Inflammatory response in the acute phase of deep vein thrombosis

Prevalence and Risk Factors of Deep Venous Thrombosis in Intensive Inpatient Neurorehabilitation Unit

Venous thromboembolism (VTE) (deep vein thrombosis and its complication, pulmonary embolism) is a major cause of morbidity and mortality in hospitalized patients and about 7% of these cases are due to immobility secondary to a neurological impairment. Acquired brain injury (ABI) has also been recognized as one of the main risk factors for VTE. Numerous epidemiological studies have been conducted to assess the risk factors for VTE in institutionalized polytrauma patients, although there is a lack of information about neurorehabilitation wards. Since VTE is often undiagnosed, this prospective study aimed to determine the prevalence and clinical characteristics of lower-limb deep venous thrombosis (DVT) in ABI patients at neurorehabilitation admission.

METHODS

ABI patients were screened for DVT on admission to the intensive rehabilitation unit (IRU) with compression ultrasonography and basal D-dimer assay and were daily clinically monitored until discharge. A total of 127 consecutive ABI patients (mean age: 60.1 ± 17.6 years; 63% male; time from event: 30.9 ± 22.1 days; rehabilitation time in IRU: 84.6 ± 58.4 days) were enrolled.

RESULTS

On admission to the IRU, the DVT prevalence was about 8.6%. The mean D-dimer level in patients with DVT was significantly higher than in patients without DVT (6 ± 0.9 vs. 1.97 ± 1.61, p-value = 0.0001). ABI patients with DVT did not show any significant clinical characteristics with respect to ABI without DVT, although a prevalence of hemorrhagic strokes and patients originating from the Intensive Care Unit and Neurosurgery ward was revealed. During the rehabilitation period, patients with DVT showed a significant difference in pharmacological DVT prophylaxis (high prevalence of nadroparin with 27.3% vs. 1.7%, p-value = 0.04) and a prevalence of transfers in critical awards (36% versus 9.5% of patients without DVT, p-value = 0.05). The mortality rate was similar in the two groups.

CONCLUSIONS

Our research offers a more comprehensive view of the clinical development of DVT patients and confirms the prevalence rate of DVT in ABI patients as determined upon IRU admission. According to our findings, screening these individuals regularly at the time of rehabilitation admission may help identify asymptomatic DVT quickly and initiate the proper treatment to avoid potentially fatal consequences. However, to avoid time-consuming general ultrasonography observation, a more precise selection of patients entering the rehabilitation ward is required.

Circulating Cytokines and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

 Epidemiological evidence has linked circulating cytokines to venous thromboembolism (VTE). However, it remains uncertain whether these associations are causal due to confounding factors or reverse causality. We aim to explore the causality between circulating cytokines and VTE, encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

 In the current bidirectional Mendelian randomization (MR) study, instrumental variables of 41 circulating cytokines were obtained from the genome-wide association study meta-analyses (8,293 individuals). Summary statistics for the association of VTE (17,048 cases and 325,451 controls), DVT (8,077 cases and 295,014 controls), and PE (8,170 cases and 333,487 controls) were extracted from the FinnGen Study. A multivariable MR study was conducted to adjust for potential confounders. The inverse-variance weighted method was employed as the main analysis, and comprehensive sensitivity analyses were conducted in the supplementary analyses.

RESULTS

 The MR analysis indicated stromal cell-derived factor-1α was suggestively associated with a reduced risk of VTE (odds ratio [OR]: 0.90; 95% confidence interval [CI]: 0.81-0.99; p = 0.033) and DVT (OR: 0.85; 95% CI: 0.75-0.97; p = 0.015). In addition, suggestive association of granulocyte colony-stimulating factor with PE (OR: 1.20; 95% CI: 1.06-1.37; p = 0.005) was observed. Multivariable MR analysis showed that the effect of cytokines on VTE was partly mediated through hemoglobin A1c and systolic blood pressure. Reverse MR analysis revealed that VTE was linked to decreased levels of several cytokines.

CONCLUSION

 We provide suggestive genetic evidence supporting the bidirectional causal effect between circulating cytokines and VTE, highlighting the importance of targeting circulating cytokines to reduce the incidence of VTE.

Metabolomic profiling of deep vein thrombosis

Deep vein thrombosis (DVT) of the lower extremities is one of the most common peripheral vascular diseases, with significant complications and sequelae. Metabolomics aims to identify small molecules in biological samples. It can serve as a promising method for screening compounds that can be used for early disease detection, diagnosis, treatment response prediction, and prognosis. In addition, high-throughput metabolomics screening can yield significant insights into the pathophysiological pathways of DVT. Currently, the metabolomic profiles of DVT have yielded inconsistent expression patterns. This article examines the recent advancements in metabolomic studies of DVT and analyzes the factors that may influence the results.

Increased miR-6132 promotes deep vein thrombosis formation by downregulating FOXP3 expression

Background

Deep vein thrombosis (DVT) is associated with aberrant gene expression that is a common peripheral vascular disease. Here, we aimed to elucidate that the epigenetic modification of forkhead box protein 3 (FOXP3) at the post-transcriptional level, which might be the key trigger leading to the down-regulation of FOXP3 expression in DVT.

Methods

In order to explore the relationship between microRNAs (miRNAs) and FOXP3, mRNA and microRNA microarray analysis were performed. Dual luciferase reporter assay was used to verify the upstream miRNAs of FOXP3. Quantitative real-time polymerase chain reaction, flow cytometry and Western blot were used to detect the relative expression of miR-6132 and FOXP3. Additionally, DVT models were established to investigate the role of miR-6132 by Murine Doppler Ultrasound and Hematoxylin-Eosin staining.

Results

Microarray and flow cytometry results showed that the FOXP3 expression was decreased while miR-6132 level was increased substantially in DVT, and there was significant negative correlation between miR-6132 and FOXP3. Moreover, we discovered that overexpressed miR-6132 reduced FOXP3 expression and aggravated DVT formation, while miR-6132 knockdown increased FOXP3 expression and alleviated DVT formation. Dual luciferase reporter assay validated the direct binding of miR-6132 to FOXP3.

Conclusion

Collectively, our data elucidate a new avenue through which up-regulated miR-6132 contributes to the formation and progression of DVT by inhibiting FOXP3 expression.

Exploring the potential mechanism and molecular targets of Taohong Siwu Decoction against deep vein thrombosis based on network pharmacology and analysis docking

This study aims to investigate the mechanism of Taohong Siwu Decoction (THSWD) against deep vein thrombosis (DVT) using network pharmacology and molecular docking technology. We used the Traditional Chinese Medicine Systems Pharmacology database and reviewed literature to identify the main chemical components of THSWD. To find targets for DVT, we consulted GeneCards, Therapeutic Target Database, and PharmGKB databases. We used Cytoscape 3.8.2 software to construct herb-disease-gene-target networks. Additionally, we integrated drug targets and disease targets on the STRING platform to create a protein-protein interaction network. Then, we conducted Kyoto Encyclopedia of Genes and Genomes and gene ontology analysis. Finally, We employed the molecular docking method to validate our findings. We identified 56 potential targets associated with DVT and found 61 effective components. beta-sitosterol, quercetin, and kaempferol were the most prominent among these components. Our analysis of the protein-protein interaction network revealed that IL6, L1B, and AKT1 had the highest degree of association. Gene ontology analysis showed that THSWD treatment for DVT may involve response to inorganic substances, negative regulation of cell differentiation, plasma membrane protein complex, positive regulation of phosphorylation, and signaling receptor regulator activity. Kyoto Encyclopedia of Genes and Genomes analysis indicated that lipid and atherosclerosis, pathways in cancer, as well as the PI3K-Akt pathway are the main signal pathways involved. Molecular docking results demonstrated strong binding affinity between beta-sitosterol, quercetin, kaempferol, and AKT1 proteins as well as IL1B and IL6 proteins. The main targets for THSWD treatment of DVT may include AKT1, IL1B, and IL6. Beta-sitosterol, quercetin, and kaempferol may be the active ingredients responsible for producing this effect. These compounds may slow down the progression of DVT by regulating the inflammatory response through the PI3K/Akt pathway.

Biomarkers and the post-thrombotic syndrome: A systematic review of biomarkers associated with the occurrence of the post-thrombotic syndrome after lower extremity deep venous thrombosis

INTRODUCTION

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep venous thrombosis (DVT). Biomarkers are potentially valuable clinical tools for handling PTS. The purpose of this review was to examine which biomarkers are associated with the development of PTS in adults with lower extremity DVT.

METHODS

We performed a systematic review of all English language prospective studies of biomarkers and PTS published in PubMed and EMBASE. Studies were included if diagnosing DVT by diagnostic imaging and assessing PTS by clinical scales, for example, the Villalta scale. Biomarkers of thrombophilia and pathological clot properties were not assessed. Data was reported qualitatively.

