C-reactive protein and risk of venous thromboembolism in the general population

Association and Pathways between Dietary Manganese Intake and Incident Venous Thromboembolism

BACKGROUND

 The association between dietary manganese (Mn) intake and the risk of venous thromboembolism (VTE) remains unknown. We aimed to investigate the associations of dietary Mn intake with incident VTE, and the underlying mediating roles of obesity markers (body mass index [BMI] and waist circumference), hemorheological parameters (red cell distribution width [RDW], platelet count [PLT], and mean platelet volume [MPV]), and inflammatory biomarkers (C-reactive protein [CRP] and white blood cell count [WBC]) in this association.

METHODS

 A total of 202,507 adults from the UK Biobank with complete dietary data and without VTE at baseline were included. Dietary information was collected by the online 24-hour diet recall questionnaires (Oxford WebQ). The primary outcome was incident VTE, a composite of incident deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

 During a median follow-up of 11.6 years, 4,750 participants developed incident VTE. Overall, there were significantly inverse relationships of dietary Mn intake with incident VTE (per 1 mg/day increment; adjusted hazard ratio [HR]: 0.92; 95% confidence interval [CI]: 0.90-0.95), incident DVT (per 1 mg/day increment; adjusted HR: 0.93; 95% CI: 0. 90-0.96), and incident PE (per 1 mg/day increment; adjusted HR: 0.91; 95% CI: 0.88-0.95). BMI, waist circumference, RDW, CRP, and WBC significantly mediated the association between dietary Mn intake and incident VTE, with the mediated proportions of 36.0, 36.5, 4.2, 4.3, and 1.6%, respectively. However, MPV and PLT did not significantly mediate the association.

CONCLUSION

 Our study shows that dietary Mn intake was inversely associated with incident VTE. The inverse association was mainly mediated by obesity, followed by inflammatory biomarkers and RDW. Our findings are just hypothesis-generating, and further confirmation of our findings in more studies is essential.

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.

The Role of Biomarkers, Metabolomics, and COVID-19 in Venous Thromboembolism-A Review of Literature

In recent years, the field of venous thromboembolism has undergone numerous innovations, starting from the recent discoveries on the role of biomarkers, passing through the role of metabolomics in expanding our knowledge on pathogenic mechanisms, which have opened up new therapeutic targets. A variety of studies have contributed to characterizing the metabolic phenotype that occurs in venous thromboembolism, identifying numerous pathways that are altered in this setting. Among these pathways are the metabolism of carnitine, tryptophan, purine, and fatty acids. Furthermore, new evidence has emerged with the recent COVID-19 pandemic. Hypercoagulability phenomena induced by this viral infection appear to be related to altered von Willebrand factor activity, alteration of the renin-angiotensin-aldosterone system, and dysregulation of both innate and adaptive immunity. This is the first literature review that brings together the most recent evidence regarding biomarkers, metabolomics, and COVID-19 in the field of venous thromboembolism, while also mentioning current therapeutic protocols.

Association between inflammatory biomarkers and venous thromboembolism: a systematic review and meta-analysis

BACKGROUND

Venous thromboembolism (VTE) is a common thrombotic vascular disease that has a significant impact on people's well-being and quality of life. A plethora of clinical studies explore the relationship between inflammatory biomarkers and VTE but yield conflicting results. This article proposed to pool these studies to draw a more convincing conclusion.

METHODS

We searched several databases for studies before April 2023. Available data was processed using Stata software (version 15.0 SE) and R (version 4.1.2). This meta-analysis has been registered in PROSPERO (CRD42022321815). The VTE in this review encompassed pulmonary embolism, deep vein thrombosis, and cerebral venous thrombosis.

RESULTS

A total of 25 articles were finally involved in this study. Our results revealed that higher levels of high-sensitivity C-reactive protein (hs-CRP, MD, 0.63, 95%CI, 0.21-1.05) and C-reactive protein (CRP)> 3ug/ml (OR, 1.52, 95%CI, 1.18-1.96) might be regarded as risk factors for future VTE occurrence. The elevated levels of monocyte (MD, 0.03, 95%CI, 0.00-0.05), hs-CRP (0.85, 0.61-1.08), CRP (0.66, 0.20-1.13) and IL-6 (0.47, 0.25-0.70) might represent the previous VTE; a series of markers such as white blood cell (1.43, 0.88-1.98), neutrophil (1.79, 1.02-2.56), monocyte (0.17, 0.14-0.21), hs-CRP (3.72, 1.45-5.99), IL-6 (5.99, 4.52-7.46), platelet-lymphocyte ratio (33.1, 24.45-41.78) and neutrophil-lymphocyte ratio (1.34, 0.95-1.73) increased during the acute phase of VTE.

CONCLUSIONS

In general, activated inflammatory biomarkers might not only be correlated with an increased risk of VTE, but may also give a hint of the occurrence of VTE in clinical settings.

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.

Hemostatic factors, inflammatory markers, and risk of incident venous thromboembolism: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Several hemostatic factors and inflammatory markers are associated with the risk of incident venous thromboembolism (VTE), however, most existing data are from case-control studies in Caucasian populations.

OBJECTIVES

We aimed to prospectively confirm previous findings and explore less studied biomarkers in relation to VTE risk in a multi-racial/multi-ethnic cohort.

METHODS

Circulating levels of factor VIII, fibrinogen, D-dimer, plasmin-antiplasmin complex (PAP), C-reactive protein (CRP), and interleukin-6 (IL-6) were measured at baseline (2000-2002) in 6706 participants of the Multi-Ethnic Study of Atherosclerosis. Incident VTE was identified using hospitalization discharge codes from baseline to December 31, 2015. Hazard ratios (HRs) of VTE were estimated in Cox regression models.

