1
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Affiliation(s)
- M Makris
- The Departments of Haematology, Doncaster Royal Infirmary and Royal Hallamshire Hospital, Sheffield, UK
| | - G Bardhan
- The Departments of Haematology, Doncaster Royal Infirmary and Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The Departments of Haematology, Doncaster Royal Infirmary and Royal Hallamshire Hospital, Sheffield, UK
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2
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Kitchen S, Walker ID, Woods TAL, Preston FE. Thromboplastin Related Differences in the Determination of International Normalised Ratio: A Cause for Concern? Thromb Haemost 2018. [DOI: 10.1055/s-0038-1648883] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.
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Affiliation(s)
- S Kitchen
- From University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - I D Walker
- Department of Haematology, Glasgow Royal Infirmary, Glasgow, UK
| | - T A L Woods
- From University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- From University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
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3
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Ford I, Li C, Cooke ID, Preston FE. Changes in Haematological Indices, Blood Viscosity and Inhibitors of Coagulation during Treatment of Endometriosis with Danazol. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1648842] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe effects of treatment with danazol (600 mg daily) on haemostatic and haematological function were investigated in 18 pre-menopausal women with endometriosis. Blood samples were taken at 2 pre-treatment visits, at 6, 12 and 24 weeks on treatment, and at 6 weeks after discontinuation of the drug. Haemoglobin, red cell count, haematocrit and platelet count all rose significantly during treatment with danazol (p <0.01 vs. baseline). Plasma fibrinogen levels fell significantly (p <0.01), while whole blood viscosity increased during treatment and remained significantly elevated at follow-up. The prothrombin time shortened, but remained within normal limits, and there were no significant changes in factor VII:C, Vila, or fibrinopeptide A. No significant changes were found in platelet function. Plasma B-beta 15-42 increased significantly. Functional levels of protein C, protein S, and antithrombin III, all rose significantly, above the normal range, while C4b-binding protein levels fell. We conclude that the observed changes in coagulation inhibitors and fibrinolytic activity may be considered beneficial in the context of venous thromboembolism. The rheological effects, however, indicate a degree of caution in the use of the drug in individuals considered to be at risk from arterial cardiovascular disease.
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Affiliation(s)
- I Ford
- The Section of Haematology, University Department of Medicine and Pharmacology, Royal Hallamshire Hospital, U. K
| | - C Li
- University Department of Obstetrics and Gynaecology, Jessop Hospital for Women, Sheffield, U. K
| | - I D Cooke
- University Department of Obstetrics and Gynaecology, Jessop Hospital for Women, Sheffield, U. K
| | - F E Preston
- The Section of Haematology, University Department of Medicine and Pharmacology, Royal Hallamshire Hospital, U. K
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4
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Kluft C, Preston FE, Malia RG, Bertina RM, Wijngaards G, Greaves M, Verheijen JH, Dooijewaard G. Stanozolol-Induced Changes in Fibrinolysis and Coagulation in Healthy Adults. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1661049] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe effects of orally-administered stanozolol, 5 mg b. d. on fibrinolysis, coagulation and on various haematological and biochemical parameters have been studied in 16 healthy adults, 8 males and 8 females. Statistically significant enhancement of extrinsic (tissue-type) plasminogen activator activity was detected in all subjects studied. This was associated with significant increases in plasma plasminogen and a concomitant reduction in histidine-rich glycoprotein. There were no changes in plasma urokinase activity. Changes in the coagulation system included significant reduction in plasma fibrinogen and elevation of protein C and anti thrombin III. Changes in plasma lipids included significant reduction of HDL cholesterol associated with an increase in LDL triglycerides. No change occurred in total cholesterol. There were no major differences between the sexes, nor were there serious side effects.The effects of stanozolol on extrinsic (tissue-type) plasminogen activator activity, “free” plasminogen, protein C and antithrombin III, argue strongly in favour of its therapeutic potential.
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Affiliation(s)
- C Kluft
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
| | - F E Preston
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, U. K
| | - R G Malia
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, U. K
| | - R M Bertina
- The Haemostasis and Thrombosis Research Unit, Leiden University Hospital, Leiden, The Netherlands
| | - G Wijngaards
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
| | - M Greaves
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, U. K
| | - J H Verheijen
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
| | - G Dooijewaard
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
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5
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Abstract
SummaryFibrinolytic activity in plasma euglobulin fractions can be increased by oral administration of stanozolol. This increase is not caused by increased synthesis or release of tissue-type plasminogen activator. A decreased level of fast acting t-PA inhibition is very probably the cause of the higher activity. These results suggest that this inhibition has a regulatory role on fibrinolysis in vivo.
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Affiliation(s)
- J H Verheijen
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
| | - D C Rijken
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
| | - G T G Chang
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
| | - F E Preston
- The University Dept. of Haematology, Royal Hallamshire Hospital, Sheffield, U.K
| | - C Kluft
- The Gaubius Institute, Health Research Division TNO, Leiden, The Netherlands
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6
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Greer IA, Greaves M, Madhok R, McLoughlin K, Porter N, Lowe GDO, Preston FE, Forbes CD. Effect of Stanozolol on Factors VIII and IX and Serum Aminotransferases in Haemophilia. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1661320] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe treatment of haemophilia has been dramatically improved since the introduction of factor VIII and IX concentrates, however these concentrates have brought new problems such as hepatitis and A.I.D.S. An oral agent which could raise endogenous levels of factor VIII and IX would be of great benefit. Danazol, an anabolic steroid, has recently been shown to increase levels of factors VIII and IX in haemophilia. We therefore studied the effect of stanozolol, a closely related anabolic steroid, in 15 patients with haemophilia A or Christmas disease over a 2-4 week period. There was no consistent change in factor VIIIc or factor IX, and fibrinolysis was significantly enhanced. No effect was apparent on the incidence of spontaneous bleeds. However serum aminotransferases which were abnormal in 11 of the 15 patients at the start of the study fell significantly with stanozolol therapy. This raises the interesting possibility that anabolic steroids may be beneficial in patients with chronic liver diseases.
