chronic infections with recurrent inflammatory symptoms. Mycoplasmas' parasitic lifestyle relies on metabolite uptake from the host. Mycoplasmas induce NET release, but their surface or secreted nucleases digest the NETs' DNA scaffold, allowing them to escape from entrapment and providing essential nucleotide precursors, thus promoting the infection. The presence of Mycoplasma species has been associated with chronic inflammatory disorders, such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, Crohn's disease, and cancer. The persistence of mycoplasma infection and prolonged NET release may contribute to the onset of chronic inflammatory diseases and needs further investigation and insights.

PAD4 and Its Inhibitors in Cancer Progression and Prognosis

The systemic spread of malignancies and the risk of cancer-associated thrombosis are major clinical challenges in cancer therapy worldwide. As an important post-translational modification enzyme, peptidyl arginine deiminase 4 (PAD4) could mediate the citrullination of protein in different components (including nucleus and cytoplasm, etc.) of a variety of cells (tumor cells, neutrophils, macrophages, etc.), thus participating in gene regulation, neutrophil extracellular trap (NET) and macrophage extracellular trap (MET). Thereby, PAD4 plays an important role in enhancing the growth of primary tumors and facilitating the distant metastasis of cancer cells. In addition, it is related to the formation of cancer-associated thrombosis. Therefore, the development of PAD4-specific inhibitors may be a promising strategy for treating cancer, and it may improve patient prognosis. In this review, we describe PAD4 involvement in gene regulation, protein citrullination, and NET formation. We also discuss its potential role in cancer and cancer-associated thrombosis, and we summarize the development and application of PAD4 inhibitors.

Analysis of cell-free circulating DNA fragment size and level in patients with lumbar canal stenosis

Cell-free circulating DNA (cfDNA), extracted by liquid biopsy, has been studied as a noninvasive biomarker for various diseases. The potential of cfDNA fragment size and level as a marker in lumbar canal stenosis (LCS) patients has never been studied. We investigated whether cfDNA is a biomarker of low back pain, leg pain, leg numbness severity in patients with an LCS. Blood samples were obtained from patients with LCS (n = 22) before and immediately after spinal surgery. Plasma DNA was isolated and examined for cfDNA fragment size and concentration. A cohort of healthy volunteers (n = 5) constituted the control group. The cfDNA fragment size tended to be shorter in patients than in healthy controls, but this difference was not significant (P = .186). cfDNA level was significantly higher in LCS patients (mean 0.614 ± 0.198 ng/μL, range 0.302-1.150 ng/μL) than in healthy controls (mean 0.429 ± 0.064 ng/μL, range 0.366-0.506 ng/μL) (P = .008). cfDNA level correlated positively with average pain (r = .435, P = .026) and leg numbness (r = .451, P = .018). cfDNA fragment size did not differ from before to after surgery, but cfDNA level increased postoperatively in patients with LCS. This was the first study investigating whether cfDNA fragment size and level are associated with pain in patients with LCS. Our findings suggest that cfDNA level may be an objective indicator of pain and surgical invasiveness in patients with LCS.

The thrombodynamic ratio as a predictor of 28-day mortality in sepsis patients

BACKGROUND

The thrombodynamic ratio (TDR) as a composite thromboelastography (TEG) parameter, has been proven to be valuable in multiple diseases. However, the association between TDR and mortality in sepsis has not been studied.

METHODS

One hundred forty-one patients were enrolled in this retrospectively study. TEG was performed immediately at admission. Two cox proportional hazards models were developed for the prediction of 28-day mortality. The C statistic, continuous net reclassification index (cNRI) and integrated discriminatory index (IDI) were calculated to compare the discrimination performance of clinical models with and without the TDR value. The integrated calibration index (ICI) and E50 were calculated to compare the calibration.

RESULTS

Patients with lower TDR were more likely to have organ impairments and increased 28-day mortality. The TDR value improved discrimination performance in both Model 1 (C statistic, 0.745 vs 0.735; cNRI 19.4%, p =0.044; IDI 5.6%, p =0.012) and Model 2 (C statistic, 0.761 vs 0.751; IDI, 5.1%, p = 0.012). Compared to the calibration curve of Model 1 without TDR, addition of TDR displayed better calibration (ICI, 0.023; E50, 0.021).

CONCLUSION

TDR value significantly predicts 28-day mortality in patients with sepsis and could improve the discrimination and calibration performance of clinical prediction models.

