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PubMed2002

Evaluation of the marker of hypercoagulability prothrombin fragment F 1+2 in patients with mechanical or biological heart valve prostheses.

OBJECTIVE: To investigate whether patients with heart valve prostheses and similar International Normalized Ratios (INR) have the same level of protection against thromboembolic events, that is, whether the anticoagulation intensity is related to the intensity of hypercoagulability suppression. METHODS: INR and plasma levels of prothrombin fragment 1+2 (F1+2) were assessed in blood samples of 27 patients (7 with mechanical heart valves and 20 with biological heart valves) and 27 blood samples from healthy donors that were not taking any medication. RESULTS: Increased levels of F1+2 were observed in blood samples of 5 patients with heart valve prostheses taking warfarin. These findings reinforce the idea that even though patients may have INRs, within the therapeutic spectrum, they are not free from new thromboembolic events. CONCLUSION: Determination of the hypercoagulability marker F1+2 might result in greater efficacy and safety for the use of oral anticoagulants, resulting in improved quality of life for patients.

Administration, Oral↗
PubMed1961

Prothrombin time. Determination by a whole blood micro-method for control of anticoagulant therapy.

A micro technique that is here described for "prothrombin time" determinations, employing capillary whole blood, provides a range of values which is closely correlated with the Quick one-stage plasma method, thus providing inter-changeability of results both in normal persons and in patients who have been treated with anticoagulant drugs. Avoidance of the use of a water bath and centrifuge permit this technique to yield immediate results at the bedside, in the office or in the patient's home. The use of a whole blood instead of a plasma technique lends additional safety to control of anticoagulant medication, since it may reflect depression of clotting factors not apparent by the usual plasma methods.

Anticoagulants↗
PubMed2006

Prothrombin Suresnes: a case of homozygous F299V mutation responsible for hypodysprothrombinemia.

A patient with a severe prothrombin deficiency and a hemorrhagic diathesis was found to have positive cross-reactive material in plasma and a homozygous F299V mutation (F7V in the A chain). This mutation reinforces the previous conclusion that the A chain affects the geometry of the catalytic triad. Marked prolongation of the Taipan venom and Russell venom clotting times also demonstrated a defective activation mechanism and a defective interaction with factor Xa.

Adult↗
PubMed1990

Levels of acarboxy prothrombin (PIVKA-II) and coagulation factors in warfarin-treated patients.

PIVKA-II (protein induced by vitamin K absence or antagonists-II) was determined and compared with other coagulation factors in normal subjects and patients treated with the anticoagulant warfarin. In 18 (60%) of 30 patients treated with warfarin, PIVKA-II values were 1 microgram/ml or more, although they were less than 1 microgram/ml in all 39 normal subjects (100%). In patients treated with warfarin, values of prothrombin time and partial thromboplastin time were significantly higher than those in normal subjects. However, values of hepaplastintest (normotest) and thrombotest in the patients were greatly lower than those in normal subjects. There were no significant differences between bleeding time or plasma fibrinogen values in the patients and normal subjects. The values of PIVKA-II were inversely correlated (P less than 0.01) with those of hepaplastintest and thrombotest. The measurement of PIVKA-II in the plasma should be useful in detecting vitamin K-deficient status among haemorrhagic disorders.

Biomarkers↗
PubMed1988

Extrinsic-pathway enzyme-linked coagulation assay (EP-ELCA). A clot-based alternative to prothrombin time for measurement of extrinsic pathway factors in plasma.

This solid-phase colorimetric microtiter-plate clotting assay is much more sensitive than standard clotting tests. In enzyme-linked coagulation assay (ELCA), enzyme-labeled fibrinogen and solid-phase fibrinogen are the substrate for thrombin generated in the clotting cascade. We used this assay to measure the factors of the extrinsic pathway by an extrinsic pathway-specific assay (EP-ELCA) and to determine the individual factors of the extrinsic pathway (VII, X, V, II) in plasmas of coumadin-treated and heparin-treated patients, with prothrombin time (PT) values used as a reference. In the ELCA method, samples and controls are incubated on the same plate, eliminating the requirement for pre-standardization of the substrate "plasma" before the factor assay is done. Concentrations of factors are determined by serially diluting sample and control plasmas to yield equivalent activity at given dilutions, a more direct approach for measuring specific factors than determining log concentrations vs log clotting time. Changes in the concentrations of clotting factors are seen before changes are apparent by PT. For coumadin-treated patients, all vitamin K-dependent factors were significantly (P less than or equal to 0.001) less than in normal controls, whereas factor V concentrations were normal, as expected. For patients treated with heparin, concentrations of factors X and VII were less than in normal controls (P less than 0.01) and results for EP-ELCA, II, and V assays were normal. This methodology can readily be automated.