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Affiliation(s)
- I A Greer
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - M Greaves
- The Dept. of Haematology, University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - R Madhok
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - K McLoughlin
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - N Porter
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - G D O Lowe
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - F E Preston
- The Dept. of Haematology, University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
| | - C D Forbes
- The University Dept. of Medicine, Royal Infirmary, Glasgow, UK
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7
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Abstract
SummaryUmbilical cord plasmas from 24 normal full-term neonates were studied. We confirmed the prolonged prothrombin time and low levels of Vitamin K dependent clotting factors previously described (1), but using a number of recently developed immunological and coagulation techniques we could find no evidence of vitamin K deficiency. We conclude that the decreased levels of vitamin K dependent clotting factors of normal neonates are the result of decreased synthesis by the immature liver and that it is questionable whether vitamin K prophylaxis is necessary for these infants.
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Affiliation(s)
- R G Malia
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, England
| | - F E Preston
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, England
| | - V E Mitchell
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, England
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8
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Jennings I, Kitchen S, Woods TA, Preston FE, Greaves M. Potentially Clinically Important Inaccuracies in Testing for the Lupus Anticoagulant: an Analysis of Results from three Surveys of the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1656080] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe identification of the presence of antiphospholipid in plasma is recognised to be of diagnostic and prognostic importance in subjects with thrombotic disease, recurrent miscarriage or collagen vascular disorders. A number of coagulation assays are currently employed for the detection of lupus anticoagulant (LA), many of which are influenced by reagent dependent and methodological variables.In the present study lyophilised plasma samples from three subjects with “strong”, “weak” and “absent” LA were tested in 220 centres. The most commonly used tests for LA were Activated Partial Thromboplastin Time (APTT), Dilute Russell Viper Venom Time (DRVVT) and Kaolin Clotting Time (KCT). Median DRVVT ratios were 1.75, 1.17 and 1.10 for the three samples. The presence of a strong LA was not detected by 4% of laboratories. The correct diagnosis was made by 94% of users of DRVVT and 85% of users of KCT. A weak LA was not detected by over half of centres. Correction was observed on addition of plasma and also in platelet neutralisation. The correct diagnosis was made by 37% of users of DRVVT and 27% of users of KCT. Lupus Anticoagulant was falsely considered to be present in a Factor IX deficient plasma by approximately one quarter of laboratories. Amongst users of DRVVT and KCT absence of LA in this sample was correctly reported by 73% and 69% of centres respectively.The accuracy of testing for LA in the present study is suboptimal and this is likely to have important clinical consequences. There is clearly a need for greater conformity in the selection and performance of LA tests to facilitate accurate diagnosis of this important group of disorders.
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Affiliation(s)
- I Jennings
- (on behalf of the UK National External Quality Assessments Scheme for Blood Coagilation)
| | - S Kitchen
- (on behalf of the UK National External Quality Assessments Scheme for Blood Coagilation)
| | - T A.L Woods
- (on behalf of the UK National External Quality Assessments Scheme for Blood Coagilation)
| | - F E Preston
- (on behalf of the UK National External Quality Assessments Scheme for Blood Coagilation)
| | - M Greaves
- The Department of Medicine and Therapeutics, Aberdeen University, UK
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9
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Nesbitt IM, Goodeve AC, Guilliatt AM, Makris M, Preston FE, Peake IR. Characterisation of Type 2N von Willebrand Disease Using Phenotypic and Molecular Techniques. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1650401] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Summaryvon Willebrand factor (vWF) is a multimeric glycoprotein found in plasma non covalently linked to factor VIII (FVIII). Type 2N von Willebrand disease (vWD) is caused by a mutation in the vWF gene that results in vWF with a normal multimeric pattern, but with reduced binding to FVIII.We have utilised methods for the phenotypic and genotypic detection of type 2N vWD. The binding of FVIII to vWF in 69 patients, 36 with type 1 vWD, 32 with mild haemophilia A and one possible haemophilia A carrier with low FVIII levels was studied. Of these, six were found to have reduced binding (five type 1 vWD, one possible haemophilia A carrier), DNA was extracted from these patients and exons 18-23 of the vWF gene encoding the FVIII binding region of vWF were analysed. After direct sequencing and chemical cleavage mismatch detection, a Thr28Met mutation was detected in two unrelated individuals, one of whom appears to be a compound heterozygote for the mutation and a null allele. No mutations were found in the region of the vWF gene encoding the FVIII binding region of vWF in the other four patients
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Affiliation(s)
- I M Nesbitt
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - A C Goodeve
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - A M Guilliatt
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - M Makris
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - I R Peake
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
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10
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Nesbitt IM, Goodeve AC, Preston FE, Peake IR. von Willebrand Factor/Factor VIII Binding Is not Affected by the Arg89Gln Polymorphism in von Willebrand Factor. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1650671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- I M Nesbitt
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - A C Goodeve
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
| | - I R Peake
- The Sections of Molecular Genetics and Haematology, Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
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11
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Kitchen S, Jennings I, Woods TAL, Walker ID, Preston FE. Two Recombinant Tissue Factor Reagents Compared to Conventional Thromboplastins for Determination of International Normalised Ratio: A Thirty-three-laboratory Collaborative Study. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1650586] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryRecent advances in recombinant technology have led to the development of prothrombin time (PT) reagents containing recombinant tissue factor which has been lipidated to allow expression of procoagulant activity. In this study we have compared International Normalised Ratios (INRs) determined using two such reagents and conventional thromboplastins in widespread use in the UK.Lyophilised plasma samples from eight different warfarinised patients were distributed to 33 laboratories in the UK. Each participant determined prothrombin times on 20 local fresh normal plasmas (used to derive mean normal PT and calculate INR) and the eight lyophilised samples, using manual technique and the following thromboplastins; Recombiplastin (Ortho Diagnostics Ltd); Innovin (Baxter Diagnostics Ltd); the conventional thromboplastin in local use.For eight plasmas the mean INRs determined with different reagents were as follows: Innovin (33 laboratories) - 3.4; Manchester Reagent (MR = 8 laboratories) - 3.4; Recombiplastin (33 laboratories) - 3.7; Instrumentation Laboratory (IL = 13 laboratories) - 4.4.Mean INR results with Recombiplastin were on average 7% greater than those obtained with Innovin, 8% greater than results with MR and 18% less than INRs with IL thromboplastin. There was no significant difference between results obtained with Innovin and MR. In contrast INRs obtained with IL were markedly (mean 28%) greater than results obtained with Innovin.This study employed lyophilised plasma and it is possible that some of the relationships described are influenced by this. However, the lyo-philisation process employed did not influence the relationship between INRs of warfarinised plasmas obtained by the four main reagents described, indicating that the results are relevant to routine clinical practice.In conclusion, our data show some important differences are present between INRs determined using Recombiplastin, Innovin and two conventional thromboplastins.
