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PubMed1989

Evaluation of antithrombin-III activity as a coindicator of disseminated intravascular coagulation in cats with induced feline infectious peritonitis virus infection.

Six adult specific-pathogen-free cats were inoculated intraperitoneally with a cell culture-adapted strain of feline infectious peritonitis virus. Plasma samples were evaluated for antithrombin-III (AT-III) activities at post-inoculation days (PID) 0, 4, and 11 and at termination on PID 16 (1 cat) or 21 (5 cats). Other hemostatic values evaluated were activated partial thromboplastin times, prothrombin times, thrombin times, fibrinogen, platelet counts, and fibrin/fibrinogen degradation products. Antithrombin-III activity remained within normal or above normal range (89 to 246%) in all cats, with the exception of one cat on PID 4 (AT-III, 70%). Mean baseline AT-III activity for 6 cats at PID 0 was 123%. Mean AT-III activity on PID 4, 11, and 16 or 21 was 98, 162, and 130%, respectively. On PID 4 and 16 or 21, results of coagulation screening tests indicated that all cats had disseminated intravascular coagulation. Histologically, cats also had severe fibrinonecrotizing thrombovasculitis.

Acute Disease↗
PubMed1985

Role of plasmin, thrombin, and antithrombin III as etiological factors in delayed cerebral vasospasm.

The fibrinolytic enzyme plasmin at 0.25 units/ml produced a contraction of isolated canine basilar arteries that developed slowly and was sustained for at least 2 hours. Plasmin and thrombin (1 unit/ml) acted synergistically to enhance the contractile response. In contrast to plasmin, the marked contraction elicited by thrombin ended within 1 hour, and afterward the artery was completely tachyphylactic to thrombin. Fibrin clot, fibrinopeptides, and fibrin degradation products did not prolong significantly the effect of thrombin or prevent the tachyphylaxis. Plasmin and thrombin may occupy a common membrane receptor because exposing the artery briefly to trypsin (24 micrograms/ml) thereafter abolished the contractile effect of plasmin and thrombin without affecting the action of other agonists. Antithrombin III (1.0 unit/ml) relaxed basilar arteries that were precontracted with plasmin (0.5 unit/ml), thrombin (1.0 unit/ml), serotonin (10(-5) M), uridine triphosphate (10(-4) M), or KCl (8 X 10(-2) M). The results suggest that the vasoconstrictor effect of thrombin might contribute to hemostasis after subarachnoid hemorrhage (SAH) but, because of tachyphylaxis, not to delayed vasospasm. On the other hand, the constrictor action of plasmin might appear late in the course of SAH in association with clot lysis and tissue repair. Last, the level of the vasorelaxant antithrombin III in cerebrospinal fluid could control the appearance and severity of cerebral arterial spasm in SAH.

Aminocaproic Acid↗
PubMed1989

[Heterogeneity of mammalian antithrombin III].

Affinity chromatography on heparin-Sepharose was used to isolate two forms of antithrombin III(AT) from human, bovine, rabbit and rat blood plasma. The two isolated forms of AT are the major form. AT alpha, making up to 90% of the whole inhibitor molecule, and the minor form, AT beta (10% of AT). The molecular mass of AT beta in all mammalian species under study is by 3-5 kDa lower than that of AT alpha. The isoelectric point for bovine AT alpha lies within the range of 4.95-4.5, whereas that for AT beta--at 5.28-4.76. No significant differences in the progressive antithrombin activity of the major and minor forms of the bovine inhibitor were observed. In contrast, the heparin-cofactor activity of the AT beta-heparin complex exceeds that of the AT alpha-heparin complex--3-fold. The functional differences in the AT forms are due to the differences in their affinities for heparin. It was shown that AT beta exhibits a higher affinity for free and bound heparin.

Animals↗
PubMed1989

[Familial antithrombin deficiency].

When known causes of a disposition to thrombosis are discovered (e.g. antithrombin, protein C or protein S deficiency) it is important to investigate family members and inform individuals who are deficient in the factor in question. Knowledge about the cause of the thrombophilia will stimulate prophylactic efforts, and may be very important for diagnosis and treatment of the patient. A recently discovered new family with antithrombin deficiency is presented.

Adult↗
PubMed1989

Homozygous variant of antithrombin III that lacks affinity for heparin, AT III Kumamoto.

