FV Leiden Mutation Research Articles

Do hospital doctors test for thrombophilia in patients with venous thromboembolism?

The predictive value of factor V Leiden and the G20210A prothrombin mutation regarding recurrent venous thromboembolism (VTE) is limited and does not influence subsequent patient management. Systematic testing for such genetic thrombophilia should be avoided, but to which extent such testing is practiced in a Swiss Hospital is unknown. To examine the current practice of factor V Leiden and/or G20210A prothrombin mutation testing in a University Hospital, and to assess the clinical consequences of testing on patients. 1388 adult patients (48.7% women) with a main diagnosis of VTE hospitalized at the Lausanne university hospital between January 2013 and December 2015. FV Leiden and/or prothrombin G20210A mutation testing was performed in 61 (4.4%) patients with VTE, an average of 20 patients/year. On multivariable analysis, age < 65years [odds ratio and (95% confidence interval) 5.91 (3.12-11.19)], being admitted in a medical ward [5.71 (2.02-16.16)] and staying in the intensive care unit [0.34 (0.12-0.97)] were associated with thrombophilia testing. No differences were found between patients with and without testing regarding in-hospital mortality [OR and 95% CI for tested vs. non-tested: 0.23 (0.03-1.73), p = 0.153] and length of stay (multivariable adjusted average ± standard error: 16.9 ± 3.3 vs. 20.0 ± 0.7days for tested and non-tested patients, respectively, p = 0.875). Thrombophilia testing in hospitalized patients with a main diagnosis of VTE is seldom performed. FV Leiden and/or prothrombin G20210A mutation should not be routinely assessed in patients with acute VTE.

Association of factor V activity with risk of venous thromboembolism and atherothrombotic cardiovascular events: A retrospective population-based cohort study

IntroductionFactor V (FV) deficiency is a rare inherited coagulation disorder associated with bleeding tendency. As a result, it has been postulated that decreased FV activity may confer protection against venous thromboembolism and atherothrombotic cardiovascular events. Materials and methodsUsing the electronic database of the largest health care provider in Israel, we identified all adult individuals who were tested for FV activity between January 2004 and June 2017. Subjects with liver cirrhosis or FV Leiden mutation were excluded. FV activity was classified into three predefined categories; FV activity >50%, FV activity 30–50%, and FV activity ≤30%. Patients were followed from January 2004 to June 2017 for new atherothrombotic cardiovascular events (composite of myocardial infarction, stroke, and TIA) and venous thromboembolism (VTE). ResultsOverall 2021 individuals were included; 83.2% had FV activity >50%, 9.6% FV activity 30–50%, and 7.2% had FV activity ≤30%. Compared to individuals with FV activity >50% the adjusted HR for atherothrombotic cardiovascular events was 1.10 (95% CI, 0.63–1.90) in those with FV activity 30–50%, and 0.95 (0.49–1.8) in those with FV activity ≤30%. None of the patients with FV activity 30–50% had VTE during follow-up; therefore those with FV activity ≤50% were classified into one group. VTE incidence was lower in those with FV activity ≤50% compared to those with FV >50% activity; adjusted HR = 0.28 (0.09–0.91). ConclusionThis study suggests that decreased FV activity might be associated with decreased incidence of VTE. No significant association appears to exist between FV activity and atherothrombotic cardiovascular events.

New functional assays to selectively quantify the activated protein C‐ and tissue factor pathway inhibitor‐cofactor activities of protein S in plasma

Background Protein S plays an important role in the down-regulation of coagulation as cofactor for activated protein C (APC) and tissue factor pathway inhibitor (TFPI). Aim To develop functional assays to quantify the APC- and TFPI-cofactor activities of protein S in plasma. Methods APC- and TFPI-cofactor activities of protein S in plasma were measured using calibrated automated thrombography in protein S-depleted plasma supplemented with a small amount of sample plasma either in the presence of anti-TFPI antibodies and APC (APC-cofactor activity) or at excess full-length TFPI without APC (TFPI-cofactor activity). Total and free protein S levels in plasma were measured by ELISAs. Results Average APC-cofactor activities of protein S were 113%, 108% and 89% in plasma from normal individuals (n = 15), FV Leiden heterozygotes (n = 14) and FV Leiden homozygotes (n = 7), respectively, whereas the average APC-cofactor activity of protein S in plasma from heterozygous protein S-deficient individuals (n = 21) was significantly lower (55%). Similar trends were observed for the TFPI-cofactor activity of protein S, with averages of 109%, 115% and 124% in plasma from individuals with normal protein S levels and different FV Leiden genotypes, and 64% in plasma from protein S-deficient patients. APC-cofactor activities of protein S correlated significantly with free and total protein S antigen levels, whereas TFPI-cofactor activities correlated less with protein S antigen levels. Conclusion We have developed functional protein S assays that measure both the APC- and TFPI-cofactor activities of protein S in plasma, which are hardly if at all affected by the FV Leiden mutation.