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Affiliation(s)
- S Kitchen
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield
| | - I Jennings
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield
| | - T A L Woods
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield
| | - I D Walker
- The Department of Haematology, Glasgow Royal Infirmary, Glasgow, UK
| | - F E Preston
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield
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12
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Hay CRM, Oilier W, Pepper L, Cumming A, Keeney S, Goodeve AC, Colvin BT, Hill FGH, Preston FE, Peake IR. HLA Class II Profile: A Weak Determinant of Factor VIII Inhibitor Development in Severe Haemophilia A. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1655944] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe risk of developing factor VIII inhibitor antibodies in haemophilia A may relate both to factor VIII genotype and genes within the HLA complex known to influence immune response. We investigated a cohort of 176 patients with severe haemophilia A and with either high-level inhibitors (>10BU/ml) or with no history of an inhibitor, stratified according to the presence or absence of the factor VIII gene intron 22 inversion.HLA DRB1, DQA1 and DQB1 polymorphisms were determined by PCR. HLA frequencies from 137 United Kingdom controls were used for comparison. HLA phenotype frequency differences, expressed as odds ratios with 95% confidence intervals were as follows: HLA- DRB*1501, DQB 1*0602 and DQA1*0102 were all increased in frequency in patients with inhibitors, only DQA1*0102 reaching statistical significance (OR 2.7,1.2-5.9). These alleles form part of an established HLA haplotype. The frequencies of HLA-DRB 1*1501, DQB1*0602 and DQA1*0102 were particularly raised in patients with inhibitors and a factor VIII gene intron 22 inversion, although again only DQA1*0102 achieved significance (OR 3.1, 1.0-10.1). The frequency of DRB 1*01, DQB 1 *0501, DQA 1*0101 were also increased in inhibitor patients lacking the intron 22 inversion although this failed to achieve statistical significance. This data suggests that HLA class II profile constitutes a weak risk factor for developing inhibitor antibodies to factor VIII. This may be more pronounced in patients with an intron 22 inversion.
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Affiliation(s)
- C R M Hay
- The University Department of Haematology, Manchester Royal Infirmary, Manchester, Ladywood, UK
| | - W Oilier
- Arthritis and Rheumatism Council Epidemiology Research Unit, Manchester Medical School, Manchester, Ladywood, UK
| | - L Pepper
- Arthritis and Rheumatism Council Epidemiology Research Unit, Manchester Medical School, Manchester, Ladywood, UK
| | - A Cumming
- The University Department of Haematology, Manchester Royal Infirmary, Manchester, Ladywood, UK
| | - S Keeney
- The University Department of Haematology, Manchester Royal Infirmary, Manchester, Ladywood, UK
| | - A C Goodeve
- Department of Haematology, Royal Hallamshire Hospital, Sheffield, Ladywood, UK
| | - B T Colvin
- Department of Haematology, Royal London Hospital, Whitechapel, Ladywood, UK
| | - F G H Hill
- Department of Haematology, Birmingham Children’s Hospital, Birmingham, Ladywood, UK
| | - F E Preston
- Department of Haematology, Royal Hallamshire Hospital, Sheffield, Ladywood, UK
| | - I R Peake
- Department of Haematology, Royal Hallamshire Hospital, Sheffield, Ladywood, UK
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13
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Kitchen S, Preston FE. The Therapeutic Range for Heparin Therapy: Relationship between Six Activated Partial Thromboplastin Time Reagents and Two Heparin Assays. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1650358] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe activated partial thromboplastin time (APTT) is the most commonly used test for laboratory monitoring of unfractionated heparin therapy. Since there are differences between APTT reagents in respect of responsiveness to heparin the widely used therapeutic range of 1.5-2.5 (APTT ratios) may not be appropriate for all reagents.The aim of this study was to assess the relationship between 6 different APTT reagents using a manual technique, 2 of these reagents used in combination with a coagulometer, a heparin assay by protamine titration and a chromogenic anti-Xa assay. Samples from 42 patients treated with unfractionated heparin for thromboembolic disease were studied, 12 of whom were receiving warfarin therapy with International Normalised Ratios (INR) of >1.3.For normal subjects, APTT results were highly dependent on the method used and statistically significant differences were noted. The ratio of patient to mean normal APTT was calculated for each APTT method. When 30 samples from heparinised patients (with INRs of <1.3) were analysed manually, the APTT ranges equivalent to 0.2-0.4 u/ml heparin by protamine titration (by regression analysis) were 1.6-1.9 for Boehringer reagent (the least responsive) up to 2.2-2.9 for Instrumentation Laboratory reagent (the most responsive). The concentration of heparin associated on average with APTT ratios of 1.5-2.5 varied approximately twofold to threefold between reagents.
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Affiliation(s)
- S Kitchen
- The Coagulation Unit, University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The Coagulation Unit, University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
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14
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Abstract
SummaryTo improve the management and therapeutic control of inpatients on anticoagulant drugs, combined prescription and monitoring charts have been developed for both heparin and warfarin which incorporate clinical guidelines. These have been introduced throughout a 700-bedded acute teaching hospital via a structured program of change management.We have demonstrated improvements in the quality of anticoagulant control (assessed with a custom-written computer program), adherence to clinical guidelines and quality of monitoring and prescribing of anticoagulants in inpatients.The percentage time spent under-anticoagulated with heparin (activated partial thromboplastin time ratio <1.5) fell from 32.7% to 18.5% (p<0.0001), whereas there was no change in percentage time over-anticoagulated (5.1% vs. 5.8%; p = ns). The percentage time spent under-anticoagulated with warfarin was unaltered (26.3% vs. 29.8%; p = ns) but the percentage time spent over-anticoagulated (International Normalised Ratio >4.5) was halved from 5.4% to 2.7% (p<0.001).We conclude that the introduction of the charts led to significant improvements in anticoagulant control.
