Plasma Levels Of Prothrombin Fragment Research Articles

Haemostatic Activation before and after Surgery in Patients with and without Gastric Malignancy

Pre- and postoperative plasma levels of Prothrombin Fragment 1 + 2 (F1 + 2), Thrombin-antithrombin III complex (TAT), Fibrinopeptide A (FpA), Fibrin and Fibrinogen Degradation Products (FbDP, FgDP) and Soluble Fibrin (SF) were measured in 40 patients undergoing gastric surgery in order to compare patients operated for benign (n = 21) and malignant (n = 19) disease. Plasma levels of F1 + 2, TAT, FbDP and SF on the first postoperative day were significantly higher than before operation. F1 + 2 and FbDP levels were further increased one week after surgery, at which time FgDP levels were also higher than preoperatively. A significant postoperative increase in FpA levels was found only in patients with malignant disease. When age was taken into consideration, significant differences between patients with and without malignancy were found only in the late postoperative period, as cancer patients had higher FpA and FbDP levels one week after surgery and higher FbDP levels one month after discharge from hospital.

Thrombosis and hormone replacement therapy in postmenopausal women

The effects of postmenopausal hormone replacement therapy on thrombosis remain controversial. We tested the hypothesis that estrogen or progesterone has no significant effect on thrombosis by means of newly developed markers of blood clotting, specifically prothrombin fragment 1 + 2, a marker of factor Xa generation, and thrombin-antithrombin III complex, a marker of thrombin generation. A prospective study that included 106 women, 68 postmenopausal women on hormone replacement therapy and 38 postmenopausal controls, was performed. Plasma levels of prothrombin fragment 1 + 2 and thrombin-antithrombin III complex were measured by enzyme-linked immunosorbent assay. Multivariate analysis of the covariance was used for statistical analysis, controlling for patient's age because the hormone replacement therapy group was older. There were no statistically significant differences between the hormone replacement therapy and control groups in either of the clotting parameters measured. A comparison of the levels of prothrombin fragment 1 + 2 and thrombin-antithrombin III complex in patients receiving estrogen alone or estrogen plus progestin also revealed no differences. Current doses of postmenopausal hormone replacement therapy do not appear to enhance in vivo clotting. Thromboembolic complications among postmenopausal women receiving hormone replacement therapy may therefore be secondary to congenital or other acquired coagulation defects.

Markers of procoagulant imbalance in patients with localized melanomas and autoimmune disorders.

Hypercoagulability can be defined as a condition of procoagulant imbalance due to heightened enzymatic activation of coagulation zymogens, but with no laboratory evidence of fibrin deposition nor clinical signs of thrombosis. The imbalance can be detected by measuring the plasma levels of prothrombin fragment 1 + 2 (F1 + 2), fibrinopeptide A (FPA) and thrombin-antithrombin III (TAT) complexes. The aims of this study were to establish the frequency of existence and biochemical pattern of hypercoagulability in patients with cancer and autoimmune disorders, clinical conditions associated with an increased risk of thrombosis, and to ascertain the most sensitive method for its diagnosis. In approximately one-fourth of the patients hypercoagulability was identified by finding high levels of FPA F1 + 2 or TAT unaccompanied by signs of fibrin deposition (expressed by normal levels of D-dimer). In a smaller proportion of patients (approximately 10%), the concomitant presence of high levels of D-dimer indicated that the activation of the coagulation cascade had gone beyond the stage of heightened enzymatic activity to the point of cross-linked fibrin deposition. Of the markers used to detect hypercoagulability. FPA seems to be the most sensitive, being significantly increased in all clinical conditions studied.

Evaluation of oral anticoagulant therapy by measuring plasma prothrombin fragment 1 + 2

To assess the degree of haemostatic system activation, plasma levels of prothrombin fragment 1 + 2 (F1 + 2), a direct indicator for thrombin generation in vivo, were measured in 49 patients with thrombotic disease undergoing long-term warfarin therapy (Thrombotest values < or = 40%). In these patients, vitamin K dependent coagulation factors (factors II, VII, IX and X) were decreased together with the anticoagulant proteins C and S, but the mean plasma concentration of F1 + 2 was significantly decreased compared with 48 healthy subjects. In warfarin-treated patients, F1 + 2 was positively correlated with the Thrombotest value, factors II, VII, IX and X. When analysed according to the intensity of anticoagulation, patients with Thrombotest values less than 30% showed a significant decrease in F1 + 2, but the mean F1 + 2 level was normal in patients with Thrombotests higher than 30%. These findings indicate that long-term oral anticoagulant therapy suppresses thrombin generation approximately in parallel to the decrease in coagulation factors, and levels of F1 + 2 lower than healthy subjects are observed when Thrombotest values are less than 30%.

