Cancer and increased age are risk factors for coagulation activation. Patients with advanced prostate cancer, which usually presents in the seventh to eighth decade of life, are likely to be at increased risk for thrombosis. We report results of a controlled study of changes in specific and sensitive markers of coagulation activation in patients with prostate cancer. Complete blood count, <em>prothrombin</em> time, partial thromboplastin time, <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (F<em>1</em> + <em>2</em>), thrombin-antithrombin complex (TAT) and quantitative D-dimers (DD) were measured in 30 patients of advanced prostate cancer (androgen ablated), in 30 newly diagnosed localized prostate cancer patients, in 30 healthy age-matched volunteers, and in <em>2</em>0 healthy young volunteers. Plasma F<em>1</em> + <em>2</em> (P < 0.05) and DD (P < 0.05), but not TAT, were significantly elevated in healthy elderly males (mean age, 77 years) when compared with healthy young volunteers (mean age, 35 years). F<em>1</em> + <em>2</em>, TAT and DD were significantly elevated in advanced prostate cancer when compared with healthy age-matched controls (P < 0.00<em>1</em>). In conclusion, advanced prostate cancer patients have significantly increased levels of sensitive markers of coagulation activation compared with healthy age-matched controls. This data can be used to plan studies to determine the risk of clinically significant coagulopathy and the role of primary prophylaxis in patients with advanced prostate cancer.

A number of hemostatic parameters reflecting the activation of coagulation and fibrinolysis were investigated in a prospective study of <em>2</em>4 patients undergoing cardiopulmonary bypass (CPB) during heart surgery. The patients were randomized to a group in which either a roller (group <em>1</em>) or a centrifugal pump (group <em>2</em>) was used. Blood samples were taken preoperatively, at the onset of and every <em>2</em>0 min during CPB, after the administration of protamine, and 4, <em>2</em>0, 44, and 68 h postoperatively. The groups did not differ significantly in hematocrit, fibrinogen, factor XIII, and antithrombin III. Significant differences in favor of group <em>2</em> during and after CPB were found in <em>prothrombin</em> <em>fragment</em> F<em>1</em> + <em>2</em>, plasmin-antiplasmin complex (PAP), thrombin-antithrombin complex (TAT), and D-dimer (F<em>1</em> + <em>2</em> P < 0.0<em>1</em> after 80-min CPB, PAP P < 0.005 after 40-min CPB, TAT and D-dimer P < 0.05 after <em>1</em>00-min CPB, D-dimer and PAP P < 0.05 after protamine administration, TAT and F<em>1</em> + <em>2</em> 4 h after CPB). These findings indicate the activation of fibrinolysis preceding thrombin generation during cardiopulmonary bypass. In addition, we conclude that centrifugal blood pumping is beneficial in avoiding excessive activation of both coagulation and fibrinolysis.

OBJECTIVE

To evaluate the frequency of arterial thrombotic events in patients with peripheral arterial occlusive disease during 3-5 years of follow-up and to determine whether baseline levels of haemostatic factors were related to the risk of future thrombotic events.

RESULTS

One hundred and twenty-three patients, mean age 56 years, with peripheral arterial occlusive disease and intermittent claudication were followed prospectively for an average of 4.<em>2</em> years. Fibrinogen, <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em>, D-dimer, tissue plasminogen activator, plasminogen activator inhibitor type I antigen and activity, plasmin-alpha(<em>2</em>)-antiplasmin complex, beta thromboglobulin and ADP-induced platelet aggregation were measured at the recruitment. Thirty-eight new vascular events (<em>1</em>5 fatal) were identified. Age- (and other clinical and laboratory variables) -adjusted relative risks (RR) of thrombotic events were significantly elevated (P<0.05) per higher value of D-dimer (RR: <em>1</em>4.<em>1</em>, 95% CI <em>1</em>.7;<em>1</em><em>1</em>5.8) and platelet aggregation was low (RR: 4.6, 95% CI <em>1</em>.3;<em>1</em>6.3). Diabetes mellitus, cerebrovascular disease, and continuing deterioration of intermittent claudication at the recruitment were also independently associated with risk of thrombotic events in the multiple regression model (RR: 5.<em>2</em>, 95% CI <em>1</em>.5;<em>1</em>7.5; RR: 8.6, 95% CI <em>2</em>.7;<em>2</em>7.4; RR: <em>2</em>.6, 95% CI <em>1</em>.<em>2</em>;5.7 respectively).

CONCLUSIONS

Elevated level of D-dimer and low platelet aggregation are independent haemostatic predictors of thrombotic events in patients with peripheral arterial occlusive disease.

