Comparative behaviour of the components of the factor VIII complex in acute myocardial infarction

Interleukin-1-beta and dyslipidemic syndrome as major risk factors for thrombotic complications in type 2 diabetes mellitus

Diabetes mellitus (DM) is a complex disease characterized by chronic hyperglycemia, a known risk factor for accelerated atherosclerosis and vascular disease. The aim of this study was to show that the connection between DM and other risk factors, such as dyslipidemia, inflammatory phenomena, or the development of certain vascular injuries, leads to a high frequency of thrombotic events in diabetic patients compared to the nondiabetic population. The study included one hundred eighty patients divided in the following groups: diabetic without ischemic cardiopathy-related disorders (DM), diabetic with clinical or off-clinical (electrocardiogram, cardiac ultrasound) ischemic cardiopathy-related disorders (DM + IC), and nondiabetic with ischemic cardiopathy-related disorders (IC). We investigated the following parameters: von Willebrand Factor, HDL-cholesterol, LDL-cholesterol, interleukin-1-beta, protein C, and plasminogen activator inhibitor type 1. The results achieved in our study have revealed the highest thrombotic risk among the groups of diabetic patients, which is in direct correlation with the high values of interleukin-1-beta and the modifications of lipid parameters, acknowledging the data in the literature, according to which hyperglycemia alters endothelial functions directly and indirectly by synthesis of growth factors and cytokines and generates metabolic disorders which would explain the high risk for thrombotic events.

Plasma thrombomodulin activity, tissue factor activity and high levels of circulating procoagulant phospholipid as prognostic factors for acute myocardial infarction

Several studies have indicated an association between haemostatic markers and acute myocardial infarction, but few or no studies refer to their activity. We studied plasma levels of 10 coagulation factors (fibrinogen, protein C, protein S, von Willebrand factor, D-dimers, factor VIIa, free tissue factor pathway inhibitor, tissue-type plasminogen activator, plasminogen activator inhibitor-1, thrombomodulin) and using new specific assays analysed the activity of plasma tissue factor (TFa), thrombomodulin (TMa), and procoagulant phospholipid in 46 consecutive patients with acute myocardial infarction at the time of hospital admission, and compared them with 34 healthy normal volunteers. Plasma levels of TFa, TMa, and procoagulant phospholipid were significantly higher in cases than in control patients (P < 0.001). In addition the ratio of TFa/free tissue factor pathway inhibitor was higher in patients than in controls, whereas the tissue-type plasminogen activator (t-PA)/plasminogen activator inhibitor-1 ratio was lower in patients. Interestingly, patients with an unfavourable outcome during a 2-month follow-up had higher levels of TFa, TMa, procoagulant phospholipid, a higher ratio of TFa/free tissue factor pathway inhibitor and a lower ratio of t-PA/plasminogen activator inhibitor-1 than patients who recovered. The combination of these different parameters reveals an increase in procoagulant activity as well as impaired fibrinolytic activity during the acute phase of an acute myocardial infarction. The association of the level of the activity of these three factors may provide a new tool to assess the prognosis of acute myocardial infarction. Further studies are needed to support our findings and to elucidate the clinical interest of measuring these factors.

Markers of thrombosis and hemostasis in acute coronary syndromes: relationship to increased heart rate and reduced heart-rate variability

BACKGROUND

Acute coronary syndromes (ACS) are characterized by abnormal heart-rate variability (HRV) and biomarkers of endothelial damage and thrombosis.

HYPOTHESIS

We hypothesized an association between these factors in patients with ACS.

METHODS

We studied 99 patients with ACS measuring HRV and plasma markers of endothelial damage/dysfunction (von Willebrand factor, vWF) and thrombosis/hemostasis (soluble P-selectin (s-Psel); CD(40)-ligand (CD(40)-L); D-dimer). HRV and plasma indices were compared to age- and gender-matched controls. Measures were repeated at 4 months in a subset. vWF, s-Psel and D-Dimer levels were raised compared to control.

