Vitamin K2 (Menaquinone-7) supplementation does not affect vitamin K-dependent coagulation factors activity in healthy individuals.

BACKGROUND: Vitamin K has long been regarded as a procoagulant drug by physicians, and concerns have been raised with regard to its effects on hemostasis. Although many studies have shown that vitamin K supplementation is safe for thrombotic events, the effect of vitamin K supplementation on the activities of vitamin K dependent procoagulation factors in healthy individuals is not available. OBJECTIVES: This study aimed to investigate whether vitamin K2 supplementation at recommended doses affects the activity of vitamin K dependent procoagulation factors in healthy individuals without any anticoagulation treatment. DESIGN: Forty healthy volunteers between 25 and 40 years of age were recruited. Menaquinone-7 (MK-7) was administrated at 90 µg for 30 days. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and blood coagulation factors II, VII, IX, and X activities and Protein induced by vitamin K absence or antagonist-II (PIVKA-II) were measured on days 0 and 30 after MK-7 administration. RESULTS: PT, APTT, and TT showed no significant differences on day 30 when compared with baseline. The activities of coagulation factors II, VII, IX, and X on day 30 showed no significant differences with those at baseline. PIVKA-II levels were unchanged after 30 days of MK-7 supplementation. CONCLUSIONS: MK-7 supplementation at recommended dosage does not affect vitamin K-dependent coagulation factors' coagulation activity, and does not enhance the carboxylation of prothrombin in healthy individuals. This indicated that MK-7 administration does not alter hemostatic balance in healthy populations without anticoagulation treatment.

Maggot excretion products from the blowfly Lucilia sericata contain contact phase/intrinsic pathway-like proteases with procoagulant functions.

For centuries, maggots have been used for the treatment of wounds by a variety of ancient cultures, as part of their traditional medicine. With increasing appearance of antimicrobial resistance and in association with diabetic ulcers, maggot therapy was revisited in the 1980s. Three mechanisms by which sterile maggots of the green bottle fly Lucilia sericata may improve healing of chronic wounds have been proposed: Biosurgical debridement, disinfecting properties, and stimulation of the wound healing process. However, the influence of maggot excretion products (MEP) on blood coagulation as part of the wound healing process has not been studied in detail. Here, we demonstrate that specific MEP-derived serine proteases from Lucilia sericata induce clotting of human plasma and whole blood, particularly by activating contact phase proteins factor XII and kininogen as well as factor IX, thereby providing kallikrein-bypassing and factor XIa-like activities, both in plasma and in isolated systems. In plasma samples deficient in contact phase proteins, MEP restored full clotting activity, whereas in plasma deficient in either factor VII, IX, X or II no effect was seen. The observed procoagulant/intrinsic pathway-like activity was mediated by (chymo-) trypsin-like proteases in total MEP, which were significantly blocked by C1-esterase inhibitor or other contact phase-specific protease inhibitors. No significant influence of MEP on platelet activation or fibrinolysis was noted. Together, MEP provides contact phase bypassing procoagulant activity and thereby induces blood clotting in the context of wound healing. Further characterisation of the active serine protease(s) may offer new perspectives for biosurgical treatment of chronic wounds.

Homeopathic medicines substantially reduce the need for clotting factor concentrates in haemophilia patients: results of a blinded placebo controlled cross over trial.

BACKGROUND: Modern management of haemophilia patients is expensive: 90% of expenditure is on clotting factor concentrates. Any intervention which reduces the need for clotting factor concentrates in these patients without compromising the quality of life is of interest. AIMS AND OBJECTIVES: To investigate the effectiveness of individualised homeopathic medicines in reducing the requirement of factor concentrates in haemophilia patients. MATERIALS AND METHODS: In a single blind placebo controlled cross over trial 28 consecutive persons with haemophilia (PWH) with severe (24) or moderately severe (4) disease received standard management with placebo homeopathy for 1 year and active homeopathic treatment in the subsequent year with the same conventional management. There was no wash out period. They received standard managements for any acute emergency during the study period. Development of inhibitor during the study period was a withdrawal criterion. Sample size for the trial was calculated as 24 PWH. Transfusion requirements, bleeding scores, pain scores were evaluated blind by independent experts. Homeopathic medicines were selected by experienced homeopathic physicians depending on clinical condition of the patient. Chi-squared and paired t tests were used in statistical analysis. RESULTS: 28 patients were recruited. Homeopathic medicines improved frequency of bleeding, extent of bleeding, blood products consumed and pain scores (P<0.0001). There was also significant improvement in well being. Plasma levels of clotting factors did not change. No patients developed inhibitors during the study there were no dropouts. CONCLUSION: Individualised homeopathic medicines may have an important supportive role in the management of PWH, where blood products and factor concentrates are not easily available. Larger, perhaps multicentric trials are warranted.

