A Single Genetic Origin for the Common Prothrombotic G20210A Polymorphism in the Prothrombin Gene

Impact of thrombophilia on venous thromboembolism management

Hypercoagulable states, also called thrombophilia, can either be congenital or acquired. Congenital thrombophilia, associated mainly with venous thrombosis, is either secondary to coagulation-inhibitor deficiencies, i.e., antithrombin, protein C and Protein S, or gain of function mutations, i.e., factor V Leiden and prothrombin G20210A mutations. Despite the relative frequency of these two mutations, they have not been associated with venous thrombosis recurrence. Most prevalent thrombophilia have a limited impact and usually does not change indications for duration of antithrombotic treatment or prophylaxis compared to decisions based on clinical factors. However, rare inherited thrombophilia such as antithrombin deficiency could justify a long-term anticoagulation. The main acquired thrombophilia, the Antiphospholipid syndrome (APS), is associated with both arterial and venous thrombosis. Its impact on patient management is significant: choice of the anticoagulant (DOAC vs. warfarin), duration of anticoagulation, screening of any organ involvement and systemic autoimmune disease, introduction of immunosuppressive therapy.

Preoperative incidence and risk factors of deep vein thrombosis in Japanese patients undergoing total hip arthroplasty

PURPOSE

Preoperative deep vein thrombosis (DVT) is a risk factor for postoperative venous thromboembolism (VTE), causing severe mortality. Early detection of preoperative DVT is essential to prevent postoperative VTE. However, little is known regarding preoperative DVT in patients undergoing major surgery. The present study aimed to determine the incidence and risk factors of preoperative DVT in patients admitted for total hip arthroplasty (THA).

METHODS

From August 2017 to September 2022, 243 patients admitted for THA at our institution were enrolled in this study. Patients medical records and preoperative laboratory data were retrospectively collected. According to the results of lower-limb ultrasonography, patients were divided into either the non-DVT (n = 136) or DVT (n = 43) group. The incidence of DVT and independent risk factors for preoperative DVT were investigated using univariate and multivariate logistic regression analyses.

RESULTS

The mean age was 74.0 ± 8.4 years. Preoperative DVT was diagnosed in 43 of the 243 (17.7%) patients. The risk of DVT was significantly high (p < 0.05) in patients with advanced age, increased D-dimer levels, and malnutrition status, as assessed by the Geriatric Nutritional Risk Index (GNRI). Multivariate analysis showed that advanced age, increased D-dimer level, and malnutrition status assessed by the GNRI were independent risk factors for preoperative DVT.

CONCLUSION

A high incidence of preoperative DVT was observed in patients undergoing THA. Advanced age, increased D-dimer levels, and malnutrition assessed by the GNRI increased the risk of preoperative DVT. Screening high-risk subgroups for preoperative DVT is necessary to prevent postoperative VTE.

Prothrombin Gene Mutation as a Teaching Tool: An Autobiographical Case Report

The prothrombin G20210A factor II mutation carrier status has been reported to cause complications during pregnancy. This report presents the case of a patient diagnosed with heterozygous prothrombin G20210A factor II mutation at 29 years of age during preconception genetic screening. The patient had two uncomplicated pregnancies. The patient underwent laparoscopic cholecystectomy with a complicated postoperative course. The complications included deep vein thrombophlebitis (DVT), portal vein thrombosis (PVT), and pulmonary embolization (PE). The treatment options and contraceptive choices are also discussed in this report. Our report discusses the subsequent risks inherent in a heterozygote following the administration of oral contraceptives, prolonged immobilization related to lower extremity trauma, and extended motor vehicle excursion.

Prothrombin G20210A Gene Mutation-Induced Recurrent Deep Vein Thrombosis and Pulmonary Embolism: Case Report and Literature Review

Inherited thrombophilia is an important cause of venous thrombosis. The Factor V Leiden (FVL) is the most commonly encountered mutation, followed by the prothrombin G20210A gene mutation (PTM). The typical venous thrombotic events (VTEs) associated with PTM mutations are deep vein thrombosis (DVT) and pulmonary embolisms (PE). The PTM is inherited in an autosomal dominant pattern with variable penetrance. While heterozygous PTM mutations are more frequent and well documented in the literature, rare cases of homozygous PTM mutations are also reported. In this report, we discuss a 56-year-old male with a past medical history of homozygous prothrombin gene mutation (G20210A) who presented with an unprovoked DVT of the right lower extremity involving both the proximal and distal veins associated with multiple bilateral PEs. This case is unique in terms of the homozygous PTM inheritance, the age at which the patient presented (usually presentation is earlier in life), and the fact that he had a recurrence of both DVT and PE simultaneously.