A case of pulmonary thromboembolism due to coagulation factor V Leiden in Japan\u2009~\u2009usefulness of next generation sequencing~

BackgroundBecause the venous thromboembolisms (VTEs) due to the coagulation factor V R506Q (FV Leiden) mutation is often seen in Caucasians, the VTE onset in Japan has not been reported.Case presentationA 34-year-old man from north Africa experiencing sudden dyspnea went to a hospital for advice.The patient had pain in his right leg and a high plasma D-dimer level. A contrast-enhanced computed tomography scan revealed a contrast deficit in the bilateral pulmonary artery and in the right lower extremity. The patient was diagnosed with VTE, and anticoagulation therapy was initiated. Our targeted gene panel sequencing revealed that the occurrence of VTE was attributed to a presence of the FV Leiden mutation.ConclusionsThis is the first report demonstrating VTE caused by the FV Leiden mutation in Japan.

Targeting factor VIII expression to platelets for hemophilia A gene therapy does not induce an apparent thrombotic risk in mice

Background Targeting factor (F) VIII expression to platelets is a promising gene therapy approach for hemophilia A, and is successful even in the presence of inhibitors. It is well known that platelets play important roles not only in hemostasis, but also in thrombosis and inflammation. Objective To evaluate whether platelet-FVIII expression might increase thrombotic risk and thereby compromise the safety of this approach. Methods In this study, platelet-FVIII-expressing transgenic mice were examined either in steady-state conditions or under prothrombotic conditions induced by inflammation or the FV Leiden mutation. Native whole blood thrombin generation assay, rotational thromboelastometry analysis and ferric chloride-induced vessel injury were used to evaluate the hemostatic properties. Various parameters associated with thrombosis risk, including D-dimer, thrombin-antithrombin complexes, fibrinogen, tissue fibrin deposition, platelet activation status and activatability, and platelet-leukocyte aggregates, were assessed. Results We generated a new line of transgenic mice that expressed 30-fold higher levels of platelet-expressed FVIII than are therapeutically required to restore hemostasis in hemophilic mice. Under both steady-state conditions and prothrombotic conditions induced by lipopolysaccharide-mediated inflammation or the FV Leiden mutation, supratherapeutic levels of platelet-expressed FVIII did not appear to be thrombogenic. Furthermore, FVIII-expressing platelets were neither hyperactivated nor hyperactivatable upon agonist activation. Conclusion We conclude that, in mice, more than 30-fold higher levels of platelet-expressed FVIII than are required for therapeutic efficacy in hemophilia A are not associated with a thrombotic predilection.

New Functional Assays to Selectively Quantify APC- and TFPI-Cofactor Activities of Protein S in Plasma

Background: Protein S is an important anticoagulant in the down-regulation of blood coagulation by acting as cofactor for two main regulators of coagulation. Protein S acts as a cofactor for activated protein C (APC) in the inactivation of the procoagulants FVa and FVIIIa and for TFPI in the formation of the TFPI-FXa encounter complex that subsequently inactivates TF-FVIIa. Several studies have indicated that protein S deficiency is associated with increased risks of venous thrombosis.Aims: Current protein S functional assays are influenced by plasma determinants such as FVLeiden. The aim of the study was to develop thrombin generation based assays that enable quantification of both the APC- and TFPI-cofactor activities of protein S in plasma whereas the outcome of the assays should not be affected by the presence of FVLeiden or other plasma variables.Methods: APC- and TFPI-cofactor activities of protein S in plasma were measured using calibrated automated thrombography (CAT) in protein S-depleted plasma supplemented with a small amount of sample plasma either in the presence of anti-TFPI antibodies and APC (APC-cofactor activity) or at excess full-length TFPI without APC (TFPI-cofactor activity). Total and free protein S levels in plasma were measured by ELISA's.Results: Average APC-cofactor activities of protein S were 113%, 122%, and 87% in plasma from normal individuals (n=10), FV Leiden heterozygotes (n=4), and FV Leiden homozygotes (n=2), respectively, while the average APC-cofactor activity of protein S in plasma from heterozygous protein S-deficient individuals (n=21) was significantly lower (55%). Similar trends were observed for the TFPI-cofactor activity of protein S, with averages of 108%, 112%, and 97% in plasma from individuals with normal protein S levels and different FV Leiden genotypes, and 64% in plasma from protein S-deficient patients. APC-cofactor activities of protein S correlated significantly with free and total protein S antigen levels, while TFPI-cofactor activities correlated less with protein S antigen levels.Summary/Conclusion: We have developed functional protein S assays that measure both the TFPI- and APC-cofactor activities of protein S in plasma and that are not affected by the FV Leiden mutation or other plasma influences. DisclosuresNo relevant conflicts of interest to declare.

