Tissue Plasminogen Activator Antigen Research Articles

An observational study of haemostatic changes, leptin and soluble endoglin during pregnancy in women with different BMIs

Obesity increases the risk of venous thromboembolism (VTE) in pregnancy. The pathogenesis is hypothesized to be because of multiple factors including prothrombotic changes, but there has been minimal haemostatic research looking at the combined state of obesity and pregnancy. We aimed to determine whether variation in BMI in the third trimester of pregnancy was associated with prothrombotic changes. We recruited 110 women into four groups depending on their BMI at first antenatal appointment: normal, overweight, obese and morbidly obese. Women with increased risk of VTE, and/or receiving thromboprophylaxis, and/or more than 35 years and those in labour were excluded. Thromboelastography, platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, prothrombin fragment 1 + 2, free and total protein S, plasminogen activator inhibitor type 1, tissue plasminogen activator antigen, D-dimers, soluble endoglin and leptin levels were measured. There were no significant differences in haemostatic measures with changing BMI. There was a positive correlation between BMI and both platelet count (correlation coefficient r = 0.214, P = 0.036) and leptin (r = 0.435, P < 0.001), but only leptin had a significant association with BMI once adjusted for age, gestation and parity. Despite recruitment into the morbidly obese group being suboptimal, these findings suggest that in pregnancy, the increased risk of VTE seen in obese mothers is not mediated through increased prothrombotic changes, and thus the increased risk of VTE in obese pregnant women may be because of other mechanisms, for example endothelial dysfunction, inflammation and venous stasis.

Fibrinolysis in patients with a mild-to-moderate bleeding tendency of unknown cause

In more than 50% of patients with a mild-to-moderate bleeding tendency, no underlying cause can be identified (bleeding of unknown cause, BUC). Data on parameters of fibrinolysis in BUC are scarce in the literature and reveal discrepant results. It was the aim of this study to investigate increased fibrinolysis as a possible mechanism of BUC. We included 270 patients (227 females, median age 44 years, 25–75th percentile 32–58) with BUC and 98 healthy controls (65 females, median age 47 years, 25–75thpercentile 39–55). Tissue plasminogen activator (tPA-) antigen and activity, plasminogen activator inhibitor type-1 (PAI-1), tPA-PAI-1 complexes, thrombin activatable fibrinolysis inhibitor (TAFI), α2-antiplasmin, and D-dimer were determined. While PAI-1 deficiency was equally frequent in patients with BUC and controls (91/270, 34%, and 33/98, 34%, p = 0.996), tPA activity levels were more often above the detection limit in patients than in controls (103/213, 48%, and 23/98, 23%, p < 0.0001). We found lower levels of tPA-PAI-1 complexes (6.86 (3.99–10.00) and 9.11 (7.17–13.12), p < 0.001) and higher activity of TAFI (18.61 (15.80–22.58) and 17.03 (14.02–20.02), p < 0.001) and α2-antiplasmin (102 (94–109) and 98 (90–106], p = 0.003) in patients compared to controls. Detectable tPA activity (OR 3.02, 95%CI 1.75–5.23, p < 0.0001), higher levels of TAFI (OR 2.57, 95%CI 1.48–4.46, p = 0.0008) and α2-antiplasmin (OR 1.03, 95%CI 1.01–1.05, p = 0.011), and lower levels of tPA-PAI-1 complexes (OR 0.90, 95%CI 0.86–0.95, p < 0.0001) were independently associated with BUC in sex-adjusted logistic regression analyses. We conclude that the fibrinolytic system can play an etiological role for bleeding in patients with BUC.

Increased heart rate is associated with a prothrombotic state: The Framingham Heart Study.

Background Although a higher heart rate is associated with an increased risk of cardiovascular disease, the mechanism is not well understood. As thrombosis has an important role in plaque development and acute coronary syndromes, the increase related to heart rate may result from a prothrombotic imbalance. Methods We investigated the relation between heart rate and thrombotic potential in 3451 participants from the Offspring Cohort of the Framingham Heart Study (mean age 54 years, 55% women). Participants were divided into quintiles based on heart rate derived from a resting electrocardiogram. Results Higher heart rates were associated with significant age-adjusted increases in fibrinogen, viscosity, factor VII antigen, and impaired fibrinolytic potential (plasminogen activator inhibitor and tissue plasminogen activator antigen) among men and women, and von Willebrand factor antigen among men. Fibrinogen levels were 9% higher among men with a heart rate of 80.9 ± 8.1 beats/min (quintile 5) vs. 50.0 ± 3.9 beats/min (quintile 1) (314 vs. 287 mg/dl, p < 0.001 for linear trend) and 13% higher among women (83.5 ± 7.7 beats/min vs. 53.7 ± 3.5 beats/min (330 vs. 291 mg/dl, p < 0.001). The significant relations persisted after multivariate adjustment, other than among men, in whom factor VII was not significant and fibrinogen was borderline significant ( p = 0.065). Conclusions Higher heart rates are associated with a prothrombotic state. Because these factors are also associated with endothelial dysfunction and inflammation, these findings are consistent with an injurious effect of higher heart rates on the endothelium. Measures to reduce thrombotic potential may be of particular value in people with higher heart rates.

