Soluble p-selectin, D-dimer, and high-sensitivity C-reactive protein after acute deep vein thrombosis of the lower limb

Evaluation of soluble P-selectin as a predictive biomarker in acute symptomatic pulmonary embolism: Insights from a prospective observational study

BACKGROUND

Soluble P-selectin (sP-selectin) has been proposed as a potential biomarker for venous thromboembolism (VTE) diagnosis with interesting results. However, its role in predicting early mortality in pulmonary embolism (PE) remains unexplored.

METHODS

This observational, prospective, single-center study enrolled consecutive patients aged 18 or older with confirmed acute symptomatic PE and no prior anticoagulation. The study aims to assess the prognostic capacity of sP-selectin measured at the time of PE diagnosis for short-term mortality and major bleeding.

RESULTS

A total of 196 patients, with a mean age of 69.1 years (SD 17), were included, of whom 52.6% were male. Within 30 days, 9.7% of patients (n = 19) died, and 5.1% (n = 10) suffered major bleeding. PE risk stratification revealed 4.6% (n = 9) with high-risk PE, 34.7% (n = 68) with intermediate-high-risk PE, 38.3% (n = 75) with intermediate-low-risk PE, and 22.5% (n = 44) with low-risk PE according to the European Society of Cardiology score. Mean plasma sP-selectin levels were comparable between survivors and non-survivors (489.7 ng/mL ±63 vs. 497.3 ng/mL ±51; p = .9). The ROC curve for 30-day all-cause mortality and major bleeding yielded an AUC of 0.49 (95% CI 0.36-0.63) and 0.46 (95% CI 0.24-0.68), respectively. Multivariate and survival analyses were precluded due to lack of significance.

CONCLUSIONS

sP-selectin was not useful for predicting short-term mortality or major bleeding in patients with acute symptomatic pulmonary embolism. Further studies are required to clarify the role of sP-selectin in VTE, particularly in prognosticating PE outcomes.

Plasma levels of P-selectin and future risk of incident venous thromboembolism

BACKGROUND

P-selectin levels are elevated following acute deep vein thrombosis and reported to predict recurrent venous thromboembolism (VTE) and cancer-associated VTE. Yet, it is unknown whether plasma P-selectin levels are associated with incident VTE.

OBJECTIVES

We aimed to investigate the association between plasma P-selectin levels and risk of future incident VTE.

METHODS

We performed a nested case-control study in 415 patients with VTE and 843 age- and sex-matched controls derived from the general population (Tromsø IV Study). Plasma P-selectin levels were measured using enzyme-linked immunosorbent assay. Logistic regression models were used to estimate odds ratios (ORs) for VTE across quartiles of plasma P-selectin level. Sex-stratified analysis was also performed.

RESULTS

Plasma P-selectin levels were higher in men (41.4 ng/mL) than in women (38.7 ng/mL, p = .0046). We found no association between plasma P-selectin levels and risk of VTE in the overall analyses. However, sex-stratified analyses revealed that women with P-selectin levels in the highest quartile (>44.3 ng/mL) had higher risk of VTE (OR, 1.63; 95% CI, 1.01-2.64) than women with P-selectin levels in the lowest quartile (≤29.9 ng/mL). In contrast, higher levels of P-selectin were apparently associated with lower risk of VTE in men (OR for highest vs lowest quartile of P-selectin, 0.69; 95% CI, 0.42-1.15). The observed associations were stronger when the time between blood sampling and VTE was shorter.

CONCLUSION

Elevated levels of plasma P-selectin were associated with increased risk of VTE in women but not in men, suggesting a differential impact of sex on the association between P-selectin and VTE risk.

Platelet Selectin Levels in Patients with Cerebral Venous Sinus Thrombosis: Preliminary Findings

Background

Cerebral Venous Sinus Thrombosis (CVST) is a cerebrovascular disease with an estimated annual incidence of 3-4 cases per 1 million population with an 8% mortality rate caused by hypercoagulable conditions and hyper aggregation and also Platelet Selectin (P-Selectin) as one of coagulation biomarker for both of them. This study aimed to describe the levels of P-selectin in CVST patients at RSHS Bandung.

Objective

This study aimed to describe the levels of P-selectin in CVST patients at RSHS Bandung.

Methods

This is a descriptive observational study on patients ≥18 years old diagnosed with CVST at the Neurology outpatient polyclinic of RSUP Dr. Hasan Sadikin Bandung for March-May 2022. All samples that meet the inclusion criteria will be included as research subjects.

Results

There were 55 research subjects with a median age of 48 (range 22-69 years), the majority were women (80%), the most complaints were headaches (92.7%), the majority onset was chronic (96.4%) with a length of treatment ≥12 months (61.8%). P-selectin levels were found to increase in the group of subjects with subacute onset (mean 5.20 ± 2.977), infectious etiology (mean 5.26 ± 3.561), duration of treatment <3 Months (mean 3.79 ± 3.065), history of hyper aggregation (mean 3.89±2.805), hypercoagulation (mean 3.50±2.719), increased D-dimer (mean 3.93±2.710), normal fibrinogen (mean 3.38±2.693), and in the group with multiple affected sinuses (mean 6.08±2.681).

Conclusion

P-selectin could be a diagnostic marker for hyper aggregation and hypercoagulable state in patients with CVST, but it still needs further research to prove it.

P- and E- selectin in venous thrombosis and non-venous pathologies

Venous thromboembolism is a very common and costly health problem worldwide. Anticoagulant treatment for VTE is imperfect: all have the potential for significant bleeding, and none prevent the development of post thrombotic syndrome after deep vein thrombosis or chronic thromboembolic pulmonary hypertension after pulmonary embolism. For these reasons, alternate forms of therapy with improved efficacy and decreased bleeding are needed. Selectins are a family (P-selectin, E-selectin, L-selectin) of glycoproteins that facilitate and augment thrombosis, modulating neutrophil, monocyte, and platelet activity. P- and E-selectin have been investigated as potential biomarkers for thrombosis. Inhibition of P-selectin and E-selectin decrease thrombosis and vein wall fibrosis, with no increase in bleeding. Selectin inhibition is a promising avenue of future study as either a stand-alone treatment for VTE or as an adjunct to standard anticoagulation therapies.

Risk factors for preoperative deep venous thrombosis in hip fracture patients: a meta-analysis

Study design

A meta-analysis.