Pro-Coagulant and Pro-Inflammatory Effect of Interferon Alpha in Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPN) are associated with an increased risk of arterial and venous thrombosis. Besides clinical factors (previous history of thrombosis, age > 60 years, cardiovascular risk factors), procoagulant phenotype, proadhesive properties of the endothelium and secretion of inflammatory cytokines, contribute to the pathogenesis of thrombosis in MPN. Pegylated interferon alpha (IFN) has obviously a great therapeutic efficacy on hematopoietic cell proliferation but its other biological effects particularly on hemostasis and inflammation have not been determined.The aim of the study was to determine whether IFN impacts the biological profile including endothelial and platelet markers compared to MPN patients treated by hydroxyurea (HU) and non-treated (NT) patients.Patients with polycythemia vera (PV) or essential thrombocythemia (ET) treated with IFN or HU or without any cytostatic drug were included. Platelet membrane glycoproteins and platelet activation were measured by flow cytometry. We evaluated shear-induced platelet aggregation (SIPA) at 4000 sec-1 that mimics stenotic arteries. We measured coagulation proteins by their activity and endothelial parameters (von Willebrand factor (VWF) antigen and activity, soluble thrombomodulin). Thrombin generation was measured in platelet poor plasma and platelet rich plasma. Platelet accumulation on immobilized collagen was measured using whole blood perfused at 1500 sec-1 in flow chambers. Statistical analysis was performed by ANOVA to compare the 3 groups of patients (p<0.05) and post-test Newman-Keuls to compare groups side-by-side (p<0.01).Eighty-eight patients were included: 28 treated by IFN (20 PV and 8 ET), 38 treated by HU (27 PV and 11 ET) and 22 NT (6 PV and 16 ET). All patients were treated with aspirin 75 or 100 mg/day. Prior history of thrombosis occurred in 25.7% of ET and in 31.5% of PV. During the follow up (> 6months), only 1 arterial and 2 venous thrombosis were observed.Hematological parameters and JAK2 V617F status was in the expected range in ET and PV patients.Surprisingly, we observed some significant effect of IFN on 1) platelets with a decreased GPVI expression compared to HU- and non-treated patients and increased levels of SIPA at 4000 sec-1. 2) endothelial cells with significantly increased levels of Willebrand antigen and activity. 3) coagulation parameters with decreased protein S activity and increased levels of factor VIII:C and fibrinogen (table 1). All the other parameters tested were similar in the 3 groups of patients.We had the opportunity to test 10 patients at least 6 months after IFN discontinuation. IFN was stopped for side effects in 6 patients, for complete molecular response in 2 and for normalization of hematological parameters in 2 others. GPVI expression, SIPA, VWF activity and antigen, protein S activity, FVIIIC and fibrinogen returned to levels similar to those of non-treated patients and were significantly different from the levels in IFN-treated patients (table 2). These results indicate that IFN was responsible for these biological modifications.In conclusion, these unexpected data showing an increase of procoagulant and inflammatory markers in IFN-treated MPN patients could be considered as a part of IFN biological activity. Though minimal, these alterations could require more intensive preventive anticoagulation than aspirin in patients with heterozygous FV Leiden or FII G20210A mutation. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Association of thrombophilia and catheter‐associated thrombosis in children: a systematic review and meta‐analysis

Essentials It is unclear if thrombophilia increases the risk of catheter-associated thrombosis in children. We conducted a meta-analysis on thrombophilia and pediatric catheter-associated thrombosis. Presence of ≥1 trait confers additional risk of venous thrombosis in children with catheters. Limitations of included studies preclude us from recommending routine thrombophilia testing. Background The association between thrombophilia and deep vein thrombosis (DVT) associated with central venous catheter (CVC) use, the most important pediatric risk factor for thrombosis, is unclear in children. Pediatric studies with small sample sizes have reported conflicting results. We sought to evaluate whether, among children with CVCs, thrombophilia increases the risk of CVC-associated DVT (CADVT). Materials and methods We systematically searched MEDLINE, EMBASE, the Web of Science, the Cochrane Central Register for Controlled Trials, PubMed and reference lists for controlled studies published from the inception of the database until September 2015. Included were studies of children aged <21 years with CVCs who were systematically tested for thrombophilic traits that are commonly screened for in clinical practice. Pooled prevalence rates and pooled odds ratios (pORs) of CADVT with thrombophilia were estimated by use of a random effects model. Results We analyzed 16 cohort studies with 1279 children, 277 of whom had CADVT, and with 12 traits tested. There was significant heterogeneity in the included studies. The presence of one or more traits was associated with CADVT (pOR 3.20; 95% confidence interval [CI] 1.56-6.54). Although the prevalence of most traits was < 0.10, children with protein C deficiency, elevated factor VIII levels and the FV Leiden mutation had an increased prevalence of CADVT. The association with thrombophilia seemed to be stronger for symptomatic CADVT (pOR 6.71; 95% CI 1.93-23.37) than for asymptomatic CADVT (pOR 2.14; 95% CI 1.10-4.18). Conclusions On the basis of the low prevalence of specific traits, the relatively weak association with CADVT, and the limitations of the included studies, we cannot recommend routine testing of thrombophilias in children with CADVT.