RESULTS

There were 227 events during a median of 14 years of follow-up. Compared with participants in the lowest quartile, the HRs for those above the 95th percentile and p for trend across categories were 3.50 (95% confidence interval [CI] 1.98-6.19; p < .001) for D-dimer, 1.49 (95% CI 0.84-2.63; p = .02) for factor VIII, 1.32 (95% CI 0.76-2.28; p = .99) for fibrinogen, 1.92 (95% CI 1.08-3.42; p = .15) for PAP, 1.68 (95% CI 0.81-3.48; p = .08) for CRP, and 2.55 (95% CI 1.15-5.66; p = .07) for IL-6, after adjustment for demographics and body mass index. For CRP and IL-6, follow-up was restricted to 10 years because of violations of the proportional hazards assumption. No significant interactions by age/ethnicity were observed.

CONCLUSIONS

We demonstrated a fairly novel association between PAP and risk of incident VTE, and contributed further prospective confirmation regarding the associations of D-dimer, factor VIII, and IL-6 with VTE.

Global assessment of C-reactive protein and health-related outcomes: an umbrella review of evidence from observational studies and Mendelian randomization studies

C-reactive protein (CRP) has been studied extensively for association with a large number of non-infectious diseases and outcomes. We aimed to evaluate the breadth and validity of associations between CRP and non-infectious, chronic health outcomes and biomarkers. We conducted an umbrella review of systematic reviews and meta-analyses and a systematic review of Mendelian randomization (MR) studies. PubMed, Scopus, and Cochrane Database of Systematic Reviews were systematically searched from inception up to March 2019. Meta-analyses of observational studies and MR studies examining associations between CRP and health outcomes were identified, excluding studies on the diagnostic value of CRP for infections. We found 113 meta-analytic comparisons of observational studies and 196 MR analyses, covering a wide range of outcomes. The overwhelming majority of the meta-analyses of observational studies reported a nominally statistically significant result (95/113, 84.1%); however, the majority of the meta-analyses displayed substantial heterogeneity (47.8%), small study effects (39.8%) or excess significance (41.6%). Only two outcomes, cardiovascular mortality and venous thromboembolism, showed convincing evidence of association with CRP levels. When examining the MR literature, we found MR studies for 53/113 outcomes examined in the observational study meta-analyses but substantial support for a causal association with CRP was not observed for any phenotype. Despite the striking amount of research on CRP, convincing evidence for associations and causal effects is remarkably limited.

Pulmonary Artery Thrombosis: A Diagnosis That Strives for Its Independence

According to a widespread theory, thrombotic masses are not formed in the pulmonary artery (PA) but result from migration of blood clots from the venous system. This concept has prevailed in clinical practice for more than a century. However, a new technologic era has brought forth more diagnostic possibilities, and it has been shown that thrombotic masses in the PA could, in many cases, be found without any obvious source of emboli. Chronic obstructive pulmonary disease, asthma, sickle cell anemia, emergency and elective surgery, viral pneumonia, and other conditions could be complicated by PA thrombosis development without concomitant deep vein thrombosis (DVT). Different pathologies have different causes for local PA thrombotic process. As evidenced by experimental results and clinical observations, endothelial and platelet activation are the crucial mechanisms of this process. Endothelial dysfunction can impair antithrombotic function of the arterial wall through downregulation of endothelial nitric oxide synthase (eNOS) or via stimulation of adhesion receptor expression. Hypoxia, proinflammatory cytokines, or genetic mutations may underlie the procoagulant phenotype of the PA endothelium. Both endotheliocytes and platelets could be activated by protease mediated receptor (PAR)- and receptors for advanced glycation end (RAGE)-dependent mechanisms. Hypoxia, in particular induced by high altitudes, could play a role in thrombotic complications as a trigger of platelet activity. In this review, we discuss potential mechanisms of PA thrombosis in situ.

Predicting the Risk of Recurrent Venous Thromboembolism: Current Challenges and Future Opportunities

Acute venous thromboembolism (VTE) is a commonly diagnosed condition and requires treatment with anticoagulation to reduce the risk of embolisation as well as recurrent venous thrombotic events. In many cases, cessation of anticoagulation is associated with an unacceptably high risk of recurrent VTE, precipitating the use of indefinite anticoagulation. In contrast, however, continuing anticoagulation is associated with increased major bleeding events. As a consequence, it is essential to accurately predict the subgroup of patients who have the highest probability of experiencing recurrent VTE, so that treatment can be appropriately tailored to each individual. To this end, the development of clinical prediction models has aided in calculating the risk of recurrent thrombotic events; however, there are several limitations with regards to routine use for all patients with acute VTE. More recently, focus has shifted towards the utility of novel biomarkers in the understanding of disease pathogenesis as well as their application in predicting recurrent VTE. Below, we review the current strategies used to predict the development of recurrent VTE, with emphasis on the application of several promising novel biomarkers in this field.

From Classical Laboratory Parameters to Novel Biomarkers for the Diagnosis of Venous Thrombosis

Venous thrombosis is a common and potentially fatal disease, because of its high morbidity and mortality, especially in hospitalized patients. To establish the diagnosis of venous thrombosis, in the last years, a multi-modality approach that involves not only imaging modalities but also serology has been evolving. Multiple studies have demonstrated the use of some biomarkers, such as D-dimer, selectins, microparticles or inflammatory cytokines, for the diagnosis and treatment of venous thrombosis, but there is no single biomarker available to exclusively confirm the diagnosis of venous thrombosis. Considering the fact that there are some issues surrounding the management of patients with venous thrombosis and the duration of treatment, recent studies support the idea that these biomarkers may help guide the length of appropriate anticoagulation treatment, by identifying patients at high risk of recurrence. At the same time, biomarkers may help predict thrombus evolution, potentially identifying patients that would benefit from more aggressive therapies. This review focuses on classic and novel biomarkers currently under investigation, discussing their diagnostic performance and potential benefit in guiding the therapy for venous thrombosis.