Background

Hip fracture (HF), as common geriatric fracture, is related to increased disability and mortality. Preoperative deep vein thrombosis (DVT) is one of the most common complications in patients with hip fractures, affecting 8–34.9% of hip fracture patients. The study aimed to assess the risk factors of preoperative DVT after hip fractures by meta-analysis.

Methods

An extensive search of the literature was performed in the English databases of PubMed, Embase, and the Cochrane Library; and the Chinese databases of CNKI and WAN FANG. We collected possible predictors of preoperative DVT from included studies, and data analysis was conducted with RevMan 5.3 and STATA 12.0.

Results

A total of 26 English articles were included, and the rate of DVT was 16.6% (1627 of 9823 patients) in our study. Our findings showed that advanced age [p = 0.0003, OR = 0.13 95% CI (0.06, 0.21)], female patients [p = 0.0009, OR = 0.82 95% CI (0.72, 0.92)], high-energy injury [p = 0.009, OR = 0.58 95% CI (0.38, 0.87)], prolonged time from injury to admission [p < 0.00001, OR = 0.54 95% CI (0.44, 0.65)], prolonged time from injury to surgery [p < 0.00001, OR = 2.06, 95% CI (1.40, 2.72)], hemoglobin [p < 0.00001, OR = − 0.32 95% CI (− 0.43, − 0.21)], coronary heart disease [p = 0.006, OR = 1.25 95% CI (1.07, 1.47)], dementia [p = 0.02, OR = 1.72 95% CI (1.1, 2.67)], liver and kidney diseases [p = 0.02, OR = 1.91 95% CI (1.12, 3.25)], pulmonary disease [p = 0.02, OR = 1.55 95% CI (1.07, 2.23)], smoking [p = 0.007, OR = 1.45 95% CI (1.11, 1.89)], fibrinogen [p = 0.0005, OR = 0.20 95% CI (0.09, 0.32)], anti-platelet drug [p = 0.01, OR = 0.51 95% CI (0.30, 0.85)], C-reactive protein [p = 0.02, OR = 5.95 95% CI (1.04, 10.85)], < 35 g/l albumin [p = 0.006, OR = 1.42 95% CI (1.1, 1.82)], and thrombosis history [p < 0.00001, OR = 5.28 95% CI (2.85, 9.78)] were risk factors for preoperative DVT.

Conclusions

Many factors, including advanced age, female patients, high-energy injury, prolonged time from injury to admission, prolonged time from injury to surgery, patients with a history of coronary heart disease, dementia, liver and kidney diseases, pulmonary disease, smoking, and thrombosis, fibrinogen, C-reactive protein, and < 35 g/l albumin, were found to be associated with preoperative DVT. Our findings suggested that the patient with above characteristics might have preoperative DVT.

Level of evidence: Level III.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10195-022-00639-6.

Inflammatory Biomarkers in the Short-Term Prognosis of Venous Thromboembolism: A Narrative Review

The relationship between inflammation and venous thrombosis is not well understood. An inflammatory response may be both the cause and consequence of venous thromboembolism (VTE). In fact, several risk factors of VTE modulate thrombosis through inflammatory markers. Acute pulmonary embolism (PE) is burdened by a remarkable mortality rate, up to 34% in severely ill patients presenting with hemodynamic instability. Initial mortality risk stratification is based on hemodynamic instability. Patients with a situation of hemodynamic stability require immediate further risk assessment based on clinical, imaging, and circulating biomarkers, as well as the presence of comorbidities. Some inflammatory biomarkers have shown potential usefulness in the risk stratification of patients with VTE, especially acute PE. C-reactive protein on admission is associated with 30-day mortality and bleeding in VTE patients. P-selectin is associated with right ventricle dysfunction in PE patients and might be associated with VTE recurrences and the extension of thrombosis. Tissue factor microparticles are associated with VTE recurrence in cancer-associated thrombosis. Other inflammatory biomarkers present scarce evidence (inflammatory cytokines, erythrocyte sedimentation rate, fibrinogen, leukocyte count). In this manuscript, we will review the prognostic role of different inflammatory biomarkers available both for clinical practice and research in VTE patients.

Age over 65 years and high levels of C-reactive protein are associated with the risk of preoperative deep vein thrombosis following closed distal femur fractures: a prospective cohort study

Background

In this study, we investigated the epidemiological characteristics and predictors of preoperative new-onset deep vein thrombosis (DVT) in adult patients with closed distal femur fractures (DFFs).

Methods

The study was designed as a prospective cohort trial at the Third Hospital of Hebei Medical University. From October 2018 to June 2020, a total of 160 patients with closed DFFs were enrolled to assess the location and prognosis of preoperative DVT. The patients were followed up for 2 months. Duplex ultrasonography (DUS) was used to diagnose patients with DVT. The patients were divided into two groups (DVT group and non-DVT group). The DVT was then classified into proximal, distal, and mixed thromboses. The Mann-Whitney U test or t test, receiver operating characteristic (ROC) analyses, univariate Chi-square analyses, and multiple logistic regression analyses were used to analyze the adjusted predictors of DVT.

Results

The overall incidence of preoperative DVTs was 52.5% (n = 84), which was diagnosed at a mean period of 3.1 days after injury. Among patients diagnosed with DVTs, 50.0% (n = 42) had distal thrombosis while 47.6% (n = 40) had mixed thrombosis. The calf muscle veins were the most common sites of DVTs (90.5%, n = 76). Of note, 45.2% (n = 38) of diagnosed DVTs were completely recanalized at a mean period of 12.0 days after the initial (first) diagnosis. Multivariate analysis revealed that age of ≥ 65 years of age (odds ratio [OR], 4.390; 95% confidence interval [CI] 1.727–11.155; p = 0.002), C-reactive protein (CRP) levels exceeding 11 mg/L (OR 4.158; 95% CI 1.808–11.289; p = 0.001), platelet (PLT) levels over 217 × 109/L (OR, 2.55; 95% CI 1.07–6.07; p = 0.035), D-dimer levels over 1.0 mg/L (OR 3.496; 95% CI 1.483–8.237; p = 0.004), and an American Society of Anesthesiologists (ASA) score of III-V (OR 2.753; 95% CI 1.216–6.729; p = 0.026) were the independent risk factors of preoperative DVT.