Adult↗
PubMed1977

Prothrombin complex concentrates.

The use of the prothrombin complex products for the treatment of inhibitor patients is discussed in relation to our difficulty in identifying the effective therapeutic principle, as well as the factors responsible for thrombogenicity. It would appear that combination of factors is responsible for either or both therapeutic and thrombogenic phenomena. Possible intermediate or aggregate forms of the procoagulants are present in the products, protected from the neutralizing effects of antithrombin III.

Antithrombin III↗
PubMed1981

The inhibitor of prothrombin conversion in plasma of patients on oral anticoagulant treatment.

Pooled plasma of patients under stable oral anticoagulation has been analysed with respect to the presence of the vitamin-K dependent factors (factors II, VII, IX and X). Of all factors 1.5-2 times more antigen than procoagulant activity was present. The concentration of factors II, X (measured spectrophotometrically) and VI is about 0.25 U/ml while factor IX is slightly higher. Coagulation assays of factor X always gave lower values than the spectrophotometric assay. This discrepancy was not influenced by the removal of either factor II-, factor VII- or factor IX antigen. However, when the factor X antigen was replaced by normal factor X, all factor X assay gave identical results, indicating that PIVKA X is responsible for these discrepancies. Using the technic of the Thrombotest-dilution curve it was shown that PIVKA X is the factor that causes the abnormal prolongation of ox-brain prothrombin time in these plasmas.

Administration, Oral↗
PubMed1978

Prothrombin complex concentrates. Use in treatment of hemophiliacs with factor VIII inhibitors.

The development of factor VIII inhibitors has been a major problem in the management of hemophiliacs. The use of prothrombin complex concentrates (PCC) has been advocated as a method of overcoming this problem. We utilized PCC in the treatment of nine hemophiliac patients who had significant levels of inhibitor. Acute bleeding episodes were successfully treated in all nine patients. Single infusions of PCC were usually adequate for control of joint and soft tissue bleeding episodes, while multiple infusions were usually required for more serious hemorrhages. In addition, programs of repeated infusions were used to heal chronically inflamed joints in three patients. The only side effect of treatment was one episode of asymptomatic elevation of liver function values that resolved spontaneously. There were no thrombotic events associated with the PCC infusions. Therapy with PCC is recommended for the management of hemophiliacs with factor VIII inhibitors.

Adolescent↗
PubMed2000

Multiple arterial thromboembolisms in a patient with the 20210 A prothrombin gene mutation.

The most recently characterized genetic defect contributing to venous thrombophilia is the 20210 A prothrombin gene mutation. We describe a patient with this defect who had arterial thrombosis resulting in considerable mesenteric ischemia. Several environmental factors, which might otherwise be considered of low thrombotic risk, may also have contributed to her condition. The recognition of the potential for novel presentations of hypercoagulable states may contribute to a reduction in the morbidity associated with acute mesenteric ischemia.

Female↗
PubMed1982

Prothrombin and partial thromboplastin times as preoperative screening tests.

Preoperative tests of coagulation function have been suggested to detect patients who are likely to have abnormal bleeding during and after surgery. A study was designed to determine the yield of prothrombin time (PT) and partial thromboplastin time (PTT), both in discovering patients who are at risk for abnormal bleeding and in inducing changes in patient care or outcome. Of 750 patients on three surgical services, 611 (81%) patients had no indication of a bleeding disorder on history or physical examination. Of the 139 patients who had clinical indications, 25 (18.0%) patients had an abnormal PT or PTT. Of the 611 patients without clinical indications, 480 patients had the PT or PTT determined, and 13 (2.7%) patients had abnormal results. One (0.2%) of the 480 patients might have benefited from the test result (this patient required a second operation to control arterial bleeding). The prolonged PT or PTT was of no apparent clinical importance in the remaining 12 patients without indications of bleeding disorders preoperatively. The low yield of the PT and PTT in detecting unsuspected bleeding disorders preoperatively was further obscured by the larger number of apparently false-positive results.

Blood Coagulation Tests↗
PubMed1996

Buffer may be the critical factor in measurement of anti-prothrombin antibody on a gamma-ray-irradiated plate by enzyme-linked immunosorbent assay.

We investigated the influence of different buffers (Tris-buffer and phosphate buffered saline (PBS)/Tween-20 buffer) on anti-prothrombin antibody (aPT) measurement by enzyme-linked immunosorbent assay (ELISA), employing a gamma-ray-irradiated plate. We found considerable discrepancies in aPT positivity between each buffer, and we suggest that the use of Tris-buffer is not suitable for aPT measurement with a gamma-ray-irradiated plate to measure aPT.