Abnormal antithrombin III (AT III) was found in the plasma of a 31-year-old female who suffered from recurrent thrombotic episodes. Heparin cofactor activity was 28% of normal and undetectable when measured by inhibition of thrombin and factor Xa (F.Xa), while both progressive antithrombin and antifactor Xa activities were normal. The concentration of plasma AT III antigen was 37 mg/dl. Analysis by crossed-immunoelectrophoresis (CIE) in the presence of heparin and affinity chromatography on heparin-Sepharose revealed that the propositus' AT III did not bind to heparin. When heparin cofactor II (HC II) was removed from propositus' plasma, heparin cofactor activity of AT III was not detected. Thus, HC II seemed to account for the plasma heparin cofactor activity found in the presence of thrombin. The patient's parents and three of her brothers demonstrated qualitative abnormality of AT III; heparin cofactor activity was 30-50% of normal levels in the presence of both thrombin and F.Xa. These findings indicate that the propositus' AT III lacks affinity for heparin and the mode of its inheritance seems to be autosomal dominant and, hence, the propositus would be a homozygote. For this variant, the name of AT III Kumamoto is proposed.

Adult↗
PubMed1987

[Acquired deficiencies in antithrombin III and C protein during treatment with L-asparaginase].

Fourteen children treated by L-Asparaginase for acute lymphoblastic leukemia had sequential coagulation studies performed including cephalin-kaolin time, Quick time, fibrinogen, factors II, VII + X and V, as well as antithrombin III and protein C, the major coagulation inhibitors. A severe antithrombin III and protein C deficiency was observed during therapy, with a coexisting hypocoagulability. This equilibrium partially explains the lack of thrombo-embolic phenomena in these children, despite the risk factors present. Although no substitutive therapy was instituted in these cases, their use in high-risk cases is discussed.

Adolescent↗
PubMed1978

Effect of experimental inflammation on the synthesis and distribution of antithrombin III and alpha1-antitrypsin in rabbits.

Local inflammation, induced by s.c. injection of turpentine, evoked characteristic changes in the metabolism of antithrombin III, and alpha1-antitrypsin. For a period of approximately 36 h, the plasma half-lives of both protease inhibitors were shortened to 70--74% of the respective preinjection values. Similar changes were also observed in the slope of iodine-labelled albumin, suggesting that increased capillary permeability was primarily responsible for the losses of labelled proteins from the circulation. Incorporation of [3H]- or [14C]-leucine into albumin changed little during inflammation, but markedly increased values were measured for anti-thrombin III (3-fold), alpha1-antitrypsin (4-fold) and, above all, for fibrinogen (7-fold) 24 h and 48 h after the injection of turpentine. These changes in synthesis and elimination rates resulted in the following net balances: fibrinogen concentrations in plasma rose substantially during the early phase of inflammation; alpha1-antitrypsin concentrations increased gradually but to a significantly lesser extent, peak concentrations being reached after a reverse trend in fibrinogen concentrations had become apparent; antithrombin III concentrations remained steady throughout at levels which were only marginally above the pretreatment values.

Animals↗
PubMed1988

Laboratory and clinical evaluation of an assay of thrombin-antithrombin III complexes in plasma.

We evaluated a recently developed commercial assay for quantifying thrombin-antithrombin III (TAT) complexes in human plasma. The assay is precise (within-assay CV less than 10%, between-assay CV less than 13%), and sensitive (detection limit 0.7 micrograms of TAT per liter of plasma). Measurements for healthy volunteers yielded a normal reference (95 percentile) interval of 0.8 to 5.0 micrograms/L (n = 50, mean 2.1 micrograms/L, range 1.1 to 7.5 micrograms/L). TAT concentrations were increased in 25 of the 41 patients who fulfilled the clinical criteria of disseminated intravascular coagulation (DIC, overall mean 15.8 micrograms/L) and in 30 of the 35 patients with deep-vein thrombosis of the leg (overall mean 9.4 micrograms/L). We assessed the accuracy of the TAT assay by comparison with established criteria for the laboratory diagnosis of DIC involving various cutoff values for antithrombin III, factor V, fibrinogen, platelet count, fibrin/fibrinogen degradation products, and activated partial thromboplastin time. The low specificity of the TAT assay with regard to some of these criteria indicates that the latter are probably insensitive.

Antithrombin III↗
PubMed1988

Determination of human thrombin-antithrombin III complex in plasma with an enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) was developed for the determination of thrombin-antithrombin III complex (TAT) in human plasma. The test system follows the sandwich principle and uses two different antibodies directed against human thrombin and human antithrombin III, respectively. The antibodies bind selectively to the corresponding antigen moieties of TAT. The assay was calibrated with definite concentrations of preformed purified TAT added to TAT-poor plasma. The lower limit of sensitivity of the assay was 0.5 microgram/l. Mean coefficients of variation of 4.2% (intraassay) and 3.5% (interassay) were found for TAT concentrations between 2 and 60 micrograms/l. A reference range from 0.85 to 3.2 micrograms/l was calculated from TAT concentration in plasma samples from 88 healthy donors (mean value +/- SD: 1.45 +/- 0.4 micrograms/l). In plasma samples from patients with pulmonary embolism (n = 17), TAT concentrations between 3 and 25 micrograms/l were measured. In 15 patients with deep vein thrombosis, TAT was found up to 3 to 25 micrograms/l. From these data we conclude that measurement of TAT can be a sensitive parameter for specific detection of a latent activation of the clotting pathway.