Cholesterol crystals (CC) are strong activators of complement and could potentially be involved in thromboinflammation through complement-coagulation cross-talk. To explore the coagulation-inducing potential of CC, we performed studies in lepirudin-based human whole blood and plasma models. In addition, immunohistological examinations of brain thrombi and vulnerable plaque material from patients with advanced carotid atherosclerosis were performed using polarization filter reflected light microscopy to identify CC. In whole blood, CC exposure induced a time- and concentration-dependent generation of <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (PTF<em>1</em>.<em>2</em>), tissue factor (TF) mRNA synthesis, and monocyte TF expression. Blocking Abs against TF abolished CC-mediated coagulation, thus indicating involvement of the TF-dependent pathway. Blockade of FXII by corn trypsin inhibitor had a significant inhibitory effect on CC-induced PTF<em>1</em>.<em>2</em> in platelet-free plasma, although the overall activation potential was low. CC exposure did not induce platelet aggregation, TF microparticle induction, or TF on granulocytes or eosinophils. Inhibition of complement C3 by CP40 (compstatin), C5 by eculizumab, or C5aR<em>1</em> by PMX53 blocked CC-induced PTF<em>1</em>.<em>2</em> by 90% and reduced TF⁺ monocytes from <em>1</em>8-<em>2</em>0 to <em>1</em>-<em>2</em>%. The physiologic relevance was supported by birefringent CC structures adjacent to monocytes (CD<em>1</em>4), TF, and activated complement iC3b and C5b-9 in a human brain thrombus. Furthermore, monocyte influx and TF induction in close proximity to CC-rich regions with activated complement were found in a vulnerable plaque. In conclusion, CC could be active, releasable contributors to thrombosis by inducing monocyte TF secondary to complement C5aR<em>1</em> signaling.

BACKGROUND

We examined potential prothrombotic and proinflammatory effects of angiotensin II in <em>1</em>6 otherwise healthy familial hypercholesterolaemia subjects and <em>1</em>6 matched controls.

METHODS

Markers of fibrinolysis, thrombin generation and inflammation were assessed in plasma before, during and <em>1</em>h after a 3h intravenous infusion of angiotensin II. In addition, placebo experiments with saline infusion were carried out.

RESULTS

Baseline plasminogen activator inhibitor type-<em>1</em> activity and plasmin-antiplasmin-complex concentrations were similar in FH and controls, as were interleukin-6, leukocyte counts and C-reactive protein. Fibrinogen levels were higher in FH, and we observed a greater thrombin generating potential in FH (calibrated automated thrombogram), but no signs of elevated thrombin generation in vivo (<em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em>). During angiotensin infusion plasminogen activator inhibitor type-<em>1</em> activity decreased and plasmin-antiplasmin-complex concentrations increased similarly in FH and controls. Total and maximal amount of thrombin generated was unchanged, as were <em>prothrombin</em>-<em>fragment</em>-<em>1</em>+<em>2</em> levels. Interleukin-6 and leukocyte counts increased similarly in both groups during angiotensin infusion, while fibrinogen tended to increase in FH and increased in controls. During saline infusion plasminogen activator inhibitor type-<em>1</em> activity and <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> concentrations fell, whereas other markers were unchanged.

CONCLUSIONS

FH exhibits an increased thrombin generation potential, an intact fibrinolysis, and has no convincing signs of inflammation. Angiotensin has proinflammatory effects, and might have minor profibrinolytic and procoagulatory effects.

Coagulopathy is still a frequent complication in the surgical treatment of acute aortic dissection. However, the physiopathology of surgically induced coagulopathy has never been systematically and comprehensively studied in patients with acute aortic dissection. The aim of the present study was to describe the perioperative hemostatic system in patients with acute aortic dissection.The 87 patients who underwent aortic arch surgery for acute Stanford type A aortic dissection from January <em>2</em>0<em>1</em>3 to September <em>2</em>0<em>1</em>5 were enrolled in this study. The perioperative biomarkers of hemostatic system were evaluated using standard laboratory tests and enzyme-linked immunosorbent assays (ELISAs) at 5 time points: anesthesia induction (T<em>1</em>), lowest nasopharyngeal temperature (T<em>2</em>), protamine reversal (T3), 4 hours after surgery (T4), and <em>2</em>4 hours after surgery (T5).The ELISAs biomarkers revealed activation of coagulation (thrombin-antithrombin III complex [TAT] and <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> [F<em>1</em> + <em>2</em>] were elevated), suppression of anticoagulation (antithrombin III [AT III] levels were depressed), and activation of fibrinolysis (plasminogen was decreased and plasmin-antiplasmin complex [PAP] was elevated). The standard laboratory tests also demonstrated that surgery resulted in a significant reduction in platelet counts and fibrinogen concentration.Systemic activation of coagulation and fibrinolysis, and inhibition of anticoagulation were observed during the perioperative period in patients with acute aortic dissection. Indeed, these patients exhibited consumption coagulopathy and procoagulant state perioperatively. Therefore, we believe that this remarkable disseminated intravascular coagulation (DIC)-like coagulopathy has a high risk of bleeding and may influence postoperative outcome of patients with acute aortic dissection.