Changes in Plasma Levels of Prothrombin Fragment F1+2 in Cases of Disseminated Intravascular Coagulation

Plasma levels of prothrombin fragment F 1 + 2 (PTF) and thrombin-antithrombin III complex (TAT) were assayed in 86 cases of disseminated intravascular coagulation (DIC). A significant elevation of both parameters was observed in most cases of DIC, which suggested that the in vivo generation of thrombin is highly accelerated by the cleavage of the prothrombin molecule by factor Xa. On the contrary, no significant elevation of plasma levels of PTF was observed in cases of DIC with severe hepatic failure or fulminant hepatitis in spite of significant elevation of TAT. Plasma levels of PTF were directly proportional to those of TAT in 86 cases of DIC as a whole (r = 0.682, p < 0.001). The measurement of both parameters was considered to be useful to estimate the hemostatic activation in DIC.

Haemostatic activation in patients with head injury with and without simultaneous multiple trauma.

In a prospective study including 16 patients with multiple trauma and head injury and 14 patients with isolated head injury we measured plasma levels of prothrombin fragment 1 and 2 (F1 + 2) and thrombin/antithrombin III complex (TAT) on admission and on days 1, 2, 3, and 7 after the incident. On admission, all patients had values of F1 + 2 and TAT above the reference range. Admission levels of both F1 + 2 and TAT were significantly higher compared with levels on the following days. Admission levels of F1 + 2 was significantly correlated to the Injury Severity Score. TAT was higher in patients with multiple trauma than in patients with isolated head injury and were significantly correlated to the Injury Severity Score on admission and on day 3. Levels of F1 + 2 were significantly lower on day 1 in four patients with post-traumatic pulmonary dysfunction compared with patients without pulmonary dysfunction. With respect to levels of TAT, no differences were detected between patients with and without pulmonary dysfunction.

Influence of Long Term Oral Anticoagulants upon Prothrombin Fragment 1 + 2, Thrombin-Antithrombin III Complex and D-Dimer Levels in Patients Affected by Proximal Deep Vein Thrombosis

We have investigated the influence of long term oral anticoagulants (OAC) upon the plasma levels of prothrombin fragment 1 + 2 (F1 + 2), of thrombin-antithrombin III complexes (TAT) and of D-Dimer in 20 patients affected by a proximal deep vein thrombosis (DVT) diagnosed by ultrasonic duplex scanning. Patients (63 +/- 17 years, mean +/- SD) were sampled at the beginning of the OAC treatment (day 1), which was started 1 to 6 days after diagnosis confirmation and full heparinization, and then 8, 35 and 92 days after. The results were compared to those obtained in a blood donor population (39 +/- 10 years) and to an age-matched healthy population (63 +/- 19 years). The mean INR determined on days 8, 35 and 92 were almost identical (2.8 +/- 0.7, 2.9 +/- 0.9 and 2.8 +/- 0.6 respectively). In contrast, highly significant variations of the three markers were recorded during the observation period. Eight days after the beginning of OAC, increased levels of TAT complexes were associated with subnormal levels of F1 + 2 suggesting persistence of a hypercoagulable state. On the further sampling times, TAT complexes were in the normal range while F1 + 2 were far below the normal range. Between day 1 and day 92, the levels of D-Dimer continuously decreased reflecting a long-term fibrinolytic process. This study clearly indicates that high INR are not systematically associated with very low F1 + 2 levels, particularly in the acute phase of thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of prothrombin fragment 1 + 2 with thrombin-antithrombin III complex in plasma of patients with disseminated intravascular coagulation.