Estimating the associations of apparent temperature and inflammatory, hemostatic, and lipid markers in a cohort of midlife women

Associations between temperature and cardiovascular (CVD) mortality have been reported, but the underlying biological mechanisms remain uncertain. We explored the association between apparent temperature and serum biomarkers for CVD. Using linear mixed effects models, we examined the relationships between residence-proximate apparent temperature (same day and 1, 7, and 30 days prior) and several inflammatory, hemostatic, and lipid biomarkers for midlife women from 1999 through 2004. Our study population consisted of 2,306 women with mean age of 51 years (± 3 years) enrolled in Study of Women's Health Across the Nation (SWAN) in Chicago, Illinois; Detroit, Michigan; Los Angeles and Oakland, California; Newark, New Jersey; and Pittsburgh, Pennsylvania. Mean daily apparent temperature was calculated using temperature and relative humidity data provided by the National Climatic Data Center and the US Environmental Protection Agency, while daily data for fine particles, ozone, carbon monoxide, and nitrogen dioxide from the US Environmental Protection Agency Air Quality Data Mart were considered as confounders. All analyses were stratified by warm and cold seasons.More significant (p < 0.10) negative associations were found during the warm season for various lag times, including hs-CRP, fibrinogen, tissue plasminogen activator antigen (tPA-ag), tissue plasminogen activator antigen (PAI-1), Factor VIIc, high-density lipoprotein (HDL), and total cholesterol. During the cold season, significant negative associations for fibrinogen and HDL, but significant positive associations for tPA-ag, PAI-1, and triglycerides were observed for various lag times. With the exception of ozone, pollutants did not confound these associations. Apparent temperature was associated with several serum biomarkers of CVD risk in midlife women, shedding light on potential mechanisms.

Inflammatory/hemostatic biomarkers and coronary artery calcification in midlife women of African-American and White race/ethnicity: the Study of Women's Health Across the Nation (SWAN) heart study.

Inflammatory/hemostatic biomarkers are associated with coronary heart disease events, but relationships in asymptomatic midlife women are uncertain. We evaluated separately whether high-sensitivity C-reactive protein (hsCRP), fibrinogen, plasminogen-activator inhibitor 1, tissue plasminogen activator antigen, and circulating factor VII (factor VIIc) were associated with coronary artery calcification (CAC) in healthy midlife women. A cross-sectional study was performed of participants from the Study of Women's Health Across the Nation. Logistic and Tobit regression was used to assess associations between log-transformed biomarkers, and CAC presence (CAC > 0) and extent. Effect modification by race/ethnicity was evaluated. The study included 372 women (mean age 51.3 y; 35.2% African-American). All biomarkers were positively associated with CAC presence and extent (P < 0.001 for all), adjusting for Framingham risk score, site, race/ethnicity, menopause status, income, and education. Additional adjustment for body mass index explained all associations except for factor VIIc, which remained associated with CAC extent only (P = 0.02). Final adjustment for insulin resistance, family history of cardiovascular disease, and cardiovascular medication use produced similar results. Associations between hsCRP, and CAC presence and extent were modified by race/ethnicity (P < 0.05). Log(hsCRP) was positively associated with CAC presence (odds ratio 3.25; 95% CI, 1.53-6.90; P = 0.002; per 1 log unit increase) and CAC extent (β = 19.66; SE = 7.67; P = 0.01; per 1 log unit increase) in African-Americans only. Inflammatory/hemostatic biomarkers were associated with CAC through obesity, except for factor VIIc. Among African-American women only, hsCRP was independently associated with CAC, suggesting that hsCRP may have a role in coronary heart disease prevention in African-American midlife women.

Inflammatory/Hemostatic Biomarkers and Coronary Artery Calcium Progression in Women at Midlife (from the Study of Women's Health Across the Nation, Heart Study)

It is unknown whether inflammatory/hemostatic biomarkers are associated with coronary artery calcium (CAC) progression. Our purpose was to evaluate the associations of baseline levels of C-reactive protein, fibrinogen, plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen, and circulating factor VII with CAC progression in healthy midlife women. Inflammatory/hemostatic biomarkers were measured at baseline. CAC was quantified by computed tomography scans at baseline and after 2.3 ±0.5years of follow-up. Significant CAC progression was defined as present if (1) follow-up CAC Agatston score was >0 if baseline CAC score= 0; (2) annualized change in CAC score was ≥10 if baseline CAC score >0 to <100; and (3) annualized percent change in CAC score was ≥10% if baseline CAC score ≥100. Extent of CAC progression was defined as [log(CAC(follow-up)+25)- log(CAC(baseline)+25)]/year. Logistic and linear regression models were used as appropriate, and the final models were adjusted for baseline CAC score, age, study site, race/ethnicity, menopausal status, sociodemographics, traditional cardiovascular disease (CVD) risk factors, family history of CVD, and CVD medication use. The study included 252 women (baseline age 51.2 ± 2.6years; 67.5% white; 56.4% premenopausal or early perimenopausal). In final models, only log(PAI-1) was associated with presence of CAC progression (odds ratio 1.91, 95% CI 1.24 to 2.93; per 1 log unit increase in PAI-1; p= 0.003). In addition, higher log(PAI-1) was marginally associated with greater extent of CAC progression (p= 0.06). In conclusion, PAI-1 is associated with the presence of CAC progression in middle-aged women. Targeting PAI-1 may decrease atherogenesis beyond conventional CVD risk factors.