RESULTS

15 prospective studies were included. Studies varied widely in study design and methods of data analysis. Forty-six different biomarkers were examined, with seven being measured in two or more studies. The most frequently studied biomarkers were D-dimer, CRP, and IL-6. Associations between PTS and D-dimer were predominantly significant, while results on CRP and IL-6 were inconsistent. ICAM-1 was consistently associated with PTS in all studies and at all timepoints. IL-10 was significantly related to PTS development in the largest study and at all time points. Adiponectin, tPA, HRG and TAFI, MMP-1 and -8, and TIMP-1 and -2 were significantly associated with PTS in single studies.

CONCLUSION

(1) Further research on biomarkers and PTS is clearly warranted. (2) Significant differences in study designs made it difficult to draw reliable conclusions regarding individual biomarkers. We suggest the implementation of a standardized framework for the study of biomarkers and PTS, to make comparison of future studies more feasible. (3) D-dimer, ICAM-1, IL-10, MMP-1 and 8, TIMP-1, TIMP-2, and adiponectin are clinical biomarkers of particular interest to include in future studies of PTS. Large scale systemic quantitative proteomic analyses of DVT patients could help identify novel biomarkers of interest in PTS-patients.

Inflammasome Signaling, Thromboinflammation, and Venous Thromboembolism

Venous thromboembolism (VTE) remains a major health burden despite anticoagulation advances, suggesting incomplete management of pathogenic mechanisms. The NLRP3 (NACHT-, LRR- and pyrin domain-containing protein 3) inflammasome, interleukin (IL)-1, and pyroptosis are emerging contributors to the inflammatory pathogenesis of VTE. Inflammasome pathway activation occurs in patients with VTE. In preclinical models, inflammasome signaling blockade reduces venous thrombogenesis and vascular injury, suggesting that this therapeutic approach may potentially maximize anticoagulation benefits, protecting from VTE occurrence, recurrence, and ensuing post-thrombotic syndrome. The nonselective NLRP3 inhibitor colchicine and the anti-IL-1β agent canakinumab reduce atherothrombosis without increasing bleeding. Rosuvastatin reduces primary venous thrombotic events at least in part through lipid-lowering independent mechanisms, paving the way to targeted anti-inflammatory strategies in VTE. This review outlines recent preclinical and clinical evidence supporting a role for inflammasome pathway activation in venous thrombosis, and discusses the, yet unexplored, therapeutic potential of modulating inflammasome signaling to prevent and manage VTE.

Experimental venous thrombus resolution is driven by IL-6 mediated monocyte actions

Deep venous thrombosis and residual thrombus burden correlates with circulating IL-6 levels in humans. To investigate the cellular source and role of IL-6 in thrombus resolution, Wild type C57BL/6J (WT), and IL-6-/- mice underwent induction of VT via inferior vena cava (IVC) stenosis or stasis. Vein wall (VW) and thrombus were analyzed by western blot, immunohistochemistry, and flow cytometry. Adoptive transfer of WT bone marrow derived monocytes was performed into IL6-/- mice to assess for rescue. Cultured BMDMs from WT and IL-6-/- mice underwent quantitative real time PCR and immunoblotting for fibrinolytic factors and matrix metalloproteinase activity. No differences in baseline coagulation function or platelet function were found between WT and IL-6-/- mice. VW and thrombus IL-6 and IL-6 leukocyte-specific receptor CD126 were elevated in a time-dependent fashion in both VT models. Ly6Clo Mo/MØ were the predominant leukocyte source of IL-6. IL-6-/- mice demonstrated larger, non-resolving stasis thrombi with less neovascularization, despite a similar number of monocytes/macrophages (Mo/MØ). Adoptive transfer of WT BMDM into IL-6-/- mice undergoing stasis VT resulted in phenotype rescue. Human specimens of endophlebectomized tissue showed co-staining of Monocyte and IL-6 receptor. Thrombosis matrix analysis revealed significantly increased thrombus fibronectin and collagen in IL-6-/- mice. MMP9 activity in vitro depended on endogenous IL-6 expression in Mo/MØ, and IL-6-/- mice exhibited stunted matrix metalloproteinase activity. Lack of IL-6 signaling impairs thrombus resolution potentially via dysregulation of MMP-9 leading to impaired thrombus recanalization and resolution. Restoring or augmenting monocyte-mediated IL-6 signaling in IL-6 deficient or normal subjects, respectively, may represent a non-anticoagulant target to improve thrombus resolution.

A vein wall cell atlas of murine venous thrombosis determined by single-cell RNA sequencing

Deep vein thrombosis (DVT) is a common clinical problem, but its cellular and molecular mechanisms remain incompletely understood. In this study, we performed single-cell RNA sequencing on mouse inferior vena cava (IVC) 24 h after thrombus-inducing IVC ligation or sham operation. 9 cell types composed of multiple subpopulations were identified. Notable transcriptomic changes induced by DVT included a marked inflammatory response, elevated hypoxia, and globally reduced myogenesis. Analysis of individual cell populations revealed increased inflammation and reduced extracellular matrix production across smooth muscle cells and fibroblasts, juxtaposed against an early phenotypic shift in smooth muscle cell populations away from a contractile state. By characterizing the transcriptomic changes in the vein wall during acute venous thrombosis at the single-cell level, this work provides novel insights into early pathological events in the vein wall that may potentiate thrombus formation and result in long term adverse venous remodeling.

Evaluation of the relationship between monocyte to high-density lipoprotein cholesterol ratio and thrombus burden in patients with deep vein thrombosis

OBJECTIVE

The purpose of this study was to evaluate monocyte count and high-density lipoprotein cholesterol levels and their ratio (monocyte/high-density lipoprotein ratio) in patients with deep venous thrombosis as well as to determine whether this ratio at the time of diagnosis can be an indicator of thrombus burden in terms of thrombus location in deep venous thrombosis.

METHODS

We retrospectively analyzed the patient's diagnosis of deep venous thrombosis confirmed with venous Doppler ultrasound, using a database query for outpatients between 2018 and 2022. Of 378 patients included, blood count results at the time of diagnosis were available for 356. We recruited 300 age- and sex-matched patients with appropriate blood counts, without a diagnosis of deep venous thrombosis, as the control group, by querying the outpatient clinic database. The monocyte/high-density lipoprotein ratio was computed from the ratio of monocyte count to high-density lipoprotein-C. Patients were categorized based on the level of thrombus and the number of vein segments involved as evidenced by Doppler ultrasound findings.

RESULTS

The serum level of monocyte/high-density lipoprotein ratio was significantly higher in the patient group compared to the control group (p<0.01). Patients with proximal deep venous thrombosis had a higher mean monocyte/high-density lipoprotein ratio (19.6±5.1 vs. 17.1±5.5; p<0.01) than patients with distal deep venous thrombosis. Monocyte/high-density lipoprotein ratio increased with the number of vein segments involved (p<0.01).

CONCLUSION

Monocyte/high-density lipoprotein ratio is significantly elevated in patients with deep venous thrombosis when compared to the control group. Monocyte/high-density lipoprotein ratio levels were correlated with disease burden reflected by thrombus location and the number of vein segments involved in deep venous thrombosis patients.

The Association of Neutrophil-Lymphocyte Ratio with Venous Thromboembolism: A Systematic Review and Meta-Analysis

The neutrophil–lymphocyte ratio(NLR) has been used for diagnosing venous thromboembolism (VTE). We aimed to assess the accuracy of NLR to diagnose VTE by meta-analysis. Systematic electronic searches were conducted June 2, 2021 in PubMed, Embase(Ovid), and Cochrane Library. The search did not have any language or time restriction applied. Our search strategy was based on keywords in combination with both medical subject headings (MeSH) terms and text words. The diagnostic odds ratio, summary receiver operating characteristics, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were estimated. 10 articles with 1513 VTE participants and 2593 control participants were included for quantitative synthesis. The pooled values were as follows: sensitivity = 0.68(95% CI 0.45-0.84), specificity = 0.73(95% CI 0.6-0.83), positive likelihood ratio = 2.5(95% CI 1.8-3.4), negative likelihood ratio = 0.44(95% CI 0.26-0.75), diagnostic odds ratio = 6(95% CI 3-11), and SROC = 0.76(95% CI: 0.73-0.8). NLR could be diagnostic factor for the detection of potential VTE, the accuracy thereof in the current meta-analysis exhibited moderate accuracy for diagnosing VTE. Furthermore, further large cohort studies are needed to determine optimal cut-off values of NLR.

Case Report of a Massive Life-threatening Neonatal Thrombosis Treated With a Targeted, Goal-oriented Scheme of Urokinase

BACKGROUND

Thrombotic events are severe, often under-diagnosed, complications occurring in newborn infants during their hospital stay. Currently, there is no consensus regarding the optimal treatment scheme for thrombolysis in neonates.

OBSERVATIONS

We present the case of a newborn suffering from a life-threatening thrombosis. Diagnosis was suggested by a gradual increase of C-reactive protein, with repeatedly normal procalcitonin. Thrombosis was successfully and safely treated with a long scheme of 21 days of urokinase, supported by vascular ultrasound and d-dimer trend.