<b>Background</b>: In <em>2</em>00<em>1</em>, we studied the presence and coagulant properties of "microparticles" in the blood of healthy humans. Since then, multiple improvements in detection, isolation and functional characterization of the now called "extracellular vesicles" (EVs) have been made, and shortcomings were identified. <b>Aim</b>: To revisit the presence and function of EVs in blood from healthy humans. <b>Methods</b>: Blood was collected from <em>2</em>0 healthy donors. EV-containing plasma was prepared according to new guidelines, and plasma was diluted to prevent swarm detection. Single EVs were measured by flow cytometry with known sensitivity of fluorescence and light scatter. The haemostatic properties of EVs were measured by thrombin-, fibrin-, and plasmin generation. Plasma concentrations of thrombin-antithrombin complexes and <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> were measured to assess the coagulation status <i>in vivo</i>. <b>Results</b>: Compared to <em>2</em>00<em>1</em>, the total concentrations of detected EVs increased from <em>1</em>90- to <em>2</em>64-fold. In contrast to <em>2</em>00<em>1</em>, however, EVs are non-coagulant which we show can be attributed to improvements in blood collection and plasma preparation. No relation is present between the plasma concentrations of EVs and either TAT or F<em>1</em> + <em>2</em>. Finally, we show that EVs support plasmin generation. <b>Discussion</b>: Improvements in blood collection, plasma preparation and detection of EVs reveal that results from earlier studies have to be interpreted with care. Compared to <em>2</em>00<em>1</em>, higher concentrations of EVs are detected in blood of healthy humans which promote fibrinolysis rather than coagulation.

Sepsis commonly progresses to disseminated intravascular coagulation and induces the activation of heparanase (HPA) and the shedding of endothelial glycocalyx constituents, including syndecan-<em>1</em> (SDC-<em>1</em>) and heparan sulphate (HS). However, the degradation of glycocalyx and its association with coagulation disorders remains undetermined. The present study aimed to evaluate the effect of unfractionated heparin (UFH) and N-acetylheparin (NAH), which is a non-anticoagulant heparin derivative, on endothelial glycocalyx and coagulation function in a lipopolysaccharide (LPS)-induced sepsis rat model, and to compare the differences observed in coagulation function between UFH and NAH. Experimental rats were randomly assigned to four groups: Control; LPS; UFH + LPS; and NAH + LPS. Rats were administered UFH or NAH and subsequently, ~<em>1</em> min later, administered LPS (<em>1</em>0 mg/kg; intravenous). The blood and lung tissues of rats were collected 0.5, <em>2</em> and 6 h after LPS injection, and were used for subsequent analysis. The results demonstrated that HPA activity and SDC-<em>1</em> and HS levels increased, and this increase was associated with inflammatory cytokines and coagulation/fibrinolysis markers in the sepsis rat model. Histopathological examination was performed, and the lung injury score and lung wet/dry ratio indicated that UFH and NAH also significantly improved lung tissue injury. The results of the ELISA analysis demonstrated that UFH and NAH treatment: i) significantly decreased the levels of inflammatory cytokines including tumor necrosis factor-α and interleukin-6; ii) inhibited HPA activity and protected the integrity of the glycocalyx, which was identified by decreased HS and SDC-<em>1</em> levels; and iii) decreased the levels of <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em>, thrombin-antithrombin complex, and plasminogen activator inhibitor-<em>1</em> and increased the levels of fibrinogen and antithrombin-III. Preconditioning with UFH decreased the plasma activated partial thromboplastin time. These results indicated that UFH and NAH may alleviate sepsis-induced coagulopathy, and this effect may have been due to an inhibition of HPA activity and decrease in the shedding of the endothelial glycocalyx.

Recent studies have found that hormone replacement therapy (HRT) is associated with a two- to fourfold increased risk of venous thromboembolism, but the thrombogenic mechanism of HRT remains unclear. To investigate whether HRT use induces a procoagulant state, we undertook a prospective cohort study in postmenopausal women to investigate the effects of 3 months of treatment with oral HRT (conjugated equine estrogen 0.6<em>2</em>5 mg daily and medroxyprogesterone <em>2</em>.5 mg daily) on markers of thrombin generation (<em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em>, thrombin-antithrombin complexes), fibrinolytic potential (plasminogen activator inhibitor-<em>1</em> (PAI-<em>1</em>) activity), and activated protein C (APC) resistance. In addition, we reviewed the literature for studies investigating the effects of HRT on markers of thrombin generation and fibrinolytic potential. In <em>1</em><em>2</em> patients who received HRT for a mean of 3.8 months, there was no significant effect of HRT on levels of F<em>1</em>+<em>2</em>, thrombin-antithrombin complexes, or the APC ratio. HRT use had the greatest effect on PAI-<em>1</em> activity (mean difference = -3.75 UI/mL; 95% confidence interval: - 8.9, <em>1</em>.<em>1</em>) compared to other coagulation parameters, but this did not attain statistical significance (p = 0.<em>1</em><em>2</em>). In the literature review, the effects of HRT on markers of thrombin generation were inconsistent across studies. There was a consistent pattern of increased fibrinolytic potential with HRT use associated with one marker (PAI-<em>1</em>), but not with another marker (tissue plasminogen activator antigen). We conclude that there is a lack of consistent evidence that the increased risk of venous thromboembolism associated with HRT use is due to a procoagulant state related to increased thrombin generation, decreased fibrinolytic potential, or acquired APC resistance.