Pregnancy complications in G20210A mutation carriers associated with high prothrombin activity

OBJECTIVE

To study the association between high activity of Factor II (prothrombin) in blood plasma with G20210A mutation and the development of great obstetrical syndromes.

MATERIAL AND METHODS

A prospective clinical cohort study was conducted on 290 pregnant women (average age 31.7 ± 4.7 years old). The main group was made up of 140 G20210A patients, while the control group comprised 150 women with the wild G20210G type. The aim was to evaluate the activity of Factor II in the venous blood plasma during the stages of pregnancy with regard to trophoblast invasion waves. As per results, association analysis of Factor II activity value and gestational complications was carried out.

RESULTS

In the control group, the median (Me) of Factor II activity ranged from 108% (preconception period) to 144% (pregnancy) [95% CI 130-150]. In patients with the GA type, the value was significantly higher in related periods, ranging from 149 to 181% [95% CI 142-195], p < 0.0001. With Factor II activity ranging from 148.5 to 180.6%, pregnancies in the main group had no complications. Higher levels of Factor II activity were associated with the development of early and/or severe preeclampsia (PE) and fetal growth retardation (FGR).

CONCLUSION

The data obtained regarding Factor II activity in blood plasma, juxtaposed with the development of great obstetrical syndromes, allow to assume that manifestation of G20210A in early and/or severe PE and FGR is associated with this coagulation factor's level of activity. Threshold value of the Factor II activity with G20210A mutation, allowing to predict the development of PE, comprised 171.0% at the preconception stage (AUC - 0.86; p < 0.0001) and within 7-8 weeks of gestation it was 181.3% (AUC - 0.84; p < 0.0001).

Evolving paradigm in thrombophilia screening

: The role of genetic thrombophilia screening for identifying a hypercoagulable state in the management of venous thromboembolism. We searched MEDLINE and EMBASE from 1995 to 2017, the websites of the professional bodies including American Society of Hematology, British Society of Hematology, International Society of Thrombosis and Hemostasis, College of American Pathologists, American College of Medical Genetics, and American Society of obstetrics and gynecology for their clinical practice guidelines. We used search strategy terms - venous thromboembolism, inherited, thrombophilia, and hypercoagulable state. Thrombophilia screening does not alter management in pregnancy, infertility, recurrent miscarriages, in primary occlusive arterial syndromes, and for primary prevention in relatives of venous thromboembolism patients considering hormonal manipulation including oral contraceptives. Routine thrombophilia screening for identifying a hypercoagulable state is not indicated in venous thromboembolism, as it is only useful in a select group of patients. There is no difference in the treatment of venous thromboembolism in patients with or without an inherited hypercoagulable state.

Deep Vein Thrombosis Prophylaxis after Total Hip Arthroplasty in Asian Patients

In Western patient populations, the reported incidence of imaging-demonstrated deep vein thrombosis (DVT) after total hip arthroplasty (THA) is as high as 70% without prophylaxis. The reported rates of symptomatic pulmonary embolism (PE) after THA in recent studies range from 0.6% to 1.5%, and the risk of fatal PE ranges from 0.11% to 0.19% in the absence of prophylaxis. Predisposing factors to DVT in western patients include advanced age, previous venous insufficiency, osteoarthritis, obesity, hyperlipidemia, dietary and genetic factors. However, Asian patients who have undergone THA have a strikingly low prevalence of DVT and virtually no postoperative PE. Some authors suggest low clinical prothrombotic risk factors and the absence of some DVT-related genetic factors in Asian patient populations decrease the risk of DVT, PE or both. In Korea, the prevalence of DVT after THA without thromboprophylaxis have ranges from 6.8% to 43.8%, and asymptomatic PE have ranges from 0% to 12.9%; there have been only two reported cases of fatal PE. Deep-wound infections resulting from postoperative hematomas or prolonged wound drainage have been reported with routine thromboprophylaxis. The prevalence of DVT differs varies based on patient ethnicity. Guidelines for the use of thromboprophylaxis were altered and focus on the potential value of outcomes compared with possible complications (e.g., bleeding).

Triple thrombophilic simultaneous mutations in patients after bariatric surgery: is there a role for screening in the Eastern Mediterranean?