Conclusions

High levels of CRP, PLT, D-dimer, ASA, and ≥ 65 years of age increase the risk of preoperative DVTs in adult patients with closed DFFs. Thus, the prediction of preoperative DVTs can significantly be improved by identifying older patients over the age of 65, and establishing the biochemical cut-off values of CRP, PLT, ASA, and D-dimer.

Trial registration

No. 2018-026-1, 24 October 2018, prospectively registered.

This trial was registered prospectively on 24 October 2018 before the first participant was enrolled. This study protocol conformed to the Declaration of Helsinki and approved by the Institutional Review Board. The ethics committee approved the study on the factors of prognosis for patients with fractures. Data used in this study were obtained from the patients who underwent orthopedic surgery between October 2018 and June 2020.

Downregulation of interleukin-6 and C-reactive protein underlies a novel inhibitory role of microRNA-136-5p in acute lower extremity deep vein thrombosis

Deep vein thrombosis (DVT) comprises a critical and common health condition with high incidence, mortality, and long-term adverse sequelae. Several differentially expressed microRNAs (miRNAs) have emerged as promising prognostic markers in DVT. The present study intended to explore the functional relevance of miR-136-5p in acute lower extremity DVT (LEDVT). Rat models of acute LEDVT were established and miR-136-5p expression was altered by agomir or antagomir to assess its effects. In addition, in vitro gain- and loss-experiments, prior to exposure to CoCl₂, were performed to investigate effects of miR-136-5p on human umbilical vein endothelial cell (HUVEC) apoptosis and levels of interleukin-6 (IL-6) and C-reactive protein (CRP). miR-136-5p was downregulated, whereas IL-6 and CRP were elevated in acute LEDVT patients. Notably, miR-136-5p was confirmed to target both IL-6 and CRP. Overexpression of miR-136-5p led to reduced length, weight, and ratio of weight to length of the venous thrombus. Furthermore, overexpressed miR-136-5p downregulated the expression of IL-6 and CRP, consequently inhibiting HUVEC apoptosis. Conjointly, our data indicate that the overexpression of miR-136-5p has the potential to bind to the 3’-UTR in the mRNAs for IL-6 and CRP and mitigate acute LEDVT, which provides a basis for new therapeutic targets in acute LEDVT treatment.

A prospective, multicentre study in acute non-cirrhotic, non-malignant portal vein thrombosis: comparison of medical and interventional treatment

BACKGROUND

To evaluate medical versus interventional treatment (transjugular thrombus fragmentation, local thrombolysis with or without stent implantation) in patients with acute non-cirrhotic, non-malignant portal vein thrombosis (PVT).

METHODS

This prospective, observational study enrolled 65 patients with acute (<28 days since begin of symptoms, no cavernoma) PVT in nine centres. Thirty patients received medical treatment and 35 patients received interventional treatment. PVT was graded into grade 1: short thrombosis and incomplete occlusion of the vessel lumen and grade 2: extended thrombosis or complete occlusion. Treatment response was classified as partial or complete, if thrombosis was reduced by one grade or to <25% of the vessel diameter respectively.

RESULTS

Partial and complete response rates were 7% and 30% in the medical compared to 17% and 54% (P < 0.001) in the interventional treatment group. In the multivariate analysis, interventional treatment showed a strong positive (OR 4.32, P < 0.016) and a myeloproliferative aetiology a negative (OR 0.09, P = 0.006) prediction of complete response. Complications were rare in the medical group and consisted of septicaemia and upper gastrointestinal bleeding of unknown origin in one patient each. Interventional treatment was accompanied by mild and self-limiting bleeding complications in nine patients, moderate intra-abdominal bleeding requiring transfusions (2 units) in one patient and peritoneal bleeding requiring surgical rescue in one patient. Four patients in each group developed intestinal gangrene requiring surgery. One patient died 52 days after unsuccessful interventional treatment.

CONCLUSIONS

Compared to medical treatment alone, interventional treatment doubled response rates at the cost of increased bleeding complications.

C-reactive protein level predicts 30-day mortality and bleeding in patients with venous thromboembolism: A prospective single-center study

AIMS

The association of on-admission CRP and early adverse outcomes in acute venous thromboembolism (VTE) has not been investigated. We hypothesized that increased on-admission CRP levels would correlate with adverse outcomes in patients with acute VTE.

METHOD

In this prospective observational study, consecutive patients with acute VTE were enrolled and CRP levels were measured within the first 24h after diagnosis. Mortality, bleeding and recurrence were recorded during a 30-day follow-up.

RESULTS

586 patients were included. Higher CRP levels were found in patients with mortality (7.5 vs 4.0mg/dL; p=0.01) and bleeding (7.8 vs 3.9mg/dL; p=0.03). Multivariable logistic regression showed that CRP levels >5mg/dL were associated with higher mortality (OR 6.25; 95% CI, 2.1-18.6) and bleeding (OR 2.7; CI 95% 1.3-5.7). These results were independent to ESC risk score and simplified PESI score for mortality prediction. The predictive capacity of CRP showed an area under the ROC curve - AUC - of .7 (CI 95% .56-.85) for mortality and .65 (CI 95% .54-.75) for bleeding. The prognostic capacity of the ESC risk score and simplified PESI score was improved after adding the CRP cutoff of 5mg/dL (AUC of .87 CI 95% .79-.95).

CONCLUSION

Our findings suggest that on-admission CRP level may be a simple, widely available and valuable biomarker to identify high-risk VTE patients for early mortality and bleeding. CRP ≥5mg/dL was independently associated with 30-day VTE related death and bleeding.

Survival after cardiac arrest secondary to high-risk pulmonary embolism without reperfusion therapies: A case report

INTRODUCTION

High-risk pulmonary embolism (PE) needs reperfusion therapies. However, it is difficult to make medical decisions when thrombolysis is contraindicated, though pulmonary embolectomy and percutaneous catheter-directed treatment (CTD) are recommended for these patients.

PATIENT CONCERNS

We reported here a case of high-risk PE patient with cardiac arrest (CA), vertebral compression fracture, as well as scalp and frontal hematoma.

DIAGNOSIS

The diagnosis of PE was based on computed tomography pulmonary angiography (CTPA) which demonstrated filling defects in the right and left pulmonary arteries.