RESULTS

HRV indices were reduced (mean RR, SDNN, SDNNi, RMSSD, Triangular index, LF and HF). There were weak correlations between mean RR and s-Psel (R = - 0.234, p = 0.023) and D-dimer (R = - 0.219, p = 0.041). At 4-month follow-up, significant correlations were between mean RR and CD(40)L (R = - 0.414, p = 0.008) and D-dimer (R = - 0.363, p = 0.012). On multivariate logistic regression analysis statin use (p = 0.046) was the only independent predictor of acute s-Psel levels. Age (p = 0.004) and mean RR interval (p = 0.01) were independent predictors of D-dimer levels at follow-up.

CONCLUSIONS

Abnormal HRV is associated with markers of hemostasis and thrombosis in ACS, and present both in the acute and rehabilitation phases.

Systemic blood coagulation activation in acute coronary syndromes

We evaluated systemic alterations to the blood coagulation system that occur during a coronary thrombotic event. Peripheral blood coagulation in patients with acute coronary thrombosis was compared with that in people with stable coronary artery disease (CAD). Blood coagulation and platelet activation at the microvascular injury site were assessed using immunochemistry in 28 non-anticoagulated patients with acute myocardial infarction (AMI) versus 28 stable CAD patients matched for age, sex, risk factors, and medications. AMI was associated with increased maximum rates of thrombin-antithrombin complex generation (by 93.8%; P< .001), thrombin B-chain formation (by 57.1%; P< .001), prothrombin consumption (by 27.9%; P= .012), fibrinogen consumption (by 27.0%; P= .02), factor (f) Va light chain generation (by 44.2%; P= .003), and accelerated fVa inactivation (by 76.1%; P< .001), and with enhanced release of platelet-derived soluble CD40 ligand (by 44.4%; P< .001). FVa heavy chain availability was similar in both groups because of enhanced formation and activated protein C (APC)-mediated destruction. The velocity of coagulant reactions in AMI patients showed positive correlations with interleukin-6. Heparin treatment led to dampening of coagulant reactions with profiles similar to those for stable CAD. AMI-induced systemic activation of blood coagulation markedly modifies the pattern of coagulant reactions at the site of injury in peripheral vessels compared with that in stable CAD patients.

Relationship between plasma cholesterol, von Willebrand factor concentrations, extent of atherosclerosis and antibody titres to heat shock proteins-60, -65 and -70 in cholesterol-fed rabbits

Epidemiological studies have shown an association between atherosclerosis, Heat shock protein (Hsp) expression, and Hsp antibody titres. We aimed to investigate the time course of appearance of Hsp-60, -65 and -70 antibodies in the cholesterol-fed rabbit and to relate antibody titres to serum concentrations of von Willebrand factor (vWF), a marker of endothelial injury. Rabbits were fed with 0.25-1.0% cholesterol diet for 13 weeks. Plasma levels of anti Hsp-60, -65 and -70 IgG titres, were measured using in-house enzyme-linked immunosorbent assays (ELISAs) together with plasma vWF concentrations. Plasma titres of anti-Hsp-60, -65 and -70 antibodies were all significantly increased by weeks 5, 7 and 9 following commencement of the experimental diet compared with baseline (P < 0.05 for all). In non-cholesterol-fed rabbits, plasma levels of anti-Hsp titres were unchanged over this period. Increased plasma vWF concentrations were also found in the cholesterol-fed rabbits, reaching a maximum at approximately week 8, and falling thereafter. Furthermore, plasma vWF concentrations at 13 weeks correlated strongly with antibody titres to all three Hsps (r = 0.90, P = 0.002; r = 0.80, P = 0.017; r = 0.86, P = 0.006 for Hsp 60, -65 and -70 respectively) and titres were also strongly correlated with final plasma cholesterol concentrations in cholesterol-fed animals (r = 0.95, P = 0.002; r = 0.8, P = 0.001; r = 0.84, P = 0.01 respectively). In cholesterol-fed rabbits, antibody titres to Hsp-60, -65 and -70 appear to rise in association with a marker of endothelial injury, peaking at approximately the same time (8 weeks) after starting a high cholesterol diet.