Coexistence Of A Huge Venous Thromboembolism And Bleeding Tendency In Cytokine Release Syndrome During CAR-T Therapy

Chimeric antigen receptor (CAR)-modified T cell therapy is increasingly administered for hematological malignancies. Cytokine release syndrome (CRS) is a common and severe complication of CAR-T therapy. In the present case, a 62-year-old male patient was diagnosed with relapsed and refractory multiple myeloma (RRMM). Treated with CART-CD19/BCMA therapy, his symptoms remitted, during which occasional but severe CRS associated with coagulation disorder still appeared, as evidenced by the coexistence of a huge thrombosis and bleeding tendency. Through the First Generation Sequencing, we extracted genomic DNA from the patient’s peripheral blood to analyze the distribution of polymorphism at the –572C/G site of the promoter of IL-6 gene. The results showed that the genotype of –572C/G promoter polymorphism was CC, indicating that high level of IL-6 and –572C/G polymorphism might be associated with the risk of thrombotic disorders. We concluded that immediate diagnosis and appropriate treatment of coagulopathy could reduce CRS-related mortality.

Risk stratification of elderly patients with acute pulmonary embolism

BACKGROUND

Combining high-sensitivity cardiac Troponin T (hs-cTnT), NT-pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) may improve risk stratification of patients with pulmonary embolism (PE) beyond the PESI risk score.

METHODS

In the prospective multicentre SWITCO65+ study, we analysed 214 patients ≥ 65 years with a new submassive PE. Biomarkers and clinical information for the PESI risk score were ascertained within 1 day after diagnosis. Associations of hs-TnT, NT-proBNP, hs-CRP and the PESI risk score with the primary endpoint defined as 6-month mortality were assessed. The discriminative power of the PESI risk score and its combination with hs-cTnT, NT-proBNP and hs-CRP for 6-month mortality was compared using integrated discrimination improvement (IDI) index and net reclassification improvement (NRI).

RESULTS

Compared with the lowest quartile, patients in the highest quartile had a higher risk of death during the first 6 months for hs-cTnT (adjusted HR 10.22; 95% CI 1.79-58.34; P = 0.009) and a trend for NT-proBNP (adjusted HR 4.3; 95% CI 0.9-20.41; P = 0.067) unlike hs-CRP (adjusted HR 1.97; 95% CI 0.48-8.05; P = 0.344). The PESI risk score (c-statistic 0.77 (95% CI 0.69-0.84) had the highest prognostic accuracy for 6-month mortality, outperforming hs-cTnT, NT-proBNP and hs-CRP (c-statistics of 0.72, 0.72, and 0.54), respectively. Combining all three biomarkers had no clinically relevant impact on risk stratification when added to the PESI risk score (IDI = 0.067; 95% CI 0.012-0.123; P = 0.018; NRI = 0.101 95% CI -0.099-0.302; P = 0.321).

CONCLUSIONS

In elderly patients with PE, 6-month mortality can adequately be predicted by the PESI risk score alone.

Circulating ceruloplasmin, ceruloplasmin-associated genes and the incidence of venous thromboembolism in the Atherosclerosis Risk in Communities study

Essentials Ceruloplasmin (CP) is an acute-phase reactant and a potential biomarker of atherothrombotic risk. We assessed associations between CP and venous thromboembolism (VTE) risk in 9933 individuals. Higher circulating CP but not CP-related genes were associated with greater incident VTE rates. Circulating CP could be considered a non-causal biomarker of VTE risk in the community. SUMMARY: Background Ceruloplasmin (CP) is an acute-phase reactant and a potential biomarker of atherothrombotic risk. We assessed the associations between CP, CP-associated genetic variants and incident venous thomboembolism (VTE) in the Atherosclerosis Risk in Communities study. Methods and results In an observational study, 9933 men and women aged 53-75 years without prevalent VTE were included in 1996-1998 and followed through 2011. Circulating CP was measured in stored blood samples obtained in 1996-1998. Polymorphisms rs11708215 and rs13072552, which have been previously associated with CP concentrations, were measured in 8439 participants. VTEs were identified from hospital discharge codes and validated by physician review of medical records and imaging reports. Over a mean of 10.5 years of follow-up, 376 cases of VTE were identified. The association between circulating CP, CP-associated polymorphisms and the incidence of VTE was estimated. After adjustment for traditional risk factors and biomarkers, higher concentrations of circulating CP were associated with greater incident VTE rates (hazard ratio 1.82, 95% confidence interval 1.12-2.95, comparing the 87.5-100th percentile with the bottom quartile). Both rs11708215 and rs13072552 were associated with CP concentrations but not with VTE risk. Conclusions Even though high CP concentrations were associated with an increased VTE risk, CP-associated genetic variants were not associated with a higher risk of VTE. Our results suggest that circulating CP concentrations may not be causally related to the risk of incident VTE.

Searching for a Common Thrombo-Inflammatory Basis in Patients With Deep Vein Thrombosis or Peripheral Artery Disease

Background: Inflammation and hypercoagulability play a pivotal role in venous thromboembolism and atherothrombosis. Since venous thrombosis increases the risk of atherothrombotic events and vice versa, common mechanisms may be involved.

Objectives: To elucidate the role of neutrophils and coagulation in the occurrence of atherothrombotic events in patients with a history of deep vein thrombosis (DVT or peripheral artery disease (PAD).

Materials and Methods: We studied 115 patients from two cohorts (75 DVT, 40 PAD). From those with PAD, 20 patients had progressive disease; from those with DVT, 25 patients had a recurrent DVT and 25 suffered from post thrombotic syndrome (PTS); patients were age and sex matched to DVT and PAD patients without events. Markers of neutrophil recruitment (p-selectin) and activation [nucleosomes, human neutrophil elastase- α1anti-trypsin (HNE-AT)], an anti-inflammatory marker (Lipoxin A4) and a clotting activity marker (d-dimer), were measured with ELISA. Coagulation potential was analyzed by thrombin generation (CAT method).