CONCLUSIONS

Laboratory and ultrasound results may help in adjusting the duration of the thrombolytic treatment, allowing for longer therapeutic schemes that could optimize treatment success. In addition, our case may suggest a possible combined role of C-reactive protein and procalcitonin as an early diagnostic aid in neonatal thrombosis.

C-reactive protein, immunothrombosis and venous thromboembolism

C-reactive protein (CRP) is a member of the highly conserved pentraxin superfamily of proteins and is often used in clinical practice as a marker of infection and inflammation. There is now increasing evidence that CRP is not only a marker of inflammation, but also that destabilized isoforms of CRP possess pro-inflammatory and pro-thrombotic properties. CRP circulates as a functionally inert pentameric form (pCRP), which relaxes its conformation to pCRP* after binding to phosphocholine-enriched membranes and then dissociates to monomeric CRP (mCRP). with the latter two being destabilized isoforms possessing highly pro-inflammatory features. pCRP* and mCRP have significant biological effects in regulating many of the aspects central to pathogenesis of atherothrombosis and venous thromboembolism (VTE), by directly activating platelets and triggering the classical complement pathway. Importantly, it is now well appreciated that VTE is a consequence of thromboinflammation. Accordingly, acute VTE is known to be associated with classical inflammatory responses and elevations of CRP, and indeed VTE risk is elevated in conditions associated with inflammation, such as inflammatory bowel disease, COVID-19 and sepsis. Although the clinical data regarding the utility of CRP as a biomarker in predicting VTE remains modest, and in some cases conflicting, the clinical utility of CRP appears to be improved in subsets of the population such as in predicting VTE recurrence, in cancer-associated thrombosis and in those with COVID-19. Therefore, given the known biological function of CRP in amplifying inflammation and tissue damage, this raises the prospect that CRP may play a role in promoting VTE formation in the context of concurrent inflammation. However, further investigation is required to unravel whether CRP plays a direct role in the pathogenesis of VTE, the utility of which will be in developing novel prophylactic or therapeutic strategies to target thromboinflammation.

Plasma lipopolysaccharide-binding protein is a biomarker for future venous thromboembolism: Results from discovery and validation studies

BACKGROUND

Effect-size underestimation impedes biomarker identification. Long follow-up time in prospective studies attenuates effect-size estimates for transient biomarkers, while disease category-specific biomarkers are affected by merging of categories. Venous thromboembolism (VTE) encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE).

OBJECTIVES

(i) To re-analyze untargeted proteomic data to identify biomarker candidates for future VTE that differ between DVT and PE and are attenuated by extended time between sampling and VTE. (ii) To perform targeted candidate validation.

PATIENTS/METHODS

A VTE case-control discovery study and a nested case-control validation study were derived from the general population surveyed in 1994-95. Plasma was obtained at study enrollment, and VTE events were registered until 2007. Untargeted proteomic data were re-analyzed for candidate discovery. Lipopolysaccharide-binding protein (LBP) was validated by enzyme-linked immunosorbent assay.

RESULTS

Elevated LBP was discovered as a candidate DVT biomarker in women with less than 3 years between blood sampling and DVT. In the validation study, the odds ratio (OR) for DVT was 2.03 (95% confidence intervals [CI]: 1.53-2.74) per standard deviation (SD) increase in LBP for women with less than 3 years between blood sampling and DVT. Adjustment for age, body mass index, and C-reactive protein attenuated the OR to 1.79 (95% CI: 1.25-2.62) per SD. In the validation study, we observed an OR for VTE of 0.47 (95% CI: 0.28-0.77) for men in the 25^th to 50^th percentiles when compared to the lowest quartile.

CONCLUSIONS

We discovered and validated increased LBP as a predictive biomarker for DVT in women. We found an increased VTE risk for men in the lowest quartile of LBP.

Co-Occurrence of Interleukin-6 Receptor Asp358Ala Variant and High Plasma Levels of IL-6: An Evidence of IL-6 Trans-Signaling Activation in Deep Vein Thrombosis (DVT) Patients

Interleukin-6 (IL-6) is a pleiotropic cytokine involved in several mechanisms, and the alteration of IL-6 signaling leads to the overactivation of various processes including immunity, inflammation, and hemostasis. Although IL-6 increase has been documented in venous thromboembolic diseases, the exact involvement of IL-6 signaling in deep vein thrombosis (DVT) has not been fully understood. Consequently, we investigated the involvement of IL-6 trans-signaling in inflammatory events occurring in DVT, focusing on the role of the interleukin-6 receptor (IL6-R) Asp358Ala variant. The circulating levels of IL-6, soluble IL6-R (sIL6-R), and soluble glycoprotein 130, as well as the Asp358Ala genotyping, were assessed in a consecutive cohort of DVT patients and healthy controls. The results indicated that IL-6 was higher in DVT compared to controls. Moreover, sIL6-R levels were strongly correlated to Asp358Ala variant in both groups, showing a high frequency of this mutation across all samples. Interestingly, our results showed a high frequency of both Asp358Ala mutation and raised IL-6 levels in DVT patients (OR = 21.32; p ≤ 0.01), highlighting that this mutation could explain the association between IL-6 overactivation and DVT outcome. Overall, this study represents a proof of concept for the targeting of IL-6 trans-signaling as a new strategy for the DVT adjuvant therapy.

Mono-articular idiopathic heterotopic ossification in a Coronavirus infected patient admitted in the intensive care unit

Heterotopic ossification (HO) designates a bone tissue formation within an atypical anatomical location and is commonly diagnosed in patients whom have suffered major traumas. The following case report presents a non-traumatic source of HO. A causality is deduced between the HO formation and an important inflammatory reaction originating from a Coronavirus infection. In contrast to other studies not only is the source non traumatic but the HO formation is unilateral. In systemic inflammatory reactions vigilance towards HO should be enhanced especially in patients treated during prolonged periods of time in intensive care units (ICU).

Neutrophil Extracellular Traps in Atherosclerosis and Thrombosis

Despite effective therapeutic and preventive strategies, atherosclerosis and its complications still represent a substantial health burden. Leukocytes and inflammatory mechanisms are increasingly recognized as drivers of atherosclerosis. Neutrophil granulocytes within the circulation were recently shown to undergo neutrophil extracellular trap (NET) formation, linking innate immunity with acute complications of atherosclerosis. In this chapter, we summarize mechanisms of NET formation, evidence for their involvement in atherosclerosis and thrombosis, and potential therapeutic regimens specifically targeting NET components.

Pathogenesis of Two Faces of DVT: New Identity of Venous Thromboembolism as Combined Micro-Macrothrombosis via Unifying Mechanism Based on “Two-Path Unifying Theory” of Hemostasis and “Two-Activation Theory of the Endothelium”

Simple Summary

DVT is an intravascular blood clotting disorder that can be a life-threatening disease, particularly if it occurs in critically ill patients. Typically, distal DVT develops following a vascular injury associated with incidental trauma commonly involving lower extremities, which is transient and benign condition localized in the lower legs as solitary lesion. However, proximal/central DVT (i.e., venous thromboembolism) typically occurs in association with critical illnesses such as sepsis, diabetes, hypertension, cancer, autoimmune disease and others in the hospitalized patient, especially in the ICU. Recognition of different pathogenesis between distal DVT and proximal/central DVT is critically important because the prognosis is poorer in VTE. Its therapeutic approach should be different from distal DVT. The aim of this review is to identify the pathogenesis of two different types of DVT based on in vivo hemostatic mechanisms, which can explain their distinct phenotypes by clinical characteristics, laboratory data and imaging findings. An appropriate preventive measure can be put into the practice to avoid the onset of VTE. Additionally, should VTE be developed, proper and rational therapeutic regimen based on its pathogenesis can be designed for clinical trials to improve the outcome.

Abstract

Venous thrombosis includes deep venous thrombosis (DVT), venous thromboembolism (VTE), venous microthrombosis and others. Still, the pathogenesis of each venous thrombosis is not clearly established. Currently, isolated distal DVT and multiple proximal/central DVT are considered to be the same macrothrombotic disease affecting the venous system but with varying degree of clinical expression related to its localization and severity. The genesis of two phenotypes of DVT differing in clinical features and prognostic outcome can be identified by their unique hemostatic mechanisms. Two recently proposed hemostatic theories in vivo have clearly defined the character between “microthrombi” and “macrothrombus” in the vascular system. Phenotypic expression of thrombosis depends upon two major variables: (1) depth of vascular wall damage and (2) extent of the injury affecting the vascular tree system. Vascular wall injury limited to endothelial cells (ECs) in sepsis produces “disseminated” microthrombi, but intravascular injury due to trauma extending from ECs to subendothelial tissue (SET) produces “local” macrothrombus. Pathogen-induced sepsis activates the complement system leading to generalized endotheliopathy, which releases ultra large von Willebrand factor (ULVWF) multimers from ECs and promotes ULVWF path of hemostasis. In the venous system, the activated ULVWF path initiates microthrombogenesis to form platelet-ULVWF complexes, which become “microthrombi strings” that produce venous endotheliopathy-associated vascular microthrombotic disease (vEA-VMTD) and immune thrombocytopenic purpura (ITP)-like syndrome. In the arterial system, endotheliopathy produces arterial EA-VMTD (aEA-VMTD) with “life-threatening” thrombotic thrombocytopenic purpura (TTP)-like syndrome. Typically, vEA-VMTD is “silent” unless complicated by additional local venous vascular injury. A local venous vessel trauma without sepsis produces localized macrothrombosis due to activated ULVWF and tissue factor (TF) paths from damaged ECs and SET, which causes distal DVT with good prognosis. However, if a septic patient with “silent” vEA-VMTD is complicated by additional vascular injury from in-hospital vascular accesses, “venous combined micro-macrothrombosis” may develop as VTE via the unifying mechanism of the “two-path unifying theory” of hemostasis. This paradigm shifting pathogenetic difference between distal DVT and proximal/central DVT calls for a reassessment of current therapeutic approaches.