INTERVENTIONS

Cardiopulmonary resuscitation was performed until the patient returned to idioventricular rhythm 3 minutes after admitted. She suffered another half-hour of hemodynamic disturbance after her shock improved 3 days later. The diagnosis of PE was confirmed by CTPA at that time. The patient did not receive any reperfusion therapies because hemoglobin decreased significantly. Moreover, anticoagulation was postponed for 2 weeks when bleeding appeared to be stopped. She received overlapping treatment with low molecular weight heparin and warfarin for 5 days then warfarin alone and discharged.

OUTCOMES

She was discharged with normal vital signs and neurologically intact. She received anticoagulant therapy with warfarin and international normalized ratio regularly monitored after she was discharged, moreover, the pulmonary artery pressure turned normal, as determined by transthoracic echocardiography 1 month later. The warfarin treatment was discontinued after 12 months and no evidence of recurrence was seen until recently.

CONCLUSIONS

This is the first case report of PE combined with CA that did not receive reperfusion therapy. We hypothesized that there was a spontaneous resolution in pulmonary emboli.

Association of complete blood count parameters, d-dimer, and soluble P-selectin with risk of arterial thromboembolism in patients with cancer

BACKGROUND

Patients with cancer are at risk of developing arterial thromboembolism (ATE). With the prevalence of cancer and cardiovascular diseases on the rise, the identification of risk factors for ATE in patients with cancer is of emerging importance.

OBJECTIVES

As data on the association of potential biomarkers with risk of ATE in patients with cancer are scarce, we conducted a cohort study with the aim to identify blood-based biomarkers for ATE risk prediction in patients with cancer.

PATIENTS/METHODS

Overall, 1883 patients with newly diagnosed cancer or progressive disease after complete or partial remission were included and followed for 2 years. Venous blood was drawn at study inclusion for measurement of complete blood count parameters, total cholesterol, d-dimer, and soluble P-selectin (sP-selectin) levels.

RESULTS

The 2-year cumulative incidence of ATE was 2.5%. In univariable analysis, red cell distribution width (subdistribution hazard ratio (SHR) per doubling: 4.4, 95% CI: 1.4-14.1), leukocyte count (1.2, 1.1-1.5), neutrophil count (1.6, 1.1-2.3), and sP-selectin levels (1.9, 1.3-2.7) were associated with risk of ATE in patients with cancer; d-dimer was not associated with the risk of ATE (1.1, 0.9-1.4). After adjustment for age, sex, and smoking status the association prevailed for the neutrophil count (adjusted [adj.] SHR per doubling: 1.6, 1.1-2.4), and sP-selectin levels (1.8, 1.2-2.8).

CONCLUSIONS

An elevated absolute neutrophil count and higher sP-selectin levels were associated with an increased risk of ATE in patients with cancer. Their role for predicting cancer-related ATE needs to be validated in further studies.

Correlation of Interleukin-18 and High-Sensitivity C-Reactive Protein with Perioperative Deep Vein Thrombosis in Patients with Ankle Fracture

BACKGROUND

In the present study, we aimed to inspect the correlation of interleukin-18 (IL-18) and high-sensitivity C-reactive protein (hs-CRP), if any present, with the occurrence of perioperative deep vein thrombosis (DVT) in patients suffering from an ankle fracture (AF).

METHODS

Sixty-seven AF patients with complicated DVT (DVT group) and 448 AF patients without DVT (non-DVT group) were enrolled in the present study. To begin with, hemorheological indexes were detected. Turbidimetric immunoassay and enzyme-linked immunosorbent assay were used for the determination of the expressions of hs-CRP and IL-18, respectively. Coagulation method was used to detect prothrombin time (PT), thrombin time (TT), fibrinogen, and activated partial thromboplastin time (APTT). Logistic regression analysis was used to analyze the independent risk factors for DVT occurrence in AF patients after operation.

RESULTS

The results revealed that the DVT group presented an increased expression of hs-CRP and IL-18 1 day before operation and 1, 3, and 7 days after operation in comparison with the non-DVT group. The DVT group also had increased levels of PT, APTT, and prolonged TT and fibrinogen at 3 and 7 days after operation compared to the non-DVT group. After operation, it was observed that the patients in the DVT group had increased plasma viscosity, whole blood reduced viscosity, red blood cell (RBC) aggregation index, RBC deformation index, erythrocyte sedimentation rate, and declined erythrocrit. The independent risk factors for the occurrence of DVT were identified to be high-energy injury, TT, fibrinogen, hs-CRP, and IL-18 in AF patients after operation.

CONCLUSIONS

Based on the results obtained from the study, it was concluded that AF patients with DVT have higher levels of IL-18 and hs-CRP expressions, which is associated with the occurrence and development of DVT. These results may be particularly useful for diagnosis and treatment on DVT occurrence in AF patients.

Soluble endothelial cell molecules and circulating endothelial cells in patients with venous thromboembolism

: To evaluate the plasma levels of soluble endothelial cell molecules in patients with venous thromboembolism (VTE) out of the acute phase as compared with healthy individuals. We also investigated the possible associations of the soluble endothelial cell molecules among them, as well as with other clinical and laboratory data, including the numbers of circulating endothelial cells (CEC), circulating endothelial progenitor cells (CEP), and CEC expressing activation-related [cluster of differentiation (CD)54 and CD62E] and procoagulant (CD142) markers. In total, 15 patients with VTE and 20 normal individuals were studied. The CEC and CEP were quantified and characterized by flow cytometry. The soluble molecules studied included P-selectin, E-selectin, intercellular cell adhesion molecule 1, vascular cell adhesion molecule 1 and tissue factor (ELISA), and von Willebrand factor antigen (immunoturbidimetry). VTE patients had significantly higher levels of vascular cell adhesion molecule 1 and von Willebrand factor antigen and lower levels of soluble E-selectin than controls. They also showed significantly higher numbers of CEC, as of activated/procoagulant CEC and lower numbers of CEP, compared with controls. We did not find any correlation between the levels of soluble molecules and the numbers of endothelial cell in circulation, but there was with several clinical and laboratory data in VTE patients. Our results would suggest that in VTE patients, the endothelium remains activated and in some hypercoagulable state. The levels of soluble endothelial cell molecules did not seem to be directly related to the numbers of CEC and CEP neither reflected the number of activated CEC, which may be because of the different function that surface and soluble molecules may have.