Results: Higher nucleosome levels were found in DVT patients [11.3 U/mL (7.4–17.7)] compared to PAD patients [7.1 U/mL (5.1–13.8)], lower HNE-AT levels were found in DVT patients [33.4 ng/mL (23.5–40.5)] in comparison to PAD patients [158 ng/mL (88.1–283)]. No difference in nucleosome levels was found between DVT patients with cardiovascular (CV) events [12.6 U/mL (8.2–16.1)], and PAD patients with CV events [6.9 U/mL (4.9–11.2)]. Lipoxin A4 levels appeared to be significantly lower in DVT [2.4 ng/mL (1.7–4.8)] vs. PAD [35.6 ng/mL (16.6–80.1)], with similar results in DVT patients with CV events vs. PAD patients with CV events. Thrombin generation showed higher ETP [160.4% (141.1–215.4)], and peak height [292.1% (177.9–330)] values in DVT patients. D-dimer levels were significantly lower in the DVT cohort [330 ng/mL (220–550)] compared to the PAD cohort [550 ng/mL (369–959)].

Conclusion: In DVT patients, neutrophil activity does not appear to be an important driver of CV events. Although neutrophil activity is more pronounced in PAD, its effect is partly dampened by Lipoxin A4. Moreover, no associations were found between NET products and coagulation activity, suggesting that neutrophil activation does not play a pivotal role in the risk of thrombosis in either DVT or PAD.

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.

Predictive value of neutrophil to lymphocyte ratio and platelet to lymphocyte ratio for acute deep vein thrombosis after total joint arthroplasty: a retrospective study

Background

Deep vein thrombosis (DVT) is a common and severe complication of total joint arthroplasty (TJA). Inflammation has been proved to play a role in DVT. The neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) are biomarkers for systemic inflammation. The aim of the study is to investigate the predictive value of NLR and PLR for acute TJA-induced DVT.

Method

A total of 773 patients who underwent primary TJA in our hospital were included in this retrospective study. Venography was performed routinely after the surgery to define acute DVT. NLR and PLR before and after operation were calculated according to the blood routine test. Multiple logistic regression analyses and ROC curve analyses were performed to assess the association of NLR and PLR with TJA-induced DVT.

Results

One hundred twenty out of 773 patients (15.5%) were diagnosed with DVT by venography. In patients with DVT, preoperative NLR (P = 0.030) and postoperative NLR (P = 0.015) were significantly higher but postoperative PLR (P = 0.002) was significantly lower. Multiple logistic regression analyses indicated that age (OR = 1.05, P < 0.005), gender (OR = 0.47, P = 0.005), BMI (OR = 1.06, P < 0.014), preoperative NLR (OR = 1.11, P < 0.035), postoperative NLR (OR = 1.20, P < 0.001), and PLR (OR = 0.99, P < 0.001) were independently associated with DVT. However, the ROC curve analysis demonstrated the specificity and sensitivity of NLR or PLR in predicting DVT were low.

Conclusion

Although the present study demonstrated significant association of perioperative NLR or PLR with acute TJA-induced DVT, NLR or PLR cannot predict TJA-induced DVT accurately.

Analysis of risk factors for venous thromboembolism in patients after thoracic surgery: A clinical study of 167 cases

Background

This study aims to identify risk factors of venous thromboembolism in the patients undergoing thoracic surgery.

Methods

A total of 167 patients (107 males, 60 females; mean age 56.7±16.8 years; range 16 to 81 years) who underwent thoracic surgery between September 2015 and December 2016 were included in this study. D-dimer and C-reactive protein values were analyzed and clinical data recorded. The patients received color Doppler ultrasound and thoracic computed tomography before and after surgery. The risk factors for venous thromboembolism were analyzed.

Results

Of the patients, 57 (34.1%) developed venous thromboembolism after thoracic surgery, among whom two patients developed pulmonary embolism and another 55 developed deep vein thrombosis. Age, D-dimer, operation time, and body mass index of venous thromboembolism patients were significantly higher than non-venous thromboembolism patients. There was no significant difference in the C-reactive protein values between the two patient groups. Age, smoking history, operation time, and body mass index were found to be the risk factors of venous thromboembolism. There was a significant difference in the incidence of venous thromboembolism among different surgeries. The patients who underwent esophagectomy had the highest incidence of thrombosis.

Conclusion

Age, smoking history, operation time and body mass index are independent risk factors for venous thromboembolism. A special attention should be given to the patients undergoing esophagectomy to prevent the development of venous thromboembolism.

Serum C-reactive protein increases the risk of venous thromboembolism: a prospective study and meta-analysis of published prospective evidence

Evolving debate suggests that C-reactive protein (CRP) might be associated with the development of venous thromboembolism (VTE); however, the evidence is conflicting. We aimed to assess the prospective association of CRP with VTE risk. C-reactive protein was measured in serum samples at baseline from 2420 men aged 42–61 years, from the Kuopio Ischemic Heart Disease study. Within-person variability in CRP levels was corrected for using repeat measurements of CRP taken 11 years after baseline. Incident VTE events (n = 119) were recorded during a median follow-up of 24.7 years. The age-adjusted regression dilution ratio for log_e CRP was 0.57 [95% confidence interval (CIs): 0.51–0.64]. In age-adjusted Cox regression analysis, the hazard ratio (95% CIs) for VTE per 1 standard deviation (SD) increase in log_e baseline CRP was 1.17 (0.98–1.40). Further adjustment for several established and emerging risk factors did not alter the association. In a meta-analysis of nine population-based studies (including the current study) comprising 81,625 participants and 2225 VTE cases, the fully-adjusted risk estimate for VTE was 1.14 (1.08–1.19) per SD increase in log_e baseline CRP. In a pooled dose–response analysis, a linear association between CRP and VTE risk was suggested (P for nonlinearity = 0.272). The pooled risk estimate for VTE per 5 mg/l increment in CRP levels was 1.23 (1.09–1.38). C-reactive protein was only modestly associated with VTE risk in the primary analysis. Pooled evidence, however, suggests that elevated CRP is associated with greater VTE risk, consistent with a linear dose–response relationship.

