Prediction of Vitamin K Response Using the Echis Time and Echis-Prothrombin Time Ratio

Summary Echis carinatus venom contains proteases capable of activating both normal and descarboxy prothrombin. We showed this venom (Sigma) principally activates prothrombin with almost no factor X activation. Echis time in combination with prothrombin time can predict vitamin K responsiveness since the Echis time is usually normal in the presence of descarboxy prothrombin associated with vitamin K deficiency.38 patients with abnormal routine prothrombin times (PT) had both coagulant and immunogenic factor II assays along with Echis times done before and after vitamin K. Of 22 patients responding to vitamin K, based on correction of PT, 21 had normal initial Echis times and of 16 not responding, 11 had abnormal Echis times, giving a sensitivity of 95.4% and specificity of 68.8% for vitamin K responsiveness. 90% of patients with a PT/Echis time ratio <1.3 and a prolonged Echis time did not correct their PTs with vitamin K therapy.The 5 non-responders with normal Echis times all showed normal initial coagulant and antigenic prothrombin, but 3 had low F V and/or F VII.

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Spectrophotometric Assays of Prothrombin in Plasma of Patients Using Oral Anticoagulants

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657025 ◽

1979 ◽

Vol 42 (04) ◽

pp. 1296-1305 ◽

Cited By ~ 29

Author(s):

R M Bertina ◽

W van der Marel-van Nieuwkoop ◽

E A Loeliger

Keyword(s):

Prothrombin Time ◽

Vitamin K ◽

Oral Anticoagulation ◽

Vitamin K Antagonists ◽

Oral Anticoagulants ◽

Factor Xa ◽

Factor V ◽

Anticoagulant Treatment ◽

Factor Ii ◽

K Deficiency

SummaryTwo spectrophotometric assays for prothrombin have been developed and compared with a one stage coagulant and an immunological assay. One of these assays (called the XAPC assay) uses a combination of factor Xa, phospholipid, Ca2+ and factor V as activator of prothrombin, and measures only normal prothrombin. The second (the ECAR assay) uses Echis carinatus venom as activator. This assay measures both normal prothrombin and PIVKA II (protein induced by vitamin K antagonists/absence). Combination of the results obtained by the XAPC and ECAR assays provides rapid and reliable information on the degree of “subcarboxylation” of prothrombin (oral anticoagulation, vitamin K deficiency).For patients on long term anticoagulant treatment the prothrombin time (Thrombotest) shows better correlation with the ratio prothrombin/prothrombin plus PIVKA II (XAPC/ ECAR) than with the factor II concentration. For patients starting the anticoagulant treatment there is no correlation between the Thrombotest time and the XAPC/ECAR ratio.It seems doubtful that (a) spectrophotometric factor II assay(s) will be as useful as the prothrombin time in the control of oral anticoagulation.

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Four methods compared for measuring des-carboxy-prothrombin (PIVKA-II).

Clinical Chemistry ◽

10.1093/clinchem/33.11.2074 ◽

1987 ◽

Vol 33 (11) ◽

pp. 2074-2078 ◽

Cited By ~ 33

Author(s):

J Widdershoven ◽

P van Munster ◽

R De Abreu ◽

H Bosman ◽

T van Lith ◽

...

Keyword(s):

Snake Venom ◽

Vitamin K ◽

Barium Sulfate ◽

Reliable Method ◽

Clinical Symptoms ◽

Vitamin K Deficiency ◽

Factor Ii ◽

K Deficiency ◽

Echis Carinatus ◽

Functional Factor

Abstract PIVKA-II (Protein Induced by Vitamin K Absence) is abnormal des-carboxylated prothrombin, which is present in vitamin K deficiency or in patients using warfarin. With a sensitive method for PIVKA-II, biochemical vitamin K deficiency can be established before clinical symptoms occur. We give an overview of methods used to detect PIVKA-II, and four selected methods are inter-compared: (a) measuring total factor II including PIVKA-II by using Echis carinatus snake venom as an activator of prothrombin; (b) measuring PIVKA-II by using snake venom as an activator of factor II after adsorption of functional factor II onto barium sulfate; (c) electrophoresis-immunofixation method; and (d) enzyme immunoassay. We found d to be the most sensitive and reliable method for PIVKA-II.

