Enhanced expression of monocyte tissue factor in patients with liver cirrhosis

Background—Previous studies have shown that cirrhotic patients produce increased amounts of thrombin but the underlying mechanism is still unknown.
Aims—To analyse the relation between the rate of thrombin generation and monocyte expression of tissue factor (TF) in cirrhosis.
Patients—Thirty three cirrhotic patients classified as having low (n=7), moderate (n=17), or severe (n=9) liver failure according to Child-Pugh criteria.
Methods—Prothrombin fragment F1+2, monocyte TF activity and antigen, and endotoxaemia were measured in all patients. Polymerase chain reaction (PCR) analysis of TF mRNA was performed in monocytes of five cirrhotic patients.
Results—Prothrombin fragment F1+2 was higher in cirrhotic patients than in controls (p<0.0001). Monocytes from cirrhotic patients had higher TF activity and antigen than those from controls (p<0.001) with a progressive increase from low to severe liver failure. Monocyte expression of TF was significantly correlated with plasma levels of F1+2 (TF activity: r=0.98, p<0.0001; TF antigen: r=0.95, p<0.0001) and with endotoxaemia (TF activity: r=0.94, p<0.0001; TF antigen: r=0.91, p<0.0001). PCR analysis of TF mRNA showed TF expression only in three patients with endotoxaemia (more than 15 pg/ml).
Conclusions—Cirrhotic patients have enhanced expression of TF which could be responsible for clotting activation, suggesting that endotoxaemia might play a pivotal role.

     

Increased monocyte tissue factor expression in coronary disease.

OBJECTIVE--To investigate whether monocyte expression of tissue factor is increased in patients with acute coronary syndromes and chronic stable angina. DESIGN--Cross sectional study of monocyte tissue factor expression in patients with ischaemic heart disease and control subjects. BACKGROUND--Unstable angina and myocardial infarction are associated with enhanced mononuclear cell procoagulant activity. Procoagulant activity of blood monocytes is principally mediated by tissue factor expression. Tissue factor initiates the coagulation cascade and monocyte tissue factor expression may therefore be increased in these syndromes. METHODS--Monocyte tissue factor expression was measured cytometrically in whole blood flow using a polyclonal rabbit antihuman tissue factor antibody. PATIENTS--30 patients with acute myocardial infarction, 17 with unstable angina, 13 with chronic stable angina, and 11 normal control subjects. RESULTS--Increased proportions of monocytes expressing tissue factor (> 2.5%) were found in none of 11 (0%) normal subjects, five 13 (38%) patients with stable angina, 11 of 17 (64%) patients with unstable angina, and 16 of 30 (53%) patients with myocardial infarction (2P = 0.006). Blood from all subjects showed similar monocyte tissue factor expression similar monocyte tissue factor expression (46.1 (15.1)%) after lipopolysaccharide stimulation. CONCLUSION--Hypercoagulability associated with acute myocardial infarction, unstable angina, and chronic stable angina may be induced by tissue factor expressed on circulating monocytes.     

Vitamin E reduces monocyte tissue factor expression in cirrhotic patients

Clotting activation may occur in liver cirrhosis, but the pathophysiological mechanism has not been fully elucidated. Because a previous study demonstrated that lipid peroxidation is increased in cirrhosis, we analyzed whether there is a relationship between lipid peroxidation and clotting activation. Thirty cirrhotic patients (19 men and 11 women; age, 34 to 79 years) and 30 controls matched for sex and age were investigated. In all subjects, monocyte expression of tissue factor (TF) antigen and activity; plasma levels of prothrombin fragment 1+2 (F1+2), a marker of thrombin generation; and urinary excretion of Isoprostane-F2alpha-III, a marker of lipid peroxidation, were measured. Furthermore, the above-reported variables were re-evaluated after 30 days of treatment with standard therapy (n = 5) or standard therapy plus 300 mg vitamin E twice daily (n = 9). In addition, we analyzed in vitro if vitamin E (50 micromol/L) influenced monocyte TF expression and F1+2 generation. Cirrhotic patients had higher values of Isoprostane-F2alpha-III (P <. 0001), F1+2 (P <.0001), and monocyte TF antigen (P <.0001) and activity (P <.03) than controls. Isoprostane-F2alpha-III was significantly correlated with F1+2 (Rho = 0.85; P <.0001) and TF antigen (Rho = 0.95; P <.0001) and activity (Rho = 0.94; P <.0001). After vitamin E treatment, Isoprostane-F2alpha-III (P =.008), F1+2 (P <.008), and monocyte TF antigen (P =.012) and activity (P =.008) significantly decreased; no changes of these variables were detected in patients not receiving vitamin E. In vitro, vitamin E significantly reduced the expression of monocyte TF antigen (-52%; P =.001) and activity (-55%; P =.003), as well as F1+2 generation (-51%; P =.025). This study shows that vitamin E reduces both lipid peroxidation and clotting activation and suggests that lipid peroxidation may be an important mediator of clotting activation in liver cirrhosis.     