Antithrombin III↗
PubMedDate not supplied

[The role of the antithrombin III-heparin-thrombin complex in the defense reaction of the anticoagulation system].

Complexes antithrombin III-heparin-thrombin exhibiting the anticoagulation and nonenzymatic fibrinolytic activities were isolated from human blood children of 4-II years old with burns or with traumatic shock and from rat blood. The complexes antithrombin III-heparin-thrombin with high nonenzymatic fibrinolytic activity were shown to develop during activation of the anticoagulation system. In depression of the anticoagulation system these complexes, isolated from blood, demonstrated the lower nonenzymatic fibrinolytic activity, thus indicating that complex-formation is restricted.

Animals↗
PubMed1986

Interaction of factor XIa and antithrombin in the presence and absence of heparin.

We have studied the interaction between purified human factor XIa and antithrombin in the presence and absence of well-characterized preparations of heparin. The concentrations of hemostatic enzyme, protease inhibitor, and mucopolysaccharide were 5.76 X 10(-8) mol/L, 5.76 X 10(6) mol/L, and either 5.88 X 10(6) mol/L or 0, respectively. Kinetic investigation of this process using a tritiated factor IX substrate demonstrated that the pseudo first-order rate constants of this reaction in the presence and absence of heparin are approximately 1.0 min-1 and approximately 0.025 min-1, respectively. Thus, the rate of hemostatic enzyme-protease inhibitor complex formation is accelerated by about 40-fold in the presence of saturating levels of the mucopolysaccharide. These results were confirmed in a qualitative manner by directly monitoring the generation of factor XIa-antithrombin interaction product with sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis using an antibody population specific for the protease inhibitor.

Antithrombins↗
PubMed1986

Antithrombin III Alger: a new homozygous AT III variant.

A qualitative abnormality of antithrombin III (AT III) was found in the plasma of a 41-year old patient. The plasmatic AT III antigen concentration was 130% and the progressive anti-F IIa and anti-F Xa activities were normal (105% and 137%). The plasma heparin cofactor activity was less than 10%, when measured by F IIa or F Xa inhibition. Crossed immunoelectrophoresis of AT III in the presence of heparin revealed in the plasma an abnormal slow-moving peak. When tested by affinity chromatography on heparin Sepharose, this abnormal AT III did not bind to heparin. Among the investigated relatives, 5 subjects had normal AT III levels, whatever the test used, the nine others having reduced levels of antithrombin heparin cofactor activity (45-61%) but normal levels of immunoreactive AT III (97-122%). Consanguinity was found in the family history. We therefore considered our patient as homozygous for an AT III molecular abnormality affecting the binding site for heparin.

Adult↗
PubMed1986

[Assessment of the risk of postpartum thromboembolism by measuring antithrombin III levels. A false hope].

In order to predict better thrombo-embolic complications that sometimes occur after delivery, we studied the variations of antithrombin III levels (A.T. III) in 703 women, at the 8th month pregnancy (275 levels), on the first day (609 levels) and the 5th day (516 levels) after delivery. The average antithrombin III levels were respectively 90.8%, 83.4% and 98.7%. We found 120 levels (8.5%) lower than 80% (normal range for A.T. III = 80-120%), 107 of which on the first day after delivery were followed by a rapid increase to the normal range; these women however were satisfactory in the post-partum period. Therefore predicting thrombo-embolic complications in the post-partum period through A.T. III levels determination would seem to be pointless.

Adult↗
PubMed1986

Polyethylene glycol can be validly omitted from chromogenic peptide substrate assay for antithrombin III.

To investigate whether the characteristics of a commercial test kit for antithrombin III (Berichrom Antithrombin III) could be influenced by surfactants such as Tween-80 or polyethylene glycol (PEG), we performed some experiments with the original kit reagents and with the reagents dissolved in surfactants. Neither the reliability of the calibration curve nor the data for precision and assay kinetics were amended by the addition of either PEG to the (human) thrombin reagent or Tween-80 to the chromogenic substrate. In the same test system, assays with some other chromogenic substrates and with bovine thrombin showed comparable behavior. Evidently, if one follows the working scheme proposed for this kit, the use of surfactants is not warranted.