Prothrombotic Fibrin Clot Phenotype Is Associated With Recurrent Pulmonary Embolism After Discontinuation of Anticoagulant Therapy

OBJECTIVE

Pulmonary embolism (PE) is a life-threatening manifestation of venous thromboembolism with a high recurrence rate after anticoagulation cessation. Recently, we have reported that prothrombotic clot phenotype in venous thromboembolism patients is associated with an increased risk of recurrent deep-vein thrombosis.

APPROACH AND RESULTS

We tested whether abnormal clot properties are predictive of recurrent PE. We investigated 156 consecutive white patients aged 18 to 65 years after the first-ever provoked or unprovoked PE (n=89), with or without deep-vein thrombosis. Plasma fibrin clot permeability (K_s), turbidity measurements, calibrated automated thrombography, and efficiency of fibrinolysis using clot lysis time, maximum D-dimer levels, and rate of increase in D-dimer levels were evaluated at ≥3 months of anticoagulant therapy, at least 4 weeks since the anticoagulation withdrawal. The primary end point was recurrent PE during a median follow-up of 50 months. Recurrent PE was diagnosed in 23 (14.7%; 5%/yr) patients. Recurrent PE was associated with formation of denser fibrin networks reflected by lower K_s (P=0.007) and impaired fibrinolysis, as evidenced by prolonged clot lysis time (P=0.012) and reduced maximum rate of increase in D-dimer levels in the lysis assay (P=0.004). Patients with recurrent PE had higher plasma D-dimer (P<0.001) and thrombin peak (P=0.007) compared with the remainder, whereas turbidity measurements and maximum D-dimer levels did not differ in the recurrence. Multivariate model showed that independent predictors of recurrent PE were female sex, unprovoked venous thromboembolism, higher plasma D-dimer, reduced K_s, and reduced maximum rate of increase in D-dimer levels in the lysis assay (all P<0.05).

CONCLUSIONS

Altered fibrin clot properties including formation of more compact clots displaying impaired susceptibility to lysis may predispose to recurrent PE.

C-reactive protein, obesity, and the risk of arterial and venous thrombosis

Essentials We performed repeated measurements of C-reactive protein (CRP) and obesity in a cohort study. CRP was associated with risk of myocardial infarction and venous thromboembolism. CRP was a mediator for risk of myocardial infarction in obese men and women. CRP was a partial mediator for risk of venous thromboembolism in obese women, but not in men.

SUMMARY

Background Low-grade inflammation in obesity may be a shared pathway for the risk of venous thromboembolism (VTE) and myocardial infarction (MI). Objectives To investigate the associations between repeated measurements of C-reactive protein (CRP) and the risks of MI and VTE, and to explore whether CRP mediated these risks in obese subjects. Methods CRP and obesity measures were collected from 15 134 subjects who participated in one or more surveys of the Tromsø study in 1994-1995, 2001-2002, or 2007-2008. Incident VTEs and MIs were registered until 1 January 2011. Time-varying Cox regression models were used to calculate hazard ratios of MI and VTE according to categories of CRP and obesity measures. Results There were 291 VTEs and 920 MIs during follow-up. High levels of CRP (≥ 3 mg L(-1) versus < 1 mg L(-1) ) were associated with increased risks of MI (hazard ratio [HR] 1.73; 95% confidence interval [CI] 1.32-2.26) and VTE (HR 1.84; 95% CI 1.22-2.78) in women, but only with MI in men (HR 1.93; 95% CI 1.53-2.44). All obesity measures showed stronger associations with CRP in women than in men. In obese women (body mass index [BMI] of ≥ 30 kg m(-2) versus < 25 kg m(-2) ), adjustment for CRP attenuated the risk estimate for VTE by 22%, whereas the incidence rates of VTE increased with combined categories of higher BMI and CRP. No association was found in men. Conclusions Our findings suggest that low-grade inflammation, assessed by measurement of CRP, is associated with the risks of MI and VTE, and may be a shared pathway for MI and VTE in obesity.

Proinflammatory proteins in female and male patients with primary antiphospholipid syndrome: preliminary data

The latest classification criteria for the diagnosis of the antiphospholipid syndrome (APS, an autoimmune disease characterized by thromboses, miscarriages and presence of antiphospholipid antibodies (Abs)) emphasized that thrombotic manifestations of APS should be without any signs of an inflammatory process. However, atherosclerosis (a chronic inflammatory response to the accumulation of lipoproteins in the walls of arteries) and APS are characterized by some similar features. We evaluated whether proinflammatory proteins were associated with the features of the primary APS (PAPS). PAPS patients without obstetric complications and with impaired lipid profile were included in the study. Antiphospholipid antibodies, TNF-alpha, and apo(a) were determined by ELISA. Complement components and hsCRP were measured by immunonephelometry. Decreased C3c was observed in female patients with increased titers of IgG anti-β2gpI (χ(2) = 3.939, P = 0.047) and in male patients with increased IgM anticardiolipin Abs (χ(2) = 4.286, P = 0.038). Pulmonary emboli were associated with interleukin (IL)-6 in male (χ(2) = 6.519, P = 0.011) and in female (χ(2) = 10.405, P = 0.001) patients. Cerebrovascular insults were associated with LDL-cholesterol (P = 0.05, 95 % CI: 1.003 - 12.739) in female and with apo(a) (P = 0.016, 95 % CI: 0.000-0.003) in male patients. Older female patients had increased LDL-cholesterol levels and frequency of myocardial infarctions. Proinflammatory proteins were associated with features of primary APS. No real gender differences in regard to proinflammatory protein levels were observed. Premenopausal state of female PAPS patients confers lower cardiovascular risk.

Complement C3 and High Risk of Venous Thromboembolism: 80517 Individuals from the Copenhagen General Population Study

BACKGROUND

Complement activation may contribute to venous thromboembolism, including deep venous thrombosis and pulmonary embolism. We tested the hypothesis that high complement C3 concentrations are associated with high risk of venous thromboembolism in the general population.