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.

Regulation of platelet membrane protein shedding in health and disease

Extracellular proteolysis of platelet plasma membrane proteins is an event that ensues platelet activation. Shedding of surface receptors such as glycoprotein (GP) Ibα, GPV and GPVI as well as externalized proteins P-selectin and CD40L releases soluble ectodomain fragments that are subsequently detectable in plasma. This results in the irreversible functional downregulation of platelet receptor-mediated adhesive interactions and the generation of biologically active fragments. In this review, we describe molecular insights into the regulation of platelet receptor and ligand shedding in health and disease. The scope of this review is specially focused on GPIbα, GPV, GPVI, P-selectin and CD40L where we: (1) describe the basic physiological regulation of expression and shedding of these proteins in hemostasis illustrate alterations in receptor expression during (2) apoptosis and (3) ex vivo storage relevant for blood banking purposes; (4) discuss considerations to be made when analyzing and interpreting shedding of platelet membrane proteins and finally; (5) collate clinical evidence that quantify these platelet proteins during disease.

Evaluation the value of markers for prediction of portal vein thrombosis after devascularization

AIM

To evaluate the value of D-dimer and P-selectin in cirrhotic portal hypertension (PHT) patients for prediction of portal vein thrombosis (PVT) after devascularization.

MATERIAL AND METHODS

137 patients with cirrhotic PHT who undergone devascularization from January 2012 to April 2014 were retrospectively reviewed, all of them were divided into two groups (PVT group and non-PVT group) by Doppler ultrasonography (DU) examination. The level of D-dimer and P-selectin was tested during the peri-operative period.

RESULTS

38 patients (27.7%) were found PVT by DU examination post-operatively. In contrast to the non- PVT group, the level of D-dimer and P-selectin in the PVT group was much higher significantly at 1, 3 and 7 days after devascularization (P < 0.05). However, in the 15 days after surgery, the difference of P-selectin between the two groups was not significant (P = 0.260). It was shown that the higher sensitivity of the two markers for PVT was D-dimer, the higher specificity belonged to P-selectin. The area under receiver operating characteristic (ROC) curve of P-selectin was the bigger of the two markers. When the two markers were combined to be used to diagnose PVT, the sensitivity was increased to 0.911, with a slight drop of specificity to 0.715, the area under ROC curve was 0.919.

CONCLUSION

The level of D-dimer and P-selectin might be good candidate predictive markers for PVT in patients with cirrhotic PHT after devascularization. The combined test of the two markers can increase the value of prediction.

The Effect of Treatment of Vitamin D Deficiency on the Level of P-Selectin and hs-CRP in Patients With Thromboembolism: A Pilot Randomized Clinical Trial

Despite the known role of vitamin D deficiency in development of thrombosis, no studies have evaluated the impact of treating of vitamin D deficiency on the markers of thrombosis. A pilot randomized clinical trial was done on 40 vitamin D-deficient patients with deep vein thrombosis (DVT) or pulmonary embolism (PE). The intervention group received an oral dose of 50,000 IU vitamin D₃ every week for 8 weeks, followed by 1 pearl every 2 weeks for 4 weeks (a total of 3 months), while the control group did not receive vitamin D. Then, P-selectin and hs-CRP were measured at baseline and 1 and 3 months after the intervention. There was no significant decrease in hs-CRP in either group after 1 month (P = .955) or after 3 months (P = .525). Likewise, there was no significant decrease in P-selectin between the 2 groups after 1 month (P = .921) or 3 months (P = .795). The results indicated that treatment of vitamin D deficiency had no significant effect on hs-CRP or P-selectin after 3 months among DVT/PE patients. However, treatment of vitamin D deficiency in these patients resulted in the control of the international normalized ratio (INR) with the lower doses of warfarin. This observation is the first clinical report of enhancement of the anticoagulant effect of warfarin by the supplementing of vitamin D. Larger trials are needed to clearly show the effect of treating of vitamin D deficiency on thrombosis.

Diagnostic biomarkers in venous thromboembolic disease

OBJECTIVE

Venous thromboembolism (VTE) is a common disease with serious, often fatal sequelae. The optimal strategy for diagnosis of VTE remains unclear, although considerable progress has been made in this area. Several new biomarkers have showed promise for diagnosis of VTE, and more are under active investigation. We reviewed the literature for studies evaluating these diagnostic biomarkers.

METHODS

We reviewed the English literature between 1990 and 2015, searching for papers evaluating diagnostic performance of biomarkers in VTE.

RESULTS

D-dimer, a fibrin degradation product, has been thoroughly investigated, and performs well in select populations, although it is best as a rule-out test because of its generally low specificity. Soluble P-selectin, a marker of endothelial activation, has shown good diagnostic performance in several studies but has not yet been adopted widely. Others, including cellular adhesion molecules, tissue factor, circulating microparticles, and C-reactive protein, are under investigation, with varying results in a few studies.

CONCLUSIONS

At this time, D-dimer and P-selectin remain the most clinically valuable. New biomarkers are needed for clinical use in VTE.

Association between inflammation biomarkers, anatomic extent of deep venous thrombosis, and venous symptoms after deep venous thrombosis

OBJECTIVE

Inflammation may play a role in pathogenesis of venous thromboembolism, but the nature of this relationship is not yet understood. The objective of this study was to assess whether inflammation marker levels measured at diagnosis of deep venous thrombosis (DVT) and change in levels during the first month after DVT are associated with anatomic extent of DVT and severity of venous signs and symptoms at baseline and 1 month.

METHODS

The BioSOX study is a biomarker substudy of the Compression Stockings to Prevent the Post-Thrombotic Syndrome (SOX) trial, a multicenter, randomized controlled trial that included patients with a first, acute, symptomatic, proximal DVT. Blood samples were collected from participants at baseline and 1 month, and C-reactive protein (CRP), intercellular adhesion molecule 1, interleukin (IL)-6, and IL-10 were measured by established assays. Linear regression was used to assess the association between continuous log-transformed baseline biomarker levels and anatomic extent of DVT, classified as iliac or common femoral DVT vs femoral or popliteal DVT (reference). Proportional odds ordinal logistic regression models were used to analyze the association between biomarker level and Villalta score (as a measure of severity of venous signs and symptoms) at baseline and 1 month.

