Increased plasma levels of tissue factor pathway inhibitor-activated factor X complex in patients with disseminated intravascular coagulation

Effects of Lipid Abnormalities on Arteriosclerosis and Hemostatic Markers in Patients under Hemodialysis

Vascular events caused by arteriosclerosis are the major cause of death in patients under hemodialysis (HD). Arteriosclerosis is associated with lipoprotein abnormalities such as increased serum levels of low-density lipoprotein (LDL), especially of modified LDL (M-LDL) and oxidized LDL (Ox-LDL). We examined the relationship between markers of arteriosclerosis, hemostasis, and lipid metabolism in patients with chronic renal failure, hyperlipidemia, and healthy volunteers. In patients under HD, the serum levels of total cholesterol, LDL, and triglyceride (TG) were decreased, but the serum levels of M-LDL were increased compared to HL and healthy volunteers. In patients with CRF, the serum levels of OxLDL in patients under HD were lower than in those under continuous ambulatory peritoneal dialysis or conservative therapy. The plasma levels of antithrombin and protein C were significantly lower and the plasma levels of thrombomodulin were significantly higher in patients under HD compared to those under conservative therapy. These data show that patients under HD were more in hypercoagulable state than those under conservative therapy. Among patients under HD, only the plasma levels of von Willebrand factor were significantly increased in patients with more than 30 U/L of Ox-LDL compared to those with less than 30 U/L of Ox-LDL. There was no significant difference in the tests of arteriosclerosis among M-LDL values and OxLDL values. These findings suggest that abnormalities of lipid are not the main risk factor for arteriosclerosis disease in patients under HD.

Disseminated intravascular coagulation

The diagnosis of disseminated intravascular coagulation (DIC) was initially based on the detection of microthrombi. Current diagnosis involves laboratory assessment of hemostatic abnormalities although additional studies may often be necessary. DIC is characterized by hypercoagulability and hyperfibrinolysis and is caused by high offense factors or low defense factors. DIC is divided two stages: overt-DIC and non-overt-DIC. The diagnosis of overt-DIC state is based on the criteria developed by the International Society of Thrombosis Haemostasis in conjunction with the Japanese Ministry Health and Welfare. However, no criteria are currently available for the diagnosis of non-overt DIC. Although scientifically supported modalities for treatment of DIC are few, the use of activated protein C (APC) and low-molecular-weight heparin appear to hold promise.

Atherosclerotic and hemostatic abnormalities in patients undergoing hemodialysis

Vascular events caused by atherosclerosis are the major cause of death in patients undergoing hemodialysis (HD). The relationship between the tests of atherosclerosis and hemostasis in 84 patients with HD was examined. Abnormal test results indicting the occurrence of atherosclerosis were found in 66% by the Fontaine score, in 33% by ankle blood pressures, and in 79% by aortic calcification index (ACI). When HD was prolonged, the mean Fontaine score and ACI were further increased. Particularly, the ACI tended to correlate with HD duration. The ankle-brachial index (ABI) was decreased in patients with HD duration of more than 10 years. Before HD, the plasma levels of fibrinogen, plasmin-plasmin inhibitor complex (PIC), thrombomodulin (TM), and D-dimer were increased, while the plasma levels of protein C (PC), antithrombin (AT), thrombin-antithrombin complex (TAT), and tissue plasminogen activator (tPA)-plasminogen activator inhibitor-I (PAI-I) complex (tPA-PAI-1 complex) were decreased. With prolonged HD, the plasma levels of AT and PC were decreased, while those of D-dimer were increased. The plasma levels of TAT and TPA-PAI-1 complex were significantly increased and those of PIC, soluble fibrin (SF) and D-dimer tended to be high in patients with less than 0.7 of ABI. The plasma levels of D-dimer, TPA-PAI-1 complex, TAT, PIC, and SF tended to be high in patients with more than 0.5 in ABI. These findings suggest that patients undergoing HD have progressive atherosclerosis and that this is associated with some hemostatic abnormalities.

Hemostatic markers with bolus versus prolonged heparin after carotid artery stenting

BACKGROUND

The evolving technique of carotid stenting (CS) requires optimal antithrombotic strategies to reduce periinterventional thromboembolic risk. In animal models of balloon injury, tissue factor (TF) was shown to be the major procoagulant of the atherosclerotic plaque mediating prolonged procoagulant activity.

METHODS

We analyzed TF and TF-dependent hemostatic markers before and 2, 6 and 24 h after CS with two antithrombotic drug regimens. Group A (n=20) received prolonged unfractionated heparin (UFH) for 18-20 h starting at intervention next to aspirin and thienopyridine. In group B (n=16), single bolus UFH was administered next to combined antiplatelet therapy. Natural anticoagulants were determined at baseline.

RESULTS

Patients with symptomatic and asymptomatic cerebrovascular disease did not differ in plasma TF levels. Furthermore, no statistically significant difference for TF, TFPI/Xa-complex and prothrombin fragment F1.2 was observed between bolus and prolonged heparin treatment. No significant change was found in time course for these parameters. Two patients (5.5%; one in each treatment group) suffered periinterventional minor stroke associated with increased levels of F1.2 and TFPI/Xa-complex. Both were resistant to activated protein C (APC ratio<1.9) due to heterozygous factor V Leiden mutation.

CONCLUSIONS

No significant activation of the TF pathway was seen with both antithrombotic regimens suggesting that single bolus UFH combined with antiplatelet therapy is generally sufficient to control TF-dependent procoagulant activity after CS. However, patients with resistance to activated protein C may be at increased periinterventional stroke risk.

Plasma levels of heparin cofactor II (HCII) and thrombin-HCII complex in patients with disseminated intravascular coagulation

Plasma levels of heparin cofactor II (HCII), thrombin-HCII complex (THC), antithrombin (AT), and thrombin-AT complex (TAT) were evaluated in patients with disseminated intravascular coagulation (DIC) associated with several underlying diseases. Plasma levels of AT were significantly reduced in almost all underlying diseases associated with DIC, but the plasma levels of HCII and HCII/AT ratio were significantly reduced only in patients with infections. While the plasma level of TAT was significantly increased in patients with all underlying diseases associated with DIC, the increase of THC was not significant. Plasma levels of AT were significantly reduced in DIC and pre-DIC associated with almost all underlying diseases, but those of HCII were significantly reduced only in DIC and pre-DIC patients with inflammatory diseases. The plasma levels of TAT were significantly increased in DIC, pre-DIC, and non-DIC patients with all underlying diseases, and those of THC were significantly increased in DIC and pre-DIC patients with inflammatory diseases. The plasma levels of THC were not significantly increased in non-DIC patients of any disease group. The decrease of AT may be caused by thrombin generation or inflammatory reaction that occurs in DIC associated with underlying diseases, while the decrease of HCII might be caused by both thrombin generation and inflammatory reaction. Finally, AT inhibits thrombin more strongly than HCII in several underlying diseases associated with DIC except for inflammatory diseases. In inflammatory diseases, HCII might play an important role in preventing the onset of DIC.