Longitudinal Study of Circulating Biomarkers in Patients with Resectable Pancreatic Ductal Adenocarcinoma

While patients with resectable pancreatic ductal adenocarcinoma (PDAC) show improved survival compared to their non-resectable counterparts, survival remains low owing to occult metastatic disease and treatment resistance. Liquid biopsy based on circulating tumor cells (CTCs) and cell-free DNA (cfDNA) has been shown to predict recurrence and treatment resistance in various types of cancers, but their utility has not been fully demonstrated in resectable PDAC. We have simultaneously tracked three circulating biomarkers, including CTCs, cfDNA, and circulating tumor DNA (ctDNA), over a period of cancer treatment using a microfluidic device and droplet digital PCR (ddPCR). The microfluidic device is based on the combination of filtration and immunoaffinity mechanisms. We have measured CTCs, cfDNA, and ctDNA in a cohort of seven resectable PDAC patients undergoing neoadjuvant therapy followed by surgery, and each patient was followed up to 10 time points over a period of 4 months. CTCs were detectable in all patients (100%) at some point during treatment but were detectable in only three out of six patients (50%) prior to the start of treatment. Median cfDNA concentrations remained comparable to negative controls throughout treatment. ddPCR was able to find KRAS mutations in six of seven patients (86%); however, these mutations were present in only two of seven patients (29%) prior to treatment. Overall, the majority of circulating biomarkers (81% for CTCs and 91% for cfDNA/ctDNA) were detected after the start of neoadjuvant therapy but before surgery. This study suggests that a longitudinal study of circulating biomarkers throughout treatment provides more useful information than those single time-point tests for resectable PDAC patients.

Impact of Circulating Tumor DNA-Based Detection of Molecular Residual Disease on the Conduct and Design of Clinical Trials for Solid Tumors

Earlier detection of cancer recurrence using circulating tumor DNA (ctDNA) to detect molecular residual disease (MRD) has the potential to dramatically affect cancer management. We review evidence supporting the use of ctDNA as a biomarker for detection of MRD and highlight the potential impact that ctDNA testing could have on the conduct of clinical trials.

Exploitation of treatment induced tumor lysis to enhance the sensitivity of ctDNA analysis: A first-in-human pilot study

INTRODUCTION

Blood-based liquid biopsies examining circulating tumour DNA (ctDNA) have increasing applications in non-small cell lung cancer (NSCLC). Limitations in sensitivity remain a barrier to ctDNA replacing tissue-based testing. We hypothesized that testing immediately after starting treatment would yield an increased abundance of ctDNA in plasma because of tumor lysis, allowing for the detection of genetic alterations that were occult in baseline testing.

METHODS

Three prospective cohorts of patients with stage III/IV NSCLC were enrolled. Cohort 1 (C1) contained patients starting platinum doublet chemoradiation (n = 10) and cohort 2 (C2) initiating platinum doublet cytotoxic chemotherapy ± immunotherapy (n = 10). Cohort 3 (C3) contained patients receiving palliative radiation. Two baseline samples were collected. In C1 and C2, subsequent samples were collected 3, 6, 24 and 48 h post initiation of chemotherapy. Patients in C3 had samples collected immediately prior to the next three radiotherapy fractions. Samples were analyzed for ctDNA using the 36-gene amplicon-based NGS Inivata InVisionFirst®-Lung assay.

RESULTS

A total of 40 patients were enrolled. Detectable ctDNA was present at baseline in 32 patients (80%), 4 additional patients (50%) had detectable ctDNA in post-treatment samples. Seven patients with detectable ctDNA at baseline (23%) had new genetic alterations detected in post-treatment samples. Mutant molecule numbers increased with treatment in 24 of 31 (77%) pts with detectable ctDNA. ctDNA levels peaked a median of 7 h (IQR:2-26 h) after the initiation of chemotherapy and a median of 2 days (IQR:1-3 days) after radiation was commenced.

CONCLUSION

ctDNA levels increase in the hours to days after starting treatment. ctDNA testing in the acute post-treatment phase can yield results that were not evident in pre-treatment testing. Application of this principle could improve ctDNA utility as an alternate to tissue-based testing and improve sensitivity for the detection of treatment-resistant clones.(NCT03986463).

Cancer-associated venous thromboembolism

Cancer-associated thrombosis (including venous thromboembolism (VTE) and arterial events) is highly consequential for patients with cancer and is associated with worsened survival. Despite substantial improvements in cancer treatment, the risk of VTE has increased in recent years; VTE rates additionally depend on the type of cancer (with pancreas, stomach and primary brain tumours having the highest risk) as well as on individual patient's and cancer treatment factors. Multiple cancer-specific mechanisms of VTE have been identified and can be classified as mechanisms in which the tumour expresses proteins that alter host systems, such as levels of platelets and leukocytes, and in which the tumour expresses procoagulant proteins released into the circulation that directly activate the coagulation cascade or platelets, such as tissue factor and podoplanin, respectively. As signs and symptoms of VTE may be non-specific, diagnosis requires clinical assessment, evaluation of pre-test probability, and objective diagnostic testing with ultrasonography or CT. Risk assessment tools have been validated to identify patients at risk of VTE. Primary prevention of VTE (thromboprophylaxis) has long been recommended in the inpatient and post-surgical settings, and is now an option in the outpatient setting for individuals with high-risk cancer. Anticoagulant therapy is the cornerstone of therapy, with low molecular weight heparin or newer options such as direct oral anticoagulants. Personalized treatment incorporating risk of bleeding and patient preferences is essential, especially as a diagnosis of VTE is often considered by patients even more distressing than their cancer diagnosis, and can severely affect the quality of life. Future research should focus on current knowledge gaps including optimizing risk assessment tools, biomarker discovery, next-generation anticoagulant development and implementation science.