RESULTS

Among 717 patients, 60.2% were male, and the mean age was 55.2 years. There was a significant association between more extensive DVT (common femoral or iliac) and levels of CRP and IL-6 at DVT diagnosis. Median (interquartile range) CRP level was 11.6 mg/L (3.84-39.5) in patients with common femoral or iliac DVT vs 6.86 mg/L (3.11-22) in patients with popliteal or femoral DVT, and median IL-6 level was 6.36 pg/mL (1.09-14.37) vs 4.40 pg/mL (2.35-8.27), respectively. These differences were statistically significant in linear regression analyses. In addition, compared with those in the lowest quartile, each higher quartile of baseline CRP concentration was associated with an odds ratio of 2.89 (1.93-4.33) for having a more severe Villalta category at baseline and 1.98 (1.28-3.08) for having a more severe Villalta category 1 month after DVT. Higher baseline levels of IL-6 were associated with Villalta severity category at baseline (odds ratio, 2.40 [1.61-3.59]). Change in biomarker levels during the first month after DVT was not strongly associated with the 1-month Villalta score.

CONCLUSIONS

Levels of CRP and IL-6 at DVT diagnosis were associated with thrombotic disease burden, as measured by DVT extent, and severity of DVT symptoms and signs. Further studies are required to more fully elucidate the role of inflammation in DVT and its clinical course.

Genetic variations in sites of affinity between FVIII and LRP1 are not associated with high FVIII levels in venous thromboembolism

Increased factor VIII (FVIII) levels are a prevalent and independent risk factor for venous thromboembolism (VTE). The low density lipoprotein receptor-related protein 1 (LRP1) has been associated with FVIII catabolism. After a median of 10 years of the first thrombotic episode, we evaluated FVIII activity levels in 75 patients with VTE and high FVIII levels and in 74 healthy controls. Subsequently, we evaluated the regions of F8 and LRP1 genes coding sites of affinity between these proteins, with the objective of determining genetic alterations associated with plasma FVIII levels. After a median time of 10 years after the VTE episode, FVIII levels were significantly higher in patients when compared to controls (158.6 IU/dL vs. 125.8 IU/dL; P ≤ 0.001]. Despite the fact that we found 14 genetic variations in F8 and LRP1 genes, no relationship was found between FVIII levels with these variations. We demonstrated a persistent increase of FVIII levels in patients with VTE, but in a much lower magnitude after 10 years when compared to 3-years after the episode. Moreover, we observed no relationship of genetic variations in the gene regions coding affinity sites between LRP1 and FVIII with FVIII levels.

Evaluation of the Value of d-Dimer, P-Selectin, and Platelet Count for Prediction of Portal Vein Thrombosis After Devascularization

Background/Aim:

To evaluate the value of d-dimer, P-selectin, and platelet count in patients with cirrhotic portal hypertension (PHT) for prediction of portal vein thrombosis (PVT) after devascularization.

Methods:

A total of 137 patients with cirrhotic PHT who undergone devascularization from January 2012 to April 2014 were retrospectively reviewed, all of them were divided into 2 groups (PVT group and non-PVT group) by Doppler ultrasonography (DU) examination. The level of d-dimer, P-selectin, and platelet count was tested during the perioperative period.

Results:

In all, 38 (27.7%) patients were found to have PVT by DU examination postoperatively. In contrast to the non-PVT group, the level of d-dimer, P-selectin, and platelet count in the PVT group was much higher significantly at 1, 3, and 7 days after devascularization. ( P < .05). However, in the 15 days after surgery, the difference in P-selectin between the 2 groups was not significant ( P = .260). It was shown that the highest sensitivity of the 3 markers for PVT was d-dimer, the highest specificity belonged to P-selectin. The area under receiver–operating characteristic (ROC) curve of P-selectin was the biggest of the 3 markers. When the 3 markers were combined to be used to diagnose PVT, the sensitivity was increased to 0.907, with a slight drop of specificity to 0.693, the area under the ROC curve was 0.927.

Conclusion:

The level of d-dimer, P-selectin, and platelet count might be good candidate predictive markers for PVT in patients with cirrhotic PHT after devascularization. The combined test of the 3 markers can increase the value of prediction.

The Effect of High-Dose Vitamin D3 on Soluble P-Selectin and hs-CRP Level in Patients With Venous Thromboembolism

High plasma level of P-selectin is associated with the development of venous thromboembolism (VTE). Furthermore, supplementation of vitamin D could decrease thrombotic events. Hence, this study was designed to examine whether the administration of vitamin D can influence the plasma level of P-selectin in patients with VTE. In the randomized controlled trial, 60 patients with confirmed acute deep vein thrombosis and/or pulmonary embolism (PE) were randomized into the intervention (n = 20) and control (n = 40) groups. The intervention arm was given an intramuscular single dose of 300 000 IU vitamin D3. Plasma level of 25-hydroxy vitamin D, P-selectin, and high-sensitive C-reactive protein (hs-CRP) was measured at baseline and 4 weeks after. The plasma level of P-selectin (95% confidence interval = −5.99 to −1.63, P = .022) and hs-CRP ( P = .024) significantly declined in vitamin D-treated group, while only hs-CRP was significantly decreased in the control group ( P = .011). However, the magnitude of these reductions was not statistically significant. This study could not support the potential benefit of the high-dose vitamin D on plasma level of P-selectin and hs-CRP in patients with VTE.

Long-term increased factor VIII levels are associated to interleukin-6 levels but not to post-thrombotic syndrome in patients with deep venous thrombosis

INTRODUCTION

Increased FVIII levels are a well established risk factor for deep venous thrombosis (DVT), whose etiopathogenesis is not yet well understood. In this study, we aimed to evaluate the possibility that inflammatory markers and post-thrombotic syndrome (PTS) could contribute to FVIII levels in patients with a history of DVT.

DESIGN AND METHODS

It is a case-control study that included 68 patients with DVT of the lower limbs 32 months after the acute episode, and 67 healthy adults as controls. We evaluated plasma levels of FVIII, VWF, D-dimer and serum levels of CRP, IL-6, IL-8, TNF-α in patients and controls. The presence of PTS was evaluated by the Villalta scale.