Effects of statins in primary and secondary prevention for venous thromboembolism events: A meta analysis

OBJECTIVE

The associations between statins use and incidence or recurrence of venous thromboembolism (VTE) are controversial. We aimed to conduct a meta-analysis to reconcile the conflicting results.

METHODS

We searched PubMed, Embase and Cochrane Library for studies published from database inception until May 31, 2021. Cohort studies and Randomized Controlled Trials that reported incidence or recurrence of VTE using statins compared with placebo or non-statins were included for meta-analysis.

RESULTS

A total of 43 studies comprising over 8.6 million participants were included for analysis. The median follow-up duration was 38.1 months. Compared with no statins treatment, statins appeared to have a protective effect in primary prevention of VTE (RR 0.78, 95% CI 0.72-0.85), but significant heterogeneity was found among included studies (I² = 81%). Statins was also associated with a 26% reduced risk of recurrent VTE (RR 0.74, 95% CI 0.70-0.78), even in patients receiving anticoagulant therapy (RR 0.77, 95% CI 0.65-0.92). In patients with a history of VTE, statins was associated with a reduced risk of bleeding and all cause mortality. The NNT of statins to prevent one case of VTE in the cancer population, and one case of recurrent VTE in patients with a history of VTE was 103.1 and 90.7 person-years respectively.

CONCLUSION

In high-risk patients, statins treatment may reduce the incidence of VTE. Statins can also reduce the risk of recurrent VTE and all-cause mortality in patients with a history of VTE.

Isolated calf deep venous thrombosis: frequency on venous ultrasound and clinical characteristics

Background

It remains controversial whether to include calf veins in the initial ultrasound evaluation of suspected deep venous thrombosis (DVT). We sought to investigate the frequency and clinical characteristics of isolated calf DVT.

Materials and methods

In this retrospective analysis, we investigated a cohort of 596 patients (median age 69 years, 52.3% women) who had been imaged with complete lower extremity venous duplex ultrasound for suspected acute DVT. Radiology reports were analyzed for the presence and localization of DVT. Clinical information was collected from patients’ electronic charts.

Results

DVT was found in 157 patients (26.3%), of which 74 patients (47.1%) had isolated calf DVT. Isolated calf DVTs were located in the posterior tibial veins (22 patients, 29.7%), peroneal veins (41 patients, 55.4%) and muscle veins (19 patients, 25.7%). There were no differences in age or sex between patients with isolated calf DVT and patients with proximal DVT. Isolated calf DVT was more commonly associated with leg pain (52.7% vs. 33.7%, p = 0.0234) and less commonly associated with subjective leg swelling (35.1% vs. 55.4%, p = 0.0158) and objectively measured difference in leg circumference (23% vs. 39.8%, p = 0.0268). D-Dimers were significantly lower in patients with isolated lower leg DVT (median 2.3 vs. 6.8 mg/L, p < 0.0001) compared to patients with proximal DVT.

Conclusions

Isolated calf DVT represents approximately half of DVT cases and has different clinical characteristics than proximal DVT.

Skin manifestations as potential symptoms of diffuse vascular injury in critical COVID-19 patients

As a respiratory viral infection caused by a novel coronavirus, COVID-19 became rapidly pandemic within a few months. Despite the wide range of manifestations and organ involvement in COVID-19 patients, the exact pathogenesis of severe and fatal types of COVID-19 and causes involved with the individual base of the disease is not yet understood. Several studies have reported clinical, laboratory, and histopathological data in favor of vascular injury in multiple organs of critically ill patients with COVID-19 as a result of hyperactive immune response, inflammation, and cytokine storm. Also, both clinical and histopathological evidence points to such vascular involvements in the skin. Given the ease of clinical examinations and skin biopsy and the lower risks of transmission of COVID-19 to healthcare workers, the present review article was conducted to investigate the vascular skin manifestations of COVID-19 patients clinically and/or histopathologically as helpful clues for better understanding the pathogenesis and predicting the prognosis of the disease, especially in severe cases.

Upregulation of Inflammatory Cytokines in Pulmonary Embolism Using Biochip-Array Profiling

The complex pathophysiology of pulmonary embolism (PE) involves hemostatic activation, inflammatory processes, cellular dysfunction, and hemodynamic derangements. Due to the heterogeneity of this disease, risk stratification and diagnosis remains challenging. Biochip-array technology provides an integrated high throughput method for analyzing blood plasma samples for the simultaneous measurement of multiple biomarkers for potential risk stratification. Using biochip-array method, this study aimed to quantify the inflammatory biomarkers such as interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and epidermal growth factor (EGF) in 109 clinically confirmed PE patients in comparison to the control group comprised of plasma samples collected from 48 healthy subjects. Cytokines IL-4, IL-6, IL-8, IL-10, IL-1β, and MCP-1 demonstrated varying level of significant increase (P < 0.05) in massive-risk PE patients compared to submassive- and low-risk PE patients. The upregulation of inflammatory cytokines in PE patients observed in this study suggest that inflammation plays an important role in the overall pathophysiology of this disease. The application of biochip-array technology may provide a useful approach to evaluate these biomarkers to understand the pathogenesis and risk stratification of PE patients.

FXII regulates the formation of deep vein thrombosis via the PI3K/AKT signaling pathway in mice

Deep vein thrombosis (DVT) is a common peripheral vascular disease, which may result in pulmonary embolism and is accompanied by endothelial injury. However, the pathogenesis of DVT remains unclear. Coagulation factor XII (FXII), as an important coagulation factor, has been reported to be closely associated with thrombosis. However, the association between FXII protein and DVT formation is not yet fully understood. The present study examined the effects of FXII protein on DVT formation and aimed to reveal the underlying mechanism. In the present study, histological characterization of the femoral vein tissue was examined by hematoxylin and eosin staining. The damage to the femoral vein tissue was examined by TUNEL assay. Superoxide dismutase (SOD) and malondialdehyde (MDA) concentrations were examined using ELISA. Tumor necrosis factor (TNF)‑α, interleukin (IL)‑6, IL‑8 and phosphoinositide 3‑kinase (PI3K)/AKT signaling were determined by ELISA, immunohistochemical staining and western blot analysis. The results demonstrated that thrombosis, FXII protein, cell apoptosis and the SOD concentrations were decreased, while the MDA concentrations were increased in mice with DVT compared with the control or sham groups. TNF‑α, IL‑6, IL‑8 and PI3K/AKT signaling was also upregulated in the mice with DVT. Furthermore, the knockdown of FXII significantly upregulated the SOD concentrations and downregulated thrombosis and cell apoptosis, as well as the MDA concentrations in mice with DVT. The knockdown of FXII also significantly downregulated the protein expression of TNF‑α, IL‑6 and IL‑8, and the activation of PI3K/AKT signaling. Additionally, LY294002 pre‑treatment markedly downregulated thrombosis and cell apoptosis and the MDA content, whereas it upregulated the SOD concentrations in mice with DVT. LY294002 pre‑treatment also significantly downregulated the TNF‑α, IL‑6 and IL‑8 protein levels. Taken together, the present study demonstrates that FXII protein promotes DVT via the activation of PI3K/AKT signaling by inducing an inflammatory response. Targeting FXII protein may thus prove to be a potential approach for the treatment of DVT.

Thromboembolic Adverse Drug Reactions in Janus Kinase (JAK) Inhibitors: Does the Inhibitor Specificity Play a Role?

Recent advances in immunology enabled the characterization of several signal transmitting pathways responsible for proper cytokine and chemokine signaling. Among them, Janus kinases (JAKs) are essential components of receptor activation systems. The discovery of JAK kinases enabled the synthesis of JAK kinase inhibitors (JAKi or Jakinibs), which have proven to be efficacious in the treatment of hematologic malignancies and several rheumatological disorders and continue to be investigated in many clinical indications. Blocking multiple cytokines belonging to several cytokine families with a single small molecule may, however, create a potential risk for the patients. Recently, a higher risk of thromboembolic complications, namely, deep vein thrombosis and pulmonary embolism, has been recognized as the main concern during treatment with Jakinibs. At present, it is not entirely clear whether this increased risk is related to direct cytokine blockade, the presence of concomitant diseases in treated patients or other unknown circumstances that work together to increase the risk of this side effect. In this review, we discuss data on the risk of thromboembolic side effects, with special emphasis on the mechanism that may be responsible for this increased risk. Many indirect data indicate that higher thromboembolic risk may be related to the specificity of JAK inhibitor action, such that preferentially blocking one signaling pathway upsets the balance between pro and anti-thrombotic activities.