Mechanistic Studies of DNase I Activity: Impact of Heparin Variants and PAD4

Background

Excessive production of neutrophil extracellular traps (NETs) in sepsis contributes to vascular occlusion by acting as a scaffold and stimulus for thrombus formation. Removal of extracellular DNA, the major structural component of NETs, by DNase I may reduce host injury.

Objectives

(1) To determine how heparin variants (unfractionated heparin, enoxaparin, Vasoflux, and fondaparinux) affect DNase I activity, (2) to measure temporal changes in circulating DNA and DNase I in septic patients.

Methods

DNA–histone complexes were treated with DNase I ± heparin variants and visualized via agarose gels. We compared the ability of DNase I ± heparin variants to digest NETs released by phorbol 12-myristate 13-acetate-stimulated neutrophils versus DNA–histone complexes released by necrotic HEK293 cells. Plasma DNA and DNase I levels were measured longitudinally in 76 septic patients.

Results

Heparin enhances DNase I-mediated digestion of DNA–histone complexes in a size-dependent manner that does not require the antithrombin-binding region. In contrast, DNase I alone was able to degrade the DNA–histone component of NETs presumably due to peptidylarginine deiminase 4 (PAD4)-mediated histone citrullination that weakens DNA–histone interactions. In purified systems, PAD4 treatment of DNA–histone complexes enhanced the ability of DNase I to degrade histone-bound DNA. In septic patients, endogenous DNase I levels remained persistently low over 28 days, and there were no significant correlations between DNA and DNase I levels.

Conclusion

Heparin enhances DNA-mediated digestion of DNA–histone complexes in a size-dependent manner that is independent of its anticoagulant properties. Citrullination of histones by PAD4 renders DNA–histone complexes susceptible to DNase I digestion. Endogenous DNase I levels are persistently decreased in septic patients, which supports the potential utility of DNase I as a therapy for sepsis.

NETosis in ischemic/reperfusion injuries: An organ-based review

Neutrophil extracellular trap (NETosis), the web-like structures induced by neutrophil death, is an important inflammatory mechanism of the immune system leading to reactive oxygen species production/coagulopathy, endothelial dysfunction, atherosclerosis, and ischemia. NETosis exerts its role through different mechanisms such as triggering Toll-like receptors, inflammatory cytokines, platelet aggregation, neutrophil activation/infiltration, and vascular impairment. NETosis plays a key role in the prognosis of coronary artery disease, ischemic injury of kidney, lung, gastrointestinal tract and skeletal muscles. In this review, we explored the molecular mechanisms involved in NETosis, and ischemic/reperfusion injuries in body organs.

Influence of nanoparticles on the haemostatic balance: between thrombosis and haemorrhage

Maintenance of a delicate haemostatic balance or a balance between clotting and bleeding is critical to human health. Irrespective of administration route, nanoparticles can reach the bloodstream and might interrupt the haemostatic balance by interfering with one or more components of the coagulation, anticoagulation, and fibrinolytic systems, which potentially lead to thrombosis or haemorrhage. However, inadequate understanding of their effects on the haemostatic balance, along with the fact that most studies mainly focus on the functionality of nanoparticles while forgetting or leaving behind their risk to the body's haemostatic balance, is a major concern. Hence, our review aims to provide a comprehensive depiction of nanoparticle-haemostatic balance interactions, which has not yet been covered. The synergistic roles of cells and plasma factors participating in haemostatic balance are presented. Possible interactions and interference of each type of nanoparticle with the haemostatic balance are comprehensively discussed, particularly focusing on the underlying mechanisms. Interactions of nanoparticles with innate immunity potentially linked to haemostasis are mentioned. Various physicochemical characteristics that influence the nanoparticle-haemostatic balance are detailed. Challenges and future directions are also proposed. This insight would be valuable for the establishment of nanoparticles that can either avoid unintended interference with the haemostatic balance or purposely downregulate/upregulate its key components in a controlled manner.