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Affiliation(s)
- W S Phillips
- The Department of Cardiology, Royal Hallamshire Hospital Sheffield, UK
| | - J Smith
- The Department of Cardiology, Royal Hallamshire Hospital Sheffield, UK
| | - M Greaves
- The Department of Cardiology, Royal Hallamshire Hospital Sheffield, UK
| | - F E Preston
- The Department of Cardiology, Royal Hallamshire Hospital Sheffield, UK
| | - K S Channer
- The Department of Cardiology, Royal Hallamshire Hospital Sheffield, UK
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15
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Affiliation(s)
- F E Preston
- Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
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16
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Abstract
SummaryA number of different methods are available for the measurement of factor VIIa. Almost all of these employ ratios of two different measurements of factor VII. In order to determine which is the most sensitive to activated factor VII we have compared currently available methods in the following groups: two patients with haemophilia A following treatment with activated recombinant factor VII (rVII a); 6 normal plasmas during cold promoted activation of factor VII; normal individuals (n = 23); and patients with unequivocal disseminated intravascular coagulation (DIC, n = 19). Factor VII was measured in an amidolytic assay (VII: Amid) and an antigen assay (VII:Ag). Clotting activity was measured using rabbit (VII:C Rab), human (VII:C Hum) and bovine (VII:C Bov) thromboplastin.Of the clotting assays the most sensitive to the presence of factor VIIa was that which utilised bovine thromboplastin. Amidolytic and immunological measurements were unaffected by the activity state of factor VII. The ratios VII:C Rab/VII: Ag and VII:C Rab/VII:Amid were insensitive to activated factor VII. The ratios most sensitive to the presence of factor VII a were VII:C Bov/VII: Amid and VII: C Bov/VII:Ag. The ratios VII:C Bov/VII:C Rab and VII:C Bov/VII:C Hum are less sensitive but have the advantage for epidemiological studies of narrower reference ranges.
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Affiliation(s)
- S Kitchen
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - R G Malia
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The University Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
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17
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Abstract
SummaryWe have examined the in vitro effects of DN 9693 (piperidinylimidazo-quinazolinone) on various aspects of platelet reactivity. Our results are consistent with its known function as a phosphodiesterase inhibitor in that it increased platelet cyclic AMP, particularly in conjunction with an adenylate cyclase stimulator, and exerted a profound inhibitory effect on platelet aggregation responses to a variety of agonists. DN 9693 also inhibited ristocetin-induced platelet agglutination (RIPA). We therefore examined its effect on ristocetin co-factor assays and on the binding of a monoclonal antibody (McAb) to platelet membrane glycoprotein lb (GPIb). The drug inhibited the binding of the monoclonal antibody in a dose-dependent manner. This suggests an effect of the drug on the platelet surface membrane with reduced expression of GPIb. Our results indicate that in addition to its anticipated inhibitory effect on platelet aggregation, DN 9693 may also inhibit platelet adhesion.
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Affiliation(s)
- C Jackson
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - J Ball
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - J Peel
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - J Lawry
- The Department of Virology, University Medical School, Sheffield, UK
| | - M Greaves
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
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18
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Abstract
SummaryThrombospondin, a trimeric glycoprotein contained in the platelet α-granules, has been proposed as a marker of in vivo platelet activation. However, it is also synthesised by a range of other cells. The extraplatelet contribution to plasma levels of thrombospondin was therefore estimated by investigating the relationship between plasma thrombospondin levels and platelet count in samples from profoundly thrombocytopenic patients with marrow hypoplasia, using the platelet-specific α-granule protein β-thromboglobulin as control. Serum concentrations of both proteins were highly correlated with platelet count, but while plasma β-thromboglobulin levels and platelet count also correlated, there was no relationship between the number of platelets and thrombospondin concentrations in plasma. Serial sampling of patients recovering from bone marrow depression indicated that the plasma thrombospondin contributed by platelets is superimposed on a background concentration of at least 50 ng/ml probably derived from a non-platelet source, and plasma thrombospondin levels do not simply reflect platelet release.
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Affiliation(s)
- J Dawes
- The MRC/SNBTS Blood Components Assay Group, Edinburgh, UK
| | - D A Pratt
- The MRC/SNBTS Blood Components Assay Group, Edinburgh, UK
| | - M S Dewar
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
| | - F E Preston
- The Department of Haematology, Royal Hallamshire Hospital, Sheffield, UK
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Jennings I, Kitchen S, Smith J, Woods TAL, Preston FE. Between-centre Agreement in Homocysteine Assays: Experience from the UK NEQAS Proficiency Testing Scheme. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Kitchen S, Jennings I, Woods TAL, Preston FE. A UK National External Quality Assessment Scheme (UK Neqas) for Molecular Genetic Testing for the Diagnosis of Familial Thrombophilia. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1614873] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Beauchamp NJ, Makris M, Preston FE, Peake IR, Daly ME. Major Structural Defects in the Antithrombin Gene in Four Families with Type I Antithrombin Deficiency. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613898] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThe molecular basis of quantitative antithrombin deficiency was investigated in four families predicted to have major antithrombin gene rearrangements. A 1,442 bp deletion and insertion of the sequence 5’T(n = 38-40)GAGACG was characterised in one case. Sequence surrounding the breakpoints contained two perfect, and one imperfect, inverted repeats which may have mediated formation of a stem loop structure on one strand during DNA replication potentiating the deletion. A 9,219 bp deletion spanning introns 2 to 5 was identified in a second family. The identical 6 bp sequence was upstream of each breakpoint and the 5’ breakpoint was located in a sequence of the Alu 3 repeat predicted to be susceptible to strand breakage during transcription. This may have promoted misalignment, and deletion, of one of the repeats and the intervening DNA. A novel 1.8 kb antithrombin gene fragment was present in DNA digests from affected members of the third family suggesting a partial antithrombin gene duplication event while in the remaining family, evidence supporting a complete gene deletion was obtained.