Effects of L-Carnitine supplement on plasma coagulation and anticoagulation factors in hemodialysis patients.

BACKGROUND: Hypercoagulability is an important risk factor for thrombosis and its complications in hemodialysis patients. This study was designed to investigate the effects of l-carnitine supplement on plasma coagulation and anticoagulation factors in hemodialysis patients. METHODS: Thirty-six hemodialysis patients were randomly assigned to either a carnitine or a placebo group. Patients in the carnitine group received 1000 mg/day oral l-carnitine for 12 weeks, whereas patients in the placebo group received a corresponding placebo. At baseline and the end of week 12, 5 mL blood was collected after a 12- to 14-hour fast and plasma fibrinogen concentration, activity of plasma protein C, coagulation factors V, VII, IX, and serum concentrations of tissue plasminogen activator (tPA), plasminogen activator inhibitor type-1 (PAI-1), free carnitine, and C-reactive protein (CRP) were measured. RESULTS: In the carnitine group, mean serum free carnitine concentration increased significantly to 150% of baseline (p < 0.001), whereas plasma fibrinogen and serum CRP had 98 mg/dL (p < 0.01) and 41% (p < 0.01) significant decreases, respectively, at the end of week 12 compared with baseline. The reductions were significant compared with the placebo group (p < 0.05). No significant differences were observed between the two groups with regard to mean changes of the activity of plasma protein C, coagulation factors V, VII, IX, and serum PAI-1 to tPA ratio. CONCLUSION: l-Carnitine supplement reduces serum CRP, a marker of systemic inflammation, and plasma fibrinogen, an inflammation-related coagulation factor, in hemodialysis patients. Therefore, l-carnitine may play an effective role in preventing cardiovascular diseases in these patients.

Evaluation of hemostatic effects of Ankaferd as an alternative medicine.

Ankaferd Blood Stopper (ABS), a unique traditional herbal mixture, has been used topically to stop bleeding for centuries in Anatolia. ABS is a standardized mixture of the plants Thymus vulgaris, Glycyrrhiza glabra, Vitis vinifera, Alpinia officinarum, and Urtica dioica. Through its effects on the endothelium, blood cells, angiogenesis, cellular proliferation, vascular dynamics, and cell mediators, ABS is now becoming an official alternative hemostatic medicine for intractable bleedings that are resistant to conventional anti-hemorrhagic measurements in Turkey. Furthermore, ABS seems to have a considerable therapeutic benefit, because of its anti-infective, anti-neoplastic, and wound healing properties, to restore and maintain tissue homeostasis in a variety of diseases.

Haemostatic actions of the folkloric medicinal plant extract Ankaferd Blood Stopper.

Ankaferd Blood Stopper (ABS), a standardized mixture of five plants, has been used historically as a haemostatic agent but its mechanism of action remains unknown. This study investigated the in vitro effects of ABS on haemostatic parameters. When added to plasma or serum, ABS induced the very rapid formation of a protein network and erythrocyte aggregation. The levels of coagulation factors II, V, VII, VIII, IX, X, XI, and XIII were not affected by ABS. Plasma fibrinogen activity and antigen levels were decreased following the addition of ABS, in parallel with the prolonged thrombin time. Total protein, albumin, and globulin levels decreased after the addition of ABS. Our findings suggest that ABS stimulates the formation of an encapsulated protein network that provides focal points for erythrocyte aggregation. ABS has the therapeutic potential to be used for the management of haemorrhage and this agent should be investigated further in clinical trials.

Effects of Ginkgo biloba on haemostatic factors and inflammation in chronic peritoneal dialysis patients.

Ginkgo biloba extract decreased plasma D-dimer concentration, a marker of intravascular coagulation, in chronic peritoneal dialysis patients. Blood levels of fibrinogen, von Willebrand factor, hs-CRP, albumin and liver enzyme levels were not significantly changed. No bleeding episode was reported. These results suggest that Ginkgo biloba extract was effective in partially reversing the thrombogenic coagulation profile without increasing the risk of bleeding.

[Effects of Yangyin Shengjin Decoction on hemorheological parameters and coagulation factors in model rabbits with syndrome of excessive heat consuming body fluid and blood stasis].