Plasminogen activator inhibitor and the risk of cardiovascular disease: The Framingham Heart Study

IntroductionAlthough plasminogen activator inhibitor (PAI-1) plays a key regulatory role in fibrinolysis, it has not been clearly shown to independently predict cardiovascular disease (CVD) among individuals without prior CVD. We investigated, in the Framingham Heart Study offspring cohort, whether PAI-1 predicted CVD risk among individuals without prior CVD. MethodsPlasma PAI-1 antigen and tissue plasminogen activator (TPA) antigen were measured in 3203 subjects without prior CVD between 1991 and 1995; average follow-up of 10years. PAI-1 was remeasured 4years after baseline, to determine the effect of serial change on risk. ResultsPAI-1 levels (mean±SD) were 29.1ng/ml (19.2) versus 22.1 (16.5) for those and without incident CVD; p<0.001, and TPA levels were 12.0ng/ml (5.7) versus 9.0 (4.7); p<0.001. PAI-1 and TPA antigen levels had a strong unadjusted linear relation with incident CVD (p<0.001). After adjustment for conventional risk factors, the hazard ratios (HRs) for higher quartiles of PAI-1, compared with the lowest, were 1.9, 1.9, 2.6 (linear trend p=0.006), and 1.6, 1.6, 2.9 (p<0.001) for TPA antigen. The adjusted HRs for increasing quartiles of serial change in PAI-1 at 4years, compared with the lowest, were 0.9, 0.8, 1.3 (p=0.050). C statistic assessment showed that adding PAI-1 or TPA to conventional risk factors resulted in small increases in discrimination and modest reclassification of risk, which was statistically significant for TPA (net reclassification 6.8%, p=0.037) but not PAI-1 (4.8%, p=0.113). ConclusionPAI-1 and TPA antigen levels are predictive of CVD events after accounting for established risk factors. A serial increase in PAI-1 is associated with a further increase in risk. These findings support the importance of fibrinolytic potential in CVD.

Increased plasma clot permeability and susceptibility to lysis are associated with heavy menstrual bleeding of unknown cause: a case-control study.

BackgroundFormation of compact and poorly lysable clots has been reported in thromboembolic disorders. Little is known about clot properties in bleeding disorders.ObjectivesWe hypothesized that more permeable and lysis-sensitive fibrin clots can be detected in women with heavy menstrual bleeding (HMB).MethodsWe studied 52 women with HMB of unknown cause and 52 age-matched control women. Plasma clot permeability (Ks), turbidity and efficiency of fibrinolysis, together with coagulation factors, fibrinolysis proteins, and platelet aggregation were measured.ResultsWomen with HMB formed looser plasma fibrin clots (+16% [95%CI 7–18%] Ks) that displayed lower maximum absorbancy (-7% [95%CI -9 – -1%] ΔAbsmax), and shorter clot lysis time (-17% [95%CI -23 – -11%] CLT). The HMB patients and controls did not differ with regard to coagulation factors, fibrinogen, von Willebrand antigen, thrombin generation markers and the proportion of subjects with defective platelet aggregation. The patients had lower platelet count (-12% [95%CI -19 – -2%]), tissue plasminogen activator antigen (-39% [95%CI -41 – -29%] tPA:Ag), and plasminogen activator inhibitor-1 antigen (-28% [95%CI -38 – -18%] PAI-1:Ag) compared with the controls. Multiple regression analysis upon adjustment for age, body mass index, glucose, and fibrinogen showed that decreased tPA:Ag and shortened CLT were the independent predictors of HMB.ConclusionsIncreased clot permeability and susceptibility to fibrinolysis are associated with HMB, suggesting that altered plasma fibrin clot properties might contribute to bleeding disorders of unknown origin.

Plasma Fibrinolysis Parameters in Smokers and Non-smokers of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study.