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Daly ME, Tait RC, Walker ID, Brown K, Beauchamp NJ, Preston FE, Gyde H, Harper PL, Carrell RW, Perry DJ. Antithrombin Cambridge II (Ala384Ser): Clinical, Functional and Haplotype Analysis of 18 Families. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1614973] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThirty-one individuals from 18 unrelated families with antithrombin deficiency have been identified as having a single point mutation within codon 384 (13268 GCA→TCA) resulting in an alanine to serine substitution. Six families (11 individuals) were identified by the screening of individuals with thromboembolic disease or with a family history of thromboembolic disease, whilst the remaining 12 families (20 individuals) were identified by screening of asymptomatic blood donors. Four individuals had a history of venous thrombotic disease, a further 2 gave a history of superficial thrombophlebitis but the remaining 25 individuals were asymptomatic. Affected individuals demonstrated normal immunological levels of antithrombin but a decrease in anti-IIa activity in the presence of heparin. Haplotype analysis was used to examine the possibility of a founder effect to explain the high frequency of this non-CpG mutation. 29/31 individuals showed a single common “core” haplotype, the only variation existing in the number of copies of an (ATT)n repeat polymorphism – 13, 14, 15 or 17. The results suggest that at most there are four independent origins for this mutation.
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Doggen CJM, Zivelin A, Arruda VR, Aiach M, Siscovick DS, Hillarp A, Watzke HH, Bernardi F, Cumming AM, Preston FE, Reitsma PH, Rosendaal FR. Geographic Distribution of the 20210 G to A Prothrombin Variant. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615049] [Citation(s) in RCA: 306] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryA variant in prothrombin (clotting factor II), a G to A transition at nucleotide position 20210, has recently been shown to be associated with the prothrombin plasma levels and the risk of both venous and arterial thrombosis. The purpose of this study was to investigate the prevalence of carriership of this mutation in various populations.We combined data from 11 centres in nine countries, where tests for this mutation had been performed in groups representing the general population. We calculated an overall prevalence estimate, by a precision-weighted method, and, since the distribution of the prevalences did not appear homogeneous, by an unweighted average of the prevalences. We examined differences in the prevalences by geographical location and ethnic background as a possible explanation for the heterogeneity.Among a total of 5527 individuals who had been tested, 111 heterozygous carriers of the 20210A mutation were found. The prevalence estimates varied from 0.7 to 4.0 between the centres. The overall prevalence estimate was 2.0 percent (CI95 1.4-2.6%). The variation around the summary estimate appeared more than was expected by chance alone, and this heterogeneity could be explained by geographic differences. In southern Europe, the prevalence was 3.0 percent (CI95 2.3 to 3.7%), nearly twice as high as the prevalence in northern Europe (1.7%, CI95 1.3 to 2.2%). The prothrombin variant appeared very rare in individuals from Asian and African descent.The 20210A prothrombin variant is a common abnormality, with a prevalence of carriership between one and four percent. It is more common in southern than in northern Europe. Since this distribution within Europe is very different to that of another prothrombotic mutation (factor V Leiden or factor V R506Q), founder effects are the most likely explanation for the geographical distribution of both mutations.
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Williams IJ, Abuzenadah A, Winship PR, Preston FE, Dolan G, Wright J, Peake IR, Goodeve AC. Precise Carrier Diagnosis in Families with Haemophilia A: Use of Conformation Sensitive Gel Electrophoresis for Mutation Screening and Polymorphism Analysis. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615052] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryCausative mutations in the factor VIII gene of seven unrelated patients with severe haemophilia A were identified using the mutation screening procedure conformation sensitive gel electrophoresis (1) and characterised by direct sequencing. Female family members of all patients had requested either carrier status determination or prenatal diagnosis. However, lack of the factor VIII gene inversion, a prior family history or informative polymorphisms prevented diagnosis in these families. Identification of a mutation in each family enabled female carrier status to be determined in all cases. Six mutations were previously unreported. One Afro-Caribbean patient had two sequence changes; A670 2G and A6769G. The latter, resulting in Met2238Val and previously reported as a FVIII mutation, was shown to be polymorphic with a 42% heterozygosity rate in an Afro-Caribbean population. Conformation sensitive gel electrophoresis was found to be technically simple and efficient at locating previously unknown FVIII gene mutations.
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Daly ME, Makris M, Preston FE, Peake IR, Beauchamp NJ. A Novel Mutation in Intron K of the PROS1 Gene Causes Aberrant RNA Splicing and Is a Common Cause of Protein S Deficiency in a UK Thrombophilia Cohort. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryIn the course of investigating the molecular basis of protein S deficiency in 31 index cases with thrombophilia, we identified seven kindred where the underlying defect was a novel A to G transition 9 bp upstream of exon 12 in intron K of the PROS1 gene. In all but one case, the mutation caused type I deficiency. One individual had type III deficiency. While ectopic transcript analysis using the BstXI dimorphism in exon 15 failed to detect a transcript from the mutated allele, analysis of transcripts spanning exons 11 and 12 revealed a minor mRNA species. Sequencing confirmed the mutation created a new RNA acceptor site introducing 8 nucleotides of intronic sequence into the mature mRNA. Haplotype analysis of the defective PROS1 alleles in six families revealed the same haplotype in all affected individuals suggesting the presence of a common ancestor. Six of the fourteen relatives with the mutation experienced at least one venous thrombotic event strongly supporting the association of the mutation with venous thrombosis.
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Jennings I, Kitchen S, Cooper PC, Rimmer JE, Woods TAL, Preston FE. Further Evidence that Activated Protein C Resistance Affects Protein C Coagulant Activity Assays. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613775] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Affiliation(s)
- M Greaves
- Royal Hallamshire Hospital, Sheffield, UK
| | - FE Preston
- Royal Hallamshire Hospital, Sheffield, UK
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Abstract
In a volunteer study stanozolol was given in a dosage of 5mg twice per day for six weeks. A variety of parameters in blood coagulation and fibrinolysis were measured. Significant stimulation of the fibrinolytic system was found in seven days and this was associated with a significant fall in the levels of fibrinogen and alpha 2-macroglobulin. No major side effects were observed.