The role of phospholipid platelet membrane and tissue factor in thrombin generation and thrombus formation is accepted. In the present study we have explored antithrombotic action of strategies aimed to block exposure of negatively charged phospholipids and we compared effects with those obtained through tissue factor or a direct thrombin inhibition. Type III collagen was exposed to flowing blood (5 min, 300 s(-<em>1</em>)). Effects of inhibition of platelet deposition by annexin A5 (ANXA5), hirudin (HIR) or by an antibody against tissue factor (TF) were evaluated. <em>Prothrombin</em> <em>fragment</em> F<em>1</em> + <em>2</em> (F<em>1</em> + <em>2</em>) was monitored. Pre-incubation of whole blood with HIR or ANXA5 resulted in a statistically significant reduction of platelet deposition (<em>1</em><em>2</em>.<em>2</em> +/- 0.6% in control experiments vs. 8.3 +/- 0.4% and 8.5 +/- 0.5%, respectively, P < 0.05). A similar decrease was found when blood was incubated with an antibody against TF. Furthermore, ANXA5 and HIR inhibited the recruitment of platelets into forming aggregates. The height of platelet aggregates generated was decreased in the presence of HIR or ANXA5, but only incubation with both inhibitors reached levels of statistical significance. The presence of ANXA5 or HIR decreased levels of F<em>1</em> + <em>2</em> suggesting a reduced activation of the coagulation system. In our experimental studies, the inhibitory potential of ANXA5 on platelet-thrombus formation was as effective as that of a direct thrombin inhibitor, as HIR, or an antibody against TF. Negatively charged phospholipids exposed on activated platelets potentiate the formation of platelet aggregates on a collagen surface and further suggest that inhibition of platelet procoagulant activity might be a specific target for antithrombotic drugs.

BACKGROUND

Conflicting data have been reported concerning the relationship between Helicobacter pylori infection and coronary heart disease.

OBJECTIVE

To evaluate clotting system activation and plasma levels of tumour necrosis factor-alpha, a procoagulant cytokine, in patients with H. pylori-positive and -negative gastritis.

METHODS

Three groups of patients were identified: 38 with H. pylori-positive gastritis, <em>1</em>8 with H. pylori-negative gastritis, and 40 H. pylori-negative controls with normal gastric mucosa. Plasma levels of <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (F<em>1</em> + <em>2</em>) and tumour necrosis factor-alpha were assayed. Patients were also controlled after <em>2</em> and 6 months following standard H. pylori eradication treatment.

RESULTS

At baseline, <em>fragment</em> <em>1</em> + <em>2</em> and tumour necrosis factor-alpha levels in H. pylori-positive patients were significantly higher than those in H. pylori-negative patients with gastritis (P < 0.05 and P < 0.0<em>1</em>, respectively). After H. pylori eradication, <em>fragment</em> <em>1</em> + <em>2</em> and tumour necrosis factor-alpha levels showed a significant decrease at <em>2</em> months (P = 0.03 and P = 0.0<em>2</em>, respectively) and a further reduction at 6 months, reaching levels observed in H. pylori-negative patients and controls.

CONCLUSIONS

The increase thrombin generation rate and the correlation of plasma <em>fragment</em> <em>1</em> + <em>2</em> and tumour necrosis factor-alpha levels in H. pylori-positive patients suggest a role for inflammation in mediating the relationship between H. pylori infection and activation of the clotting system.

Enhanced oxidative stress (SOX), endothelial dysfunction and haemostatic abnormalities are common in end-stage renal failure patients undergoing maintenance haemodialysis (HD). We studied associations among circulating immunoreactive total lipid peroxides as a marker of short-time SOX, autoantibodies against oxidized LDL as a surrogate of prolonged SOX, copper/zinc superoxide dismutase (Cu/Zn SOD) as a major antioxidant enzyme, tissue factor (TF) as a principal initiator of extrinsic coagulation pathway counteracted by its inhibitor (TFPI), and <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (F <em>1</em>+<em>2</em>) as a surrogate of activated haemostasis.Pre-dialysis blood levels of all the markers studied were higher in <em>2</em>4 clinically stable HD patients compared to <em>1</em><em>1</em> healthy controls. Spearman's correlations among the three SOX markers were positive but nonsignificant in both HD patients and controls. In HD subjects, increased Cu/Zn SOD levels directly correlated with those of TF (rho=0.55<em>1</em>, p=0.005) and TFPI (rho=0.50<em>1</em>, p=0.00<em>1</em>); the coagulation markers were also positively associated with each other (rho=0.663, p=0.0004). In healthy subjects, the relations between Cu/Zn SOD, TF and TFPI levels were inverse but not significant, and the direct association between TF and TFPI was nonsignificant either. In conclusion, increased plasma levels of Cu/Zn SOD, the antioxidant enzyme with emerging endothelial cell-protective and antithrombotic properties, may be a novel part of the system counteracting activated extrinsic coagulation system in maintenance HD patients.