Antithrombin III↗
PubMed1987

Platelet antithrombin defect in malignancy: platelet protein alterations.

Sixty-eight patients with malignant disease were divided into two groups based on the results of the platelet antithrombin test (PAT). The normal group had a PAT clotting time ranging from 21.4 to 29.8 seconds, which was equivalent to 25% to 65% inactivation of the 2 U of thrombin added to the test system. The other group showed abnormal PAT clotting time, less than 21.4 seconds or less than 25% thrombin inactivation. The polypeptide composition of platelets from the two patient groups was analyzed by sodium dodecyl sulfate (SDS)-electrophoresis on 7.5% polyacrylamide gels. A polypeptide of 180,000 apparent mol wt was decreased or absent in both Coomassie blue- and Alcian blue-stained gels of the platelets from patients whose PAT was abnormal; this polypeptide comigrated with purified platelet thrombospondin. Tritium labeling of platelet surface glycoproteins by the periodate-borohydride method followed by two-dimensional electrophoresis was performed on platelets of seven patients with abnormal PAT. When they were compared with ten patients with normal PAT, a glycoprotein of 140,000 apparent mol wt with a pl of 4.5 to 5.2 was decreased in platelets of all seven patients with abnormal PAT. Nitrocellulose replicas of one-dimensional gels of platelets from 13 of 14 patients with abnormal PAT showed decreased reaction with an anti-human platelet glycocalicin antiserum. Platelets of these same patients also showed a decreased or absent platelet agglutination induced by ristocetin. Patients with normal PAT had a mean agglutination slope of 1.25 +/- 0.6 (n = 26) as compared with 0.37 +/- 0.34 (n = 26) for the abnormal PAT group (P less than .001). Results indicate that platelets from a subpopulation of tumor patients characterized by decreased platelet antithrombin activity have alterations in two platelet glycoproteins, identified as GPIb and thrombospondin.

Antithrombins↗
PubMed1985

Effect of heparin on the inactivation rate of human activated factor XII by antithrombin III.

Human antithrombin III (ATIII) is a plasma inhibitor of several serine proteases of the blood coagulation system. Previous investigations have reported that the presence of heparin has a multifold accelerating effect on the inhibition of factor XIIa and XIIf, the active species derived from factor XII. Recent studies from our laboratories have confirmed that ATIII inactivates factor XIIa and factor XIIf, but only contributes 2% to 3% to the inhibition of activated factor XII species in plasma. The major inhibitor is C1 inhibitor. Therefore, we have reexamined the heparin effect on the rate of inhibition of factor XIIa and factor XIIf in purified systems. We also have studied the effect of heparin on the inactivation of both factor XII-derived active species by various plasmas. Using purified factor XIIa and ATIII, we found that heparin (0.7 to 34.0 U/mL) increased the rate of inhibition of Factor XIIa. However, at heparin concentrations usually achieved during anticoagulant therapy (0.7 U/mL), the inhibition was accelerated only fourfold. This implies only a 6% contribution to the inhibitory effect of plasma. This suggestion was confirmed by the observation that heparin (1.5 U/mL) added to factor XII-deficient plasma and reconstituted with factor XIIa did not produce a detectable enhancement of the rate of inhibition of factor XIIa. Furthermore, using purified factor XIIf and antithrombin III, heparin (3.6 to 57.2 U/mL) increased the inactivation rate constant of factor XIIf by 1.6 to 14.0 times. This small effect was confirmed by the observation that heparin at a concentration greater than that sufficient for anticoagulation (1.4 U/mL) did not modify the inactivation rate of factor XIIf by prekallikrein-deficient plasma, and thus C1 inhibitor remains the major inhibitor even in the presence of heparin. From this study and our previous investigations on the effect of heparin on the inhibition of kallikrein and factor XIa, we conclude that heparin does not significantly affect the protease activity of purified contact activation factors or the activities expressed by these proteases in plasma.

Antithrombin III↗
PubMed1985

Antithrombin III deficiency: an etiology of Budd-Chiari syndrome.

This report documents a unique case of Budd-Chiari syndrome associated with antithrombin III deficiency and massive thrombus in the superior vena cava and right atrium. This aberration of the coagulation mechanism is proposed as an etiologic factor in the pathogenesis of hepatic venous obstruction whenever the cause is obscure. Antithrombin III was restored to a level adequate to permit thrombus extraction with cardiopulmonary bypass and relief of portal hypertension with a mesoatrial shunt. The protocol for reversing this hypercoagulable state with fresh frozen plasma and warfarin (Coumadin) is discussed, and technical innovations employed in the management of this complex problem are described.

Antithrombin III Deficiency↗