Circulating DNA changes are predictive of disease progression after transarterial chemoembolization

Transarterial chemoembolization (TACE) is used to treat patients with unresectable hepatocellular carcinoma (HCC). We evaluated the clinical impact of a-fetoprotein (AFP) and circulating cell-free and tumor DNA (cfDNA and ctDNA) changes around the TACE procedure. Our prospective monocentric study enrolled consecutive patients treated with TACE, with samples collected at baseline (D - 1), Day 2 (D + 2) and 1 month (M + 1) after TACE. cfDNA was quantified by the fluorometric method, and ctDNA was quantified by digital polymerase chain reaction designed for two hotspot TERT mutations. Computerized tomography scans or magnetic resonance imaging were performed at M + 1 every 3 months following TACE and independently reviewed. The objective was to identify thresholds of cfDNA, ctDNA and AFP changes associated with progressive disease (PD) using receiver operating characteristic curves. Thirty-eight patients were included from March 2018 to March 2019. All markers significantly increased from D - 1 to D + 2 (P < .005), and cfDNA and ctDNA significantly decreased from D + 2 to M + 1 (P < .0001). The analysis of changes from D - 1 to M + 1 identified thresholds at +31.4% for cfDNA and 0% for ctDNA that were significantly associated with PD at M + 1 (44.4% [>+31.4%] vs 3.8% [≤+31.4%] and 50.0% [>0%] vs 5.0% [≤0%], respectively). No significant threshold was identified for AFP. Using a score combining cfDNA and ctDNA, the patients were classified into high- or low-risk PD groups at M + 1, with PD rates of 80.0% vs 4.3% (P = .001) and median progression-free survival times of 1.3 vs 10.3 months (P = .002). Our study suggests that cfDNA and ctDNA increases around the TACE procedure and are associated with therapeutic failure.

Stabilin-2 deficiency increases thrombotic burden and alters the composition of venous thrombi in a mouse model

BACKGROUND

Stabilin-2 is an endocytic scavenger receptor that mediates the clearance of glycosaminoglycans, phosphatidylserine-expressing cells, and the von Willebrand factor-factor VIII (FVIII) complex. In a genome-wide screening study, pathogenic loss-of-function variants in the human STAB2 gene associated with an increased incidence of unprovoked venous thromboembolism (VTE). However, the specific mechanism(s) by which stabilin-2 deficiency influences the pathogenesis of VTE is unknown.

OBJECTIVES

The aim of this study was to assess the influence of stabilin-2 on deep vein thrombosis (DVT) and to characterize the underlying prothrombotic phenotype of stabilin-2 deficiency in a mouse model.

METHODS

DVT was induced using the inferior vena cava (IVC) stenosis model in two independent cohorts (littermates and non-littermates) of wild-type (Stab2+/+ ) and stabilin-2 (Stab2-/- )-deficient mice. Thrombus structure and contents were quantified by immunohistochemistry. Plasma procoagulant activity was assessed and complete blood counts were performed.

RESULTS

Incidence of thrombus formation was not altered between Stab2+/+ and Stab2-/- mice. When thrombi were formed, Stab2-/- mice developed significantly larger thrombi than Stab2+/+ controls. Thrombi from Stab2-/- mice contained significantly more leukocytes and citrullinated histone H3 than Stab2+/+ thrombi. Stab2-/- mice had increased FVIII activity. Circulating levels of monocytes and granulocytes were significantly elevated in Stab2-/- mice, and Stab2-/- mice had elevated plasma cell-free DNA 24 hours post-IVC stenosis compared to their Stab2+/+ counterparts.

CONCLUSIONS

These data suggest that stabilin-2 deficiency associates with a prothrombotic phenotype involving elevated levels of neutrophil extracellular trap-releasing leukocytes coupled with endogenous procoagulant activity, resulting in larger and qualitatively distinct venous thrombi.

Microparticles and Nucleosomes Are Released From Parenchymal Cells Destroyed After Injury in a Rat Model of Blunt Trauma

We investigated the relationships between circulating procoagulants and trauma severity, including cellular destruction, and the effects of thrombin generation on procoagulants in a rat blunt trauma model. The rats were subjected to tumbling blunt trauma, where they were tumbled for 0, 250, 500, or 1000 revolutions. Creatine kinase, nucleosome, and microparticle plasma levels increased gradually with trauma severity. Strong interrelationships were observed among creatine kinase, nucleosome, and microparticle levels. Time to initiation of thrombin generation shortened with increasing trauma severity. In accordance with trauma severity, prothrombin activity decreased, but the thrombin generation ratio increased. Time to initiation of thrombin generation and the thrombin generation ratio correlated with creatine kinase levels. In an in vitro study, a homogenized muscle solution, which included massive nucleosomes and microparticles, showed accelerated thrombin generation of plasma from healthy subjects. Procoagulants, such as microparticles and nucleosomes, are released from destroyed parenchymal cells immediately after external traumatic force, activating the coagulation cascade. The procoagulants shorten the time to initiation of thrombin generation. Furthermore, although coagulation factors are consumed, the thrombin generation ratio increases.