METHODS

We included 80 517 individuals without venous thromboembolism from the Copenhagen General Population Study recruited in 2003–2012. Plasma complement C3 concentrations were measured at baseline, and venous thromboembolism (n = 1176) was ascertained through April 2013 in nationwide registries. No individuals were lost to follow-up.

RESULTS

Complement C3 concentrations were approximately normally distributed, with a mean value of 1.13 g/L (interquartile range 0.98–1.26; SD 0.21). The cumulative incidence of venous thromboembolism was higher with progressively higher tertiles of complement C3 (log-rank trend: P = 3 × 10−8): at age 80, 7%, 9%, and 11% of individuals in the first, second, and third tertiles, respectively, had developed venous thromboembolism. Multivariable-adjusted hazard ratios for venous thromboembolism compared with individuals in the first tertile were 1.36 (95% CI, 1.16–1.59) for those in the second tertile and 1.58 (1.33–1.88) for those in the third tertile. Corresponding values were 1.36 (1.16–1.60) and 1.57 (1.33–1.87) after additional adjustment for C-reactive protein and 1.27 (1.09–1.49) and 1.31(1.10–1.57) after additional adjustment for body mass index. These results were similar for deep venous thrombosis and pulmonary embolism separately. The multivariable-adjusted hazard ratio for venous thromboembolism for a 1-g/L increase in complement C3 was 2.43 (1.74–3.40).

CONCLUSIONS

High concentrations of complement C3 were associated with high risk of venous thromboembolism in the general population.

Inflammation in venous thromboembolism: Cause or consequence?

Venous thromboembolism (VTE) which includes deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) is a moderately common disease especially in elderly population with high rate of recurrence and complications. Evidence is accumulating that VTE is not restricted to coagulation system and immune system appears to be involved in formation and resolution of thrombus. The present study was aimed at reviewing current evidences on immune system abnormalities such as alterations in cytokines, chemokines and immune cells. Also, current evidences suggest that; a, inflammation in general functions as a double-edged sword, b, inflammation can be both a cause and a consequence of VTE, and c, current anti-coagulation therapies are not well-equipped with the capacity to selectively inhibit inflammatory cells and pathways. Applying such inferences for selective pharmacological targeting of immune mediators in VTE and thereby for adoption of higher effective anti-thromboinflammatory strategies, either therapeutic or prophylactic, is henceforth to be considered as the line of research for future.

Rationale and design of three observational, prospective cohort studies including biobanking to evaluate and improve diagnostics, management strategies and risk stratification in venous thromboembolism: the VTEval Project

INTRODUCTION

Venous thromboembolism (VTE) with its two manifestations deep vein thrombosis (DVT) and pulmonary embolism (PE) is a major public health problem. The VTEval Project aims to investigate numerous research questions on diagnosis, clinical management, treatment and prognosis of VTE, which have remained uncertain to date.

METHODS AND ANALYSIS

The VTEval Project consists of three observational, prospective cohort studies on VTE comprising cohorts of individuals with a clinical suspicion of acute PE (with or without DVT), with a clinical suspicion of acute DVT (without symptomatic PE) and with an incidental diagnosis of VTE (PE or DVT). The VTEval Project expects to enrol a total of approximately 2000 individuals with subsequent active and passive follow-up investigations over a time period of 5 years per participant. Time points for active follow-up investigations are at months 3, 6, 12, 24 and 36 after diagnosis (depending on the disease cohort); passive follow-up investigations via registry offices and the cancer registry are performed 48 and 60 months after diagnosis for all participants. Primary short-term outcome is defined by overall mortality (PE-related death and all other causes of death), primary long-term outcome by symptomatic VTE (PE-related death, recurrence of non-fatal PE or DVT). The VTEval Project includes three 'all-comer' studies and involves the standardised acquisition of high-quality data, covering the systematic assessment of VTE including symptoms, risk profile, psychosocial, environmental and lifestyle factors as well as clinical and subclinical disease, and it builds up a large state-of-the-art biorepository containing various materials from serial blood samplings.

ETHICS AND DISSEMINATION

The VTEval Project has been approved by the local data safety commissioner and the responsible ethics committee (reference no. 837.320.12 (8421-F)). Trial results will be published in peer-reviewed journals and presented at national and international scientific meetings.

TRIAL REGISTRATION NUMBER

NCT02156401.

Mendelian randomization studies: a review of the approaches used and the quality of reporting

BACKGROUND

Mendelian randomization (MR) studies investigate the effect of genetic variation in levels of an exposure on an outcome, thereby using genetic variation as an instrumental variable (IV). We provide a meta-epidemiological overview of the methodological approaches used in MR studies, and evaluate the discussion of MR assumptions and reporting of statistical methods.

METHODS

We searched PubMed, Medline, Embase and Web of Science for MR studies up to December 2013. We assessed (i) the MR approach used; (ii) whether the plausibility of MR assumptions was discussed; and (iii) whether the statistical methods used were reported adequately.

RESULTS

Of 99 studies using data from one study population, 32 used genetic information as a proxy for the exposure without further estimation, 44 performed a formal IV analysis, 7 compared the observed with the expected genotype-outcome association, and 1 used both the latter two approaches. The 80 studies using data from multiple study populations used many different approaches to combine the data; 52 of these studies used some form of IV analysis; 44% of studies discussed the plausibility of all three MR assumptions in their study. Statistical methods used for IV analysis were insufficiently described in 14% of studies.

CONCLUSIONS

Most MR studies either use the genotype as a proxy for exposure without further estimation or perform an IV analysis. The discussion of underlying assumptions and reporting of statistical methods for IV analysis are frequently insufficient. Studies using data from multiple study populations are further complicated by the combination of data or estimates. We provide a checklist for the reporting of MR studies.

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.

Inflammation markers and incident venous thromboembolism: the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort

BACKGROUND

Inflammation biomarkers are associated with the venous thromboembolism (VTE) risk factors obesity and age; however, the relationships of inflammation with VTE risk remain controversial.