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Affiliation(s)
- F. E. Preston
- University Department of Haematology, Royal Hallamshire Hospital, Sheffield, U.K
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Jennings I, Kitchen DP, Woods TAL, Kitchen S, Preston FE, Walker ID. Stability of coagulation proteins in lyophilized plasma. Int J Lab Hematol 2014; 37:495-502. [DOI: 10.1111/ijlh.12318] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 11/04/2014] [Indexed: 11/27/2022]
Affiliation(s)
- I. Jennings
- United Kingdom National External Quality Assessment Scheme (UKNEQAS) for Blood Coagulation; Sheffield UK
| | - D. P. Kitchen
- United Kingdom National External Quality Assessment Scheme (UKNEQAS) for Blood Coagulation; Sheffield UK
| | - T. A. L. Woods
- United Kingdom National External Quality Assessment Scheme (UKNEQAS) for Blood Coagulation; Sheffield UK
| | - S. Kitchen
- United Kingdom National External Quality Assessment Scheme (UKNEQAS) for Blood Coagulation; Sheffield UK
| | - F. E. Preston
- United Kingdom National External Quality Assessment Scheme (UKNEQAS) for Blood Coagulation; Sheffield UK
| | - I. D. Walker
- United Kingdom National External Quality Assessment Scheme (UKNEQAS) for Blood Coagulation; Sheffield UK
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Kitchen S, Preston FE, Jennings I, Kitchen DP, Woods TAL, Walker I. Interlaboratory agreement in the monitoring of unfractionated heparin using the anti-factor Xa-correlated activated partial thromboplastin time: a rebuttal. J Thromb Haemost 2009; 7:2157-8; author reply 2178-9. [PMID: 19765209 DOI: 10.1111/j.1538-7836.2009.03616.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Makris M, Baglin T, Dusheiko G, Giangrande PLF, Lee CA, Ludlam CA, Preston FE, Watson HG, Wilde JT, Winter M. Guidelines on the diagnosis, management and prevention of hepatitis in haemophilia. Haemophilia 2008. [DOI: 10.1111/j.1365-2516.2001.00527.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kitchen DP, Kitchen S, Jennings I, Woods TAL, Walker ID, Preston FE. Point of care testing by health care professionals: current practice amongst the UK National External Quality Assessment Scheme Participants. Br J Haematol 2005; 130:320-1. [PMID: 16029464 DOI: 10.1111/j.1365-2141.2005.05610.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Vossen CY, Conard J, Fontcuberta J, Makris M, VAN DER Meer FJM, Pabinger I, Palareti G, Preston FE, Scharrer I, Souto JC, Svensson P, Walker ID, Rosendaal FR. Risk of a first venous thrombotic event in carriers of a familial thrombophilic defect. The European Prospective Cohort on Thrombophilia (EPCOT). J Thromb Haemost 2005; 3:459-64. [PMID: 15748234 DOI: 10.1111/j.1538-7836.2005.01197.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Reliable risk estimates for venous thrombosis in families with inherited thrombophilia are scarce but necessary for determining optimal screening and treatment policies. OBJECTIVES In the present analysis, we determined the risk of a first venous thrombotic event in carriers of a thrombophilic defect (i.e. antithrombin-, protein C- or protein S deficiency, or factor V Leiden). PATIENTS AND METHODS The asymptomatic carriers had been tested prior to this study in nine European thrombosis centers because of a symptomatic carrier in the family, and were followed prospectively for 5.7 years on average between March 1994 and January 2001. Annually, data were recorded on the occurrence of risk situations for venous thrombosis and events (e.g. venous thrombosis, death). RESULTS Twenty-six of the 575 asymptomatic carriers (4.5%) and seven of the 1118 controls (0.6%) experienced a first deep venous thrombosis or pulmonary embolism during follow-up. Of these events, 58% occurred spontaneously in the carriers compared with 43% in the controls. The incidence of first events was 0.8% per year (95% CI 0.5-1.2) in the carriers compared with 0.1% per year (95% CI 0.0-0.2) in the controls. The highest incidence was associated with antithrombin deficiency or combined defects, and the lowest incidence with factor V Leiden. CONCLUSIONS The incidence of venous events in asymptomatic individuals from thrombophilic families does not exceed the risk of bleeding associated with long-term anticoagulant treatment in the literature (1-3%).
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Affiliation(s)
- C Y Vossen
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
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Jennings I, Mackie I, Arnout J, Preston FE. Lupus anticoagulant testing using plasma spiked with monoclonal antibodies: performance in the UK NEQAS proficiency testing programme. J Thromb Haemost 2004; 2:2178-84. [PMID: 15613024 DOI: 10.1111/j.1538-7836.2004.01028.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We report here results from a United Kingdom National Quality Assessment Scheme (UK NEQAS) exercise in which both plasma spiked with monoclonal antibodies and plasma from a patient known to have lupus anticoagulant (LA) were distributed to 245 hemostasis laboratories with a request for them to test for possible LA using their routine screening procedure. In general, good agreement was seen in the diagnosis of samples spiked with monoclonal antibodies against beta2-glycoprotein 1 (beta2GP1) and prothrombin, the LA-positive patient sample, and a normal pooled plasma; over 87% of centers correctly identified each sample. However, methods employing platelet neutralizing procedures were associated with a higher proportion of false-negative responses with the antiprothrombin-spiked sample, and it is important to recognize that sensitivity and responsiveness of different methods may vary between artificial plasmas and different LA-positive patient plasmas.
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Affiliation(s)
- I Jennings
- UK NEQAS (Blood Coagulation), Sheffield, UK.
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Vossen CY, Conard J, Fontcuberta J, Makris M, Van Der Meer FJM, Pabinger I, Palareti G, Preston FE, Scharrer I, Souto JC, Svensson P, Walker ID, Rosendaal FR. Familial thrombophilia and lifetime risk of venous thrombosis. J Thromb Haemost 2004; 2:1526-32. [PMID: 15333025 DOI: 10.1111/j.1538-7836.2004.00852.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND We started a large multicenter prospective follow-up study to provide reliable risk estimates of venous thrombosis in families with various thrombophilic defects. OBJECTIVES This paper describes data collected at study entry on venous events experienced before study inclusion, i.e. the baseline data. PATIENTS/METHODS All individuals (probands, relatives) registered in nine European thrombosis centers with the factor (F)V Leiden mutation, a deficiency of antithrombin, protein C or protein S, or a combination of these defects, were enrolled between March 1994 and September 1997. As control individuals, partners, friends or acquaintances of the thrombophilic participants were included. Incidence and relative risk of objectively confirmed venous thrombotic events (VTEs) prior to entry were calculated for the relatives with thrombophilia and the controls. RESULTS Of the 846 relatives with thrombophilia (excluding probands), 139 (16%) had experienced a VTE with an incidence of 4.4 per 1000 person years. Of the controls, 15 of the 1212 (1%) controls had experienced a VTE with an incidence of 0.3 per 1000 person years. The risk of venous thrombosis associated with familial thrombophilia was 15.7 (95% CI 9.2-26.8) and remained similar after adjustment for regional and sex-effects (16.4; 95% CI 9.6-28.0). The highest incidence per 1000 person years was found in relatives with combined defects (8.4; 95% CI 5.6-12.2), and the lowest incidence was found in those with the FV Leiden mutation (1.5; 95% CI 0.8-2.6). CONCLUSIONS Considerable differences in the lifetime risk of VTE were observed among individuals with different thrombophilia defects.