PCSK9 Biology and Its Role in Atherothrombosis

It is now about 20 years since the first case of a gain-of-function mutation involving the as-yet-unknown actor in cholesterol homeostasis, proprotein convertase subtilisin/kexin type 9 (PCSK9), was described. It was soon clear that this protein would have been of huge scientific and clinical value as a therapeutic strategy for dyslipidemia and atherosclerosis-associated cardiovascular disease (CVD) management. Indeed, PCSK9 is a serine protease belonging to the proprotein convertase family, mainly produced by the liver, and essential for metabolism of LDL particles by inhibiting LDL receptor (LDLR) recirculation to the cell surface with the consequent upregulation of LDLR-dependent LDL-C levels. Beyond its effects on LDL metabolism, several studies revealed the existence of additional roles of PCSK9 in different stages of atherosclerosis, also for its ability to target other members of the LDLR family. PCSK9 from plasma and vascular cells can contribute to the development of atherosclerotic plaque and thrombosis by promoting platelet activation, leukocyte recruitment and clot formation, also through mechanisms not related to systemic lipid changes. These results further supported the value for the potential cardiovascular benefits of therapies based on PCSK9 inhibition. Actually, the passive immunization with anti-PCSK9 antibodies, evolocumab and alirocumab, is shown to be effective in dramatically reducing the LDL-C levels and attenuating CVD. While monoclonal antibodies sequester circulating PCSK9, inclisiran, a small interfering RNA, is a new drug that inhibits PCSK9 synthesis with the important advantage, compared with PCSK9 mAbs, to preserve its pharmacodynamic effects when administrated every 6 months. Here, we will focus on the major understandings related to PCSK9, from its discovery to its role in lipoprotein metabolism, involvement in atherothrombosis and a brief excursus on approved current therapies used to inhibit its action.

Reduced Serum Circulation of Cell-Free DNA Following Chemotherapy in Breast Cancer Patients

Breast cancer is the most common malignancy in women, with alarming mortalities. Neoadjuvant treatments employ chemotherapy to shrink tumours to a well-defined size for a better surgical outcome. The current means of assessing effectiveness of chemotherapy management are imprecise. We previously showed that breast cancer patients have higher serum circulating cell-free DNA concentrations. cfDNA is degraded cellular DNA fragments released into the bloodstream. We further report on the utility of cfDNA in assessing the response to chemotherapy and its potential as a monitoring biomarker. A total of 32 newly diagnosed and treatment-naive female breast cancer patients and 32 healthy females as controls were included. Anthropometric, demographic and clinicopathological information of participants were recorded. Each participant donated 5 mL of venous blood from which sera were separated. Blood sampling was carried out before the commencement of chemotherapy (timepoint 1) and after the third cycle of chemotherapy (timepoint 2). qPCR was performed on the sera to quantify ALU 115 and 247 levels, and DNA integrity (ALU247/ALU115) was determined. ALU 115 and 247 levels were elevated in cancer patients but were significantly decreased after the third cycle of chemotherapy (T2) compared to T1. DNA integrity increased after the third cycle. Serum cfDNA may provide a relatively inexpensive and minimally invasive procedure to evaluate the response to chemotherapy in breast cancer.

Myeloperoxidase has no effect on the low procoagulant activity of silica-free DNA

Blood coagulation and innate immunity are closely interrelated. At sites of inflammation, DNA and myeloperoxidase (MPO) are released from polymorphonuclear leukocytes (PMNs) as an integral component of neutrophil extracellular traps (NETs). NETs exert pleiotropic thrombogenic effects, with DNA-mediated contact activation of factor XII (FXII) likely playing a role. We have previously shown that MPO, a highly cationic protein, regulates coagulation through heteromolecular interactions with various negatively charged structures, including membrane phospholipids and low-molecular-weight heparin. The aims of our current study were to confirm that DNA activates coagulation and to investigate whether its procoagulant activity (PCA) is regulated by PMN-derived MPO. To this end, we used thrombin generation and FXIIa amidolytic activity assays to analyze the PCA of cell-free DNA isolated with silica membrane-based (cfDNA) or silica-free procedures (PaxDNA). cfDNA potently activated FXII and promoted thrombin generation in a concentration-dependent manner, but its PCA was largely attributable to contaminating silica particles. In contrast, pure, i.e. silica-free, PaxDNA was markedly less procoagulant. Although PaxDNA amplified thrombin generation in plasma, it was devoid of any direct FXII activating activity. MPO supershifted both cfDNA and PaxDNA in gel electrophoresis, but only silica-associated PCA of cfDNA was neutralized by MPO independently of its catalytic properties. Moreover, pretreatment with DNase I abolished silica-induced thrombin generation. In summary, we show that pure DNA has rather weak PCA, which is not further inhibited by heteromolecular complex formation with exogenous MPO. Our study thus provides novel mechanistic insights into the regulation of coagulation by extracellular DNA under inflammatory conditions.