Cardiovascular diseases (CVD) are an important cause of morbidity and mortality worldwide. Parameters of coagulation and fibrinolysis are risk factors of CVD and might be affected by cigarette smoking. Aim of our study was to analyze the effect of cigarette smoking on parameters of fibrinolysis in active smokers (AS) and life-time non-smokers (NS) of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study as well as the use of these parameters for risk prediction. We determined plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen (t-PA), protein C activity, and D-dimers in 3,316 LURIC patients. Smoking status was assessed by a questionnaire and measurement of plasma cotinine concentration. Cox regression was used to assess the effect of parameters on mortality. We found that of the 3,316 LURIC patients 777 were AS and 1,178 NS. Within the observation period of 10 years (median) 221 AS and 302 NS died. In male AS vs. NS, PAI-1 (19.0 (10.0-35.0) vs. 15.0 (9.0-29.0) U/ml; p=0.026) and t-PA antigen (12.7 (9.6-16.3) vs. 11.6 (8.9-14.6) μg/l; p=0.020) were slightly increased, while t-PA activity was slightly decreased (0.63 (0.30-1.05) vs. 0.68 (0.42-1.10) U/l; p=0.005). In female AS vs. NS, t-PA antigen (10.5 (8.3-13.9) vs. 11.5 (8.8-15.0) μg/l; p=0.025) and protein C (108.0±24.1% vs. 118.0±25.7%; p=0.004) were decreased. All parameters except for protein C were predictive for mortality in AS. Fully adjusted hazard ratios (95% CI) were 1.14 (1.04-1.25), 1.19 (1.06-1.34), and 1.29 (1.11-1.49) per 1SD increase for D-dimer, t-PA, and PAI-1, respectively. Including fibrinolysis parameters in risk prediction models for mortality improved the area-under-the-curve (AUC) significantly compared with the conventional risk factors. In conclusion, we found alterations in the fibrinolytic system in smokers, which were more pronounced in male AS. PAI-1, t-PA and D-dimers were significant predictors of mortality in AS in LURIC and should be included into the assessment of cardiovascular risk particularly in patients at risk.

Effects of Body Mass Index on the Lipid Profile and Biomarkers of Inflammation and a Fibrinolytic and Prothrombotic State.

Both an overweight status and obesity are associated with high cardiovascular morbidity and mortality. The aim of this study was to examine the effects of obesity on different underlying mechanisms, i.e. inflammation, fibrinolysis and a prothrombotic state, in a young high-risk population in the Mediterranean area. The study population included 237 subjects (median age: 44 years). We recorded the presence of cardiovascular risk factors and premature ischaemic heart disease and performed weight stratification using the body mass index (BMI) according to the established World Health Organization (WHO) criteria. We also measured the serum/plasma lipid, fibrinogen, D-dimer, von Willebrand factor, tissue plasminogen activator antigen (t-PA), plasminogen activator inhibitor-1 antigen (PAI-1) and high-sensitivity C-reactive protein (CRP-hs) levels in samples of peripheral blood. The subjects with premature ischaemic heart disease and hypertension had higher BMI values (p＜0.01), and the subjects with an increased weight showed an unadjusted detrimental lipid profile, with a proinflammatory, prothrombotic state and abnormal fibrinolytic parameters. According to a multivariate analysis, the HDL-cholesterol (r(2)=0.176; p＜0.001), t-PA antigen (r(2)=0.235; p＜0.001), PAI-1 antigen (r(2)=0.164; p＜0.001) and CRP-hs (r(2)=0.096; p=0.019) levels were significantly related to the weight stratification. A high BMI is a common finding in young populations at high risk of cardiovascular disease. In the current study, the patients with an increased BMI demonstrated an unhealthy lipid profile, as well as a proinflammatory and prothrombotic state and abnormal fibrinolytic parameters.

Abstract 9379: Higher Levels of Plasminogen-Activator Inhibitor 1 Are Associated with Progression of Coronary Artery Calcification in Middle-Aged Women: The Study of Women’s Health Across the Nation (SWAN) Heart Study

Introduction: Relationships of inflammatory and hemostatic biomarkers with progression of coronary artery calcification (CAC) in asymptomatic women are unknown. Hypothesis: We assessed the hypothesis that C-reactive protein (CRP), fibrinogen, plasminogen-activator inhibitor 1 (PAI-1), and tissue plasminogen activator antigen (tPA-ag) were associated with CAC progression in women free of known coronary heart disease (CHD) and stroke. Methods: CRP, fibrinogen, PAI-1, and tPA-ag were measured in SWAN Heart participants from the Pittsburgh and Chicago sites at baseline. CAC was obtained by CT scans and quantified by the Agatston score at baseline and after 2.3±0.5 years of follow-up. Significant CAC progression was defined as present if 1) CAC score was &gt;0 at follow-up in subjects with CAC score = 0 at baseline, 2) annualized change in CAC score was ≥10 in subjects with 0&lt;CAC score&lt;100 at baseline, and 3) annualized percent change in CAC score was ≥10% in subjects with CAC score ≥100 at baseline. Univariable and multivariable logistic regression were used for statistical analyses. The novel biomarkers were log-transformed. Baseline CAC was transformed as log(CAC+1). Results: The study included 252 women (32.5% black, 67.5% white; 56.4% pre- and early perimenopausal, 30.6% late peri- and postmenopausal, and 13.1% hormone therapy users) with a mean age of 51.2±2.6 years at baseline. In unadjusted analyses, log(PAI-1) and log(tPA-ag) were positively and significantly associated with CAC progression (p&lt;0.05), but log(CRP) and log(fibrinogen) were not. Adjusted analyses included the following covariates: baseline CAC, age, site, race, menopausal status, income, education, systolic blood pressure, body mass index, Homeostasis Model Assessment insulin resistance index, family history of cardiovascular (CV) disease, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, CV medication use, and current smoking. Only log(PAI-1) was significantly associated with CAC progression (OR: 1.91; 95% CI: 1.24-2.93; p=0.003). Conclusions: In conclusion, PAI-1 is associated with the presence of CAC progression in middle-aged women. Targeting PAI-1 may decrease atherogenesis beyond conventional CHD risk factors.