Procoagulant factors and the risk of myocardial infarction in young women

OBJECTIVES

We investigated whether elevated levels of factor VIII, IX and XI is associated with myocardial infarction (MI) in young women. In addition, we studied ABO blood group, von Willebrand factor (VWF) and C-reactive protein (CRP).

METHODS AND RESULTS

We compared 200 women with MI before age 49 years with 626 controls from a population-based case-control study. Mean levels of factor VIII activity (VIII), von Willebrand factor antigen (VWF), factor IX activity (IX) were higher in patients (133, 134 and 132 IU/dL) than in controls (111, 107 and 120 IU/dL, respectively). Mean levels of factor XI (XI) were equal in patients (114 IU/dL) and controls (113 IU/dL). The odds ratio (OR) for MI for blood group non-O vs. O was 1.6 [95% confidence interval (CI) 1.1-2.3]. The OR adjusted for age, index year and area of residence for the highest quartile >150 IU/dL of factor VIII was 2.7 (95% CI 1.6-4.6), of VWF 4.7 (95% CI 2.3-9.7), of factor IX 2.6 (95% CI 1.3-5.4) and of factor XI 0.9 (95% CI 0.5-1.4), all compared with the lowest quartile <100 IU/dL.

CONCLUSIONS

Non-O blood group, high VWF, factor VIII and factor IX levels are associated with an increased risk of MI in young women, while high factor XI levels are not.

Expression of the endothelial markers PECAM-1, vWf, and CD34 in vivo and in vitro

EC culture models are essential to study pathological alterations of endothelial cells (ECs) in pulmonary vascular diseases under standardized conditions. Nevertheless, little is known about the spectrum of alterations of vessel-specific endothelial phenotypes in monolayer cultures. For the comparative study of endothelial markers in vivo and in vitro we investigated immunohistochemically the expression of PECAM-1, vWf, and CD34 by pulmonary ECs in vivo and in stimulated/unstimulated human umbilical vein endothelial cells (HU-VEC) and human pulmonary microvascular endothelial cells (HPMEC). In vivo, vessel type-specific expression patterns were found for vWf and CD34, while PECAM-1 was homogeneously and strongly expressed. While all HUVEC showed a marked vWf staining, about two-thirds of HPMEC exhibited a strong and the rest a moderate vWf staining. In both in vitro models all ECs were clearly PECAM-1-positive. However, only about 20% of the HUVEC and HPMEC were CD34-positive. Our results demonstrate the reduced expression of vessel type-specific endothelial phenotypes by endothelial monolayer cultures, stressing the need to improve culture conditions as well as develop cocultures and three-dimensional culture models. Moreover, the need for endothelial markers specific for single microvascular type ECs becomes obvious in order to establish cultures consisting of only one microvascular ECs subpopulation.

Plasma levels of von Willebrand factor antigen in acute bronchitis and in a normal population

von Willebrand factor (vWF) is a large glycoprotein secreted predominantly by endothelial cells in both the systemic and pulmonary circulations and has a central role in the formation of the platelet plug. It has been put forward as a possible marker of endothelial cell injury, but is not ideal in that it is not specific for either the pulmonary or systemic circulation and may be released as part of the acute phase response from otherwise healthy endothelial cells. We undertook two studies (i) to assess within-subject to assess within-subject variation in plasma von Willebrand factor antigen (vWF:Ag) levels over time and to assess between-subject variation in a healthy patient population, and (ii) as part of a descriptive study of acute bronchitis, to assess whether plasma vWF:Ag levels altered in such a common and minor insult. A random sample of patients aged 45-74 years were taken from a local general practice. vWF:Ag levels were measured on three occasions, and spirometry was performed. The descriptive study was undertaken on patients in the general practice diagnosed with acute bronchitis without pre-existing pulmonary disease. Plasma vWF:Ag was measured on presentation and 14 and 42 days later. In 219 randomly selected patients the mean plasma vWF:Ag was similar at all three visits, the within-subject standard deviation being 0.09 U ml(-1) and 1.12 U ml(-1) respectively). There was no correlation between plasma vWF:Ag and C-reactive protein on presentation. We conclude that there is relatively little variation in an individual's plasma vWF:Ag level but that levels increase significantly with age. The observed elevation occurring with acute bronchitis is a true phenomenon; the absence of an associated acute phase response suggests that endothelial cell injury is the mechanism for the rise. These observations are important in the context of vWF as a marker of endothelial cell damage, as a common and supposedly minor insult such as acute bronchitis may markedly raise plasma levels.