The Protégé Nitinol Self-Expanding Stent for the Treatment of Iliofemoral Veno-Occlusive Disease

PURPOSE

To evaluate the safety and effectiveness of the Protégé nitinol self-expanding stent for the treatment of iliofemoral veno-occlusive disease.

MATERIALS AND METHODS

A retrospective review was performed of 376 (284 left, 92 right) Protégé stents in 212 limbs of 183 patients (mean age: 53 ± 17 years, 52% female) treated for iliofemoral veno-occlusive disease between 2011 and 2018. Binary patency was assessed with duplex ultrasound and calculated by Kaplan Meier analysis. Clinical outcomes were evaluated by clinical-etiology-anatomy-pathophysiology (CEAP) classification and Villalta scores. Adverse events were recorded and categorized per Society of Interventional Radiology reporting standards.

RESULTS

Of the 212 limbs, 125 presented with acute thrombosis and 28 with chronic thrombosis requiring thrombectomy (n = 44), catheter directed thrombolysis (n = 32), or both (n = 77). Fifty-nine limbs were non-thrombotic. Mean follow-up time was 11.44 ± 11.37 months. Kaplan Meier analysis revealed a primary limb-level patency of 92.3%, 88.6%, 86.9% and 86.9% at 6, 12, 24 and 36 months, respectively. CEAP and Villalta scores improved from a median of C3 (range: 0-6) to C1 (0-5) (p < 0.001) and from a mean of 13.4 ± 7.5 to 5.3 ± 4.9 (p < 0.001), respectively. Nine minor and 2 major adverse events were recorded.

CONCLUSIONS

Endovascular treatment of iliofemoral veno-occlusive disease with the Protégé self-expanding stent appears to have good mid-term patency.

LEVEL OF EVIDENCE

Level 4, Case Series.

CAN COMPLETE BLOOD CELL COUNT PARAMETERS PREDICT DEEP VEIN THROMBOSIS?

The aim of this study was to evaluate complete blood cell count parameters including red blood cell indices, white blood cell subtypes, and platelet indices for predicting deep vein thrombosis (DVT). A total of 71 (44 male and 27 female) patients with acute femoral and popliteal DVT diagnosed by doppler ultrasonography during a period of seven years (2011-2017) were included in the study. By matching age and gender, 142 (88 male and 54 female) subjects diagnosed with venous insufficiency in the same time interval were assigned as control group. Data were obtained by reviewing hospital records of the study participants, including clinical and demographic characteristics and complete blood cell parameters. Frequencies of hypertension, diabetes mellitus, chronic obstructive pulmonary disease, chronic renal failure, and coronary arterial disease were higher in DVT group as compared to non-DVT group (p<0.05). Hemoglobin and lymphocyte values were lower, and red blood cell distribution width, neutrophil, neutrophil to lymphocyte ratio, and platelet to lymphocyte ratio higher in DVT group as compared with non-DVT group (p<0.05). There was no significant between-group difference in terms of mean corpuscular volume, platelet, mean platelet volume, mean platelet volume to platelet ratio, and platelet distribution width (p>0.05). Hypertension, hemoglobin, neutrophil to lymphocyte ratio, and platelet to lymphocyte ratio were independent risk factors for DVT. We found that hypertension, anemia, neutrophil to lymphocyte ratio, and platelet to lymphocyte ratio were independent risk factors for DVT. In particular, neutrophil to lymphocyte ratio and hemoglobin may be used as novel, inexpensive, and reliable diagnostic tools for DVT.

In Children with Provoked Venous Thromboembolism, Increasing Plasma Coagulability during the First 3 Months Postdiagnosis is Prognostic of Recurrence

Prognostic factors for venous thromboembolism (VTE) recurrence following provoked VTE are largely unknown. Using the Clot Formation and Lysis (CloFAL) assay, single institutional research has shown overall improvement in acute hypercoagulability during the first 3 months postpediatric VTE, yet a rise in plasma coagulability in a subgroup of patients. We sought to define the incidence of rise in coagulability during the first 3 months post-provoked VTE, to investigate its relationship with elevated D-dimer, and to test the hypothesis that a marked rise in coagulability is independently prognostic of VTE recurrence. CloFAL and D-dimer assays were performed on plasma at 4 to 6 weeks and 3 months post-VTE in the Johns Hopkins pediatric VTE cohort and National Institutes of Health-sponsored Kids-DOTT trial. Associations of VTE recurrence with D-dimer and CloFAL assay measures were evaluated via logistic regression. Eighty-seven patients were included. Median follow-up was 1 year. Complete veno-occlusion was determined in 12% at 6 weeks. During the first 3 months post-VTE, a marked rise in coagulability was observed by CloFAL assay in 17% of patients, while D-dimer was elevated in 21%. Recurrent VTE occurred in 10% of patients. CloFAL assay, but not D-dimer, was associated with recurrence (odds ratio [OR] 5.87, 95% confidence interval [95% CI], 1.34-25.8]). After adjustment for veno-occlusion, patients with a marked rise in coagulability by CloFAL assay had a 10-fold increased risk of recurrent VTE (OR 10.33 [95% CI, 1.83-58.19]). Future work should seek to elucidate the mechanisms underlying a rise in plasma coagulability following provoked VTE and to substantiate its prognostic utility for recurrent VTE.

Cytokine and chemokine regulation of venous thromboembolism

Morbidity and mortality from venous thromboembolism (VTE), which refers to deep vein thrombosis and pulmonary embolism, have a substantial effect on the global burden of disease. The field of venous thrombosis research has been dramatically changed over the past 10 years with the improvement of animal models that shed some light on the interaction between inflammation and thrombosis. Important recent advances provided evidence of the implication of the innate immune system in venous thrombosis. In this review, we highlighted the cytokines and chemokines that regulate mechanisms of thrombus formation and resolution. Cytokines are pleiotropic, redundant, and multifunctional endogenous mediators orchestrating the inflammatory responses leading to thrombus formation or resolution. The use of experimental models has revealed the pro-thrombotic activity of some cytokines including interferon-γ, interleukin (IL)-6, chemokine ligand 2, IL-17A, IL-9, IL-1β, and transforming growth factor-β. Other cytokines such as IL-10, tumor necrosis factor-α, and IL-8 appear to promote thrombus resolution in late phase of venous thromboembolism. The purpose of this review is to bring together the current knowledge regarding the cytokines and chemokines that have been involved in thrombosis formation and resolution. We postulate that an imbalance between pro-thrombotic and anti-thrombotic cytokines/chemokines may be involved in the pathophysiology of VTE. However, in-depth basic and clinical research in venous thrombosis is still require to fully understand the precise mechanism of action of these cytokines.

IL (Interleukin)-6 Contributes to Deep Vein Thrombosis and Is Negatively Regulated by miR-338-5p

Supplemental Digital Content is available in the text.

Objective:

Deep venous thrombosis (DVT), one of the most common venous thromboembolic disorders, is closely linked with pulmonary embolism and post-thrombotic syndrome, both of which have a high mortality. However, the factors that trigger DVT formation are still largely unknown. Elevated expression of IL (interleukin)-6—an important inflammatory cytokine—has been linked with DVT formation. However, the molecular mechanisms leading to the elevated IL-6 in DVT remain unclear. Here, we proposed that epigenetic modification of IL-6 at the post-transcriptional level may be a crucial trigger for IL-6 upregulation in DVT.

Approach and Results:

To explore the association between microRNAs and IL-6 in DVT, we performed microRNA microarray analysis and experiments both in vitro and in vivo. Microarray and quantitative real-time polymerase chain reaction results showed that IL-6 expression was increased while miR-338-5p level was decreased substantially in peripheral blood mononuclear cells of patients with DVT, and there was significant negative correlation between miR-338-5p and IL-6. Experiments in vitro showed that overexpressed miR-338-5p reduced IL-6 expression, while miR-338-5p knockdown increased IL-6 expression. Moreover, our in vivo study found that mice with anti–IL-6 antibody or agomiR-338-5p delivery resulted in decreased IL-6 expression and alleviated DVT formation, whereas antagomiR-338-5p acted inversely. Most of miR-338-5p was found located in cytoplasm by fluorescence in situ hybridization. Dual-luciferase reporter assay identified direct binding between miR-338-5p and IL-6.

Conclusions:

Our results suggest that decreased miR-338-5p promotes DVT formation by increasing IL-6 expression.