Anticoagulant and fibrinolytic blood systems in patients with arterial hypertension stage III

Aim. To measure the indicators of the anticoagulant and fibrinolytic blood systems activity in patients with arterial hypertension after suffering a hemorrhagic stroke. Methods. 82 patients with arterial hypertension were examined at different terms after suffering a hemorrhagic stroke. Antithrombin III activity, total blood fibrinolytic activity and D-dimer levels, as well as tissue plasminogen activator activity and antigen levels were studied. Patients were examined at admission before standard treatment initiation and at discharge. Tissue plasminogen activator activity and its antigen level were determined at admission. Statistical data processing was performed using Statistica 8 (StatSoft) integrated package for Windows. Results. Inhibited fibrinolytic activity and an imbalance of its components, as well as reduced levels and activity of antithrombin III and signs of fibrin formation were revealed in patients with arterial hypertension stage III at different periods after suffering hemorrhagic stroke. Changes were most evident in early and late recovery periods after suffered cerebral stroke. Subsequent follow-up for over-a-year term after suffered cerebral stroke revealed a trend for normalization of these indicators. The study of tissue plasminogen activator activity and levels of its antigen showed significant changes in these parameters. Analysis of the obtained results for all patients with hypertension, regardless of the period of hemorrhagic stroke, showed the reduction of the antigen tissue plasminogen activator level and its increased activity. After in-patient treatment, there was a trend for improvement in all studied parameters without their complete normalization. Conclusion. The results suggest an activation of intravascular clotting in parients with arterial hypertension who suffered a hemorrhagic stroke, increasing the risk for further cardiovascular complications.

Selected parameters of hemostasis in patients with myeloproliferative neoplasms

Hemostatic disorders are a major clinical problem in patients with myeloproliferative neoplasms (MPNs) and they are the second most common cause of death in MPN patients, after infections. The aim of this study was to assess the fibrinolytic potential of the blood of patients with MPNs. The study involved 112 patients with MPNs diagnosed at the Hematology Clinic Dr J. Biziel University Hospital No. 2 in Bydgoszcz, Poland. The study group included 63 patients with essential thrombocythemia, 29 with polycythemia vera, 11 with chronic myelogenous leukemia (CML) and nine with primary myelofibrosis. The control group consisted of 25 healthy volunteers who were age and sex-matched. The following parameters were determined: concentration of tissue plasminogen activator antigen (t-PA:Ag), plasminogen activator inhibitor type 1 antigen concentration (PAI-1:Ag), D-dimer, thrombin-antithrombin complexes, fibrinogen, activated partial thromboplastin time and international normalized ratio. The study showed significantly increased t-PA:Ag, PAI-1:Ag and D-dimer levels in patients with MPNs. Moreover, we found increased concentrations of thrombin-antithrombin complexes and fibrinogen, as well as elevated platelet counts. Detailed analysis revealed that t-PA:Ag concentration was elevated in patients with essential thrombocythemia, CML and polycythemia vera. Concentration of PAI-1:Ag was increased in patients with essential thrombocythemia and polycythemia vera; D-dimer was significantly higher in essential thrombocythemia, polycythemia vera, CML and primary myelofibrosis patients. Increased concentrations of t-PA:Ag and D-dimer indicate secondary activation of the fibrinolytic system in patients with MPNs. Elevated levels of PAI-1 in MPN patients may result from its increased production by elevated number of activated platelets and vascular endothelial damage. PAI-1 by having an inhibitory effect on fibrinolysis manifests its procoagulant activity.

Effects of Hormone Replacement Therapy on Plasma and Tissue Fibrinolytic Activity in a Rat Model of Surgically Induced Menopause

The purpose of this study was to analyze the effects of estrogen deficiency and hormone replacement therapy (HRT) on fibrinolytic activity in a rat mode of surgically-induced menopause. Twelve-week-old, sexually mature female Sprague-Dawley rats, each weighing 200-250 g, were randomly divided into four groups: (1) sham-operated group, (2) ovariectomy group, (3) ovariectomy group followed by oral administration of daily 17β-estradiol (0.02 mg/kg/day) (E2) + norethisterone acetate (0.01 mg/kg/day), and (4) ovariectomy group followed by oral administration of daily 17β-estradiol (0.01 mg/kg/day) + drospirenone (0.02 mg/kg/day). Tissue plasminogen activator (tPA) antigen, plasminogen activator inhibitor-1 (PAI-1) antigen, and PAI-1/tPA levels were measured as markers of fibrinolysis in plasma and liver and brain tissue. Compared with sham-operated rats, ovariectomized rats showed higher levels of fibrinolytic activity; however, the increased fibrinolytic activity in plasma and liver tissue was significantly reduced by HRT regimens. No change was observed in the levels of fibrinolytic activity in brain tissue. HRT showed beneficial effects by decreasing fibrinolytic activity related to surgically-induced menopause. Short-term HRT treatment was associated with a shift in the procoagulant-anticoagulant balance toward a procoagulant state.