The frequencies of FV Leiden and FII G20210A mutations in patients with different clinical manifestations of venous thromboembolism: Experience from large Serbian cohort

Venous thromboembolism is a multifactorial disorder with two manifestations: deep-vein thrombosis and pulmonary embolism. Pulmonary embolism is usually considered as the complication of deep-vein thrombosis, but there are reported cases of isolated pulmonary embolism. FV Leiden and FII G20210A mutations are most common genetic risk factors for the venous thromboembolism. Several studies reported "FV Leiden paradox": lower prevalence of FV Leiden mutation among patients with isolated pulmonary embolism than among those with deep-vein thrombosis. The aim of this study was to determine FV Leiden and FII G20210A mutations frequency in thrombophilic patients in Serbian population. We tested prevalence of these mutations carriers in 1427 individuals divided in three groups of patients (with deep-vein thrombosis, deep-vein thrombosis/ pulmonary embolism and isolated pulmonary embolism) and control group. All subjects were tested for these mutations using PCR-RFLP analysis. Detected frequency of FV Leiden heterozygous carriers in patients with isolated pulmonary embolism was 6.9% (for FII G20210A 11.6%), while in other two groups of patients with deep-vein thrombosis and deep vein thrombosis/pulmonary embolism, frequency was 18.6% (for FII G20210A mutation were 11.6% and 8.3%, respectively). Our results showed that FV Leiden mutation is less frequent in patients with isolated pulmonary embolism than in patients with deep-vein thrombosis or deep-vein thrombosis accompanied with pulmonary embolism, confirming "FV Leiden paradox". On the other hand, detected frequency of FII G20210A mutation carriers was similar in all three groups of patients.

Inheritance of Factor VII and Protein S Deficiency Together with Factor V Leiden Mutation

Yard. Doc. Dr. Zafer Bicakci, Kafkas Universitesi Tip Fakultesi Cocuk Hematolojisi Kars Turkiye, Tel. 0532 513 72 71 Email. zaferbicakcib@yahoo.com.tr Gelis Tarihi: 13.02.2015 • Kabul Tarihi: 18.04.2016 ABSTRACT Homozygous or heterozygous mutations of factor V Leiden (FV Leiden) and the thrombophilic factors like protein S deficiency are associated with venous or arterial thrombosis. In these patients, thrombosis may be seen even in the presence of coexistent congenital disorders of bleeding. Factor VII (FVII) deficiency is a rare autosomal recessive disorder of blood coagulation. When FVII deficiency occurs in combination with thrombophilic mutations, the symptoms of hemorrhagic diathesis are alleviated, like in other inherited hemorrhagic disorders. Herein, a 5-year-old and a 7-yearold, an asymptomatic sister and brother who respectively had 2 (FV Leiden mutation and protein S deficiency) and 1 (FV Leiden mutation) thrombophilic factors coexistent with FVII deficiency, are presented. The levels of FVII were 36% (N: 55%-116%) in the sister and 38% (N: 52%-120%) in the brother. FV Leiden mutation was homozygous and heterozygous in the sister and the brother, respectively. The protein S activity was 47% (N: 54%-118%) in the sister and normal in the brother. Familial work-up revealed FV Leiden mutation (heterozygous) in both parents and protein S deficiency in the mother [51% (N: 55%-160%)].

Factor V Leiden mutation in Egyptian patients with deep vein thrombosis

Background Deep vein thrombosis (DVT) is a serious disease resulting from the interaction of environmental and inherited risk factors. One of the causes may be thrombosis resulting from the inherited resistance to activated protein C caused by factor V Leiden (FV Leiden) mutation. Objective The aim of this study was to investigate the presence of FV Leiden mutation among Egyptian patients with DVT in comparison with a normal population of controls, and to evaluate its relevance in thrombotic tendency. Patients and methods This cross-sectional, case-controlled study included 50 patients with DVT, with a mean age of 38.70 ± 7.96 years and a male to female ratio of 0.72. These patients were recruited among the patients admitted to the Department of Vascular Surgery in Tanta University Hospitals. For association and risk analysis, these patients were compared with 10 healthy unrelated control participants of matched age and sex. FV Leiden gene mutation (G1691A) was detected using real-time PCR. Results There was a statistically significant difference between the patients and the controls regarding FV Leiden polymorphism ( P = 0.043). Ten patients (20%) were found to be heterozygous for the gene. None of the patients was homozygous for this polymorphism. Risk factor for DVT was 1.3 (95% confidence interval). FV Leiden mutation was found to be significantly prevalent among patients with a positive family history of DVT ( P = 0.001). There were no statistical significant difference between the control participants and the DVT patients as regards age, sex, and history of previous exposure. In addition, there was no association between FV Leiden and the site of DVT. Conclusion FV Leiden mutation has a high prevalence (20%) and positive association with DVT among Egyptian patients.