OBJECTIVE: To investigate the effects of Yangyin Shengjin Decoction (YYSJD) on hemorheological parameters and coagulation factors in model rabbits with syndrome of excessive heat consuming body fluid and blood stasis. METHODS: Rabbit model with syndrome of excessive heat consuming body fluid and blood stasis was produced. The effects of YYSJD on the blood viscosity, erythrocyte sedimentation rate (ESR), hematocrit, platelet aggregation rate, prothrombin time (PT), thrombin time (TT), kaolin partial thromboplastin time (KPTT), fibrinogen (Fg), thromboxane B(2) (TXB(2)), and 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)) in the model rabbits were observed. RESULTS: YYSJD decreased the whole blood viscosity and hematocrit, inhibited the platelet aggregation, prolonged PT, TT and KPTT, and reduced the content of Fg. It also regulated the balance between TXB(2) and 6-keto-PGF(1alpha). CONCLUSION: YYSJD can promote the blood circulation, adjust the blood agglutinating function, and decrease the formation of thrombus. This is one of the pharmacological mechanisms of the therapeutic method of "nourishing yin to promote blood circulation" in the theory of traditional Chinese medicine for seasonal febrile diseases.

In vitro effects of poly-N-acetyl glucosamine on the activation of platelets in platelet-rich plasma with and without red blood cells.

BACKGROUND: This study was performed to assess the effect of poly-N-acetyl glucosamine fiber slurry on plasma clotting proteins, platelets, and red blood cells in the clotting of the blood. METHODS: Citrate phosphate dextrose whole blood was stored at 22degreesC for 48 hours to prepare platelet-poor plasma, platelet-rich plasma (PRP), and PRP plus red blood cells with hematocrit values of 20%, 35%, and 45% with and without an equal volume of poly-N-acetyl glucosamine fibers (1 mg/mL 0.9% NaCl). RESULTS: Thromboelastogram data show that poly-N-acetyl glucosamine fibers (p-GlcNAc) significantly reduced the R time in platelet-poor plasma, PRP, and PRP supplemented with red blood cells. Poly-N-acetyl glucosamine fibers increased, but not significantly, Annexin V and factor X binding to platelets, platelet microparticles, and red blood cell Annexin V binding. Poly-N-acetyl glucosamine fibers increased the production of thromboxane B2 by PRP. CONCLUSION: Poly-N-acetyl glucosamine slurry activates platelets.

Management of heparin resistance during cardiopulmonary bypass: the effect of five different anticoagulation strategies on hemostatic activation.

OBJECTIVE: Attenuation of hemostatic activation is a central goal during CPB. However, this poses a problem in patients insensitive to heparin. The present investigation was performed to assess different strategies of managing patients with heparin resistance during CPB. DESIGN: A randomized, prospective clinical investigation. SETTING: A major European heart center. PARTICIPANTS: Five groups with 20 patients each were investigated. INTERVENTIONS: The groups were handled as follows: (1). maintenance of a target ACT, (2). maintenance of the target unfractionated heparin (UFH) level and supplementation of a UFH level-based strategy with (3). AT III, (4). the direct thrombin inhibitor r-hirudin, or (5). the short-acting platelet glycoprotein (GP) IIb/IIIa antagonist tirofiban. Platelet count and generation of contact factor XIIa, thrombin, and soluble fibrin were assessed. Samples were obtained before CPB and after CPB before protamine infusion. MEASUREMENTS AND MAIN RESULTS: There were no differences observed in the generation of factor XIIa. The UFH-based strategy and supplementation with AT III, r-hirudin, and tirofiban resulted in significantly reduced (p < 0.05) thrombin generation compared with ACT management. A significant reduction of fibrin formation was seen only in patients who received AT III, r-hirudin, or tirofiban supplementation to the UFH. The administration of tirofiban resulted in a significant preservation of the platelet count compared with the other groups. There were no significant differences in the postoperative blood loss. CONCLUSIONS: Activation of hemostasis during CPB in heparin-resistant patients most likely has to be attributed to stimulation of the tissue factor pathway. Even the sole use of high concentrations of UFH does not effectively inhibit this activation. Therefore, in these patients anticoagulation during CPB with UFH should be supplemented with either AT III, a short-acting direct thrombin inhibitor, or a short-acting platelet glycoprotein IIb/IIIa antagonist.

Plasma lipoproteins, hemostasis and thrombosis.