OBJECTIVES

To examine associations of four inflammation biomarkers, i.e. C-reactive protein (CRP), serum albumin, white blood cell (WBC) count, and platelet count (PLTC), with incident VTE, and to determine whether they mediate the association of age or obesity with VTE.

PATIENTS/METHODS

Hazards models adjusted for VTE risk factors were used to calculate the prospective association of each biomarker with incident VTE in 30,239 participants of the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Mediation of the associations of obesity and age with VTE were examined by bootstrapping. Over a period of 4.6 years, there were 268 incident VTE events. After adjustment for VTE risk factors, the hazard ratios (HRs) were 1.25 (95% confidence interval [CI] 1.09-1.43) per standard deviation (SD) higher log-CRP and 1.25 (95% CI 1.06-1.48) per SD lower albumin; there were no associations for WBC count or PLTC. The association of body mass index (BMI), but not age, with VTE was partially mediated by CRP and albumin. In risk factor-adjusted models, the percentage attenuations of the BMI HR for VTE after introduction of CRP or albumin into the models were 15.4% (95% CI 7.7-33.3%) and 41.0% (95% CI 12.8-79.5%), respectively.

CONCLUSION

Higher CRP levels and lower serum albumin levels were associated with increased VTE risk, and statistically mediated part of the association of BMI with VTE. These data suggest that inflammation may be a potential mechanism underlying the relationship between obesity and VTE risk.

Links between allergy and cardiovascular or hemostatic system

In addition to a well-known immunologic background of atherosclerosis and influences of inflammation on arterial and venous thrombosis, there is growing evidence for the presence of links between allergy and vascular or thrombotic disorders. In this interpretative review, five pretty well-documented areas of such overlap are described and discussed, including: (1) links between atherosclerosis and immunoglobulin E or atopy, (2) mutual effects of blood lipids and allergy, (3) influence of atopy and related disorders on venous thromboembolism, (4) the role of platelets in allergic diseases, and (5) the functions of protein C system in atopic disorders.

Role of psoriasis as independent predictor of cardiovascular disease: a meta-regression analysis

BACKGROUND

Despite the proved association between psoriasis and cardiovascular risk exposure, there are no data about the role of psoriasis as an independent predictor of such risk. The aim of this study was to investigate whether any association between psoriasis and excess cardiovascular risk exposure is independent from confounding factors.

METHODS

Meta-analysis and meta-regression analysis were performed using data extracted from observational studies (identified by MEDLINE, EMBASE and CINAHL) investigating the relationship between psoriasis and cardiovascular disease with at least 6 points on the New Castle-Ottawa quality scale. Two reviewers with methodological expertise conducted data extraction independently.

RESULTS

Thirteen studies including patients with psoriasis showed an increased risk of cardiovascular disease (RR=1.24 [1.18-1.31]; P=0.0001). These patients still presented a significantly larger cardiovascular risk in the presence of smoking (RR=1.14 [CI=1.13-1.15] P<0.0001), obesity (RR=1.11 [CI=1.07-1.14] P=0.0003) and hyperlipidemia (RR=1.05 [CI=1.03-1.07] P=0.0006), but not in the presence of hypertension (RR=1.03 [CI=0.98-1.09] P=0.4647) and diabetes (RR=0.95 [CI=0.90-1.01] P=0.6502).

CONCLUSIONS

Patients with psoriasis carry an about 25% increased relative risk of cardiovascular disease. This risk appears to be independent of smoking, obesity and hyperlipidemia.

Risk of venous thromboembolism and myocardial infarction associated with factor V Leiden and prothrombin mutations and blood type

BACKGROUND

ABO blood type locus has been reported to be an important genetic determinant of venous and arterial thrombosis in genome-wide association studies. We tested the hypothesis that ABO blood type alone and in combination with mutations in factor V Leiden R506Q and prothrombin G20210A is associated with the risk of venous thromboembolism and myocardial infarction in the general population.

METHODS

We used data from 2 Danish studies that followed members of the general public from 1977 through 2010. We obtained the genotype of 66 001 white participants for ABO blood type, factor V Leiden R506Q and prothrombin G20210A. We calculated hazard ratios (HRs) and population attributable risk. Our main outcome measures were venous thromboembolism and myocardial infarction.

RESULTS

The multivariable adjusted HR for venous thromboembolism was 1.4 (95% confidence interval [CI] 1.3-1.5) for non-O blood type (v. O blood type). For the factor V Leiden R506Q mutation, the adjusted HR was 2.2 (95% CI 2.0-2.5) for heterozygous participants and 7.0 (95%CI 4.8-10) for homozygous participants (v. participants without the mutation). For prothrombin G20210A, the adjusted HR was 1.5 (95%CI 1.2-1.9) for heterozygous participants and 11 (95% CI 2.8-44) for homozygous participants (v. participants without the mutation). When we combined ABO blood type and factor V Leiden R506Q or prothrombin G20210A genotype, there was a stepwise increase in the risk of venous thromboembolism (trend, p<0.001). The population attributable risk of venous thromboembolism was 20% for ABO blood type, 10% for factor V Leiden R506Q and 1% for prothrombin G20210A. Multivariable adjusted HRs for myocardial infarction by genotypes did not differ from 1.0.

INTERPRETATION

ABO blood type had an additive effect on the risk of venous thromboembolism when combined with factor V Leiden R506Q and prothrombin G20210A mutations; blood type was the most important risk factor for venous thromboembolism in the general population.