Prevalence of Factor V Genetic Variants Associated With Indian APCR Contributing to Thrombotic Risk.

Phenotypic resistance to activated protein C (APC) is a complex mechanism associated with increased thrombosis risk. Activated protein C resistance (APCR) is mainly influenced by FVLeiden mutation, and various other single nucleotide polymorphisms (SNPs) in FV gene are known to be associated with APCR. The aim of present study was to investigate the incidence and assess possible mechanisms of APCR in Indian patients with deep vein thrombosis (DVT). Three hundred and ten Doppler-proven patients with DVT were screened for APCR, and 50 APCR positive patients and 50 controls were typed for FVLeiden, Hong Kong, Cambridge, HR2 haplotype, Glu666Asp, Ala485Lys, and Liverpool using either polymerase chain reaction (PCR)-restriction fragment length polymorphism or allele specific PCR. FVLeiden was commonest cause of APCR (50%) in Indian patients with DVT being statistically significant ( P = .001) compared to controls. FV Liverpool, FV Glu666Asp and FV Ala485Lys were studied for the first time in Indian population. FV Liverpool, FV Glu666Asp, Hong Kong, and Cambridge were found to be absent. High frequency of Ala485Lys in patients shows that it might be a risk factor contributing to APCR in Indian patients with DVT. HR2 haplotype was not associated with APCR; however, presence of homozygous HR2 haplotype in patients only indicates the role it might play in Indian APCR population. In conclusion, contribution of FVLeiden causing APCR in Indian population is not as strong as previously reported in Western countries. The presence of other SNPs observed in the present study requires such studies on larger sample size to understand the molecular basis of defect.

The Influence of Hemostasis Genetic Features on Thrombosis Rates in Patients with Polycythemia Vera

Background. Thrombotic complications are the main cause of disability and mortality in Polycythemia Vera (PV) patients. Thrombosis in PV is a result of both inherited (genetic) and acquired predisposition under the external factors influence. Effective personalized prophylactic antithrombotic therapy is a key factor to save quantity and quality of life in PV patients.Objective. The objective of study was to assess the prevalence of hereditary thrombophilia genetic markers in PV patients in overall and groups with or without thrombotic complications.Materials and methods. 104 PV patients (60 females, 44 males, median age 58 years, range 31-82) were researched. Blood probes were examined by PCR for the presence of nucleotide polymorphisms in the following genes: FV (Leiden mutation), FII (prothrombin), methylenetetrahydrofolate reductase (MTHFR), fibrinogen (FI), plasminogen activator inhibitor (PAI-1), and platelet fibrinogen receptor type IIIA (GPIIIA). We studed the overall hereditary thrombophilia markers rate and the statistical significance between PV patients groups with (Thr+) or without thrombosis (Thr+). We used the next statistical methods: descriptive statistics, the significances of differences by gender and genes frequencies in the groups were evaluates with Fisher exact test, differences in age at the time of diagnosis were assessed with Mann-Whitney U test.Results. Thrombotic complications occurred in 20 (19.2%) of patients (16 arterial and 5 venous thrombotic episodes, 1 patient had both arterial and venous thrombotic episodes). Myocardial infarction was found in 7 (6.7%), cerebrovascular accident in 9 (8.7%) patients. The general PV population thrombophilia markers frequencies were: heterozygous (G/A) Leiden mutation in 4 (3,8%) patients; heterozygous mutation in prothrombin gene (G20210-A) in 4 (3,8%) patients; homozygous (T/T) mutation in MTHFR in 8 (7,7%) patients, heterozygous (C/T) mutation in 43 (41,3%) patients; homozygous (A/A) mutation in FI gene in 4 (3,8%) patients, heterozygous (G/A) mutation in FI gene in 43 (41,3%) patients; combination of mutations in FI and MTHFR was registered in 23 (22,1%) patients; homozygous (4G/4G) mutation in PAI-1 gene was revealed in 35 (33,7%) patients, heterozygous (4G/5G) mutation in 49 (47,1%) patients; mutation frequencies in GPIIIA gene were as follows: homozygous (A2/A2) in 5 (4,8%) patients, heterozygous (A1/A2) in 26 (25%) patients. The markers of hereditary thrombophilia was not identified only in one patient (1%).Characteristics and difference significances in the frequency of detection of thrombophilia genes between groups of patients with thrombosis (Thr+) and without their presence in history (Thr-) are shown in table 1.Table 1Characteristics of PV patients with (Thr+) or without (Thr-) thrombotic complications.Thr+ (n=20)Thr- (n=84)pAge, median (range)63 (36-73)58 (32-82)0.75Gender, male/female9/1135/490.81Factor V Leiden mutation, GA/GG2/182/820.17Prothrombin gene (G20210A) mutation, GA/GG1/193/810.58MTHFR mutation, (TT+CT)/CC14/637/470.05FI mutation, (AA+GA)/GG6/1441/430.14PAI-1 mutation, (4G/4G+4G/5G)/(5G/5G)17/367/170.76GPIIIA mutation, (A2A2+A1A2)/A1A11/1930/540.01Conclusions. Various hereditary thrombophilia gene mutations were present in almost all PV patients. PV patients with and without thrombotic complications were significantly (p≤0.05) differed in frequencies of mutations in methylenetetrahydrofolate reductase gene (MTHR) and platelet fibrinogen receptor type IIIA (GPIIIA). We also observed statistical trends (p≤0.30) in differences of mutations frequencies in fibrinogen (FI) gene and Factor V Leiden mutation, for the confirmation of which the further research is required. DisclosuresNo relevant conflicts of interest to declare.