Regulation of hemostasis and thrombosis involves numerous plasma factors that contribute to procoagulant and anticoagulant pathways. Lipid-containing surfaces provide sites where both procoagulant and anticoagulant enzymes, cofactors and substrates are assembled to express their activities. Plasma and lipoproteins can contribute to either procoagulant or anticoagulant reactions. Procoagulant lipids/lipoproteins include triglyceride-rich particles in plasma and oxidized low density lipoprotein (LDL) which can accelerate activation of prothrombin, factor X and factor VII. Potentially anticoagulant lipids and lipoproteins, each of which enhances inactivation of factor Va by activated protein C, include phosphatidylethanolamine, cardiolipin, the neutral glycosphingolipids glucosylceramide and Gb3 ceramide (CD77), and high density lipoprotein (HDL). Remarkably, treatment of hyperlipidemia with statins not only lowers lipids but also provides antithrombotic effects whose mechanisms remain to be clarified. We hypothesize that procoagulant and anticoagulant lipids and lipoproteins in plasma may contribute to a Yin-Yang balance that helps influence the up-regulation and down-regulation of thrombin generation.

Reduction of pain episodes and prothrombotic activity in sickle cell disease by dietary n-3 fatty acids.

The effects of dietary n-3 fatty acids (n-3FAs) on the frequency of pain episodes and ex vivo blood tests of thrombosis have been evaluated in patients with sickle cell disease (SCD) utilizing a double-blind, olive oil-controlled clinical trial. Dietary n-3FA therapy (0.1 g/kg/d) was provided as menhaden fish oil (0.25 g/kg/d) containing 12% eicosapentaenoic acid (EPA), and 18% docosahexaenoic acid (DHA). Within 1 month dietary n-3FAs exchanged with n-6FAs in plasma and erythrocyte membrane phospholipids (p <0.01 in all cases). Treatment with dietary n-3FAs for 1 year reduced the frequency of pain episodes requiring presentation to the hospital from 7.8 events during the preceding year to 3.8 events/year (p <0.01; n = 5). By contrast, subjects receiving control dietary olive oil (n = 5) experienced 7.1 pain events/year, compared to 7.6 during the previous year (p >0.4). The reduction in episodes in n-3FA-treated subjects was also significant when compared to control subjects (p <0.01). Dietary n-3FA therapy was not associated with hemorrhagic, gastrointestinal or other adverse effects. Compared to 10 asymptomatic African-American controls, sickle cell subjects demonstrated significantly increased pretreatment: 1) flow cytometric expression of platelet membrane P-selectin (CD62p; p <0.01) and annexin V binding sites (p = 0.02); 2) plasma levels of platelet-specific secretory proteins platelet factor 4 (PF4) and beta-thromboglobulin (betaTG) (p <0.01 in both cases); 3) plasma products of thrombin generation, prothrombin fragment 1.2 (F1.2) and thrombin:antithrombin (TAT) complex (p <0.01 in both cases); and 4) plasma levels of thrombolytic products, D-dimer and plasmin:antiplasmin (PAP) complex (p <0.01 in both cases). Treatment with dietary n-3FAs concurrently decreased plasma levels of F1.2, D-dimer, and PAP (p <0.05, compared to olive oil controls), implying that the reduction in pain events was related to n-3FA-dependent inhibition of thrombosis. We conclude that dietary n-3FAs reduce the frequency of pain episodes perhaps by reducing prothrombotic activity in sickle cell disease.

SERMs and cardiovascular disease in women. How do these agents affect risk?

The beneficial effects of SERMs, specifically tamoxifen in the treatment and prevention of breast cancer and raloxifene in the prevention of osteoporosis, are well established. In addition, numerous groups of investigators have reported that these agents have a positive impact on cardiovascular health, possibly as a result of their cholesterol-lowering and anticoagulation actions. Although studies clearly showed that tamoxifen therapy improved the levels of some types of lipids, the changes did not appear to translate into a decreased risk of cardiovascular disease. However, the risk of thromboembolic events (as well as endometrial cancer) was increased with the use of tamoxifen, which is often prescribed for breast cancer prevention in healthy women. Similarly, raloxifene treatment had modest positive effects on cardiovascular risk factors but was associated with an increased risk of thromboembolism. When viewed as a whole, study results dictate that the benefits of SERM use for the prevention of cardiovascular disease be carefully weighed against the potential risks.

Long-chain n-3 fatty acids specifically affect rat coagulation factors dependent on vitamin K: relation to peroxidative stress.