Comparison of clinical and imaging characteristics and outcomes between provoked and unprovoked acute pulmonary embolism in Koreans

This study was performed to compare clinical and imaging parameters and prognosis of unprovoked pulmonary embolism (PE), provoked PE with reversible risk factors (provoked-rRF), and provoked PE with irreversible risk factors (provoked-iRF) in Koreans. Three hundred consecutive patients (mean age, 63.6 ± 15.0 yr; 42.8% male) diagnosed with acute PE were included. The patients were classified into 3 groups; unprovoked PE, provoked-rRF, and provoked-iRF; 43.7%, 14.7%, and 41.7%, respectively. We followed up the patients for 25.4 ± 33.7 months. Composite endpoint was all-cause mortality and recurrent PE. The provoked-iRF group had significantly higher all-cause mortality, mortality from PE and recurrent PE than the unprovoked and provoked-rRF groups (P < 0.001, P < 0.001, and P = 0.034, respectively). Prognostic factors of composite endpoint in the unprovoked group were high creatinine (> 1.2 mg/dL; P < 0.001; hazard ratio [HR], 4.735; 95% confidence interval [CI], 1.845-12.152), C-reactive protein (CRP; > 5 mg/L; P = 0.002; HR, 5.308; 95% CI, 1.824-15.447) and computed tomography (CT) obstruction index (P = 0.034; HR, 1.090; 95% CI, 1.006-1.181). In conclusion, provoked-iRF has a poorer prognosis than unprovoked PE and provoked-rRF. Renal insufficiency, high CRP, and CT obstruction index are poor prognostic factors in unprovoked PE.

Statins for the prevention of venous thromboembolism? a narrative review

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a substantial public health problem. The majority of VTE events are associated with transient periods of heightened risk, such as prolonged hospitalization, undergoing major surgery, experiencing trauma or lower extremity immobility, use of oral contraceptives, or having active cancer. Although pharmacologic thromboprophylaxis agents (eg, unfractionated heparin, low-molecular-weight heparins, warfarin, and novel oral anticoagulants) are effective, they remain underused, with concerns about increased bleeding risk often cited as a reason. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (ie, statins), although used primarily for lipid lowering and arterial thrombosis risk reduction, have pleiotrophic effects that affect coagulation and inflammation, and do not increase bleeding risk. There is emerging evidence to suggest that through these pleiotrophic effects, statins may be effective in reducing the incidence of VTE. This article summarizes the literature with regard to statins' effect on VTE and suggests that additional investigations are needed to assess a potential adjunctive role for primary VTE thromboprophylaxis.

Abdominal obesity and the risk of venous thromboembolism among women: a potential role of interleukin-6

BACKGROUND

Abdominal obesity increases the risk of venous thromboembolism (VTE). It remains unclear to what extent inflammation contributes to the risk of VTE from abdominal obesity. Our objectives were to investigate the association between abdominal obesity and VTE and the effect of inflammation on this association in a case-control study comprised of women.

METHODS

We included 84 patients with VTE (18-60 years of age) and 100 controls. Waist circumference (WC), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hsCRP) levels were determined at least 7 months after the thrombotic event.

RESULTS

A total of 51 patients (61%) and 43 (43%) controls had abdominal obesity (WC ≥88 cm). The odds ratios (OR) adjusted for age were 2.40 [95% confidence interval (CI) 1.06-5.41; P=0.035] for a WC ≥88 cm compared to a WC <80 cm; the association was attenuated after adjusting for IL-6 (OR 1.86, 95% CI 0.80-4.33; P=0.149). For every 10-cm increment in WC, the risk of VTE adjusted for age increased by 1.38 (95% CI 1.08-1.77; P=0.010). The effect of an increased WC on the risk of VTE was again attenuated when IL-6 was entered in the regression model (OR 1.24, 95% CI 0.95-1.61; P=0.109). Risk estimates did not substantially change with adjustment for hsCRP.

CONCLUSION

Our data indicate that the association between VTE and an increased WC was attenuated after adjustment for IL-6, suggesting a potential role of this interleukin in mediating the link between abdominal obesity and VTE.

Symptomatic venous thromboembolism is a disease related to infection and immune dysfunction

The characteristics of human genomics and cellular immune function between clinically symptomatic venous thromboembolism (VTE) and controls were systematically compared to explore the immunologic pathogenesis of VTE. Microarray assay showed the mRNA expressions of genes related to non-specific cellarer immune and cytokines were significantly down-regulated. Abnormal expressions of CD3+, CD4+, CD8+, NK marker CD16+56+, CD19 and aberrant CD4+/CD8+ ratio were detected in 54 among 56 patients. In PE patients, microarray assay revealed the imbalance in the expressions of genes related to the immune system. The expressions of genes related to non-specific immune cells and cytokines were markedly up-regulated and those associated with cellular immune were dramatically down-regulated. In VTE patients, cytological examination indicated the functions of NK cells were significantly compromised, and the antigen recognition and killing function of T cells markedly decreased. The consistence between genomic and cytological examination suggests the symptomatic VTE is closely associated with the infection and immune dysfunction.

Cancer risk by combined levels of YKL-40 and C-reactive protein in the general population

Background:

YKL-40 and C-reactive protein (CRP) are biomarkers that may reflect cancer-related subclinical inflammation. We assessed elevated YKL-40 and CRP levels as combined risk predictors for cancer.

Methods:

We measured plasma YKL-40 and CRP at baseline in 8706 individuals from the Danish general population.

Results:

Hazard ratio (HR) of gastrointestinal cancer for a doubling of YKL-40 levels was 1.37 (95% CI: 1.17–1.61) and indifferent to adjustment for CRP levels. Hazard ratio of lung cancer for a doubling of CRP levels was 1.35 (1.17–1.56) and indifferent to adjustment for YKL-40 levels. Compared to individuals with both low CRP (<1.7 mg l⁻¹) and YKL-40 (<154 μg l⁻¹), individuals with high YKL-40 but low CRP had an HR of gastrointestinal cancer of 3.36 (1.70–6.64), whereas individuals with high CRP but low YKL-40 had an HR of lung cancer of 2.19 (1.24–3.87). The area under the receiver operating characteristic (ROC) curve was 0.68 for the ability of YKL-40 to predict gastrointestinal cancer and 0.67 for the ability of CRP to predict lung cancer.

Conclusion:

Elevated YKL-40 levels are associated with increased risk of gastrointestinal cancer, independently of CRP levels, whereas elevated CRP levels are associated with increased risk of lung cancer, independently of YKL-40 levels.