The pathogenesis of accelerated fibrinolysis in hepatosplenic schistosomiasis.

Seventy patients with different stages of hepatosplenic schistosomiasis and 18 non-bilharzial normal controls were studied. Plasminogen, plasminogen activators (PA), tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), alpha 2-antiplasmin (alpha 2-AP), plasminogen activator inhibitor (PAI), fibrinogen/fibrin degradation products (FDP) and D-dimer were determined to elucidate the role of plasminogen activators and inhibitors in the pathogenesis of accelerated fibrinolysis in schistosomiasis. There was a progressive increase in the levels of PA, t-PA, u-PA, FDP and D-dimer indicating enhanced fibrinolytic activity with advancing disease. In addition, there was progressive decrease of plasminogen, alpha 2-AP and PAI levels which might be due to decreased hepatic synthesis and/or increased peripheral consumption. These findings suggest that the pathogenesis of accelerated fibrinolysis in schistosomiasis is multifactorial, but may be due to the progressive increase in the levels of plasminogen activators. In addition, the increase of FDP and D-dimer levels are evidence of secondary fibrinolysis following thrombin generation.     

Induction of tissue factor expression in human monocyte/endothelium cocultures

Summary. Induction of tissue factor (TF) expression on monocyctes and endothelial cells is central to the development of septic coagulopathy. Serum concentrations of endotoxin in septic patients who develop disseminated intravascular coagulation (DIC) do not, however, reach the levels that would directly stimulate TF expression on either monocytes or endothelium. We show, using an in vitro coculture system, that the interaction of monocytes with endothelium induces the expression of significant levels of TF. Unstimulated cocultures of monocytes (2 × 10⁴/well) and endothelial cells (2 × 10⁴/well) produced 35.3± 8.5 mU of PCA/well, representing a 5-fold increase over the combined PCA of each cell type cultured alone (7.1 ± 1.5 mU, n = 6, P < 0.001). Significant enhancement was also found in the presence of low concentrations of LPS. Induction of TF protein was confirmed by Western blotting. Fixation of monocytes with paraformaldehyde completely abolished TF induction in cocultures, whereas fixation of endothelium had no effect, suggesting that TF induction occurred in monocytes rather than endothelial cells. Induction of TF in cocultures could be further augmented by preincubating the endothelial cells with IFN-γ. When endothelium was prestimulated with 500U/ml IFN-γ there was 142 ±11% increase over unstimulated cocultures (n = 5, P< 0.01). TF induction was inhibited by 32 ± 6% in the presence of anti-ICAM-1 mAb (n = 5, P < 001). Our results suggest that monocyte interactions with vascular endothelium, regulated by inflammatory cytokines, and mediated by adhesive ligand binding, leads to the induction of functional monocyte TF protein, which may be responsible for the initiation of DIC in sepsis.     

Thrombosis in primary antiphospholipid syndrome. A pivotal role for monocyte tissue factor expression

Objective. The antiphospholipid syndrome (APS) is a disorder of recurrent thrombosis, pregnancy loss, and thrombocytopenia associated with the production of anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC). The mechanisms of thrombus formation remain unknown. Tissue factor (TF), an inducible cell glycoprotein, is a major initiator of coagulation in vivo. The present study was therefore undertaken to investigate TF expression and procoagulant activity on monocytes from patients with primary APS and its correlation with thrombotic events. Methods. Three groups of patients were studied: group 1 comprised 23 primary APS patients with thrombosis, group 2 consisted of 10 primary APS patients without thrombosis, and group 3 contained 20 patients with thrombosis but without antiphospholipid antibodies. Twenty age- and sex-matched healthy blood donors were used as controls (group 4). Anticardiolipin antibodies were measured by enzyme-linked immunosorbent assay (ELISA) and LAC by standard methodology. Cell surface expression of TF on monocytes was assessed by flow cytometry. The amount of TF in cell lysates (TF_Ag) and soluble TF_Ag plasma levels were analyzed by ELISA, and the TF-related procoagulant activity (PCA-TF) on intact cells and cell lysates by a chromogenic assay. Levels of the cytokines that influence TF production, i.e., tumor necrosis factor α (TNFα) and interleukin-1β (IL-1β), were determined by ELISA. Results. Cell surface expression of TF was increased in group 1 (mean ± SEM 50.2 ± 4% positive cells) compared with group 2 (14.6 ± 1.6%), group 3 (16.8 ± 3.7%), and group 4 (14.1 ± 1.6%). TF_Ag levels were also elevated in group 1 (215.8 ± 11.2 pg/10⁶) compared with group 2 (150.8 ± 15.2), group 3 (101.4 ± 14.8), and group 4 (80.32 ± 5.5). PCA-TF on intact cells and cell lysates was significantly increased in group 1 (148.8 ± 16.3 units/10⁵ lysate cells, compared with 54.5 ± 11.5, 38.6 ± 9.7, and 22.5 ± 3.1 in groups 2, 3, and 4, respectively). Among group 1 patients, there was a significant increase in the degree of TF expression in those positive for IgG aCL, but not in those positive for IgM aCL or LAC. TNFα and IL-1β plasma levels did not differ significantly between any of the groups. Conclusion. These results suggest that monocyte TF expression is directly involved in the pathogenesis of thrombotic complications in patients with the primary APS.     