Low Systemic Levels of Chemokine C-C Motif Ligand 3 (CCL3) are Associated with a High Risk of Venous Thromboembolism in Patients with Glioma

A tight interplay between inflammation and hemostasis has been described as a potential driver for developing venous thromboembolism (VTE). Here, we investigated the association of systemic cytokine levels and risk of VTE in patients with glioma. This analysis was conducted within the prospective, observational Vienna Cancer and Thrombosis Study. Patients with glioma were included at time of diagnosis or progression and were observed for a maximum of two years. Primary endpoint was objectively confirmed VTE. At study entry, a single blood draw was performed. A panel of nine cytokines was measured in serum samples with the xMAP technology developed by Luminex. Results: Overall, 76 glioma patients were included in this analysis, and 10 (13.2%) of them developed VTE during the follow-up. Chemokine C-C motif ligand 3 (CCL3) levels were inversely associated with risk of VTE (hazard ratio [HR] per double increase, 95% confidence interval [CI]: 0.385, 95% CI: 0.161–0.925, p = 0.033), while there was no association between the risk of VTE and serum levels of interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, IL-11, tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF), respectively. In conclusion, low serum levels of CCL3 were associated with an increased risk of VTE. CCL3 might serve as a potential biomarker to predict VTE risk in patients with glioma.

Correlation study of venous thromboembolism with SAA, IL-1, and TNF-a levels and gene polymorphisms in Chinese population

Background

The relationship between inflammation and venous thromboembolism (VTE) has not been fully elucidated.

Methods

Based on our previous studies, we detected the plasma levels of serum amyloid A protein (SAA), interleukin-1 (IL-1), and tumor necrosis factor-a (TNF-a) and their 8 gene polymorphisms by ELISA and a multiplex ligation detection reaction (iMLDR) method in 284 patients with VTE and 268 healthy controls.

Results

Levels of SAA (P=0.032), IL-1 (P=0.045), and TNF-a (P=0.040) were significantly higher in the VTE group than in the control group. Recessive model analysis of the IL-1 rs1800587 variant showed that the risk of VTE in patients with the GG + GA genotype was significantly higher than that in patients with the AA genotype [odds ratio (OR): 4.444; 95% CI: 1.466-13.470]. Recessive model analysis of the IL-1 rs2234650 polymorphism showed that the risk of VTE in patients with the CC + CT genotype was significantly lower than that in patients with the TT genotype (OR: 0.500; 95% CI: 0.268-0.934). Multivariate logistic regression analysis showed that the TT genotype at IL-1 rs2234650 (OR: 2.086; 95% CI: 1.091-3.985) was an independent risk factor for VTE. The AA genotype of IL-1 rs1800587 (OR: 0.226; 95% CI: 0.074-0.890) was an independent protective factor against VTE.

Conclusions

In summary, an intrinsic relationship may exist between inflammatory activation and the occurrence of VTE.

Overexpressed microRNA-103a-3p inhibits acute lower-extremity deep venous thrombosis via inhibition of CXCL12

Studies have shown that microRNAs (miRNAs) participate in almost all pathological and physiological processes including acute lower-extremity deep venous thrombosis (LEDVT). Here, this study was designed to elucidate the possible function of miR-103a-3p in acute LEDVT. Expression of miR-103a-3p and chemokine C-X-C motif ligand 12 (CXCL12) was initially quantified in plasma collected from 81 LEDVT patients. Then LEDVT mouse models were established by injection with 3% sodium pentobarbital. The interaction between miR-103a-3p and CXCL12 was identified by dual-luciferase reporter gene assay. After gain- and loss-of-function studies, interleukin-6 (IL-6) and IL-8 and tissue factor (TF) levels, and expression of plasminogen activator inhibitors (PAIs), von Willebrand factor (vWF), thromboxane A2 (TH-A2), F4/80, IL-12, Arginase-1 (Arg-1) and CD206 were determined using enzyme-linked immunosorbent assay (ELISA), reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, respectively. miR-103a-3p was downregulated, while CXCL12 was upregulated in patients and mice with LEDVT. miR-103a-3p targets CXCL12 and inhibited its expression. Overexpressed miR-103a-3p or downregulated CXCL12 decreased expression of IL-6, IL-8, TF, PAIs, vWF, TH-A2, M1 markers (IL-6 and IL-12), yet increased expression of M2 markers (Arg-1 and CD206) in LEDVT mice. Additionally, upregulated miR-103a-3p or silencing CXCL12 suppressed thrombosis in LEDVT mice. However, overexpression of CXCL12 reversed the tendency mentioned above. Altogether, miR-103a-3p can potentially downregulate CXCL12 expression to disrupt inflammatory response and thrombosis, ultimately preventing the development of LEDVT. Our findings underscore a possible alternative therapeutic strategy to limit LEDVT.

The role of serum bilirubin levels in determining venous thromboembolism

OBJECTIVE

Venous thromboembolism (VTE) is a disease that includes both deep venous thrombosis (DVT) and pulmonary embolism (PE). Bilirubin is an endogenous anti-inflammatory marker associated with atherothrombosis. The purpose of our study was to investigate the association of serum bilirubin levels with the presence of VTE.

METHODS

A total of 103 patients with VTE (distal DVT, n = 34; proximal DVT, n = 30; PE, n = 39) and 50 control patients were cross-sectionally enrolled. Peripheral venous duplex ultrasound and computed tomography were used for the diagnosis of VTE. Fasting blood samples were drawn for biochemical analyses.

RESULTS

Baseline characteristics were not different between groups. The VTE group had lower bilirubin level (9.0 ± 2.6 μmol/L vs 7.3 ± 3 μmol/L; P = .001) and higher high-sensitivity C-reactive protein (hs-CRP) concentration (0.8 [0.3-2] mg/L vs 1.1 [0.2-3] mg/L; P = .008) and white blood cell count (7.4 ± 1.5 × 10⁹/L vs 8.2 ± 2.7 × 10⁹/L; P = .02) compared with control patients. In the analysis of variance, the levels of total direct bilirubin and hs-CRP were clearly different between the control group and VTE subgroups (distal and proximal DVT and PE). The receiver operating characteristic curve analysis showed a cutoff value of 8.9 μmol/L for total bilirubin (sensitivity, 74%; specificity, 55%) and an area under the curve of 0.659 (P < .001).

CONCLUSIONS

Bilirubin level, hs-CRP concentration, and white blood cell count were independently associated with VTE.

Inflammation is correlated with severity and outcome of cerebral venous thrombosis

BACKGROUND

Few studies have suggested a relationship between inflammation and cerebral venous thrombosis (CVT). This retrospective study aimed to explore the changes in inflammation in different CVT stages and the correlation between inflammation and severity and outcome of CVT.

METHODS

In total, 95 suitable patients with CVT and 41 controls were compared. Patients with CVT were divided into three groups. The inflammatory factors studied included hypersensitive C-reactive protein (Hs-CRP), interleukin-6 (IL-6), and neutrophil-to-lymphocyte ratio (NLR) in the peripheral blood and immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) in the cerebrospinal fluid (CSF). The severity of CVT was evaluated with the modified Rankin Scale (mRS), the National Institutes of Health Stroke Scale (NIHSS), fundus condition, intracranial pressure (ICP), and complications on admission. The short-term outcome was evaluated with the mRS at discharge.

RESULTS

The following results were obtained: (1) Inflammatory factor levels in patients with CVT were higher than those in the controls. (2) Inflammatory factor levels in the acute and subacute stages were significantly higher than those in the chronic stage (all P < 0.05). (3) Serum NLR and CSF IgM levels were positively related to baseline degree of disability (odds ratio [OR], 1.279, 95% confidence interval [CI] 1.009-1.621, P = 0.042; OR 1.402, 95% CI 1.036-1.896, P = 0.028). The Hs-CRP level was positively correlated with the baseline occurrence of seizure (OR 1.040, 95% CI 1.001-1.080, P = 0.043). The baseline serum NLR (r = 0.244, P = 0.017), CSF IgA (r = 0.615, P < 0.001), CSF IgM (r = 0.752, P < 0.001), and CSF IgG (r = 0.248, P = 0.015) levels were positively associated with NIHSS. (4) The baseline NLR was significantly associated with high risk of poor outcome at discharge (OR 1.339, 95% CI 1.097-1.784, P = 0.007). Moreover, the ROC showed that NLR ≥ 4.205 could better predict the poor outcome at discharge. The data were analyzed using SPSS.

CONCLUSIONS

Inflammation may develop after CVT and gradually decrease during the course. Inflammation was significantly correlated with severity on admission and short-term poor outcome at discharge in CVT.

Impact of interleukin 6 promoter polymorphisms (-174 G > C, -572 G > C and -597 G > A) on plasma IL-6 levels and their influence on the development of DVT: a study from India

OBJECTIVES

To evaluate the association of interleukin 6 (IL-6) levels with deep vein thrombosis (DVT) and to assess the impact of IL-6 promoter polymorphisms (-174G > C, -572G > C and -597G > A) on its plasma levels and their influence in the development of DVT in India.