RESULTS

Patients with DVT presented higher levels of FVIII, VWF and D-dimer when compared to controls (P ≤ 0.001). Almost 50% of patients presented FVIII levels above 90th percentile. Furthermore, IL-6 (1.19 vs. 0.98 pg/mL, P = 0.01) and TNF-α (2.27 vs. 1.57 pg/mL, P ≤ 0.001) were also higher in patients when compared to controls. In a linear regression multivariate model, VWF and IL-6 levels were independent factors associated with FVIII levels (P ≤ 0.001). FVIII levels were not increased in patients with PTS. Patients with PTS showed higher levels of IL-8 when compared to patients without PTS (23.03 vs. 18.20 pg/mL, P = 0.04).

CONCLUSIONS

In conclusion, we demonstrated that DVT is associated with increased levels of inflammatory and coagulation markers, including FVIII, even a long time after the acute episode. Moreover, IL-6 levels were an independent factor associated with FVIII levels. Finally, PTS seems to be related to inflammatory cytokine IL-8, a proinflammatory and proangiogenic chemokine, but not to FVIII levels.

Why does aspirin decrease the risk of venous thromboembolism? On old and novel antithrombotic effects of acetyl salicylic acid

It is well established that aspirin, an irreversible inhibitor of platelet cyclooxygenase activity, is effective in secondary prevention of arterial thromboembolic events. The pooled results of the recent randomized, multicenter WARFASA and ASPIRE aspirin trials showed a 32% reduction in the rate of recurrence of venous thromboembolism (VTE) in patients receiving aspirin following VTE. These clinical data support evidence that platelets contribute to the initiation and progression of venous thrombosis and aspirin inhibits thrombin formation and thrombin-mediated coagulant reactions. In addition to the known acetylation of serine 529 residue in platelet cyclooxygenase-1, the postulated mechanisms of aspirin-induced antithrombotic actions also involve the acetylation of other proteins in blood coagulation, including fibrinogen, resulting in more efficient fibrinolysis. This review summarizes current knowledge on the aspirin-induced antithrombotic effects that potentially explain clinical studies showing reduced rates of VTE events in aspirin-treated subjects.

Time course of soluble P-selectin and von Willebrand factor levels in trauma patients: a prospective observational study

Background

Coagulopathy often develops in patients with serious trauma and is correlated with the clinical outcome. The contribution of platelet activity and endothelial dysfunction to trauma-induced coagulopathy remain to be defined. The purpose of this study was to investigate the time courses of soluble P-selectin (sPsel, an index of platelet activation) and von Willebrand factor (VWF, an index of endothelial dysfunction) in trauma patients and elucidate their relationship to coagulation parameter levels, the presence of coagulopathy, and patient outcome.

Methods

This prospective observational study, which took place in a university hospital intensive care unit (ICU), included 82 severely injured trauma patients. The sPsel, VWF antigen, protein C, and factor VII levels were measured and routine coagulation tests were performed upon admission to ICU and daily within the first week. The 30-day mortality rate was also determined.

Results

Thirty-seven (45.1%) patients developed coagulopathy upon admission to the ICU, and the 30-day mortality rate was 20.7% (n = 17). Both the admission sPsel and VWF levels were lower in patients with coagulopathy than in those without (p < 0.05) and were significantly correlated with the protein C and factor VII levels, respectively (all p < 0.05). The VWF levels were lower during the first 3 days and higher on day 7 after admission in nonsurvivors than in survivors (all p < 0.05). No significant differences in sPsel levels were found between nonsurvivors and survivors on each day during the first week.

Conclusion

In severely injured trauma patients in the ICU, lower levels of sPsel and VWF on admission were associated with the presence of coagulopathy and might not predict a better outcome. An increase in the VWF level at the end of the first week after admission to ICU was associated with increased 30-day mortality.

The role of soluble P selectin in the diagnosis of venous thromboembolism

INTRODUCTION

Soluble P selectin (sPsel), a member of the selectin family of cell adhesion receptors, has been proposed as a key molecule in hemostasis and thrombosis mediating platelet rolling, generating procoagulant microparticles and enhancing fibrin deposition. The aim of this study was to examine the role of sPsel in the diagnosis of venous thromboembolism (VTE).

MATERIALS AND METHODS

We performed a systematic review and we used meta-analysis to synthesize data from published studies reporting sPsel levels in patients with i) VTE (deep venous thrombosis; DVT or DVT and pulmonary embolism; PE) and ii) DVT only. Pooled Odds Ratios (ORs) with 95% Confidence Intervals (CIs) were appropriately calculated among patients and controls. Diagnostic performance of sPsel was tested with pooled sensitivity, specificity, Diagnostic Odds Ratio (DOR) and summary receiver operator characteristic (SROC) curve.

RESULTS

Eleven studies, comprising of 586 VTE patients and 1,843 controls were deemed eligible. The sPsel was significantly increased after VTE (OR=2.89, 95%CI=2.31-3.61, p<0.001), or DVT only (OR=2.64, 95%CI=1.95-3.56, p<0.001). Subgroup analysis evidenced that sPsel was also increased after VTE when evaluating only studies with patients that had no prior medical history (OR=2.88, 95%CI=1.98-4.19, p<0.001). Exclusion of studies including patients with solid organ tumor, HIV or lupus anticoagulants positive patients did not alter findings. Pooled sensitivity and specificity of sPsel was 0.57 (95%CI=0.30-082, p<0.001) and 0.73 (95%CI=0.51-0.90, p<0.001), respectively and DOR was 4.31 (95%CI=2.22-8.37, p<0.01). SROC curve yielded in significant accuracy of sPsel performance (AUC=0.74, p=0.05).

CONCLUSIONS

The sPsel was significantly elevated in patients with DVT, both uncomplicated and complicated with PE and presented with high levels of diagnostic performance. sPsel is a plasma biomarker that may help in the diagnosis of VTE.