Autoantibodies↗
PubMed1997

Enhanced generation of monocyte tissue factor and increased plasma prothrombin fragment1+2 levels in patients with polycythemia vera: mechanism of activation of blood coagulation.

Polycythemia vera (PV) is associated with a high incidence of thrombosis. The association of apparent and secondary polycythemia with thrombosis is not clear. It was suggested that activation of the coagulation system contributes to thrombus formation in PV. However, the mechanism of activation is unknown. Monocytes generate a potent tissue factor (TF) upon stimulation with various substances, which is involved in thrombus formation in various disorders. Therefore, we studied the possibility that the factor is involved in the activation of coagulation and thrombus formation also in PV. Unstimulated peripheral blood mononuclear cells (PBMC) from each of the different types of polycythemia expressed weak TF activity (2 U) and antigen (41.4 to 52.9 pg/ml), which were similar to normal controls. Following stimulation with endotoxin, PBMC from normal controls and from apparent and secondary polycythemia showed a 3.9- to 4.5-fold increase in TF, while cells from PV showed a 21-fold increase (P<0.001). Similar levels were generated by PBMC after treatment of PV and at the spent phase. TF was generated by monocytes but not by lymphocytes. Plasma prothrombin fragment1+2 (F1+2) levels, assayed at the same time, were significantly higher in PV (2.46 nm) compared to normals and apparent and secondary polycythemia (0.22 to 0.32 nm), and were in a significant correlation with monocyte TF activity and antigen levels (r = 0.77, 0.87). The high levels of F1+2 confirm that the coagulation system is activated in PV. The increased capacity of monocytes to generate TF may be responsible for the activation of the coagulation system and thrombus formation. The hypercoagulability state that is induced by this mechanism suggests that long-life oral anticoagulation should be considered once thrombosis has been developed in PV.

Adult↗
PubMed1999

Prevalence of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations in a Greek population of blood donors.

The pathogenesis of venous thrombosis involves the interaction of genetic and environmental factors. In order to estimate the frequency of the factor V Leiden, the prothrombin G20210A, and the MTHFR C677T mutations in the Greek population, we analyzed 160 healthy Greek blood donors by PCR amplification and detected allele frequencies of 2.5%, 2.2%, and 35.3%, respectively. The allele frequencies were compared with reported frequencies of other populations of southern Europe. The identification of these common genetic risk factors for thrombosis should enable easy DNA diagnosis and carrier detection in a high proportion of cases and will contribute to a better understanding of the interaction of genetic and environmental risk factors.

Adult↗
PubMed1996

Time-resolved fluorescence study of a calcium-induced conformational change in prothrombin fragment 1.

The wavelength dependent fluorescence decay properties of bovine prothrombin fragment 1 have been investigated employing a picosecond time-correlated single photon counting technique. All observations are discussed with using the crystal structure (Soriano-Garcia et al., Biochemistry 31:2554-2566, 1992). Fluorescence lifetimes distribution and conventional multiexponential analysis, as well as acrylamide quenching studies lead to the identification of six distinguishable tryptophan excited-states. Accessibility to the quencher and the known structure are used to associate a fluorescence decay of the tryptophan present in the Gla domain (Trp42) with two red shifted components (2.3 and 4.9 ns). The two kringle domain tryptophans (Trp90 and Trp126) exhibit four decay times (0.06, 0.24, 0.68, and 2.3 ns), which are blue shifted. The calcium-induced fluorescence quenching is a result of static quenching: the five decay times remain unchanged, whereas the fluorescence intensity of Trp42 is decreased. The static quenching process is a consequence of a ground state interaction between the Cys18-Cys23 disulfide bridge and Trp42. The monomolecular equilibrium constant for this disulfide-pi-electron interaction is found as 4.8.

Acrylamide↗
PubMed1996

Clinical significance of simultaneous determinations of alpha-fetoprotein and des-gamma-carboxy prothrombin in monitoring recurrence in patients with hepatocellular carcinoma.