Fatty acids of marine origin have been shown to affect blood coagulation in the rat. In an attempt to gain insight into the mechanisms of this phenomenon, we studied the effects of dietary linseed and fish oils on the liver antioxidant status and plasma coagulation parameters in rats on a time-course basis. Dietary enrichment in eicosapentaenoic and docosahexaenoic acids resulted in strong hypocoagulation after only 1 week and a concomitant increase in liver lipid peroxidation and tocopherolquinone content. Enrichment in linolenic acid induced similar increases in lipid peroxidation and tocopherol catabolism but negligible alteration of coagulation. A significant correlation between plasma factor II coagulant activity and liver tocopherolquinone was found in fish oil- but not in linseed oil-fed rats. Although ingestion of tocopherolquinone led to high levels of this compound in the liver, it had only marginal effects on coagulation factors. Thus, it seems unlikely that this vitamin E metabolite could be involved in the lowering of vitamin K-dependent clotting factors through inhibition of gamma-glutamylcarboxylase. Rather, our results indicate that the effects of the n-3 fatty acids of fish oil on vitamin K-dependent coagulation factors are specific and independent of liver tocopherolquinone levels.

The effect of vitamin C supplementation on coagulability and lipid levels in healthy male subjects.

Although dietary intake and plasma levels of vitamin C have been inversely associated with cardiovascular disease, the mechanism through which it may exert its effect has not been fully explained. Since thrombosis plays an important role in the onset of cardiovascular disease, we investigated the effect of vitamin C on measures of hemostasis that have been associated with cardiovascular risk. The effect of vitamin C on lipid levels was also evaluated. In a randomized, placebo-controlled, crossover study, we determined the effect of 2 g daily of vitamin C supplementation on platelet adhesion and aggregation, levels of tissue plasminogen activator antigen, plasminogen activator inhibitor, fibrinogen, plasma viscosity, von Willebrand factor, and lipid levels in 18 healthy male volunteers with low normal vitamin C levels. No striking effects of vitamin C on the hemostatic measures were observed, although tissue plasminogen activator antigen levels were inversely related to Vitamin C levels. Von Willebrand factor levels were slightly higher with vitamin C, although within the normal range. Total cholesterol levels were 10% lower when subjects were receiving vitamin C compared to placebo (167+/-7 mg/dL vs. 184+/-7 mg/dL), P=0. 007), although the total cholesterol/HDL ratio was not significantly different. Higher levels of tissue plasminogen activator antigen, which in the present study were associated with lower vitamin C levels, have been shown in prospective studies to convey an increased risk of cardiovascular events. Further studies of the effect of vitamin C on hemostatic measures are required in higher risk populations or those with known cardiovascular disease.

Hemostatic factors and platelet aggregation after a fish-enriched diet or fish oil or docosahexaenoic acid supplementation.

The effects of a fish-enriched diet or dietary supplements consisting of either fish oil or a docosahexaenoic acid-rich oil (DHA-oil) on platelet aggregation and hemostatic factors were studied in healthy male students. After an experimental period of 15 weeks, the levels of tissue factor pathway inhibitor, prothrombin fragment 1+2 and fibrinogen as well as factor VII activity were not changed. Factor X activity was slightly decreased by the fish diet (P < 0.05). Collagen but not ADP-induced maximum platelet aggregation decreased in the fish diet and the fish oil groups (P < 0.05 in both). In the DHA-oil group there was a slight, statistically insignificant, increase of platelet aggregation which correlated significantly with the decrease of plasma triglycerides. Platelet aggregation measured 4 h after a standardized fat meal was lower than in the fasting state and this decrease correlated with the increase of plasma triglycerides. These results show that a fish diet and fish oil, but not DHA-oil, inhibit in vitro platelet aggregation and that hemostatic factors are not affected by moderate n-3 fatty acid supplementation.

Unexpected hepatotoxicity after priming and treatment with molgramostim (rhGM-CSF) in acute myeloid leukemia during induction chemotherapy.

The effect of supplementing induction chemotherapy with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was studied in a randomized trial of 18 patients with acute myeloid leukemia (AML). Ten patients received rhGM-CSF, starting on day one to three before chemotherapy and continued for a maximum of 21 days after the start of induction treatment. Unexpected adverse effects of rhGM-CSF and chemotherapy combination included a transient decline in plasma coagulation factors II, VII, and X (5 of 5 patients) and an increased transcapillary escape rate of albumin (in 3 of 3 patients tested). The decline in coagulation factors was prevented in subsequent patients by prophylactic treatment with vitamin K. Although the small number of patients studied may not allow a definite conclusion, caution with regard to liver function should be shown in combining rhGM-CSF with intensive chemotherapy.