Interferon-gamma-induced expression of tissue factor activity during human monocyte to macrophage maturation.

The expression of tissue factor (TF) during differentiation of human monocytes (MO) to macrophages (MAC) in vitro is investigated in this study. In MO, TF activity can be induced by the addition of lipopolysaccharides (LPS) as detected by Northern blot analysis and measured functionally as procoagulant activity (PCA), while IFN gamma alone has only marginal stimulatory activity. During in vitro differentiation of MO into MAC, however, there is a steady increase in IFN gamma-induced PCA with a maximum on day 7. While MO during the first 2 days in culture are more responsive to LPS, IFN gamma becomes the prominent stimulus for mature MAC. The response to IFN gamma is rapid with a peak within 6-8 h and a subsequent downregulation to baseline activity within 24 h. Our results demonstrate that IFN gamma can effectively induce TF in human MAC and that its expression is developmentally regulated during MO to MAC maturation in vitro.     

Lymphoma in patients harboring hepatosplenic mansonic schistosomiasis

BACKGROUND: Correlation between infectious agents and linfoproliferative diseases are more stablished, over all virus and bacteria, through the activation of linfocytes. AIM: To describe six new cases, of a series of 254 patients (2,36%) with mansonic schistosomiasis, in the hepatosplenic form. METHODS: Six patients will be described, amongst the 254 carriers of mansonic schistosomiasis, in the hepatosplenic form, followed in the last 13 years. RESULTS: All the six cases had occurred in women. The histopathologic examinations had evidenced two cases of marginal splenic zone lymphomas, one of great cells with immunoblasts lymphomas, one diffuse lymphomas, a great cells malignant lymphomas, a great not clivads cells, and another case of Hodgkin. Half of the six evolved for the death 4-15 months after the diagnosis. The others three persist in accompaniment in the Oncology Division of the Clinics Hospital. CONCLUSION: The incidence of lymphomas in the 254 mansonic schistosomiasis patients followed in our clinic was of 2,36%. At last, this article intends to call the attention, for the occurrence of lymphomas, in the spleen of patients with mansonic schistosomiasis, in the hepatosplenic form.     

Enhanced neutrophil apoptosis in neutropenic patients with hepatosplenic schistosomiasis: evidence of serum Fas ligand

Enhanced neutrophil apoptosis has been reported in neutropenic hepatosplenic schistosomiasis. The shortening of neutrophil survival via apoptosis may explain the neutropenia that occur in these patients. However, the regulation of neutrophil apoptosis in hepatosplenic schistosomiasis has not been clearly defined. Neutrophils harvested from neutropenic patients with hepatosplenic (HS) schistosomiasis, (n=25), non-neutropenic patients with hepatointestinal (HI) schistosomiasis (n=10), and age-/gender-matched healthy control subjects (n=10) were incubated with autologous serum. Neutrophils apoptosis was quantified by flow cytometry through determination of propidium iodide nuclear staining and confirmed by DNA gel electrophoresis at 0 (i.e. fresh neutrophils), 4 and 24 h culture. Neutrophils from healthy subjects were also incubated with either 10% heterologous normal or neutropenic serum, with and without anti-Fas ligand antibody. Fas expression was assessed in fresh neutrophils using flow cytometry. Compared with normal healthy neutrophils, and HI neutrophils, neutropenic neutrophils demonstrated greater apoptosis in the presence of autologous serum (P<0.01, 0.05, respectively). Furthermore, compared with normal neutrophils exposed to heterologous normal serum, those exposed to heterologous neutropenic serum exhibited higher apoptosis rates ( P<0.01). Moreover, anti-Fas L antibody attenuated the neutropenic serum-induced neutrophil apoptosis in normal neutrophils. Fas expression was significantly higher in the neutropenic group when compared to both HI and normal healthy controls (P<0.05). In addition, Fas expression by neutrophils was paralleled by high neutrophil apoptosis. On the other hand, neutrophil apoptosis was not correlated to the size of spleen in neutropenic group. In conclusion, the rate of neutrophil apoptosis is accelerated in patients with neutropenic hepatosplenic schistosomiasisis. These findings suggest that the enhanced neutrophil apoptosis that occurs in neutropenic HS patients is triggered by a serum factor, which is mostly a Fas ligand.     