Plasma levels of prothrombin fragment 1 + 2 (F1 + 2) and thrombin-antithrombin III complex (TAT) are thought to be specific indicators of thrombin generation. To assess whether these two parameters behave similarly in vivo, we compared the plasma levels of F1 + 2 with TAT in 41 patients with disseminated intravascular coagulation (DIC). Both F1 + 2 and TAT were markedly elevated in patients with DIC compared to healthy subjects. Although a positive correlation was found between F1 + 2 and TAT (r = 0.585, P < 0.001) there was a large scatter among individuals. In addition, plasma concentrations of TAT were much lower than F1 + 2. The correlation between the TAT/F1 + 2 ratio and antithrombin III was weak (r = -0.268, P = 0.09). The TAT/F1 + 2 ratio was positively correlated with TAT (r = 0.481, P = 0.002), indicating that the difference in molar concentrations between F1 + 2 and TAT decreased as the TAT value increased. Serial determinations of these parameters showed that plasma TAT values changed roughly in parallel with F1 + 2 in the majority of patients. Although further studies are required to further clarify the observed differences between F1 + 2 and TAT, both parameters would be equally useful for the precise detection of haemostatic activation in patients with DIC.

Procoagulant effect of the OKT3 monoclonal antibody: Involvement of tumor necrosis factor

We recently observed that the prophylactic administration of high doses of OKT3 monoclonal antibody (MoAb) in cadaveric renal transplantation favors the development of thromboses of the grafts' main vessels and of thrombotic microangiopathies. These clinical observations led us to perform sequential determinations of plasma levels of prothrombin fragment 1 and 2 (F 1 + 2) and fibrin degradation products (FDP) after the first injection of 5 or 10 mg OKT3 given as prophylaxis in kidney transplant recipients. The values observed have been compared with those of kidney transplant recipients not treated with OKT3. F 1 + 2 levels peaked four hours after the first injection of 5 mg OKT3 (mean +/- SEM: 4.82 +/- 0.73 vs. 1.75 +/- 0.37 nmol/liter in controls, P < 0.01), indicating activation of the common pathway of the coagulation cascade. FDP levels were already above baseline values at four hours and continued to increase until 24 hours (mean +/- SEM at 24 hr, 4729 +/- 879 vs. 1038 +/- 320 ng/ml in controls, P < 0.05), indicating a fibrinolytic process. The magnitude and the time course of the changes in F 1 + 2 and FDP plasma levels were similar whether the patients received 5 or 10 mg dose of OKT3. The levels of von Willebrand factor (VWF) antigen, a molecule released by activated or damaged endothelial cells, were also significantly increased after injection of OKT3 (mean +/- SEM at 24 hr, 3.67 +/- 0.18 vs. 2.17 +/- 0.11 U/ml in controls, P < 0.05). The procoagulant effects of OKT3 were further investigated in vitro on human umbilical vein endothelial cells (HUVEC).(ABSTRACT TRUNCATED AT 250 WORDS)

Coagulopathy in Disseminated Intravascular Coagulation due to Abdominal Sepsis: Determination of Prothrombin Fragment 1+2 and Other Markers

To estimate the degree of coagulopathy in abdominal sepsis, we measured the plasma levels of prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin III complex (TAT) and plasmin-alpha 2-plasmin inhibitor complex (PIC) by the enzyme-linked immunosorbent assay in 38 patients with disseminated intravascular coagulation (DIC). In 20 patients with DIC due to abdominal sepsis, plasma levels of F1 + 2, TAT and PIC were 2.6 nmol/l, 27.9 micrograms/l and 1.5 micrograms/ml, respectively, with a mean antithrombin III (AT III) activity of 41.7%. F1 + 2, TAT, PIC and AT III levels were 4.7 nmol/l, 75.8 micrograms/l, 8.8 micrograms/ml and 70.9% in 18 patients with DIC as the result of malignancy. Though AT III levels in DIC due to sepsis were lower than those in DIC due to malignancy, the levels of F1 + 2, TAT and PIC in the former were not significantly more increased than those in the latter. The plasma levels of F1 + 2 were positively correlated with TAT and PIC in DIC patients with malignancy; however, there was no correlation between F1 + 2 and TAT or PIC in DIC patients with sepsis. In addition, the levels of serum albumin in the two groups were similar. These results suggest that activation of coagulation and fibrinolytic systems may not be so prominent in cases of DIC due to abdominal sepsis, compared to related events in DIC due to malignancy. It is also suggested that the depletion of AT III in cases of sepsis is not only caused by a consumption related to intravascular coagulation or to an alternate distribution of protein.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro studies on thrombin generation in citrated, r-hirudinized and heparinized whole blood