Polycystic ovarian syndrome (PCOS) affects <em>1</em><em>2</em> to <em>1</em>9% of women and has reproductive and metabolic features (endothelial dysfunction, increased diabetes, and cardiovascular risk factors). It also appears to have altered coagulation and fibrinolysis with a prothrombotic state with epidemiological evidence of increased venous thromboembolism. We aimed to comprehensively assess hemostasis in women with PCOS versus control women. In an established case-control cohort of lean, overweight, and obese women with (n = <em>1</em>07) and without PCOS (n = 67), with existing measures of plasminogen activator inhibitor <em>1</em> (PAI-<em>1</em>), asymmetric dimethylarginine (ADMA), hormonal, and metabolic markers, we also assessed <em>prothrombin</em> <em>fragments</em> <em>1</em> and <em>2</em> (PF<em>1</em> & <em>2</em>), plasminogen, tissue plasminogen activator (tPA), and thrombin generation (TG). Higher levels of ADMA (0.70 vs. 0.39 µmol/L, p < 0.0<em>1</em>), PAI-<em>1</em> (4.80 vs. 3.66 U/mL, p < 0.0<em>1</em>), and plasminogen (<em>1</em><em>1</em>8.39 vs. <em>1</em>08.46%, p < 0.0<em>1</em>) were seen in PCOS versus controls, and persisted after adjustment for age and body mass index (BMI). PF<em>1</em> & <em>2</em> was marginally lower (<em>1</em>80.0 vs. <em>2</em>36.0 pmol/L, p = 0.05), whereas tPA and TG were not different between groups, after adjustment for age and BMI. Significant relationships were observed between hormonal and metabolic factors with ADMA and PAI-<em>1</em>. We demonstrate impaired fibrinolysis in PCOS. In the context of abnormal endothelial function and known hormonal and metabolic abnormalities, this finding may underpin an increased risk of cardiovascular disease and venous thrombosis in PCOS.

In the present study we examined if, among other mechanisms, the abnormal exposure of phosphatidylserine at the surface of sickle red blood cells (RBCs) contributes to the hypercoagulability which characterizes homozygous sickle cell disease (SCD). The question was addressed by comparison of the procoagulant properties of RBCs from subjects with various phenotypes (SS, SC and AS) that differ in clinical presentation. As previously reported, SS-RBCs accelerated the <em>prothrombin</em> activation by factor Xa, by decreasing the Km of the reaction compared to normal RBCs. SC-RBCs and AS-RBCs also promoted <em>prothrombin</em> activation although their procoagulant properties were milder compared to SS-RBCs. A significant increase of the thrombin-antithrombin complexes was observed in SS subjects. <em>Prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (F<em>1</em>+<em>2</em>) was elevated in half of the SS subjects, but the difference with controls did not reach significance. Elevated levels of thrombin-antithrombin complexes were observed in a number of SC (4/<em>1</em><em>1</em>) and AS (3/<em>1</em><em>2</em>) subjects, but the difference with controls was not significant. A significant correlation was observed between the plasma levels of thrombin-antithrombin complexes in the subjects with SS, AS and AA phenotypes, and the procoagulant properties of RBCs. Our results strongly suggest that the procoagulant properties which characterize SS-RBCs also affect SC-RBCs and AS-RBCs, and that exposure of phosphatidylserine by RBCs contributes to the hypercoagulable state observed in SCD.

Patients with pancreatic carcinoma are at an increased risk of venous thromboembolism (VTE), which is a major cause of morbidity and mortality in various types of cancer. The aim of this study was to determine the incidence and clinical significance of VTE in patients with pancreatic carcinoma, and to identify biomarkers for the detection of VTE in these patients. The eligibility criteria were chemo-naïve patients with primary pancreatic carcinoma, an Eastern Cooperative Oncology Group performance status of 0-<em>2</em>, and adequate organ function. All patients were screened for VTE using compression ultrasonography and dynamic computed tomography. The primary endpoint was the incidence of VTE, which we hypothesized would be between <em>1</em>0.0-<em>2</em>0.0% for symptomatic and asymptomatic patients combined. Associations between clinical presentation and VTE were evaluated. VTE-associated markers were also investigated for their role in predicting prognosis. In total, <em>1</em>03 patients met the eligibility criteria. The overall cumulative incidence rate of VTE in patients with previously untreated pancreatic carcinoma was <em>1</em>6.5%. VTE occurrence was strongly associated with elevated serum D-dimer, fibrin degradation product, thrombin/antithrombin III complex, and <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> levels. The median overall survival time of VTE-positive and VTE-negative patients was 4<em>2</em>7 and 5<em>1</em>5 days, respectively. Approximately one-sixth of patients with advanced pancreatic carcinoma experienced VTE, although most were asymptomatic. Measurement of serum D-dimer, fibrin degradation product, thrombin/antithrombin III complex, and <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> levels may be useful for the early detection of VTE in patients with advanced pancreatic carcinoma.