Role of clotting factor VIII in effect of von Willebrand factor on occurrence of deep-vein thrombosis

To elucidate the roles of the ABO blood group, von Willebrand factor (vWF), and clotting factor VIII in the process of deep-vein thrombosis we undertook a population-based patient-control study in which 301 consecutive patients younger than 70 with a first, objectively diagnosed episode of venous thrombosis and without an underlying malignant disorder were compared with 301 healthy controls matched for age and sex. In univariate analysis, blood group, vWF concentration, and factor VIII concentrations were all related to deep-vein thrombosis. The risk of thrombosis increased with increasing vWF or factor VIII concentration and was higher in subjects of non-O blood groups than in those of group O. In multivariate analysis only factor VIII remained as a risk factor, and the dose-response relation between factor VIII concentration and risk of thrombosis persisted (subjects with factor VIII concentrations above 1500 IU/L had an adjusted odds ratio of 4.8 [95% Cl 2.3-10.0]). By contrast, the adjusted odds ratio for each vWF stratum did not differ from 1, and that for blood group was 1.5 (1.0-2.2). Our findings point to an effect on thrombosis risk of vWF and blood group, the former fully and the latter at least partly mediated through factor VIII. The 25% prevalence of factor VIII concentrations above 1500 IU/L among unselected consecutive thrombosis patients and the high adjusted relative risk for thrombosis lead to the conclusion that high factor VIII concentrations are common and represent a clear increase in risk of thrombosis, similar to the risks conferred by deficiencies of the coagulation-inhibiting proteins and activated protein C resistance.

Addition of serum from patients with collagen diseases increases to cultured human endothelial cells production and release of von Willebrand factor

The addition of sera from patients with collagen diseases, particularly those with vascular complications, to the supernatant of cultured vascular endothelial cells (EC) in vitro significantly increased the surface and intracellular amounts of von Willebrand factor antigen (vWF:Ag) compared with results obtained with sera from normal healthy subjects. Peak levels of vWF:Ag occurred after 24 h of in vitro culture. Moreover, the amounts of vWF:Ag secreted into the EC supernatant with patient serum added were significantly higher than the amounts secreted into EC supernatant with control serum added, even after 48 h of in vitro culture. Levels of large and intermediate multimers (LIM) of von Willebrand factor (vWF) increased in EC supernatant exposed to serum from patients with collagen diseases as compared with levels in supernatant exposed to serum from normal controls, whereas no significant differences were detected overall between adding the plasma of patients and of normal subjects. In addition, C-reactive protein (CRP) induced a time- and dose-related release of vWF:Ag from EC, while glucocorticoid did not effect the release of vWF:Ag from EC. These results suggest that the sera of patients with collagen diseases, particularly those with vascular complications, stimulate the production and release of LIM of vWF from EC.

Factor VIII and coronary heart disease

In plasma, Factor VIII is bound to its carrier protein, von Willebrand Factor (vWF). Therefore, the levels of these two factors vary together. From studies in the general population, in patients with coronary heart disease and in hemophilia patients, an association between Factor VIII levels and coronary heart disease clearly emerges.