Coagulation proteases and cardiovascular disease

There is increasing interest in the many possible mechanisms through which co-agulation proteases may promote arterial cardiovascular disease (CVD). Athero-sclerosis and thrombosis are the principal pathologies underlying coronary heart dis-ease (CHD), ischaemic stroke, and periph-eral arterial disease (PAD) (1). Circulating coagulation proteases (as well as their final substrate, fibrinogen) may be biomarkers for risk of arterial thrombosis and throm-bo-embolism; and may also influence the structure of fibrin clots and thrombi (2). Both coagulant and anticoagulant pro-teases can influence multiple cells in the vessel wall and in vital organs; and hence can influence processes including haemo-stasis, atherosclerosis, ischaemia and reper-fusion injury, inflammation, organ and vessel remodelling, and fibrosis (3) (Figure 1).Selective anticoagulation with new agents which target specific proteases has increased knowledge of this multitude of physiological and pathological actions; and clinical trials of NOACs (non-vitamin K-dependent oral anticoagulants; also re-ferred to as DOACs, for direct oral antico-agulants) have shown reduction in risk of major bleeding compared to traditional vit-amin K antagonists (VKAs), especially in intracranial bleeding; but in some trials in-creased risk of gastro-intestinal bleeding (4). These results require explanation of the possible mechanisms for organ-specific haemostasis.For this theme issue of the journal, we invited experts in several of these areas to provide brief reviews.Lowe and Rumley review evidence from prospective epidemiological studies for as-sociations of circulating levels of coagu-lation proteases, fibrinogen, and activation markers of coagulation and fibrinolysis with risk of CVD (5). To date, plasma fibri-nogen shows the strongest and most con-sistent associations with CVD; however, genetic studies do not support causality, and there is limited evidence that lowering fibrinogen levels reduces CVD risk. These associations may result from up-regulation of pro-inflammatory cytokines such as in-terleukin-6. In contrast, the common gen-etic polymorphisms for factors II, V and the von Willebrand factor:FVIII complex (non-O blood group) show associations with CHD risk, consistent with potential causal roles in arterial thrombosis, as with venous thrombosis. The associations of fi-brin D-dimer and tissue plasminogen acti-vator (t-PA) antigen levels with CHD risk are consistent with potential roles for acti-vation of coagulation, fibrinolysis and en-dothelial cells.Bjorkqvist et al. review in vivo activation and functions of the protease factor XII (FXII), the principal initiator of the contact system of coagulation, and an initiator of fibrinolysis and the classic complement system pathway of inflammation (6). They conclude that FXII influences thrombotic risk without altering haemostasis, and also plays a role in inflammation, sepsis and hereditary angioedema. These properties have renewed interest in FXII inhibition as a therapeutic strategy to treat aberrant vas-cular leakage and thrombotic disorders.Rezaie reviews protease-activated recep-tor (PAR) signalling by coagulation pro-teases in endothelial cells. PAR 1–4 are G-protein coupled receptors which can be specifically activated by thrombin and all vitamin K-dependent coagulation pro-teases (except FIXa) (7). While activation of PAR1 by thrombin induces pro-inflam-matory signaling responses, its activation by activated protein C (APC) elicits anti-inflammatory responses in cultured en-dothelial cells. Recombinant APC has been used as a therapeutic drug for treatment of adults with severe sepsis.Mosnier et al. review cytoprotective APC therapy for ischaemic stroke. APC is not only a natural anticoagulant, but also conveys multiple cytoprotective effects on many different cell types that involve multiple receptors including PAR1, PAR3, and the endothelial protein C receptor (EPRC) (7). Application of molecular en-gineered APC variants to rodent stroke models demonstrated that the beneficial ef-fects of APC require its cytoprotective ac-tivities but not its anticoagulant activities. The cytoprotective selective APC variant, 3K3A-APC is currently undergoing clinical trials in ischaemic stroke.Antoniak et al. review the role of tissue factor (TF)-FVII(a) activation of PARs in pathologic heart remodeling associated with myocardial infarction, viral myocardi-tis and hypertension (8). Cardiomyocyte TF is essential to maintain heart haemo-stasis. TF-dependent activation of coagu-lation and activation of PARs contribute to initial size of myocardial infarction, as well as pathologic heart remodelling including hypertrophic growth of cardiomyocytes and fibrosis.Bridge et al. review the associations of clot properties and CVD. Fibrin clot struc-ture is altered by levels of fibrinogen, thrombin, but also by metabolic disturb-ances including diabetes mellitus and hy-perhomocystinaemia; as well as treatment with aspirin, anticoagulants, statins and fi-brates (9). Change in fibrin clot structure in vitro, to a denser clot with smaller pores, which is more resistant to lysis, is strongly