Individually Tailored Prophylaxis Using a Risk Score for the Management of Pregnant Women with Increased Risk of Venous Thromboembolism

Patients with thrombophilia and/or a history of venous thromboembolism (VTE) exhibit a high risk of thrombosis during pregnancy. A risk score for pregnancies with increased risk of VTE was previously described by our group (1,2). The present work reports the results of a prospective study, evaluating the efficacy and the safety of the prophylaxis strategy based on the same risk score, in 542 pregnancies at high risk of VTE, managed between 2005 and 2015 in Lyon University Hospitals.Among 445 patients included in the study, 26 had several pregnancies during the study period. The mean age of the study population was 33±4.8 years, 132 women (29.7%) were older than 35 years. Fifty three women had a BMI of 30 or over and 61 were smokers. Among these 445 patients, 279 had a personal history of VTE (62.7%), 299 patients (67.2%) had a thrombophilia marker and 131 (29.4%) thrombophilic women had a personal history of VTE.During pregnancy, patients were assigned to one of three prophylaxis strategies according to the risk scoring system. Compression stockings were worn by the majority of the patients throughout the pregnancy and during the postpartum. In antepartum, LMWH prophylaxis was prescribed to 64.5% of patients with high risk of VTE. Among them, 34.4% were treated in the third trimester only and 30.1% were treated throughout pregnancy. In postpartum, all patients received low molecular weight heparin (LMWH) prophylaxis for at least 6 weeks.In this cohort, two antepartum-related VTE (0.37%) and four postpartum-related VTE (0.73%) occurred. One of the ante-partum related VTE was occurred in a patient who was on LMWH prophylaxis with enoxaparin 40mg/day for a personal history of spontaneous pulmonary embolism and homozygous prothrombin G20210A mutation. Despite well conducted LMWH prophylaxis, the patient had a distal deep vein thrombosis (DVT) at week 28. The second VTE was a proximal DVT during a bed resting in the eighth month of pregnancy in a patient with heterozygous FV Leiden mutation and a history of proximal DVT. According to the risk score, LMWH prophylaxis was required during bed-resting but it was not prescribed by the obstetrician. Among four postpartum-related VTE, 3 occurred after the 6 weeks of LMWH prophylaxis, between weeks 8 and 12 of the postpartum period and one was a ovarian vein thrombosis. No case of pulmonary embolism was observed during the study period. The rate of bleeding was 0.37%, no serious bleeding requiring transfusions or surgery was occurred during the study period. There was no evidence of heparin-induced thrombocytopenia or osteoporosis.The use of a risk score may provide a rational decision process to implement safe and effective antepartum thromboprophylaxis in pregnant women at high risk of VTE1.Dargaud, Y., Rugeri, L., Ninet, J., Negrier, C. & Trzeciak, M.C. Management of pregnant women with increased risk of venous thrombosis. International Journal of Gynaecology and Obstetrics 2005, 90,203-2072.Dargaud, Y., Rugeri, L., Vergnes MC, Arnuti B, Miranda P, Negrier, C., Ninet, J., Trzeciak, M.C. A risk score for the management of pregnant women with increased risk of venous thrombomebolism: a multicenter prospective study. Br J Haematol 2009;145:825-35 DisclosuresNo relevant conflicts of interest to declare.