Cancer procoagulant (CP) is a cysteine proteinase that may be produced by malignant and foetal tissue. The possible role of CP in the pathogenesis of cancer-related thrombosis has been suggested recently. The purpose of the study was to evaluate coagulation prothrombotic markers and their relation to CP concentration in the blood of patients with gastrointestinal adenocarcinomas (GIAC). The study group consisted of 45 patients with confirmed diagnosis of adenocarcinoma (stomach, <em>1</em>8 patients; colon, <em>2</em>7 patients) and without evident metastatic disease. In <em>2</em>4 patients further observation showed metastases. The control group for CP was composed of <em>1</em>0 healthy subjects. Blood samples were drawn on the admission day, before any treatment. Among 45 patients with GIAC, deep venous thrombosis was observed in two (4.4%). In all patients the CP activity in the serum was found, and the mean CP activity shortened the coagulation time almost three times compared with the healthy control group. Also, the mean thrombin-antithrombin complex concentration was above the normal range. A significant elevation of the mean <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> plasma content in this group of patients was noticed. Despite these observations, CP remained within the normal range and did not correlate with thrombin-antithrombin complex or <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> plasma concentrations. A positive correlation was observed between serum CP and fibrinogen concentration, and a negative correlation between CP and free protein S plasma content (P = 0.04 and P = 0.0<em>2</em>5, respectively). A negative correlation between activated protein C resistance ratio and protein C activity in the plasma was confirmed. Protein C activity in the plasma showed a correlation with free protein S plasma content. Analysis of factors influencing the activated partial thromboplastin time revealed the presence of antiphospholipid antibodies in seven persons from the study group (in three cases of IgG and in four cases of IgM class). Our data suggest that CP is a minor risk factor for deep venous thrombosis in GIAC patients. To confirm this, however, the number of patients and controls should be larger. After 3 years of observation, the follow-up in <em>1</em>0 living GIAC patients showed nobody with thromboembolic disease.

BACKGROUND

Congestive heart failure (CHF) is associated with a hypercoagulable state.

METHODS

A single-center, randomized, double-blind, placebo-controlled trial was performed to test the hypothesis that a prophylactic dose of low molecular weight heparin (bemiparin sodium 3500 IU/daily subcutaneously) will modify a hypercoagulable state in CHF. This study included <em>1</em>00 patients with CHF (New York Heart Association classification II to IV). All patients underwent 3 blood tests, at baseline (before randomization), <em>2</em>4 hours after randomization, and before hospital discharge or within <em>1</em>0 days from randomization.

RESULTS

In comparison of baseline bemiparin sodium 3500 IU/daily subcutaneously with after <em>2</em>4 hours, there was a significant decrease in plasma levels of D-dimer (-<em>1</em>3.8 ng/mL; P =.0<em>1</em>) and <em>prothrombin</em> <em>fragments</em> <em>1</em> and <em>2</em> (-0.<em>1</em><em>1</em> nmol/L; P =.0<em>1</em>), whereas protein C was significantly increased (+3.5%; P =.03). In comparison of baseline bemiparin sodium 3500 IU/daily subcutaneously with after 4 to <em>1</em>0 days of therapy, there were significantly decreased plasma levels for factor VII:c (-3.0%; P =.0<em>1</em>), D-dimer (-44.0 ng/mL; P =.00<em>2</em>), and thrombin-antithrombin complex (-0.7 microg/L; P =.000<em>1</em>), whereas protein C was significantly increased (+<em>1</em>6.0%; P =.03). On the other hand, in the group of patients treated with placebo after <em>2</em>4 hours, a significant decrease was observed of protein C (-4.0%; P =.04). After <em>2</em>4 hours, the changes from baseline were significantly different for some of the hemostatic factors in comparison of bemiparin sodium 3500 IU/daily and placebo (factor VII:c: -<em>1</em>.7 versus 0.0%; P =.04; D-dimer: -<em>1</em>4 versus +<em>2</em>4.3 ng/mL; P =.009; <em>prothrombin</em> <em>fragments</em> <em>1</em> and <em>2</em>: -0.<em>1</em><em>1</em> versus +0.<em>1</em><em>1</em> nmol/L; P =.0<em>1</em>; protein C: +3.5 versus -4.0%; P =.0<em>1</em>). Also at discharge, the changes from baseline were different for some of the markers in comparison of bemiparin sodium with placebo (D-dimer: -44 versus 3.8 ng/mL; P =.00<em>2</em>; thrombin-antithrombin complex: -0.70 versus +0.<em>1</em>4 microg/L; P =.00<em>2</em>; protein C: +<em>1</em>6.0 versus +0.5%; P =.0<em>2</em>).

CONCLUSIONS

Our findings suggest that a hypercoagulable state in heart failure can be modified with bemiparin sodium therapy.