BACKGROUND: Measurements of serum alpha-fetoprotein (AFP) concentration and plasma concentration of des-gamma-carboxy prothrombin (DCP) have been widely used for the early diagnosis of hepatocellular carcinoma (HCC). The two markers generally run parallel to each other. However, in our study, they sometimes fluctuated independently in response to tumor regression or recurrence. METHODS: A longitudinal series of concentrations of serum AFP and plasma DCP were determined simultaneously for 245 patients with HCC from the time of diagnosis to tumor recurrence after treatment. RESULTS: Positive reactions for AFP were noted in 168 patients (69%) and for DCP in 126 patients (51%). One hundred and ten of 245 patients with HCC (45%) were positive for both AFP and DCP. In 35 patients (14%), these 2 tumor markers fluctuated independently in response to tumor regression and recurrence. These patients were categorized into four groups as follows: Group 1 had elevated AFP only at diagnosis; it then decreased after treatment, but DCP was elevated at the time of tumor recurrence without AFP elevation (3 patients); Group 2 had elevated DCP at diagnosis and elevated AFP at tumor recurrence (4 patients); Group 3 had elevated AFP and DCP at diagnosis, but only AFP (8 patients) or DCP (7 patients) was elevated at tumor recurrence; Group 4 had only elevated AFP (2 patients) or DCP (11 patients) at diagnosis, but both AFP and DCP were elevated at tumor recurrence. CONCLUSIONS: The results of this study indicate that simultaneous determinations of AFP and DCP are useful for monitoring recurrence in patients with HCC after treatment, and that the decrease to normal levels of a single marker does not always indicate the absence of tumor recurrence.

Adolescent↗
PubMed1996

Des-gamma-carboxy prothrombin and alpha-fetoprotein positive status as a new prognostic indicator after hepatic resection for hepatocellular carcinoma.

BACKGROUND: The aim of this study was to elucidate the usefulness of measuring the positive status of both des-gamma-carboxy prothrombin (DCP) and alpha-fetoprotein (AFP) preoperatively as a new prognostic indicator of hepatocellular carcinoma (HCC). METHODS: One hundred forty-seven patients who underwent curative hepatic resection for primary HCC were studied. The definitions of DCP and AFP positivity were: positive DCP > 0.1 AU/ml, and positive AFP > 50 ng/ml. The patients were classified into four groups according to their levels of positivity for DCP and/or AFP: Group 1 (n = 59), negative levels of both DCP and AFP; Group 2 (n = 28), negative DCP and positive AFP levels; Group 3 (n = 31), positive DCP and negative AFP levels; and Group 4 (n = 29), positive levels of both DCP and AFP. RESULTS: Patient survival and disease free survival in Group 4 were the worst among the four groups. By multivariate analysis, using Cox proportional hazards model, both the DCP- and AFP-positive status (in combination) and poorly differentiated histology were independent factors of poor prognosis for patient survival; and DCP- and AFP-positive status (in combination), poorly differentiated histology, positive intrahepatic metastasis, and tumor diameter over 5 cm were independent factors of poor prognosis for disease free survival. CONCLUSIONS: The combination of DCP- and AFP-positive status is a new prognostic indicator for patients with HCC after hepatic resection.

Adult↗
PubMed1998

The usefulness of determining des-gamma-carboxy prothrombin by sensitive enzyme immunoassay in the early diagnosis of patients with hepatocellular carcinoma.

BACKGROUND: Measurements of serum concentrations of des-gamma-carboxy prothrombin (DCP) are widely used for diagnosing hepatocellular carcinoma (HCC). However, the DCP is not always sensitive enough to detect small HCCs. In the current study, the authors investigated the usefulness of DCP in the early diagnosis of HCC, using a more sensitive enzyme immunoassay than is conventionally employed. METHODS: The authors examined 148 serum samples with DCP concentrations from a conventional assay of less than 100 mAU (arbitrary unit)/mL from 91 patients with HCC and 57 with cirrhosis. DCP concentrations were determined by a more sensitive enzyme immunoassay (ED-036 kit, Eisai Laboratory, Tokyo, Japan) with a minimal detection level of 10 mAU/mL. Ninety-one HCC patients had 43 solitary small HCCs (with a greatest dimension of less than 2 cm). Of these 43 HCCs, 12 were well differentiated. RESULTS: The mean serum concentration of DCP in HCC (48.3 +/- 24.3, mean +/- standard deviation [SD]) was higher than in cirrhosis (20.3 +/- 10.3); this difference was statistically significant. When the tentative cutoff level of 40 mAU/mL (almost corresponding to the mean value + 2SD in patients with cirrhosis) was used as the level of discriminating HCC from cirrhosis, 62% of patients (56 of 91) with HCC had DCP values above this level (sensitivity). However, only three patients with cirrhosis had higher DCP levels. Thus, the specificity of this test was 95% (54 of 57 patients). The total accuracy was 74% (56 + 54/91 + 57). Twenty-three of 43 solitary small HCCs (53%) had DCP values above the cutoff level. Furthermore, 7 of 12 (58%) small, well-differentiated HCCs less than 2 cm in greatest dimension had higher DCP values. CONCLUSIONS: The results of this study indicate that DCP determination by sensitive enzyme immunoassay is useful in the early diagnosis of HCC because a high specificity is maintained.

Adult↗