The role of extracellular DNA (exDNA) in cellular processes

Nowadays, extracellular DNA or circulating cell-free DNA is considered to be a molecule with clinical applications (diagnosis, prognosis, monitoring of treatment responses, or patient follow-up) in diverse pathologies, especially in cancer. Nevertheless, because of its molecular characteristics, it can have many other functions. This review focuses on the participation of extracellular DNA (exDNA) in fundamental processes such as cell signaling, coagulation, immunity, evolution through horizontal transfer of genetic information, and adaptive response to inflammatory processes. A deeper understanding of its role in each of these processes will allow development of better tools to monitor and control pathologies, as well as helping to generate new therapeutic options, beyond the applicability of DNA in liquid biopsy.

Next-Generation Liquid Biopsies: Embracing Data Science in Oncology

Deeper and broader sequencing of circulating tumor DNA (ctDNA) has identified a wealth of cancer markers in the circulation, resulting in a paradigm shift towards data science-driven liquid biopsies in oncology. Although panel sequencing for actionable mutations in plasma is moving towards the clinic, the next generation of liquid biopsies is increasingly shifting from analyzing digital mutation signals towards analog signals, requiring a greater role for machine learning. Concomitantly, there is an increasing acceptance that these cancer signals do not have to arise from the tumor itself. In this Opinion, we discuss the opportunities and challenges arising from increasingly complex cancer liquid biopsy data.

Cell-free DNA beyond a biomarker for rejection: Biological trigger of tissue injury and potential therapeutics

Cell-free DNA, measured as donor-derived cell-free DNA is developed as a non-specific biomarker for allograft injury and transplant rejection. However, cell-free DNA characteristics are more specific, its fragment length, nucleotide content, and composition, as well as the tissue source of origin, are intrinsically linked to the underlying disease pathogenesis, showing distinct features in acute cellular rejection and antibody-mediated rejection for example. Further, cell-free DNA and cell-free mitochondrial DNA can directly trigger tissue injury as damage-associated molecular patterns through three major intracellular receptors, toll-like receptor 9 , cyclic guanosine monophosphate-adenosine monophosphate synthase, and inflammasomes (i.e., absent in melanoma 2: AIM2). Therefore, in addition to its role as a non-specific marker for allograft injury, cell-free DNA analysis may be used to phenotype transplant rejection, and to non-invasively point the underlying molecular mechanisms with allograft injury. Novel treatment approaches targeting these cell-free DNA pathways may be useful to treat transplant rejection and prevent end-organ dysfunction. In this review, we discuss the link between cell-free DNA characteristics and disease, the role of cell-free DNA as a damage-associated molecular pattern, and novel therapeutics targeting these cell-free DNA molecular pathways and their potential utility to treat transplant rejection.

Advances in the Management of Cancer-Associated Thrombosis

The association between cancer and venous thromboembolism (VTE) has been established for more than 150 years. Nevertheless, cancer-associated thrombosis still remains a major clinical challenge and is associated with significant morbidity and mortality for patients with cancer. The clinical presentation of cancer-associated thrombosis can be distinct from that of a patient without an underlying malignancy. Moreover, specific cancer types, including pancreatic cancer and hematological malignancies, as well as advanced stage disease can confer a significant thrombotic risk. This risk is further augmented by specific anticancer treatment modalities. The pathophysiology of cancer-associated thrombosis is complex and multifactorial. However, understanding the biological mechanisms underpinning VTE risk may provide insight into novel targeted prophylaxis in cancer patients. Over the last decade, low-molecular-weight heparin has been the preferred anticoagulant agent for patients with cancer-associated thrombosis due to improved efficacy compared with vitamin K antagonists. However, the advent of direct oral anticoagulants (DOACs) has added to the repertoire of ammunition now at the disposal of clinicians to aid in the management of cancer-associated thrombosis. Several randomized controlled trials have now been published, demonstrating DOAC as a noninferior alternative for both the treatment and prevention of cancer-associated thrombosis. Notwithstanding this, limitations for their widespread use remain, with the potential for increased bleeding risk, drug interactions, and poor DOAC metabolism. This review discusses the evidence base for the incidence and risk factors associated with VTE in cancer, development, and refinement of risk prediction models and novel advances in the therapeutic management of cancer-associated thrombosis.

Cancer Therapy-Associated Thrombosis

[Figure: see text].