METHODS

One hundred DVT patients and 100 age and sex-matched healthy controls were study subjects. IL-6 polymorphisms were identified by polymerase chain reaction-restriction fragment length polymorphism. IL-6 levels were detected by enzyme-linked immunosorbent assay.

RESULTS

Significantly raised IL-6 levels were observed in patients as compared to controls. (Patients: 13.73 ± 6.30 pg/ml, Controls: 11.83 ± 4.47 pg/ml, p = 0.014). The prevalence of C allele of -572G > C polymorphism was significantly higher in patients than controls (Patients: 39.5%, Controls: 27.5%, p = 0.011, χ²=6.463). Subjects with GC and CC genotype had significantly higher IL-6 levels than GG genotype (p=<0.001). Patients with GC and CC genotype increased the DVT risk by 1.39 fold (OR^a: 1.39, CI: 0.74-2.62) and 2.69 fold (OR^a: 2.42, CI: 1.08-6.70), respectively. IL-6 -174G > C and -597G > A polymorphisms were not associated with raised IL-6 levels and nor with thrombotic risk (-174G > C: p = 0.823 χ²=0.369; -597G > A: p = 0.678 χ²=1.08).

CONCLUSION

Our study emphasizes the importance of -572G > C polymorphism in increasing IL-6 levels, thereby showing its significant role in DVT in India. IL-6 -174G > C and -597G > A were neither associated with raised plasma IL-6 levels nor with thrombotic risk. Thus -572G > C polymorphism detection may be one of the connecting links between IL-6 and thrombotic risk in Indian DVT patients.

Experimental Study of Phlebitis Ointment Administration in Acute Superficial Thrombophlebitis

Acute superficial thrombophlebitis is a venous system disease. Animal models with mannitol induced phlebitis were treated with an orally administered “phlebitis ointment.” 24 rabbits were randomly divided into 4 groups. The therapy group was treated with “phlebitis ointment” and a control group received “Mai Luo Shu Tong granules.” Levels of blood TNF-α, IL-6, CRP, and IL-1β were measured. The tissue expression levels of NF-КBp65 and PKC genes were evaluated. The therapy group showed a better improvement of the clinical status and similar vascular morphology than the control group. A blank group showed no vascular changes through pathological investigation. In contrast, significant vascular changes were seen in the model group. The control group showed slight vascular modifications. Small thrombi could be found in the lumen despite the intact tunica intima. Both control and therapy group showed less inflammatory cells infiltration than the model group and upregulation of NF-КBp65 and PKC genes. The phlebitis ointment reduced the levels of necrosis factor-α, interleukin-6, C-reactive protein, and interleukin-1ß. The expressions of NF-КBp65 and PKC genes, which are the primary mechanisms underlying the development of thrombophlebitis, were improved significantly in tissues of both therapy group and control group.

Cytokines, Adhesion Molecules, and Matrix Metalloproteases as Predisposing, Diagnostic, and Prognostic Factors in Venous Thrombosis

The inflammatory response is a well-established part of, and a prerequisite for, venous thrombosis. To better understand the pathophysiology of venous thrombosis and to identify improved diagnostic biomarkers, further studies of the relationship between inflammation and coagulation are needed. We review previous studies concerning inflammatory biomarkers in venous thromboembolism, in particular cytokines, soluble adhesion molecules and matrix metalloproteases as predisposing, diagnostic and prognostic factors in venous thrombosis. Elevated cytokines and genetic alterations coding for cytokines are found in several patient cohorts which indicate that cytokines are involved as predisposing factors in venous thrombosis development. Increased levels of pro-inflammatory cytokines are detected both in animal models and in patients with acute venous thrombosis and clinical trials, although currently without evident diagnostic value. Adhesion molecules are crucial in the development of venous thrombosis, especially P-selectin seems important in initiating leukocyte accumulation and adhesion to endothelium for subsequent platelet accumulation. Several studies have demonstrated increased soluble P-selectin levels in patients with venous thrombosis, emphasizing its potential role as diagnostic marker and also as a therapeutic target. Matrix metalloproteases are essential effectors during venous thrombosis resolution and may impact vessel wall fibrosis, and together with their natural occurring inhibitors are crucial in acute and chronic thrombosis pathophysiology. Furthermore, studies in animal models of venous thrombosis have demonstrated anti-inflammatory treatment to be effective in terms of thrombus resolution and reduction of vessel wall damage, without increase in bleeding risk during the course of treatment. Thus, soluble mediators should be further investigated both as possible biomarkers and therapeutic targets in venous thromboembolic disease.

How I treat the postthrombotic syndrome

The postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that imposes significant morbidity, reduces quality of life, and is costly. After DVT, 20% to 50% of patients will develop PTS, and up to 5% will develop severe PTS. The principal risk factors for PTS are anatomically extensive DVT, recurrent ipsilateral DVT, obesity, and older age. By preventing the initial DVT and DVT recurrence, primary and secondary prophylaxis of DVT will reduce occurrence of PTS. The effectiveness of elastic compression stockings (ECSs) for PTS prevention is controversial. Catheter-directed thrombolysis is not effective to prevent PTS overall but may prevent more severe forms of PTS and should be reserved for select patients with extensive thrombosis, recent symptoms onset, and low bleeding risk. For patients with established PTS, the cornerstone of management is ECS, exercise, and lifestyle modifications. Surgical or endovascular interventions may be considered in refractory cases. Because of a lack of effective therapies, new approaches to preventing and treating PTS are needed. This article uses a case-based approach to discuss risk factors for PTS after DVT, how to diagnose PTS, and available means to prevent and treat PTS, with a focus on new information in the field.

C-reactive protein and risk of venous thromboembolism: results from a population-based case-crossover study

Long-term, low-grade inflammation does not seem to be a risk factor for venous thromboembolism. The impact of acute inflammation, regardless of cause, on risk of venous thromboembolism is scarcely studied. We aimed to investigate the impact of acute inflammation, assessed by C-reactive protein, on short-term risk of venous thromboembolism. We conducted a case-crossover study of patients with venous thromboembolism (n=707) recruited from a general population. Information on triggers and C-reactive protein levels were retrieved from hospital records during the 90 days before the event (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to obtain β coefficients for change in natural log (ln) transformed C-reactive protein from control to hazard periods and to determine corresponding odds ratios for venous thromboembolism. Median C-reactive protein was 107 mg/L in the hazard period, and ranged from 7 mg/L to 16 mg/L in the control periods. The level of C-reactive protein was 58% (95% CI 39-77%) higher in the hazard period than in the control periods. A one-unit increase in ln-C-reactive protein was associated with increased risk of venous thromboembolism (OR 1.79, 95% CI 1.48-2.16). The risk estimates were only slightly attenuated after adjustment for immobilization and infection. In stratified analyses, ln-C-reactive protein was associated with increased risk of venous thromboembolism in cases with (OR 1.55, 95% CI 1.01-2.38) and without infection (OR 1.77, 95% CI 1.22-2.57). In conclusion, we found that acute inflammation, assessed by C-reactive protein, was a trigger for venous thromboembolism.

Enoxaparin pretreatment effect on local and systemic inflammation biomarkers in the animal burn model

Low-molecular weight heparins (LMWH) are anticoagulants that have shown anti-inflammatory activity in several experimental models. Hot water burn inflammatory model accurately simulates human clinical situations allowing its use for nociception test and evaluation of anti-inflammatory drugs. The present study aims to evaluate the enoxaparin pretreatment on local and systemic inflammation biomarkers in the animal burn model. Inflammation was induced by submersing the rat left hind paw in water at 60^o C for 60 s. C-reactive protein (CRP) and thrombin-antithrombin complex (TAT) were estimated by immunosorbent assay, fibrinogen (Fg) by the gravimetric method and paw oedema by orthogonal digital photography. Highest values of paw oedema, CRP and TAT were observed at 4 h post-burn while Fg peak occurs at 12 h post-burn; enoxaparin pretreatment decreased oedema (- 32.1%), and concentration of TAT (- 66.7%), PCR (- 37.9%) and Fg (- 8%). This study shows that enoxaparin has local and systemic anti-inflammatory effects and should be considered as a potential adjuvant drug for the treatment of burns.

Diagnostic Value of Synovial White Blood Cell Count and Serum C-Reactive Protein for Acute Periprosthetic Joint Infection After Knee Arthroplasty

BACKGROUND

The diagnosis of periprosthetic joint infection (PJI) remains difficult, particularly in acute postoperative stage. The purpose of this study was to investigate the optimal cutoff value of synovial white blood cell (WBC) count, percentage of polymorphonuclear cells, erythrocyte sedimentation rate, and C-reactive protein (CRP) for diagnosing early postoperative infection after knee joint arthroplasty.