Studies on the pathogenesis of coagulopathy in patients with arterial thromboembolism and malignancy

Plasma levels of thrombin-antithrombin III complex (TAT), plasmin-alpha 2-plasmin inhibitor complex (PAP), von Willebrand factor antigen (vWF:Ag) plasminogen activator antigen (PA) and plasminogen activator inhibitor-1 antigen (PAI-1), were determined in 110 patients with arterial thromboembolic diseases within 4 weeks after attack (Th; 41 cases with myocardial infarction and 69 with cerebral infarction), 67 patients with various types of carcinoma (Ca; 31 cases without metastasis and 36 with metastasis) and 50 age-matched healthy individuals (Co). The following results were obtained: 1) Mean plasma levels of TAT, PAP, vWF:Ag, PA and PAI-1 were significantly higher in Th than Co. 2) Mean plasma levels of TAT, PA and PAI-1 were significantly higher in Ca than Co regardless of metastasis but those of PAP and vWF:Ag were significantly higher only in Ca with metastasis than Co. 3) Significant relationship was observed between plasma levels of TAT and PAP both in Th and Ca. 4) Significant relationship was also observed between plasma levels of TAT and vWF:Ag, PA or PAI-1 in Th, but not in Ca. It is suggested from these results that the coagulopathies observed in these patients result from the activation of intravascular blood coagulation and fibrinolysis, and that vascular endothelial cell damage may play an important role in the activation in Th.

Interleukin 1 or endotoxin increases the release of von Willebrand factor from human endothelial cells

von Willebrand factor (vWF), a large adhesive glycoprotein, is synthesized by vascular endothelial cells (EC). Plasma levels of vWF manifest a broad normal range, and are elevated during sepsis and in inflammatory states. Since the inflammatory mediator, interleukin 1 (IL1) and bacterial endotoxin (LPS) both initiate procoagulant changes in vascular endothelium, we investigated the effect of these substances on endothelial cell release and residual endothelial cell content of vWF-antigen (vWFAg). Cultured human EC exposed to either IL1 or LPS released greater amounts of vWFAg compared to control EC. The augmented release could be detected within 1-2 h after exposure to IL1 or LPS and was not inhibited by cycloheximide, suggesting that de novo protein synthesis was not required for release to occur. Residual cellular vWFAg was reciprocally lower in IL1- or LPS-treated EC at 24 and 48 h, indicating that compensatory increase in synthesis of vWFAg did not occur during this time interval. Released vWF contained the higher molecular weight multimers observed in normal endothelial cells, and it possessed ristocetin cofactor activity. We propose that release of functional vWF from EC exposed to inflammatory mediators may be at a mechanism for localization of platelets and enhanced thrombogenicity at inflammatory foci.

Interleukin 1 or endotoxin increases the release of von Willebrand factor from human endothelial cells

von Willebrand factor (vWF), a large adhesive glycoprotein, is synthesized by vascular endothelial cells (EC). Plasma levels of vWF manifest a broad normal range, and are elevated during sepsis and in inflammatory states. Since the inflammatory mediator, interleukin 1 (IL1) and bacterial endotoxin (LPS) both initiate procoagulant changes in vascular endothelium, we investigated the effect of these substances on endothelial cell release and residual endothelial cell content of vWF-antigen (vWFAg). Cultured human EC exposed to either IL1 or LPS released greater amounts of vWFAg compared to control EC. The augmented release could be detected within 1-2 h after exposure to IL1 or LPS and was not inhibited by cycloheximide, suggesting that de novo protein synthesis was not required for release to occur. Residual cellular vWFAg was reciprocally lower in IL1- or LPS-treated EC at 24 and 48 h, indicating that compensatory increase in synthesis of vWFAg did not occur during this time interval. Released vWF contained the higher molecular weight multimers observed in normal endothelial cells, and it possessed ristocetin cofactor activity. We propose that release of functional vWF from EC exposed to inflammatory mediators may be at a mechanism for localization of platelets and enhanced thrombogenicity at inflammatory foci.