Catastrophic antiphospholipid syndrome in obstetric practice

Thus, the Catastrophic antiphospholipid syndrome (CAPS) is much more common than has been assumed until now, in all patients the authors strongly recommend screening for AFA. Furthermore, eclampsia, HELLP-syndrome premature detachment of normally located placentae (PDNSP) can develop in the presence of other defects of hemostasis, in particular in mutation FV Leiden, MTHFR C677T, deficiency of protein C (PC), protein S (PS). The combination of acquired thrombophilia due to APS, with genetic defects worsen hemostasis during the pathological process leading to the development of thrombotic complications. Perhaps a combination of hereditary thrombophilia and APS creates a favorable environment in which, under certain conditions, possible decompensation of the hemostatic system and the development of CAPS. Patients with APS constitute a group of very high risk of thromboembolic complications in the perioperative period. Even a minimally invasive intervention (biopsy, curettage, tooth extraction) may trigger the development of CAPS. Thus, according to Erkan et al. (2003), 40% of patients develop CAPS was provoked by surgery. The main reasons for the development of thrombotic complications in connection with surgical intervention is the damage to the vessel wall, blood stasis and the abolition of indirect anticoagulants. In the study on the presence of genetic thrombophilia was found heterozygous form of FV Leiden mutation and homozygous mutation of MTHFR C677T. He was diagnosed with pregnancy 14 weeks, APS, mixed form of thrombophilia (a combination of acquisitions and multigenic thrombophilia), hyperhomocysteinemia, weighed down by obstetric and somatic history. It is very urgent and important problem remains diagnosis CAPS, which is inconceivable without the determination of AFA. The latter should be mandatory for all pregnant women with preeclampsia habitual miscarriage, Premature detachment of normally situated placenta (PDNSP), genital herpes history, initial manifestations of septic diseases. In pregnant women with APS naybolee is appropriate pathogenetic early antithrombotic therapy with LMWH immunnocorrection intravenous immunoglobulin, which allows for the prevention of fetal loss and thrombotic complications, provide a more adequate development of the placenta and fetus, as well as prevent the development of CAPS

Factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen — Results from a prospective, single center, case control study

BackgroundEstimates of the risk ratio of tamoxifen-associated venous thromboembolism (VTE) in breast cancer patients range from 2.4 to 7.1. The occurrence of thrombosis in patients with breast cancer complicates the clinical condition and causes a change of treatment. Our study was conducted in order to investigate the influence of patient-related risk factors for thrombosis development in breast cancer patients whose treatment included adjuvant tamoxifen. MethodsThe prospective, single center, case control study included 150 breast cancer women, 50 whom developed venous thrombosis during adjuvant tamoxifen and 100 whom did not have thrombosis, as a control group. Patient-related risk factors such as: age, body mass index, previous VTE, varicose veins, concomitant diseases, the presence of prothrombotic mutations (FV Leiden, FII G20210A) and FVIII activity were evaluated in both groups. ResultsIn respect of prothrombotic mutations, the FV Leiden mutation was present in a higher number of women from the VTE group (10/50 vs 7/100; P=0.020). Additionally, FVIII activity was significantly higher in the VTE group; median (IQR), of 1.79 (0.69) vs 1.45 (0.55); P<0.001 and more women in this group (24/50 vs 34/100) had increased FVIII activity; P=0.020. In those women with FVIII>1.5IU/ml, who were carriers of prothrombotic mutations, an OR of 3.76 (CI 95% 1.276–11.096; P=0.016) was obtained for VTE. ConclusionThe results of our study showed that the factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen.

Factor V Leiden, factor V Cambridge, factor II GA20210, and methylenetetrahydrofolate reductase in cerebral venous and sinus thrombosis: A case-control study.

Background:Factor V G1691A (FV Leiden), FII GA20210, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations are the most common genetic risk factors for thromboembolism in the Western countries. However, there is rare data in Iran about cerebral venous and sinus thrombosis (CVST) patients. The aim of this study was to evaluate the frequency of common genetic thrombophilic factors in CVST patients.Materials and Methods:Forty consequently CVST patients from two University Hospital in Isfahan University of Medical Sciences aged more than 15 years from January 2009 to January 2011 were recruited. In parallel, 51 healthy subjects with the same age and race from similar population selected as controls. FV Leiden, FII GA20210, MTHFR C677T, and FV Cambridge gene mutations by polymerase chain reaction technique were evaluated in case and control groups.Results:FV Leiden, FII GA20210, and FV Cambridge gene mutations had very low prevalence in both case (5%, 2%, 0%) and control (2.5%, 0%, 0%) and were not found any significant difference between groups. MTHFR C677T mutations was in 22 (55%) of patients in case group and 18 (35.5%) of control group (P = 0.09).Conclusion:This study showed that the prevalence of FV Leiden, FII GA20210, and FV Cambridge were low. Laboratory investigations of these mutations as a routine test for all patients with CVST may not be cost benefit.

Genotyping analysis for the 46 C/T polymorphism of coagulation factor XII and the involvement of factor XII activity in patients with recurrent pregnancy loss.