Acute decompression is associated with a shortening of the activated partial thromboplastin time (aPTT). This study was performed to examine whether this change in aPTT results from hypoxia or hypobaria. We exposed healthy adults on three separate occasions to <em>2</em> h of <em>1</em>) hypoxic hypobaria (4<em>1</em>0 Torr, n = 5), <em>2</em>) hypoxic normobaria (fractional inspired O<em>2</em> tension = 0.<em>1</em><em>1</em>, n = 4), or 3) normoxic hypobaria (4<em>1</em>0 Torr breathing supplemental O<em>2</em>, n = 5). The aPTT shortened during hypoxic hypobaria and hypoxic normobaria (P less than 0.05) but was unchanged during normoxic hypobaria. The <em>prothrombin</em> and thrombin times, hematocrit, and concentrations of fibrinogen, total plasma protein, and fibrinogen-fibrin <em>fragment</em> E were unchanged. During hypoxic hypobaria biologic levels of prekallikrein, high-molecular-weight kininogen, and factors XII, XI, X, VII, V, and II were unchanged, but procoagulant VIII (VIII:C) increased 50% without an increase in VIII-related antigen levels (VIIIR:Ag). Fibrin monomer was not detected in any group. In one subject who became ill after <em>1</em>.5 h of hypoxic normobaria aPTT shortened by <em>1</em>0 s; the platelet count decreased by 93,000/mm3; VIII:C increased fivefold, but VIIIR:Ag only increased three-fold. We conclude that it is the hypoxia which shortens aPTT during acute decompression to 4<em>1</em>0 Torr and speculate that it results from an increase in plasma VIII:C-like activity.

The far-ultraviolet circular dichroism spectra of bovine and human <em>prothrombin</em>, <em>prothrombin</em> <em>fragment</em> <em>1</em>, prethrombin <em>1</em>, <em>prothrombin</em> <em>fragment</em> <em>2</em>, and prethrombin <em>2</em> (prethrombin <em>2</em>des(<em>1</em>--<em>1</em>3)) were determined and the method of Chen et al. [Chen, Y. H., Yang, J. T., & Martinez, H. M. (<em>1</em>97<em>2</em>) Biochemistry <em>1</em><em>1</em>, 4<em>1</em><em>2</em>0--4<em>1</em>3<em>1</em>; Chen, Y. H., Yang, J. T., & Chau, K. H. (<em>1</em>974) Biochemistry <em>1</em>3, 3350--3359] was used to calculate the apparent alpha-helix, beta-sheet, and random-coil contents of each protein. <em>Prothrombin</em> and its activation components were found to contain a large amount of aperiodic secondary structure and there was little species difference between the spectra and, thus, secondary structures. The hypothesis that the <em>prothrombin</em> activation components exist as relative ly noncooperative "domains" within the <em>prothrombin</em> molecule was tested by comparing the circular dichroism spectrum of <em>prothrombin</em> with the sum of the spectra of the components. It support of the hypothesis, no gross alterations in the spectra and, hence, secondary structures of the components were found to have occurred upon activation.

OBJECTIVE

The aim of this study was to evaluate the quality of leucocyte-depleted plasma produced from leucocyte-depleted whole blood, stored for different periods of times before filtration through polyurethane filters.

METHODS

Whole blood was collected, from 48 voluntary donors, into quadruple blood bag sets with integrated whole-blood filters, and stored at room temperature for <em>1</em>, <em>2</em>, 6, or <em>1</em>8 h before filtration. Five samples were taken: one directly from the donor; one immediately after collection; one before and one after filtration; and one from plasma units before freezing. All samples were analysed for the following parameters: <em>prothrombin</em> time; activated partial thromboplastin time; <em>prothrombin</em> <em>fragments</em> F<em>1</em>+<em>2</em>; fibrinogen; factors VIII, XI and XII; von Willebrand factor antigen; ristocetin cofactor activity; collagen-binding capacity; multimers; and complement C3a-desArg.

RESULTS

Different whole-blood storage times before filtration did not have a significant effect on the stability of coagulation factors. The activity of all investigated coagulation factors in plasma was generally above 90 U/dl, even after <em>1</em>8 h of storage of whole blood before filtration. von Willebrand factor multimeric distribution remained stable throughout the process. However, activation of complement did occur during storage.

CONCLUSIONS

Leucodepleted plasma originating from leucodepleted whole blood maintains a satisfactory level of coagulation factors, even after the storage of whole blood for <em>1</em>8 h at room temperature before filtration.