Prevalence of hypercoagulable disorders in inflammatory bowel disease

Objective. Inflammatory bowel disease (IBD) can be associated with hypercoagulable disorders. Aim of this single-center, prospective study was an in-depth evaluation of acquired hypercoagulable states in IBD patients. Methods.A total of 110 patients with Crohn's disease (CD) (aged 19–69; mean 40.5, median 38.5 years), 43 with ulcerative colitis (UC) (aged 17–72; mean 42, median 36 years), and 30 controls were enrolled. Full blood count, serum C-reactive protein (CRP), proteins C and S, activated protein C (APC) resistance, thrombin–antithrombin complex (TAT), F1+F2 fragments, tissue factor pathway inhibitor (TFPI) total and truncated, TFPI-factor Xa, tissue plasminogen activator (tPA) and PAI-I antigen were investigated in peripheral blood samples. Results. Only 18 of 153 (11.8%) IBD patients had hemocoagulation parameters within normal range. Significant difference between IBD patients and controls was found in thrombocyte volume (p < 0.001), protein C (p = 0.025), protein S (p = 0.003), APC resistance (p < 0.001), F1+F2 fragments (p < 0.001), and tPA (p = 0.002). In CD patients who were divided into two subgroups according to serum CRP values (non-active disease: <5 mg/L; active disease ≥5 mg/L), thrombocyte count was significantly lower (p = 0.001), thrombocyte volume was significantly higher (p = 0.002), F1+F2 fragments were significantly lower (p = 0.007) and tPA was significantly higher (p = 0.038) in the subgroup with CRP <5 mg/L. In UC patients, no significant difference depending on CRP was found. Conclusions.Acquired hypercoagulable abnormalities in IBD patients are frequent. Patients with active CD, but not UC, displayed significantly different hemocoagulable parameters, when compared to non-active CD/UC subjects. In patients with active CD (with increased serum CRP concentration) and patients with active extensive UC found at endoscopy (despite low CRP values), prophylactic anticoagulation therapy should be considered.

Prospective associations between inflammatory and hemostatic markers and physical functioning limitations in mid-life women: Longitudinal results of the Study of Women's Health Across the Nation (SWAN)

BackgroundDue to the public health burden of age-related declines in physical functioning, it is important to identify targets for intervention for the prevention of functional decline. We prospectively examined whether higher levels of inflammatory and hemostatic markers (high-sensitivity C-reactive protein (hs-CRP), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen (tPA-ag), fibrinogen, and Factor VIIc (FVIIc)) were prospectively associated with reporting greater limitations in perceived physical functioning, and explored potential racial differences in the associations, in a multi-ethnic sample of mid-life women. MethodsWomen (45–56years) in the Study of Women's Health Across the Nation who completed the physical functioning scale of the Medical Outcome Short Form (SF-36) at follow-up visits 4, 6, or 8 and had inflammatory/hemostatic measures in the preceding year were included (n=2296). The continuous SF-36 physical function score was categorized as: no limitation (86–100 points), some limitation (51–85 points), and substantial limitation (0–50 points). Physical function category at time t was modeled a function of each biomarker, separately, at time t−1 using ordinal generalized estimating equations. ResultsAfter adjusting for age, race/ethnicity, body size, sociodemographic, medical and lifestyle factors, higher levels of tPA-ag and hs-CRP were associated with subsequently reporting greater limitations in physical functioning, although the latter was only marginally significant (p=0.13). For each standard deviation (SD) increase in logtPA-ag, the odds of some or substantial limitations was 1.18 (95%CI 1.09,1.27); for each SD increase in loghs-CRP, the odds of some or substantial limitation was (1.08, 95%CI 0.98,1.19). In African American women only, higher fibrinogen levels were associated with subsequently reporting greater limitations (OR=1.30, 95%CI 1.13,1.50, for each one SD increase in fibrinogen). ConclusionsHigher levels of inflammatory and hemostatic markers were prospectively associated with greater limitations in perceived physical functioning in mid-life women.