METHODS

We retrospectively reviewed primary total knee arthroplasties and unicompartmental knee arthroplasties, with a knee aspiration within 3 weeks of surgery, from January 2006 to November 2016. Twelve infected cases and 185 uninfected cases met the inclusion criteria of our study. We compared the laboratory parameters (synovial WBC count, percentage of polymorphonuclear cells, erythrocyte sedimentation rate, and CRP levels) between the 2 groups. Receiver operating characteristic curves were constructed to determine the optimal cutoff values for each parameter. Each parameter was studied to determine its sensitivity, specificity, and positive and negative predictive values (PPV and NPV) in diagnosing acute PJI.

RESULTS

There were 2 optimal cutoff values for synovial WBC count and CRP levels. With the cutoff value of synovial WBC set at 11,200 cells/μL, acute PJI could be diagnosed with the highest sensitivity (100%) and specificity (98.9%); with the cutoff value set at 16,000 cells/μL, the best PPV and NPV were found (100% and 99.5%, respectively). Similarly, the CRP level >34.9 mg/L had the best sensitivity (100%) and specificity (90.3%), whereas the CRP level >74.5 mg/L had the best PPV (100%) and NPV (99.2%).

CONCLUSION

Synovial WBC count and CRP levels are useful in diagnosing acute PJI between 1 and 3 weeks after primary knee arthroplasty.

Statins as a preventative therapy for venous thromboembolism

The anti-inflammatory effects of statins have likely not been used to their fullest extent, particularly in reducing venous thromboembolic events. Current therapy for thrombotic events hinges on anticoagulation via heparin, warfarin or new oral anticoagulants. Interventional procedures with thrombectomy may also play a critical role. Unfortunately, thrombotic events can occur and recur despite meticulous anticoagulation therapy. Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE), two complicated and prevalent diseases that can cause chronic disease states such as post-thrombotic syndrome (PTS). In 2009 the JUPITER trial demonstrated that rosuvastatin may be effective when dealing with vascular inflammation by providing an anti-inflammatory effect. Multiple subsequent studies have looked at this association with some promising findings. The mechanism of action for statins is not entirely understood but there has been a variety of proposals and subsequent testing of inflammatory biomarkers. Additional prospective trials are needed to confirm the possible benefit of VTE reduction through an anti-inflammatory effect, but if this can be shown then statins may become a safe adjunctive therapy for VTE prevention.

Perivascular Perfusion on Contrast-Enhanced Ultrasound (CEUS) Is Associated with Inflammation in Patients with Acute Deep Vein Thrombosis

Background Inflammatory processes of the venous wall in acute deep vein thrombosis (DVT) play a role in thrombus formation and resolution. However, direct evaluation of the perivascular inflammation is currently not feasible. Objective To assess perivascular perfusion in acute proximal DVT using contrast-enhanced ultrasound (CEUS) reflecting perivenous inflammation and its association with systemic inflammatory markers in a single-centre, prospective observational study. Patients/Methods Twenty patients with proximal DVT underwent CEUS imaging in the thrombosed and contralateral popliteal vein at baseline and after 2 weeks and 3 months. Perfusion was quantified by measuring peak enhancement (PE) and wash-in rate (WiR) in a perivenous region after bolus injection of the contrast agent. High-sensitive C-reactive protein (hsCRP) and interleukin-6 (IL-6) were determined at the time of each CEUS imaging. Results PE and WiR were significantly higher in the thrombosed compared with the unaffected leg at baseline (1,007 vs. 34 au and 103 vs. 4 au/s) and 2-week follow-up (903 vs. 35 au and 70 vs. 4 au/s). Compared with baseline, PE and WiR in the thrombosed leg significantly decreased to 217 au and 18 au/s at 3-month follow-up.At baseline, hsCRP and IL-6 were elevated at 20.1 mg/mL and 8.2 pg/mL and decreased significantly to 2.8 mg/mL and 2.6 pg/mL at 2-week follow-up, remaining low after 3 months. There was a weak association between the level of inflammatory markers and the CEUS parameters at baseline on the thrombosed leg. Conclusion Elevated perivascular perfusion assessed by CEUS imaging is associated with the inflammatory response in acute DVT.

Markers of coagulation activation, inflammation and fibrinolysis as predictors of poor outcomes after pediatric venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

Sequelae of venous thromboembolism (VTE) in children include recurrence, development of post thrombotic syndrome (PTS) when venous return from a limb is affected and chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism. Identification of laboratory-based risk factors may be useful for individualized risk assessment for VTE sequelae. Coagulation activation and inflammation may contribute to their pathophysiology. We performed a systematic review to investigate the association between biomarkers of coagulation activation, inflammation and fibrinolysis and adverse VTE outcomes in children and young adults.

METHODS

A systematic search of electronic databases, PubMed (NIH), EMBASE (Ovid), Web of Science (Thompson Reuters), and SCOPUS (Elsevier) for studies published through November 2016 was conducted using "VTE" including MeSH terms for "coagulation activation," "inflammation" and "fibrinolysis," with no limit on publication date. A study was eligible for inclusion when it evaluated patients (< 21years) with VTE and biomarkers of coagulation activation, inflammation, and fibrinolysis and assessed for their association with development of adverse thrombotic outcomes. A modified Newcastle Ottawa Scale was applied to examine the quality of included studies.

RESULTS

Our search strategy yielded 200 references. A total of 3 cohort studies representing 220 patients with VTE were included. Two authors independently assessed all references for inclusion. Three studies (2 prospective cohort and one mixed cohort study) were identified that reported on biomarkers of coagulation activation, inflammation and fibrinolysis, checked at least once after VTE diagnosis and assessed association with primary outcomes of recurrent VTE, PTS and CTEPH. Studies varied with regards to definition of outcomes, the type of biomarkers measured and time point of measurement. We were unable to meta-analyze results due to marked clinical heterogeneity and <3 studies available for each biomarker. Descriptively, a significant association was found for elevated plasma levels of FVIII and D-dimer for a compound outcome of PTS, recurrence and progression in one study, and positive lupus anticoagulant at DVT diagnosis and subsequent PTS by another study. No studies were found for CTEPH.

CONCLUSIONS

Elevated D-dimer, FVIII and lupus anticoagulant show promise for predicting recurrent VTE and PTS in children and young adults. Further research is needed to elucidate whether these markers might be useful to predict development of adverse outcomes after VTE in children.

Venous thromboembolism in children with cystic fibrosis: Retrospective incidence and intrapopulation risk factors

INTRODUCTION

Pediatric venous thromboembolism (VTE) is a rare but serious medical condition. Cystic fibrosis (CF) is a risk for recurrent pediatric VTE and has potential thrombophilic tendency. However, much remains unknown, including incidence and intrapopulation risk factors.

METHODS

A retrospective cohort of pediatric CF patients followed at Children's Hospital Colorado from January 1st 2003 through May 20th 2016 was examined. Cases were identified by informatics and validated manually. Data on CF severity, co-morbidities and treatment, central venous catheter (CVC) use, and thrombophilia were obtained from an institutional CF database and chart review.

RESULTS

Nineteen VTE occurred in 458 participants followed for 3595 person-years, yielding an incidence rate of 53 VTE per 10,000 children with CF. VTE cases had additional co-morbidities including CF-related diabetes (p=0.002) and sinus disease (p=0.04), more total admissions (p<0.001), admit days (p<0.001), positive respiratory cultures (p<0.001), pseudomonas infections (p<0.001), steroid courses (p=0.001), and total CVC days (PICC p=0.03, port p=0.007). On univariate analysis, older age (RR 1.162, p=0.007), sinus disease (RR 2.62, p=0.05), longer hospital stay (RR 1.03, p<0.001), higher ESR (RR 1.02, p=0.03) and CRP (RR 1.07, p=0.007), and an absence of systemic steroids (RR 0.19, p=0.004) increased the risk of VTE.

CONCLUSIONS

In this cohort, children with CF had a higher incidence of VTE when compared to the previously reported incidence in the overall pediatric population at Children's Hospital Colorado. Overall, those with VTE had a greater disease burden and older age, sinus disease, longer hospitalization and increased inflammation were VTE risk factors.

Involvement of inflammatory markers in pathogenesis of venous thromboembolism

Inflammation of the venous wall is involved in thrombogenesis, thrombus resolution, wall remodeling and the post-thrombotic syndrome. Different mechanisms are involved in both arterial and venous thrombosis and patients with atherothrombosis hold a higher risk of venous thrombosis. Although inflammation may represent the connection between arterial and venous thrombosis, it is not yet sure if it is the cause or consequence of venous thrombosis. Consequently, the relationships between inflammation markers as indicators of the inflammatory process and clinical venous thromboembolism need to be investigatd. For example, inflammation mediators such as the pro-inflammatory cytokines interleukin 8 (IL-8), IL-6, monocyte chemotactic protein 1 (MCP-1), C Reactive Protein (CRP), vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), matrix metalloproteinases and tumor necrosis factor alpha (TNF alpha) are all involved in thrombogenesis. Studies of venous thromboembolism on animal models proved that there are specific phases of the inflammatory process in venous thromboembolism and thrombus resolution. Knowing the molecular and immunologic mechanisms, identifying and understanding the inflammation markers which are relevant for venous thrombosis, can help to target specific pathways and to develop future therapies of this disease