Inflammation-induced procoagulant changes and alterations in platelet activity appear to play an important role in thromboembolic complications of infective endocarditis (IE). The aim of this study was to investigate systemic coagulation activity, fibrinolytic capacity, and platelet activation in IE patients with and without embolic events by measuring the plasma levels of <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em>, thrombin-antithrombin III complex, plasminogen activator inhibitor-<em>1</em>, beta-thromboglobulin, and platelet factor 4. The study included 76 consecutive patients with definite IE according to the Duke criteria. Among them, <em>1</em>3 (<em>1</em>7.<em>1</em>%) had major embolic events. Plasma concentrations of <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (3.<em>2</em> +/- <em>1</em>.3 vs <em>1</em>.7 +/- 0.7 and <em>1</em>.4 +/- 0.7 nmol/L, p <0.00<em>1</em>, respectively) and thrombin-antithrombin (7.3 +/- <em>1</em>.5 vs <em>2</em>.9 +/- <em>1</em>.<em>2</em> and <em>2</em>.<em>2</em> +/- <em>1</em>.<em>1</em> ng/ml, p <0.00<em>1</em>, respectively) were elevated in patients with embolic events compared with both patients without embolic events and control subjects. Similarly, patients with embolic events had increased plasma levels of beta-thromboglobulin (63.3 +/- <em>1</em>0.9 vs 33.<em>1</em> +/- <em>1</em><em>1</em>.6 and <em>1</em>9.<em>1</em> +/- <em>1</em>0.6 ng/ml, p <0.00<em>1</em>, respectively) and platelet factor 4 (<em>1</em>06.0 +/- <em>2</em>8.7 vs 50.3 +/- <em>1</em>6.7 and 43.0 +/- <em>1</em>5.8 ng/ml, p <0.00<em>1</em>, respectively) compared with those without embolic events and the control group. Embolic patients also had higher plasminogen activator inhibitor-<em>1</em> levels than both nonembolic patients and healthy subjects (<em>1</em>4.4 +/- 6.4 vs 8.6 +/- 5.9 and 5.4 +/- 4.3 ng/ml, p = 0.00<em>2</em>, respectively). In conclusion, IE patients with subsequent thromboembolism have increased systemic coagulation activation, enhanced platelet activity/damage, and impaired fibrinolysis. The resulting imbalance produces a sustained hypercoagulable state that may contribute to the increased risk of thromboembolic events in this particular group.

The aim of this study was to assess whether there is blood coagulation activation in patients with mitral stenosis (MS) and sinus rhythm (SR) and to investigate the value of left atrial spontaneous echo contrast (LASEC) as a predictive sign of increased coagulation activity. Using thrombin-antithrombin III complexes and <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> as in vivo hemostatic markers, we concluded that there is a hypercoagulable state in patients with MS and SR when LASEC is present.

OBJECTIVE

The aim of this study was to explore the presence of prothrombotic state in early stages of chronic Chagas' disease with serum markers of thrombosis and fibrinolysis, and to investigate it's association with thrombotic risk factors for venous thromboembolic disease.

METHODS

Forty two patients with chronic Chagas' disease were compared with <em>2</em><em>1</em> healthy volunteers. Thrombotic markers used were <em>fragment</em> <em>1</em> + <em>2</em>, ATM complex, fibrinogen/fibrin degradation products, D-dimer and beta-thromboglobulin. Fibrinolysis was evaluated with euglobulin lysis time, tissue plasminogen activator and it's inhibitor levels. A thrombophilic screening was performed. Antithrombin and protein C were determined by functional methods, as well as free fraction of protein S, resistance to activated protein C, factor V Leiden R506Q mutation, <em>prothrombin</em> G<em>2</em>0<em>2</em><em>1</em>0A mutation, homocysteine and antiphospholipid antibodies: lupus and anticardiolipin antibodies isoforms IgG and IgM.

RESULTS

In chronic Chagas' disease patients, statistically significant differences were observed in thrombotic markers: <em>fragment</em> <em>1</em> + <em>2</em> (p < 0.000<em>1</em>), ATM complex (p < 0.000<em>1</em>), fibrinogen/fibrin degradation products (p < 0.05) and D-dimer (p < 0.05). beta-thromboglobulin did not reach statistically significant difference (p = 0.06). Statistically significant differences (p < 0.000<em>1</em>) were found only in euglobulin lysis time, a non specific fibrinolytic marker. Specific fibrinolytic markers tissue plasminogen activator and it's inhibitor, however, did not show statistically significant differences among studied groups.

CONCLUSIONS

Eighty six percent of patients had positive thrombophilic screening for at least one thrombophilic risk factor. Thrombophilic risk factors were inherited in 39% and acquired in 83% of the patients.

Elevated plasma factor VIII coagulant activity (FVIII:C,>> <em>1</em>50 IU/dl) is a risk factor for venous thromboembolism (VTE). We hypothesized that increased FVIII:C may exert a prothrombotic effect by increasing basal thrombin generation. To test this hypothesis we have measured <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (F<em>1</em> + <em>2</em>) and thrombin-antithrombin complex (TAT) in three groups: (i) patients with objectively confirmed VTE and elevated FVIII:C; (ii) patients with VTE and no detectable thrombophilia; and (iii) healthy age- and sex-matched control subjects. In the group of patients with elevated FVIII:C, TAT and F<em>1</em> + <em>2</em> levels were increased in 85% and 78% of individuals respectively. This frequency of coagulation activation is dramatically higher than that reported for other recognized constitutional thrombophilias. In the group of patients with VTE but no proven thrombophilia, increased thrombin generation was present in 30% of individuals. Basal thrombin generation was significantly higher in patients with elevated FVIII:C compared with individuals with VTE but no documented thrombophilia (median TAT = 8.65 microg/l versus <em>2</em>.95 microg/l, median F<em>1</em> + <em>2</em> = <em>1</em>.5 nmol/l versus 0.87 nmol/l; P < 0.000<em>1</em>, P < 0.00<em>1</em>). Overall FVIII:C levels were strongly correlated with levels of thrombin generation (r= 0.5, P < 000<em>1</em>). The clinical significance of such markedly increased F<em>1</em> + <em>2</em> and TAT levels in patients with high FVIII:C levels remains unclear.