BackgroundEstablished causes of recurrent pregnancy loss (RPL) include antiphospholipid syndrome, uterine anomalies, parental chromosomal abnormalities, particularly translocations and abnormal embryonic karyotype. A systematic review concluded that coagulation factor XII (FXII) deficiency was associated with RPL. However, it could not be established whether the 46 C/T SNP of FXII or low activity of FXII was a risk factor for RPL, because of the small sample size.Methods and FindingsWe conducted a cross-sectional and cohort study in 279 patients with two or more unexplained consecutive pregnancy losses and 100 fertile women. The association between the lupus anticoagulant (LA) activity and FXII activity was examined. The frequency of the CC, CT and TT genotypes and the FXII activity were also compared between the patients and controls. Subsequent miscarriage rates among the CC, CT, TT genotypes and according to the FXII activity was examined. LA was associated with reduced FXII activity. The CT, but not the TT, genotype was confirmed to be a risk factor for RPL in the cross-sectional study using multivariate logistic regression analysis (OR, 2.8; 95% CI, 1.37–5.85). The plasma FXII activity in the patients was similar to that in the controls. Neither low FXII activity nor the CT genotype predicted the subsequent pregnancy outcome in the cohort study. On the other hand, and intermediate FXII activity level of 85–101% was predictive of subsequent miscarriage.ConclusionsLow FXII activity was not associated with RPL. The FXII gene was found to be one of the significant susceptibility genes for RPL, similar to the FV Leiden mutation. However, the clinical influence of the CT genotype might be relatively small, because the presence/absence of this genotype did not have any predictive value for the subsequent pregnancy outcome. This was the first study indicating the influence of FXII 46C/T on further pregnancy outcomes.

Genome-wide investigation of DNA methylation marks associated with FV Leiden mutation.

In order to investigate whether DNA methylation marks could contribute to the incomplete penetrance of the FV Leiden mutation, a major genetic risk factor for venous thrombosis (VT), we measured genome-wide DNA methylation levels in peripheral blood samples of 98 VT patients carrying the mutation and 251 VT patients without the mutation using the dedicated Illumina HumanMethylation450 array. The genome-wide analysis of 388,120 CpG probes identified three sites mapping to the SLC19A2 locus whose DNA methylation levels differed significantly (p<3 10−8) between carriers and non-carriers. The three sites replicated (p<2 10−7) in an independent sample of 214 individuals from five large families ascertained on VT and FV Leiden mutation among which 53 were carriers and 161 were non-carriers of the mutation. In both studies, these three CpG sites were also associated (2.33 10−11<p<3.02 10−4) with biomarkers of the Protein C pathway known to be influenced by the FV Leiden mutation. A comprehensive linkage disequilibrium (LD) analysis of the whole locus revealed that the original associations were due to LD between the FV Leiden mutation and a block of single nucleotide polymorphisms (SNP) located in SLC19A2. After adjusting for this block of SNPs, the FV Leiden mutation was no longer associated with any CpG site (p>0.05). In conclusion, our work clearly illustrates some promises and pitfalls of DNA methylation investigations on peripheral blood DNA in large epidemiological cohorts. DNA methylation levels at SLC19A2 are influenced by SNPs in LD with FV Leiden, but these DNA methylation marks do not explain the incomplete penetrance of the FV Leiden mutation.

Coincidence of Malignancy and Congenital Thrombophilia as the Cause of Deep Venous Thrombosis - Case Report and Review of the Literature

Abstract Introduction: Deep venous thrombosis (DVT, phlebothrombosis) is a very important clinical problem with its resultant fatal pulmonary embolism (PE) as one of the possible consequences. Factor V Leiden (FV Leiden) is a genetic disorder characterized by a poor anticoagulant response to activated protein C (APC) and an increased risk of venous thromboembolism (VTE). Homozygous carriers of the FV Leiden mutation are estimated to have an 80-fold increased lifetime relative risk of VTE. Most homozygous carriers present with VTE before 40 years of age, but some can live thrombosis-free until the sixth or seventh decade of life or even remain asymptomatic for life. Case-controlled studies of patients with cancer revealed a four-fold increase in thromboembolic occurrence in acute leukaemia, with the risk of thrombosis persisting even after remission of the disease. Case Report: The authors present a case report of the 61-year-old patient with leukaemic transformation of myelodysplastic syndrome (MDS) to acute myeloid leukaemia (AML) and development of DVT of the left leg (LL) as the first clinical manifestation of homozygous FV Leiden carrier. Due to his diagnosis it was not possible to indicate surgical treatment of DVT. After initial treatment with subcutaneous low molecular weight heparin (LMWH) and continuous intravenous application of unfractionated heparin (UFH) the deficiency of antithrombin III (AT III) potentiating the persistence of his hypercoagulable state developed. Treatment with the new oral anticoagulant - rivaroxaban, vasoprotective and antithrombotic drugs in the combination with mechanical methods of VTE prophylaxis led to a reduction in edema of left thigh and calf by 3.5 cm and 4 cm, respectively. Son of the patient experienced DVT at the age of 27 years, too. Conclusion: In this report, we describe a case of the patient with DVT during the leukaemic transformation of MDS to AML as a relatively late first clinical manifestation of homozygous FV Leiden mutation. At the same time the article deals with the clinical aspects of discussed thrombophilia in the relatives of the patient, as well as with the etiopathogenesis, pharmacologic treatment options and possible complications of DVT (PE, pulmonary hypertension and post-thrombotic syndrome).