Comparison of Circulating Tumour DNA and Extracellular Vesicle DNA by Low-Pass Whole-Genome Sequencing Reveals Molecular Drivers of Disease in a Breast Cancer Patient

There is increasing recognition of circulating tumour DNA (ctDNA) as a non-invasive alternative to tumour tissue for the molecular characterisation and monitoring of disease. Recent evidence suggests that cancer-associated changes can also be detected in the DNA contained within extracellular vesicles (EVs). As yet, there has been limited investigation into the relationship between EV DNA and ctDNA, and no studies have examined the EV DNA of breast cancer patients. The aim of this study was to use low-pass whole-genome sequencing to identify copy number variants (CNVs) in serial samples of both ctDNA and EV DNA from a patient with breast cancer. Of the 52 CNVs identified in tumour DNA, 36 (69%) were detected in at least one ctDNA sample and 13 (25%) in at least one EV DNA sample. The number of detectable variants in ctDNA and EV DNA increased over the natural history of the patient’s disease, which was associated with progression to cerebral metastases. This case study demonstrates that, while CNVs are detectable in patient EV DNA, ctDNA has greater sensitivity than EV DNA for serial monitoring of breast cancer.

Insights into the Procoagulant Profile of Patients with Systemic Lupus Erythematosus without Antiphospholipid Antibodies

We aimed to identify the key players in the prothrombotic profile of patients with systemic lupus erythematosus (SLE) not mediated by antiphospholipid antibodies, as well as the potential utility of global coagulation tests to characterize hemostasis in these patients. Patients with SLE without antiphospholipid antibodies and without signs of thrombosis were included. The kinetics of clot formation were determined by ROTEM^®. Platelet activation markers were determined by flow cytometry. Thrombin generation associated with Neutrophil Extracellular Traps (NETs) and microparticles (MPs) was measured by calibrated automated thrombogram (CAT). The plasma levels of PAI-1 were also determined. ROTEM^® showed a procoagulant profile in SLE patients. SLE patients had activated platelets and more leukocyte/platelet aggregates at basal conditions. The plasma PAI-1 and platelet aggregates correlated with several ROTEM^® parameters. The thrombin generation associated withthe tissue factor (TF) content of MPs and with NETs was increased. Our results suggest the utility of global tests for studying hemostasis in SLE patients because they detect their procoagulant profile, despite having had neither antiphospholipid antibodies nor any previous thrombotic event. A global appraisal of hemostasis should, if possible, be incorporated into clinical practice to detect the risk of a thrombotic event in patients with SLE and to consequently act to prevent its occurrence.

Extracellular DNA-A Danger Signal Triggering Immunothrombosis

Clotting and inflammation are effective danger response patterns positively selected by evolution to limit fatal bleeding and pathogen invasion upon traumatic injuries. As a trade-off, thrombotic, and thromboembolic events complicate severe forms of infectious and non-infectious states of acute and chronic inflammation, i.e., immunothrombosis. Factors linked to thrombosis and inflammation include mediators released by platelet granules, complement, and lipid mediators and certain integrins. Extracellular deoxyribonucleic acid (DNA) was a previously unrecognized cellular component in the blood, which elicits profound proinflammatory and prothrombotic effects. Pathogens trigger the release of extracellular DNA together with other pathogen-associated molecular patterns. Dying cells in the inflamed or infected tissue release extracellular DNA together with other danger associated molecular pattern (DAMPs). Neutrophils release DNA by forming neutrophil extracellular traps (NETs) during infection, trauma or other forms of vascular injury. Fluorescence tissue imaging localized extracellular DNA to sites of injury and to intravascular thrombi. Functional studies using deoxyribonuclease (DNase)-deficient mouse strains or recombinant DNase show that extracellular DNA contributes to the process of immunothrombosis. Here, we review rodent models of immunothrombosis and the evolving evidence for extracellular DNA as a driver of immunothrombosis and discuss challenges and prospects for extracellular DNA as a potential therapeutic target.

Like a Rolling Stone: Sting-Cgas Pathway and Cell-Free DNA as Biomarkers for Combinatorial Immunotherapy

Combining immune checkpoint inhibitors with other treatments likely to harness tumor immunity is a rising strategy in oncology. The exact modalities of such a combinatorial regimen are yet to be defined, and most attempts have relied so far on concomitant dosing, rather than sequential or phased administration. Because immunomodulating features are likely to be time-, dose-, and-schedule dependent, the need for biomarkers providing real-time information is critical to better define the optimal time-window to combine immune checkpoint inhibitors with other drugs. In this review, we present the various putative markers that have been investigated as predictive tools with immune checkpoint inhibitors and could be used to help further combining treatments. Whereas none of the current biomarkers, such as the PDL1 expression of a tumor mutational burden, is suitable to identify the best way to combine treatments, monitoring circulating tumor DNA is a promising strategy, in particular to check whether the STING-cGAS pathway has been activated by cytotoxics. As such, circulating tumor DNA could help defining the best time-window to administrate immune checkpoint inhibitors after that cytotoxics have been given.