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Kinetic Aspects of the Interaction of Blood-Clotting Enzymes

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651250 ◽

1968 ◽

Vol 20 (01/02) ◽

pp. 078-087 ◽

Cited By ~ 34

Author(s):

H. C Hemker ◽

A. D Muller

Keyword(s):

Vitamin K ◽

Blood Clotting ◽

Experimental Results ◽

Factor X ◽

Clotting Factors ◽

Vitamin K Deficiency ◽

K Deficiency

SummaryPIVKA, the circulating anticoagulant protein found in vitamin K deficiency can, on kinetical grounds, be recognized as an analogue of factor X. The existence of analogues of other vitamin K-dependent clotting factors cannot be ruled out, but need not be assumed to explain the experimental results.

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The Reaction of Thiol Compounds with the Vitamin-K Dependent Clotting Factors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653570 ◽

1969 ◽

Vol 21 (03) ◽

pp. 573-579 ◽

Cited By ~ 1

Author(s):

P Fantl

Keyword(s):

Prothrombin Time ◽

Vitamin K ◽

Anaerobic Conditions ◽

Clotting Factors ◽

Thiol Compounds ◽

Aerobic Conditions ◽

One Stage ◽

Factor Ii ◽

Ph Dependent ◽

The One

SummaryTreatment of human and dog oxalated plasma with 0.2 to 1.0 × 10−1 M 2.3-dithiopropanol (BAL) or dithiothreitol (DTT) at 2–4° C for 30 min results in the reduction of the vitamin-K dependent clotting factors II, VII, IX and X to the respective-SH derivatives. The reaction is pH dependent. Under aerobic conditions the delayed one stage prothrombin time can be partly reversed. Under anaerobic conditions a gradual prolongation of the one stage prothrombin time occurs without reversal.In very diluted plasma treated with the dithiols, prothrombin can be converted into thrombin if serum as source of active factors VII and X is added. In contrast SH factors VII, IX and X are inactive in the specific tests. Reoxidation to active factors II, VII, IX and X takes place during adsorption and elution of the SH derivatives. The experiments have indicated that not only factor II but also factors VII, IX and X have active-S-S-centres.

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Vitamin K Deficiency in Newborns: A Case Report in α-1-Antitrypsin Deficiency and a Review of Factors Predisposing to Hemorrhage

PEDIATRICS ◽

10.1542/peds.73.5.712 ◽

1984 ◽

Vol 73 (5) ◽

pp. 712-716

Author(s):

Nathaniel R. Payne ◽

Duane K. Hasegawa

Keyword(s):

Prothrombin Time ◽

Vitamin K ◽

Partial Thromboplastin Time ◽

Signs And Symptoms ◽

Serum Bilirubin Level ◽

Intracerebral Hematoma ◽

Cholestatic Liver Disease ◽

Vitamin K Deficiency ◽

Antitrypsin Deficiency ◽

K Deficiency

A 4-week-old, breast-fed female infant appeared healthy until signs and symptoms of CNS deterioration suddenly occurred. At presentation the infant was found to have a left-sided parietal intracerebral hematoma, markedly prolonged prothrombin time, and partial thromboplastin time, normal platelet count, and jaundice with a total and direct serum bilirubin level of 5.4 mg/dL and 2.6 mg/dL, respectively. Vitamin K1 and fresh frozen plasma returned the prothrombin time and partial thromboplastin time to normal values within 18 hours, suggesting that the infant had severe vitamin K deficiency complicated by intracerebral hemorrhage. Evaluation of the infant's direct hyperbilirubinemia led to the diagnosis of homozygous (pi-type ZZ [PiZZ]) α-1-antitrypsin deficiency. The clinical circumstances predisposing to vitamin K deficiency in newborns and infants are discussed. Based on our observations in this case, we suggest that cholestatic liver disease should be suspected when unexplained vitamin K deficiency occurs in early infancy. The role of vitamin K in hemostasis and the laboratory diagnosis of vitamin K deficiency are discussed as they apply to the evaluation of hemorrhage in newborns and infants.

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The Inhibitor of Prothrombin Conversion in Plasma of Patients on Oral Anticoagulant Treatment

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650178 ◽

1981 ◽

Vol 45 (03) ◽

pp. 237-241 ◽

Cited By ~ 13

Author(s):

R M Bertina ◽

M E J Westhoek-Kuipers ◽

G H J Alderkamp

Keyword(s):

Vitamin K ◽

Spectrophotometric Assay ◽

Factor Ix ◽

Factor Vii ◽

Factor X ◽

Dilution Curve ◽

Anticoagulant Treatment ◽

Oral Anticoagulant Treatment ◽

Coagulation Assays ◽

Factor Ii

SummaryPooled 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 VII 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 assays 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.