IL-10 inhibits LPS-induced human monocyte tissue factor expression in whole blood

Interleukin 4 (IL-4), IL-10 and IL-13 are all known to modulate several proinflammatory functions in human monocytes. They have also previously been shown to down-regulate lipopolysaccharide (LPS)-induced tissue factor (TF) expression in isolated cultured monocytes. In this study we investigated the effect of these three cytokines on the induction of monocytic TF in a whole blood environment at three levels: mRNA quantitation, surface antigen expression and procoagulant activity. We showed that IL-10 attenuated LPS-induced monocyte TF expression and activity in whole blood in a concentration-dependent manner, both when added to the blood prior to LPS and, although to a lesser extent, when added up to 1 h subsequent to LPS challenge. Maximum inhibition occurred at 5 ng/ml of IL-10 when the cytokine was added before LPS. IL-4 and IL-13, however, did not exhibit any inhibitory effect in the whole blood environment, contrary to the reported findings in cell culture experiments. Our results confirm the potential of IL-10 as an anti-inflammatory, TF-preventing drug, whereas the effects of IL-4 and IL-13 on monocytes in whole blood seem more complex, and require further investigation.     

The relationship between gender and age with monocyte tissue factor expression

Background In normal healthy individuals, the level of tissue factor (TF) expression on monocytes is low. However, studies have shown that patients with cardiovascular disease (CVD) have elevated levels of TF. As the risk of CVD increases with age and is more prominent in the male population, it is postulated that TF expression may be positively correlated with these factors. However, very few studies have examined the relationship between age and gender on TF expression. Methods This study evaluated the influence of age and gender on TF expression using data obtained from female (n = 44) and male (n = 27) subjects. We also examined the influence of BMI and total fat intake on TF expression in the same subjects. Results The results of our study found no significant difference in TF expression between the male and female subgroups. No correlation was found between TF and age, BMI or total fat intake in the male or female groupings. Conclusion It may be postulated that the risk of CVD development in such populations may not be due to increases in TF expression with increasing age or gender differences.     

Study of factor VII, tissue factor pathway inhibitor and monocyte tissue factor in noninsulin-dependent diabetes mellitus.

Changes in plasma tissue factor (TF)-activated factor VII (FVIIa) and plasma tissue factor pathway inhibitor (TFPI) in type II diabetes mellitus are assessed, vascular complicated and noncomplicated patients compared, and whether these novel hemostatic activity markers predict vascular complications in diabetic patients, improving risk assessment, is determined. Fifty type II diabetic patients and 20 healthy controls (age, sex and body mass matched) underwent medical history and examination, fasting plasma glucose level, glycosylated hemoglobin (HbA1c), lipid profile, hemostatic parameters, plasma TF activity, and TFPI and TF expression on blood monocytes. Mean TF, TF activity, TFPI, and FVIIa significantly increased among hyperlipidemic compared with normolipidemic diabetic patients, and normolipidemic diabetic patients compared with controls. Mean percentage TF-positive monocytes with and without lipopolysaccharide, plasma TF activity, TFPI and FVIIa were significantly higher among complicated than noncomplicated diabetic patients. Mean percentage TF-positive monocytes without and with lipopolysaccharide, plasma TF activity, plasma TFPI and FVIIa were higher among diabetic patients with macrovascular compared with microvascular complications. High significant correlation occurred between HbA1c, triglycerides and percentage TF-positive monocytes with and without lipopolysaccharide stimulation, plasma TF activity and both FVIIa and TFPI. High activity levels of plasma TF and FVIIa with increased circulating TF-positive monocytes occurred in type II diabetic patients, especially with vascular complications. Results reflect high procoagulant activity possibly involved in diabetic vascular complications. Elevated TFPI levels were observed, but were not sufficient to balance high procoagulant activity. Correlation of procoagulant activity markers with HbA1c reinforces the importance of optimal glycemic control in type II diabetes.