Coagulation Activation in Children with Sickle Cell Disease Is Associated with Cerebral Small Vessel Vasculopathy

BackgroundThrombotic complications in Sickle Cell Disease (SCD) arise since infancy, but the role of the coagulation system in children has been poorly explored. To determine its role in the development of clinical complications in childhood we measured coagulation and endothelial parameters in children with SCD at steady state.MethodsMarkers of thrombin generation, fibrin dissolution and endothelial activation were evaluated in 38 children with SS-Sβ°, 6 with SC disease and 50 age and blood group matched controls. Coagulation variables were correlated with markers of hemolysis and inflammation, with the presence of cerebral and lung vasculopathy and with the frequency of clinical complications.ResultsSS-Sβ° patients presented higher levels of factor VIII, von Willebrand factor antigen (VWF:Ag) and collagen binding activity, tissue plasminogen activator antigen (t-PA:Ag), D-dimer, p-selectin, prothrombin fragment1+2 (F1+2) and lower ADAMTS-13:activity/VWF:Ag (p<0.05) compared to controls and SC patients. In SS-Sβ° patients coagulation variables correlated positively with markers of inflammation, hemolysis, and negatively with HbF (p<0.05). Patients with cerebral silent infarcts showed significant decrease in t-PA:Ag and ADAMTS-13 Antigen and a tendency toward higher D-dimer, F1+2, TAT compared to patients without them. D-dimer was associated with a six fold increased risk of cerebral silent infarcts. No correlation was found between coagulation activation and large vessel vasculopathy or other clinical events except for decreased t-PA:Ag in patients with tricuspid Rigurgitant Velocity >2.5m/sec.ConclusionsSS-Sβ° disease is associated with extensive activation of the coagulation system at steady state since young age. ADAMTS-13 and t-PA:Ag are involved in the development of cerebral silent infarcts.

Menopause, complement, and hemostatic markers in women at midlife: The Study of Women's Health Across the Nation

ObjectiveTo evaluate whether higher circulating levels of complement proteins C3 and C4 are associated with menopausal status and with hemostatic/thrombus formation markers (circulating factor VII (factor VIIc), fibrinogen, plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator antigen (tPA-ag)) in a sample of midlife women. Methods and resultsA total of 100 women (50 late peri-/postmenopausal and 50 pre-/early peri- menopausal women) from the Study of Women's Health Across the Nation (SWAN) Pittsburgh site were included in the present analysis. Factor VIIc and PAI-1 were log transformed. Linear regression was used for analysis. The mean age of the study participants was 50.5 ± 2.6 years with 73% were Caucasian and 27% were African American. C3 but not C4 was significantly higher in postmenopausal women compared to premenopausal women (P value = 0.03), adjusting for age, race and BMI. In final model (adjusting for age, race, BMI and menopausal status), C3 was associated with higher levels of log PAI-1 (P value = 0.0009) and tPA-ag (P value = 0.0003), while C4 was associated with higher levels of log factor VIIc (P value = 0.04) and fibrinogen (P value = 0.005). ConclusionsThese data suggest that C3 and C4 may be related to blood clots via their associations with hemostatic markers and that C3 is related to menopausal status. Complement proteins C3 and C4 could be possible pathways by which postmenopausal women are at higher risk of atherosclerosis and cardiovascular related events. It is important to replicate these findings in a larger sample size.

Alterations in coagulatory and fibrinolytic systems following an ultra-marathon

The aim of this study was to examine coagulatory and fibrinolytic responses to the Western States Endurance Run (WSER, June 23 to 24, 2012). The WSER is a 161-km (100 mile) trail foot race through the Sierra Nevada Mountains that involves 6,030 m of climb and 7,001 m of descent. We examined 12 men and 4 women [mean (95 % CI), age 44.6 years (38.7-50.6)] who completed the race (24.64 h; range 16.89-29.46). Blood samples were collected the morning before the race, immediately post-race, and 1 (D1) and 2 (D2) days post-race (corresponding to 51-54 h and 75-78 h from the start of the race, respectively). Hypercoagulable state was characterized by prothrombin fragment 1+2 (PTF 1+2) and thrombin-antithrombin complex (TAT). Fibrinolytic state was assessed by plasminogen activator inhibitor antigen (PAI-1 Ag), tissue plasminogen activator antigen (tPA Ag), and D-Dimer. Muscle damage was assessed by serum creatine kinase (CK) and myoglobin concentrations. Significant (P ≤ 0.05) increases were observed immediately post-race for thrombin generation markers, PTF 1+2 (3.9-fold) and TAT (2.4-fold); markers of fibrinolysis, tPA Ag (4.0-fold), PAI-1 Ag (4.5-fold), and D-Dimer (2.2-fold); and muscle damage markers, CK (154-fold) and myoglobin (114-fold). Most markers continued to be elevated at D1, as seen by PTF 1+2, TAT (1.5- and 1.3-fold increase at D1), and D-Dimer (2.5- and 2.1-fold increase at D1 and D2, respectively). Additionally, PTF 1+2:tPA and TAT:tPA ratios, which assessed balance between coagulation and fibrinolysis, were slightly, but significantly increased at D1 (69 and 36 %) and D2 (19 and 31 %). CK and myoglobin also remained elevated at D1 (54- and 7-fold) and D2 (25- and 2-fold) time points. The WSER produced extensive muscle damage and activated the coagulation and fibrinolytic systems. Since we observed a slight imbalance response between the two systems, a limited potential for thrombotic episodes is apparent in these highly trained athletes.