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Factor VII Activity and Antigen in Haemophilia B Variants

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650001 ◽

1980 ◽

Vol 43 (01) ◽

pp. 016-019 ◽

Cited By ~ 5

Author(s):

M G Mazzucconi ◽

R M Bertina ◽

D Romoli ◽

M Orlando ◽

G Avvisati ◽

...

Keyword(s):

Prothrombin Time ◽

Vitamin K ◽

Normal Values ◽

Factor Ix ◽

Factor Vii ◽

Confidence Limits ◽

Vitamin K Deficiency ◽

Haemophilia B ◽

K Deficiency ◽

Mild Deficiency

SummaryTwenty three patients belonging to 18 different pedigrees of Haemophilia B were studied with regard to ox-brain prothrombin time and its correlation to factor VII.Eleven among them were B-negative (no detectable factor IX antigen), five were B-reduced (factor IX antigen detectable but below the normal values) and seven were B-positive (normal levels of factor IX antigen).Ox-brain prothrombin time was found prolonged (≥ x̄ + 2.5 SD:99% confidence limits) in nine patients. Factor VII Activity (VII: C) was found reduced in 1/11 B-negative, in 2/5 B-reduced and in 4/7 B-positive patients. Factor VII Antigen (VII: Ag) was found normal in all but one patient.The ratio VII:C/VII:Ag was abnormal in eight patients independently from the variant of Haemophilia B. The underlying defect which causes the prolongation of Ox-brain prothrombin time due to factor VII: C mild deficiency is heterogeneous. Age, a mild Vitamin K deficiency, the presence of an inhibitor of Factor VII activation and other unknown causes, may be responsible for this pattern.

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ACUTE INTERRUPTION OF ORAL ANTICOAGULANT THERAPY: A THROMBOTIC RISK?

10.1055/s-0038-1643265 ◽

1987 ◽

Author(s):

J Rouvier ◽

H Vidal ◽

J Gallino ◽

M Boccia ◽

A Scazziota ◽

...

Keyword(s):

Anticoagulant Therapy ◽

Vitamin K ◽

Oral Anticoagulant ◽

Protein C ◽

Oral Anticoagulant Therapy ◽

Factor Vii ◽

Factor X ◽

Functional Protein ◽

Thrombotic Risk ◽

Factor Ii

It is still on discussion how oral anticoagulant therapy must be interrupted. A progressive diminution of drug intake have been proposed in order to avoid a MreboundM of vitamin K-dependent procoagulant factors. At the present, it is well known that coumarin drugs affect not only the biologic activity of factors II, VII, IX and X but also Protein C (PC), an inhibitor of coagulation kinetics, and their cofactor Protein S. With the aim to determine the recovery level of PC in relation with the others vitamin K-dependent factors, the effect of suppression of anticoagulant therapy in patients under chronic treatment with acenocoumarin was studied.Quick time, functional factors II, VII, X (one stage methods), functional PC (Francis method) and immunological Factor II and Protein C (Laurell) were determined before and 36 hours after suspension of acenocoumarin administration.Results showed that: 1) Recovery levels of functional Protein C (increased from 28.55% ±2.57 to 72.64% ±5.9) were significantly higer than functional Factor II (22.09% ±2.34 to 30.73% ±8.64), Factor VII (22.55% ±2.01 to 40.73% ±4.85) and Factor X (23.27% ±2.66 to 39.18% ±3.19). Statistical analysis (Newmann-Keuls test) showed at least a p<0.01 between PC increase and factors II, VII or X increment.2) No significant differences were seen between immunological levels of Factor II before and after suspension of acenocoumarin.3) Levels of immunological PC in patients under anticoagulant therapy were higer than functional PC. After acenocoumarin suppression, not correlation was seen between immunological and functional Protein C recovery.It is concluded that acute suppression of acenocoumarin does not induce a thrombotic tendency because the recuperation of functional Protein C is more important than factors II, VII and X recovery.

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Causes of Vitamin K Deficiency in Patients on Haemodialysis

Nutrients ◽

10.3390/nu12092513 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2513

Author(s):

Signe Wikstrøm ◽

Katrine Aagaard Lentz ◽

Ditte Hansen ◽

Lars Melholt Rasmussen ◽

Jette Jakobsen ◽

...