<h2>Abstract</h2> The generation of thrombin in citrated, r-hirudinized and heparinized whole blood (final concentrations 10, 25, 50 μg/ml) was studied in the presence or absence of various activators. Whole blood from healthy volunteers was activated either by glass or dextran sulfate (contact activation; CA) as well as by thromboplastin/calcium chloride (extrinsic activation; EA) and by ellagic acid/cephaloplastin/calcium chloride (intrinsic activation; IA) and incubated 10 (CA, EA, IA) and 30 (CA) min at 37 °C. After the incubation period plasma levels of prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin III complex (TAT) were measured utilizing ELISA methodology. After EA or IA no blood clotting occurred in all r-hirudinized samples and in heparinized blood at the highest concentration used. Despite inhibition of clotting F1+2 levels were increased both in r-hirudinized and in heparinized blood. However, in blood anticoagulated with heparin F1+2 levels after EA, IA and especially after CA were markedly lower than in r-hirudinized blood. Furthermore, in r-hirudinized blood an increase of TAT levels was found. The enhancement of F1+2 and TAT levels by r-hirudin was concentration-dependent and was lower in the higher r-hirudin concentration. The results indicate that in r-hirudinized whole blood significant amounts of thrombin can be generated which may elicit thrombin-mediated feedback mechanisms.

In vitro studies on thrombin generation in citrated, r-hirudinized and heparinized whole blood

The generation of thrombin in citrated, r-hirudinized and heparinized whole blood (final concentrations 10, 25, 50 μg/ml) was studied in the presence or absence of various activators. Whole blood from healthy volunteers was activated either by glass or dextran sulfate (contact activation; CA) as well as by thromboplastin/calcium chloride (extrinsic activation; EA) and by ellagic acid/cephaloplastin/calcium chloride (intrinsic activation; IA) and incubated 10 (CA, EA, IA) and 30 (CA) min at 37 °C. After the incubation period plasma levels of prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin III complex (TAT) were measured utilizing ELISA methodology. After EA or IA no blood clotting occurred in all r-hirudinized samples and in heparinized blood at the highest concentration used. Despite inhibition of clotting F1+2 levels were increased both in r-hirudinized and in heparinized blood. However, in blood anticoagulated with heparin F1+2 levels after EA, IA and especially after CA were markedly lower than in r-hirudinized blood. Furthermore, in r-hirudinized blood an increase of TAT levels was found. The enhancement of F1+2 and TAT levels by r-hirudin was concentration-dependent and was lower in the higher r-hirudin concentration. The results indicate that in r-hirudinized whole blood significant amounts of thrombin can be generated which may elicit thrombin-mediated feedback mechanisms.

Prothrombin fragment 1 + 2, thrombin–antithrombin III complexes and D‐dimers in acute deep vein thrombosis: effects of heparin treatment

Plasma levels of prothrombin fragment 1 + 2 (F 1 + 2), of thrombin-antithrombin III complexes (TAT) and of D-dimers were evaluated at several time intervals in 15 patients affected by acute proximal deep vein thrombosis, complicated or not by pulmonary embolism, and treated by conventional heparin therapy for 9 d. The mean levels of the three markers remained significantly increased throughout the period of observation, except for F 1 + 2 on day 9, when compared to normal values established in a population of normal healthy blood donors. However, whereas heparin significantly decreased the plasma levels of F 1 + 2 and of TAT complexes in less than 3 d. D-dimer levels were not significantly altered. Significant correlations were observed between the plasma levels of the three markers but they were not correlated to the actual intensity of heparin treatment evaluated as the activated partial thromboplastin time prolongation. These results indicate that heparin improves the hypercoagulable state associated with a deep vein thrombosis within the first days of treatment as indicated by TAT and F 1 + 2. They also account for the performances of D-dimer assay for the diagnosis of deep vein thrombosis in patients already receiving heparin, a common situation in routine hospital practice.