Lung-protective ventilation suppresses systemic and hepatic vein levels of cell-free DNA in porcine experimental post-operative sepsis

BACKGROUND

Plasma levels of cell-free DNA (cf-DNA) are known to be elevated in sepsis and high levels are associated with a poor prognosis. Mechanical ventilation affects systemic inflammation in which lung-protective ventilation attenuates the inflammatory response. The aim was to study the effect of a lung protective ventilator regime on arterial and organ-specific venous blood as well as on trans-organ differences in cf-DNA levels in a porcine post-operative sepsis model.

METHOD

One group of anaesthetised, domestic-breed, 9-12 weeks old, pigs were ventilated with protective ventilation (V_T 6 mL x kg^- 1, PEEP 10 cmH₂O) n = 20. Another group, ventilated with a medium high tidal volume and lower PEEP, served as a control group (V_T 10 mL x kg^- 1, PEEP 5 cm H₂O) n = 10. Blood samples were taken from four sources: artery, hepatic vein, portal vein and, jugular bulb. A continuous endotoxin infusion at 0.25 μg x kg^- 1 x h^- 1 for 5 h was started following 2 h of laparotomy, which simulated a surgical procedure. Inflammatory cytokines and cf-DNA in plasma were analysed and trans-organ differences calculated.

RESULTS

The protective ventilation group had lower levels of cf-DNA in arterial (p = 0.02) and hepatic venous blood (p = 0.03) compared with the controls. Transhepatic differences in cf-DNA were lower in the protective group, compared with the controls (p = 0.03). No differences between the groups were noted as regards the transcerebral, transsplanchnic or the transpulmonary cf-DNA differences.

CONCLUSIONS

Protective ventilation suppresses arterial levels of cf-DNA. The liver seems to be a net contributor to the systemic cf-DNA levels, but this effect is attenuated by protective ventilation.

Role of HMGB1 in the Interplay between NETosis and Thrombosis in Ischemic Stroke: A Review

Neutrophil extracellular traps (NETs) comprise decondensed chromatin, histones and neutrophil granular proteins and are involved in the response to infectious as well as non-infectious diseases. The prothrombotic activity of NETs has been reported in various thrombus-related diseases; this activity can be attributed to the fact that the NETs serve as a scaffold for cells and numerous coagulation factors and stimulate fibrin deposition. A crosstalk between NETs and thrombosis has been indicated to play a role in numerous thrombosis-related conditions including stroke. In cerebral ischemia, neutrophils are the first group of cells to infiltrate the damaged brain tissue, where they produce NETs in the brain parenchyma and within blood vessels, thereby aggravating inflammation. Increasing evidences suggest the connection between NETosis and thrombosis as a possible cause of “tPA resistance”, a problem encountered during the treatment of stroke patients. Several damage-associated molecular pattern molecules have been proven to induce NETosis and thrombosis, with high mobility group box 1 (HMGB1) playing a critical role. This review discusses NETosis and thrombosis and their crosstalk in various thrombosis-related diseases, focusing on the role of HMGB1 as a mediator in stroke. We also addresses the function of peptidylarginine deiminase 4 with respect to the interplay with HMGB1 in NET-induced thrombosis.

Elevated Microparticles, Thrombin-antithrombin and VEGF Levels in Colorectal Cancer Patients Undergoing Chemotherapy

Hypercoagulable state and neoangiogenesis are common phenomena associated with malignancy. Cancer patients have increased levels of circulating endothelium-derived microparticles (EMPs), which have been hypothesized to be involved in numerous pathophysiological processes. Hemostasis and angiogenesis are also activated in colorectal cancer (CRC) patients. The study aimed to investigate potential influence of chemotherapy on EMPs, thrombin anti-thrombin complex (TAT) and vascular endothelial growth factor (VEGF) levels in CRC patients undergoing chemotherapy. The study group consisted of 18 CRC patients: 8 stage III colon cancer (CC) and 10 stage IV rectal cancer (RC) patients. EMPs, TAT and VEGF levels were assessed before chemotherapy and after the third course. Results were compared with 10 healthy subjects. EMP concentration was measured by flow cytometry, while TAT and VEGF concentrations were assayed employing ELISA. Compared to the control group, CC and RC patients had significantly higher levels of tissue factor (TF)-bearing and non-TF-bearing EMPs before and after three courses of chemotherapy. VEGF concentrations in CRC patients were higher than in the control groups and increased following chemotherapy. TAT levels were elevated in CRC patients before chemotherapy compared to healthy subjects and significantly increased after the third course of chemotherapy. No significant correlation was found either between EMP and TAT levels, or between EMP concentrations and VEGF levels in the study group. CRC patients have increased EMPs, and TAT as well as VEGF levels tend to increase during chemotherapy.