Keyword(s):

Vitamin K ◽

Absorption Capacity ◽

Protein Supplementation ◽

Matrix Gla Protein ◽

Vitamin K1 ◽

High Concentration ◽

Vitamin K Deficiency ◽

Before And After ◽

K Deficiency ◽

The Difference

Background: A low vitamin K status is common in patients on haemodialysis, and this is considered one of the reasons for the accelerated atherosclerosis in these patients. The vitamin is essential in activation of the protein Matrix Gla Protein (MGP), and the inactive form, dp-ucMGP, is used to measure vitamin K status. The purpose of this study was to investigate possible underlying causes of low vitamin K status, which could potentially be low intake, washout during dialysis or inhibited absorption capacity. Moreover, the aim was to investigate whether the biomarker dp-ucMGP is affected in these patients. Method: Vitamin K intake was assessed by a Food Frequency Questionnaire (FFQ) and absorption capacity by means of D-xylose testing. dp-ucMGP was measured in plasma before and after dialysis, and phylloquinine (vitamin K1) and dp-ucMGP were measured in the dialysate. Changes in dp-ucMGP were measured after 14 days of protein supplementation. Results: All patients had plasma dp-ucMGP above 750 pmol/L, and a low intake of vitamin K. The absorption capacity was normal. The difference in dp-ucMGP before and after dialysis was −1022 pmol/L (p < 0.001). Vitamin K1 was not present in the dialysate but dp-ucMGP was at a high concentration. The change in dp-ucMGP before and after protein supplementation was −165 pmol/L (p = 0.06). Conclusion: All patients had vitamin K deficiency. The reason for the low vitamin K status is not due to removal of vitamin K during dialysis or decreased absorption but is plausibly due to a low intake of vitamin K in food. dp-ucMGP is washed out during dialysis, but not affected by protein intake to a clinically relevant degree.

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Surface-dependent reactions of the vitamin K-dependent enzyme complexes

Blood ◽

10.1182/blood.v76.1.1.1 ◽

1990 ◽

Vol 76 (1) ◽

pp. 1-16 ◽

Cited By ~ 611

Author(s):

KG Mann ◽

ME Nesheim ◽

WR Church ◽

P Haley ◽

S Krishnaswamy

Keyword(s):

Tissue Factor ◽

Vitamin K ◽

Blood Clotting ◽

Catalytic Efficiency ◽

Coagulation Cascade ◽

Factor Xii ◽

Factor X ◽

Membrane Bound ◽

Factor X Activation ◽

Enzyme Complexes

Abstract During the past 20 years contributions from many laboratories have led to the development of isolation procedures, delineation of primary structures, and more recently, to the expression of recombinant proteins associated with the coagulation cascade. In general, studies of coagulation proteins under defined conditions have demonstrated the prescience of Davie and Ratnoff and MacFarlane in their proposals of the coagulation cascade. The more recent discovery of thrombomodulin by Esmon et al has led to the identification and characterization of components of the vitamin K-dependent anticoagulant pathway. In this review we have attempted to analyze and compare the functional properties of each of the vitamin K-dependent enzyme complexes associated with the procoagulant and anticoagulant phases of blood clotting. Although dissimilarities exist, the vitamin K-dependent complexes have analogous requirements and appear to function with a common general mode of organization. Membrane-bound cofactors serve as anchoring sites for the appropriate membrane-binding enzymes. This process localizes the complex on the membrane surface and increases the catalytic efficiency for substrate utilization. Complex formation provides extraordinary improvements in the catalytic efficiency for the complexes as compared with their soluble enzyme components. Membrane- bound complexes provide a mechanism that can be regulated at a site by membrane presentation, zymogen activation, and cofactor activation or presentation. The kinetic constants obtained for the various coagulation reactions determined in vitro provide some insights into how these pathways may function in vivo. The catalytic efficiency (kcat/Km) for factor X activation by factor VIIIa/factor IXa is far in excess of the catalytic efficiency of activation of factor X by tissue factor/factor VIIa (Table 3). This may provide a rational interpretation for the observation that patients with hemophilia A and B bleed even though they appear to have an alternative pathway to factor X activation. In addition, tissue factor is not ordinarily presented by the vascular tissue that has direct access to blood. However, it appears that extravascular constitutive tissue factor is available once the blood vessel becomes disrupted. The efforts to identify the initiating reactions of the blood coagulation process have not been unambiguously successful. We conclude that factor VII is most likely a zymogen, just as are the other proenzymes of the blood clotting process. In addition, it is difficult to rationalize the importance of the intrinsic pathway of coagulation involving factor XII, prekallikrein, and high molecular weight kininogen since the congenital absence of any one of these factors does not result in abnormal bleeding.

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