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Affiliation(s)
- C Y Vossen
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
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Vossen CY, Preston FE, Conard J, Fontcuberta J, Makris M, van der Meer FJM, Pabinger I, Palareti G, Scharrer I, Souto JC, Svensson P, Walker ID, Rosendaal FR. Hereditary thrombophilia and fetal loss: a prospective follow-up study. J Thromb Haemost 2004; 2:592-6. [PMID: 15102013 DOI: 10.1111/j.1538-7836.2004.00662.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND As the placental vessels are dependent on the normal balance of procoagulant and anticoagulant mechanisms, inherited thrombophilia may be associated with fetal loss. OBJECTIVES We performed a prospective study to investigate the relation between inherited thrombophilia and fetal loss, and the influence of thromboprophylaxis on pregnancy outcome. PATIENTS AND METHODS Women were enrolled in the European Prospective Cohort on Thrombophilia (EPCOT). These included women with factor (F)V Leiden or a deficiency of antithrombin, protein C or protein S. Controls were partners or acquaintances of thrombophilic individuals. A total of 191 women (131 with thrombophilia, 60 controls) had a pregnancy outcome during prospective follow-up. Risk of fetal loss and effect of thromboprophylaxis were estimated by frequency calculation and Cox regression modelling. RESULTS The risk of fetal loss appeared slightly increased in women with thrombophilia without a previous history of fetal loss who did not use any anticoagulants during pregnancy (7/39 vs. 7/51; relative risk 1.4; 95% confidence interval 0.4, 4.7). Per type of defect the relative risk varied only minimally from 1.4 for FV Leiden to 1.6 for antithrombin deficiency compared with control women. Prophylactic anticoagulant treatment during pregnancy in 83 women with thrombophilia differed greatly in type, dose and duration, precluding solid conclusions on the effect of thromboprophylaxis on fetal loss. No clear benefit of anticoagulant prophylaxis was apparent. CONCLUSIONS Women with thrombophilia appear to have an increased risk of fetal loss, although the likelihood of a positive outcome is high in both women with thrombophilia and in controls.
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Affiliation(s)
- C Y Vossen
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
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Preston FE, Kitchen S, Jennings I, Woods TAL, Makris M. SSC/ISTH classification of hemophilia A: can hemophilia center laboratories achieve the new criteria? J Thromb Haemost 2004; 2:271-4. [PMID: 14995989 DOI: 10.1046/j.1538-7836.2003.00447.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To assess the practicality of the recent Scientific and Standardization committee (SSC) of the International Society on Thrombosis and Haemostasis (ISTH) recommendations in respect of the classification of hemophilia we distributed samples from three untreated subjects with hemophilia A to 91 UK hemophilia centers (HCs), comprising 20 comprehensive care centers (CCCs) and 71 HCs. Laboratories were requested to perform their routine factor (F)VIII:C assays and to classify the severity of hemophilia. Median values of < 1 U dL-1 were obtained on two samples. However, for each of the two, approximately 30% of laboratories obtained results in the range 1-29 U dL-1 and 1-33 U dL-1 respectively. For one of these samples 17 laboratories diagnosed severe hemophilia despite obtaining FVIII:C levels in the range 1-5 U dL-1. The median FVIII:C for the third sample was 5.8 U dL-1 with a range of 1.5-36 U dL-1. For this sample eight centers diagnosed severe hemophilia. Fifty-four laboratories obtained a result > 5 U dL-1; 21 of these diagnosed mild hemophilia, 31 moderate hemophilia and two severe hemophilia. Results from CCCs were more accurate and more precise than those from HCs. Our results indicate a need for improved standardization of FVIII assays. In the UK there remains a lack of consensus in respect of the laboratory diagnostic criteria for the classification of hemophilia A.
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Affiliation(s)
- F E Preston
- UK NEQAS (Blood Coagulation) and The University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK.
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Abstract
Familial (F)XIII deficiency is an extremely rare bleeding disorder. In most laboratories the diagnosis is initially established through a clot-solubility screening test. We report here results from a series of UK NEQAS (Blood Coagulation). Proficiency Testing investigations, in which laboratories were provided with samples from normal individuals and from various subjects with FXIII deficiency with a request to perform their usual test for this disorder and to provide an interpretation of their results. Over 95% of centers were able to diagnose severe familial FXIII deficiency in previously untreated patients and to identify samples from normal subjects. However, both quantitative and qualitative methods produced widely variable results on samples obtained from previously treated individuals with FXIII deficiency but having measurable levels of FXIII. Data generated by UK NEQAS investigations suggested that solubility tests employing thrombin show greater sensitivity to FXIII deficiency, and this was confirmed in a subsequent single-center study. Our results lead us to recommend the use of thrombin and acetic acid in the clot-solubility screening test. Use of sensitive screening tests, and improvement in the accuracy and precision of quantitative FXIII assays will aid study of the clinical importance of moderate FXIII deficiency.
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Affiliation(s)
- I Jennings
- UK NEQAS for Blood Coagulation, Sheffield, UK.