Biomarkers for prediction of venous thromboembolism in cancer

Cancer patients are at increased risk of deep vein thrombosis and pulmonary embolism. The incidence among different groups of cancer patients varies considerably depending on clinical factors, the most important being tumor entity and stage. Biomarkers have been specifically investigated for their capacity of predicting venous thromboembolism (VTE) during the course of disease. Parameters of blood count analysis (elevated leukocyte and platelet count and decreased hemoglobin) have turned out to be useful in risk prediction. Associations between elevated levels and future VTE have been found for d-dimer, prothrombin fragment 1+2, and soluble P-selectin and also for clotting factor VIII and the thrombin generation potential. The results for tissue factor-bearing microparticles are heterogeneous: an association with occurrence of VTE in pancreatic cancer might be present, whereas in other cancer entities, such as glioblastoma, colorectal, or gastric carcinoma, this could not be confirmed. Risk assessment models were developed that include clinical and laboratory markers. In the high-risk categories, patient groups with up to a >20% VTE rate within 6 months can be identified. A further improvement in risk stratification would allow better identification of patients for primary VTE prevention using indirect or novel direct anticoagulants.

Anti-thrombosis effect of LRRFIP1 shRNA lentivirus in a mouse model of deep vein thrombosis

INTRODUCTION

Deep vein thrombosis (DVT) is one of the common complications of orthopedic surgery. Low molecular weight heparin (LMWH) is a usually used agent for DVT, but it would increase the risk of bleeding. LRRFIP1 has been shown to play an important role in the formation of thrombosis. Therefore, we investigated the effect of LRRFIP1 shRNA lentivirus on DVT in mice.

MATERIALS AND METHODS

Lentiviral Vectors carrying LRRFIP1 shRNA were constructed and transfected into cultured mouse bone marrow cells (BMCs). Male ICR mice were irradiated with a single dose of 9.5 Gy and then were injected with different agents through the tail vein. Stasis venous thrombosis was induced by inferior vena cava (IVC) ligation. Mice were sacrificed on the 1st, 3rd and 7th day post operation and the thrombi were removed, blotted the excess blood on it with filter paper and immediately weighed. P-selectin and d-Dimer were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

LRRFIP1 shRNA significantly suppressed the expression of LRRFIP1 in the thrombi. In contrast, low molecular weight heparin (LMWH) and negative shRNA exhibited little effect on the expression of LRRFIP1. LRRFIP1 shRNA, LMWH and negative shRNA inhibited the thrombus formation in vivo significantly. The plasma P-selectin and d-Dimer levels were significantly increased after IVC ligation. LRRFIP1 shRNA significantly decreased the plasma P-selectin and d-Dimer levels. However, LMWH and negative shRNA showed little effects on the levels of plasma P-selectin and d-Dimer.

CONCLUSION

LRRFIP1 shRNA might represent a promising prevention strategy for DVT.

Soluble P-selectin for the diagnosis of lower extremity deep venous thrombosis

OBJECTIVE

Although duplex ultrasound is the standard for the diagnosis of lower extremity deep venous thrombosis (LE-DVT), imaging is not always available. The use of D-dimer can exclude (high-sensitivity), but not rule in (low-specificity) LE-DVT. Previously, we demonstrated that soluble P-selectin (sP-sel) in combination with the Wells score, establishes the diagnosis of LE-DVT with a specificity of 96% and a positive predictive value of 100%. In order to validate our previous results, we applied the model to a separate but similar patient cohort. Additionally, we analyzed the role of biomarkers for diagnosing upper extremity DVT (UE-DVT).

METHODS

Between April 2009 and March 2012, all patients presenting for a duplex ultrasound exam with concern of DVT were screened. Demographics, clinical data, D-dimer, sP-sel, C-reactive protein, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13, and von Willebrand factor levels were prospectively collected in 279 patients (234 LE-DVT, 45 UE-DVT). Continuous and categorical variables among patients with DVT were compared with patients without DVT. The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value were then calculated using our previously derived cut points to rule in or exclude DVT.

RESULTS

Among 234 patients evaluated for LE-DVT, 112 (48%) patients had a confirmed LE-DVT with significant differences in all biomarkers. When Wells score ≥2, sP-sel could rule in LE-DVT with a specificity of 97.5% and a positive predictive value of 91%, which was more accurate than Wells score ≥2 and D-dimer (specificity, 65%; positive predictive value, 69%). When Wells score was <2, D-dimer was superior to sP-sel for excluding the diagnosis of LE-DVT (sensitivity, 98%; negative predictive value, 95% vs sensitivity, 91%; negative predictive value, 79%). The use of additional biomarkers did not increase accuracy. Had imaging not been available, we could have correctly ruled in or ruled out LE-DVT in 29% (67/234) of patients. The use of sP-sel in UE-DVT was nondiagnostic.

CONCLUSIONS

We demonstrate that when Wells score ≥2, sP-sel is an excellent biomarker to rule in LE-DVT. Different from our previous study, D-dimer and a Wells score <2 was most sensitive at excluding a diagnosis of LE-DVT. Combined, Wells score, sP-sel, and D-dimer can both rule in and exclude LE-DVT in approximately one-third of patients.

Biomarkers for the diagnosis of deep vein thrombosis

Venous thromboembolic disease (VTE) remains a significant source of morbidity and mortality. As non-specific subjective complaints and a paucity of objective clinical examination findings complicate the diagnosis of both deep venous thrombosis (DVT) and pulmonary embolism, diagnostic modalities remain essential. Compression ultrasound remains the gold standard for DVT diagnosis. Reliable imaging is not always available making a serologic diagnosis, or biomarker, highly desirable. While D-dimer, a highly sensitive biomarker, is useful for excluding acute VTE, it lacks the specificity necessary for diagnostic confirmation. As such, ongoing research efforts target and support the utility of alternative plasma biomarkers to aid in the diagnosis of VTE including selectins, microparticles, IL-10 and other inflammatory markers. These molecular markers may also predict recurrence risk, guide length and modality of treatment, and predict which thrombi will resolve spontaneously or recanalize, thus potentially identifying patients who would benefit from more aggressive therapies than standard anticoagulation.

Incidence and Risk Factors of the Post-thrombotic Syndrome

Annually 1–2 in every 1000 adults will develop a deep venous thrombosis of the lower extremity. A third to half of these patients will develop the post-thrombotic syndrome (PTS). However, predicting which patients will develop the PTS remains elusive. Ipsilateral thrombosis recurrence seems to be the most important risk factor. Moreover, residual venous occlusion and valvular reflux seem to predict PTS incidence to some degree. Laboratory parameters, including D-dimers and inflammatory markers, have shown promise in predicting development of the PTS in patients and are currently under investigation. Creating a model based on all combined risk factors and patient characteristics might aid in risk stratification in individual patients.