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Murray ET, Kitchen DP, Kitchen S, Jennings I, Woods TAL, Preston FE, Fitzmaurice DA. Patient self-management of oral anticoagulation and external quality assessment procedures. Br J Haematol 2003; 122:825-8. [PMID: 12930396 DOI: 10.1046/j.1365-2141.2003.04501.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The role of external quality assessment (EQA) is a contentious issue for patient self-management (PSM) of oral anticoagulation. Patients from general practices in the West Midlands undertaking PSM were recruited to compare efficacy of patients' and health professionals' EQA procedure using the UK National External Quality Assessment Scheme (NEQAS). Patients using Coaguchek (Roche Diagnostics) were trained to perform EQA as part of their PSM training. They undertook PSM for 26 weeks and were asked to perform EQA using material provided by the UK NEQAS twice at home without supervision and twice at the practice with supervision. Patients' results were compared with health care professional users of Coaguchek S. Twenty-three PSM patients were compared with 75 health care professional users of the NEQAS scheme. The PSM group international normalized ratio (INR) percentage time in range was 74%. There was no significant difference in the median results on NEQAS samples obtained by the patients and those obtained by professionals. Three patients were outwith consensus (results > 15% from the median INR) on more than one occasion. Patients were able to perform the EQA tests competently. The data show that good agreement can be achieved between patients analysing the same EQA samples, with coefficients of variation ranging from 22.3% to as low as 5.4%. Further study is required to determine how precision within these EQA schemes relates to the stability of treatment in patients' management of their own anticoagulation.
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Affiliation(s)
- E T Murray
- Department of Primary Care and General Practice, The Medical School, University of Birmingham, Edgbaston, Birmingham, UK.
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Woods TAL, Jennings I, Kitchen S, Kitchen DP, Preston FE. Use of SSC/ISTH secondary standard to evaluate laboratory performance: A UK NEQAS for blood coagulation proficiency testing exercise. J Thromb Haemost 2003. [DOI: 10.1111/j.1538-7836.2003.tb05481.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kitchen DP, Kitchen S, Jennings I, Woods TAL, Preston FE. Artificially depleted plasmas are suitable for proficiency testing of INR determination with some POC devices. J Thromb Haemost 2003. [DOI: 10.1111/j.1538-7836.2003.tb05636.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Jennings I, Kitchen S, Cooper P, Makris M, Preston FE. Sensitivity of functional protein S assays to protein S deficiency: a comparative study of three commercial kits. J Thromb Haemost 2003; 1:1112-4. [PMID: 12871384 DOI: 10.1046/j.1538-7836.2003.00215.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Jennings I, Kitchen S, Smith J, Woods TAL, Preston FE. Between-centre agreement in homocysteine assays: experience from the UK NEQAS proficiency testing scheme. Thromb Haemost 2002; 87:921-2. [PMID: 12038801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Preston FE, Laidlaw ST, Sampson B, Kitchen S. Rapid reversal of oral anticoagulation with warfarin by a prothrombin complex concentrate (Beriplex): efficacy and safety in 42 patients. Br J Haematol 2002; 116:619-24. [PMID: 11849221 DOI: 10.1046/j.0007-1048.2001.03295.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Beriplex, a prothrombin complex concentrate (PCC), was administered to 42 patients requiring immediate reversal of their oral anticoagulant therapy. The dose administered was determined using the pretreatment International Normalized Ratio (INR). Blood samples were obtained before treatment and at 20, 60 and 120 min after treatment. The following investigations were performed on all samples - INR, clotting factors II, VII, IX and X, coagulation inhibitors protein C (PC) and antithrombin (AT), and other markers of disseminated intravascular coagulation, plasma fibrinogen, D-dimer and platelet count. Immediate reversal of the INR, the vitamin K-dependent clotting factors and PC was achieved in virtually all patients. Reduced AT levels were present in 18 patients before treatment. Further slight AT reductions occurred in four patients, but other associated abnormalities of haemostasis were observed in only one of the four patients. One patient with severe peripheral vascular disease, sepsis and renal and cardiac failure died of a thrombotic stroke following leg amputation, 48 h after receiving Beriplex. No other arterial and no venous thromboembolic events occurred within 7 d of treatment. Beriplex is effective in rapidly reversing the anticoagulant effects of warfarin, including PC deficiency, without inducing coagulation activation. Caution should continue to be exercised in the use of these products in patients with disseminated intravascular coagulation, sepsis or liver disease.
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Affiliation(s)
- F E Preston
- Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital, Glossop Road, Sheffield, UK.
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Watson HG, Baglin T, Laidlaw SL, Makris M, Preston FE. A comparison of the efficacy and rate of response to oral and intravenous Vitamin K in reversal of over-anticoagulation with warfarin. Br J Haematol 2001; 115:145-9. [PMID: 11722425 DOI: 10.1046/j.1365-2141.2001.03070.x] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The role of oral Vitamin K administration in the reversal of anticoagulation is not yet clear because of a paucity of data on the early effects of treatment, apparent differences in efficacy between preparations and a lack of data comparing oral with intravenous administration. We have compared the effects on the International Normalized Ratio (INR) and activities of the Vitamin K-dependent clotting factors II, VII, IX and X at 4 h and 24 h after administration of three oral Vitamin K preparations and of intravenous Vitamin K in 64 anticoagulated patients who required non-urgent partial correction of anticoagulation. Our data confirm that correction of anticoagulation is more rapid after intravenous administration of Vitamin K than after oral administration of similar or larger doses. At 24 h, satisfactory correction of INR can be achieved using low-dose Vitamin K given by either the intravenous or oral route. Our data, and that from previous studies, suggest that there may be differences in efficacy between orally administered products. Administration of Vitamin K by either route was accompanied by changes in the activities of the Vitamin K-dependent clotting factors that reflected their respective biological half-lives. In the 24 h after treatment, the relationship between the INR and the individual Vitamin K-dependent clotting factors was similar to that described previously in stable anticoagulated patients. We conclude that the reversal of anticoagulation with warfarin is achieved more rapidly by intravenous administration of Vitamin K. Satisfactory, but slower, reversal of anticoagulation can be effected using oral Vitamin K, but there may be differences in efficacy between the products tested in our study.
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Affiliation(s)
- H G Watson
- Department of Haematology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen, UK.
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Makris M, Baglin T, Dusheiko G, Giangrande PL, Lee CA, Ludlam CA, Preston FE, Watson HG, Wilde JT, Winter M. Guidelines on the diagnosis, management and prevention of hepatitis in haemophilia. Haemophilia 2001; 7:339-45. [PMID: 11442636 DOI: 10.1046/j.1365-2516.2001.00527.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- M Makris
- Sheffield Haemophilia and Thrombosis Centre, Sheffield, UK.
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