Background and purpose: Thrombophilia is a hypercoagulable state that predisposes to thrombosis. Several genetic risk factors have been shown to predispose to thromboembolic events. Homozygosity to a thrombophilic mutation certainly predisposes the affected patient to more serious symptoms. Materials and methods: Here we present a case of a 56-year-old male patient who underwent sleeve gastrectomy for morbid obesity, presenting to our institution with abdominal pain. Investigations revealed thrombosis of the splenic, axillary vein as well as the right pulmonary artery. The patient was found to have triple thrombophilic mutations. Results: To our knowledge, this is the first reported case of three specific simultaneous thrombophilic mutations in a patient from the Eastern Middle East. Conclusion: We suggest a role for screening for thrombophilic mutations in the Eastern Mediterranean patients undergoing bariatric surgeries for morbid obesity due to the increased risk of thrombosis in this group of patients

Impact of Prothrombotic Risk Factors in a Cohort of Egyptian Hemophilia A Patients

INTRODUCTION

Hemophilias are a group of related bleeding disorders that show an X-linked pattern of inheritance. The clinical phenotype of severe hemophilia may vary markedly among patients as a result of many factors, including genetic prothrombotic risk factors.

OBJECTIVES

Our objective was to study the incidence of the most common prothrombotic risk factors for additive effects among Egyptian patients with hemophilia A and their impact on clinical phenotype; annual bleeding frequency and severity of hemophilic arthropathy, as well as the effect of a single variation in these patients.

METHODS

This study was carried out in 100 patients with hemophilia A. Genotyping for factor V Leiden (FVL) G1691A, prothrombin G20210A, MTHFR C677T, and A1298C mutations was conducted using a real time-polymerase chain reaction (RT-PCR) assay.

RESULTS

Our study revealed mutations in hemophilia patients as follows: prothrombin G20210A (3 %), FVL (14 %), MTHFR C677T (42 %), and A1298C (59 %). Despite a lack of statistical significance when each gene was analysed separately, heterozygosity of prothrombin G20210A or FVL was always associated with either a mild or moderate, but never a severe, clinical presentation. The lowest bleeding frequency (less than once per month) was identified among patients with two heterozygous variants irrespective of the involved genes. In addition, the incidence of hemarthrosis was significantly higher among patients with a wild genotype of the prothrombin gene and FVL, and the average number of affected joints was significantly higher among patients with wild-type prothrombin and FVL genes than among heterozygous patients.

CONCLUSION

These prothrombotic mutations have a cumulative effect in amelioration of the severity of bleeding in hemophiliacs. The most prominent effect is that of prothrombin G20210A and FVL, while MTHFR C677A and A1298C gene mutations are less conclusive.

The Frequency of Factor V Leiden and Concomitance of Factor V Leiden With Prothrombin G20210A Mutation and Methylene Tetrahydrofolate Reductase C677T Gene Mutation in Healthy Population of Denizli, Aegean Region of Turkey

Factor V Leiden causing activated protein C resistance is the most common inherited form of thrombophilia leading to thrombosis. Its frequency shows great ethnic and geographic variations. The aim of this study was to determine the frequency of FV Leiden and coinheritance of FV Leiden with two other frequent hereditary thrombophilia causes, namely, prothrombin G20210A and methylene-tetrahydrofolate reductase ( MTHFR) C677T mutation in the Aegean region of Turkey. The study population consisted of 1030 (500 men and 530 women) apparently healthy subjects. Functional resistance to activated protein C (APC) was measured by using the test kit STA staclot APC-R ((Diagnostica Stago, Asnieres, France, Cat. No. 00721). In subjects with APC resistance, molecular analyses of FV Leiden and of prothrombin G20210A and MTHFR C677T mutation were performed by using FV-PTH-MTHFR StripA (Vienna Lab, Labordiagnostika GmbH, Austria) kit, which was based on hybridization of polymerase chain reaction (PCR) amplified DNA products with mutation-specific oligonucleotide probes. Functional APC resistance was present in 93 subjects (9%). FV Leiden mutation was found in 87 of 93 subjects with APC resistance by PCR method. The FV Leiden carrier frequency was found to be 8.4% (87/1030). Seventy-six individuals were heterozygous (7.3%), and 11 were homozygous (1.06%). Among the 87 subjects with FV Leiden mutation, 45 subjects had MTHFR C677T gene mutation (7 homozygous, 38 heterozygous) and 4 subjects had heterozygote prothrombin G20210A gene mutation. A combination of FV Leiden and prothrombin G20210A and MTHFR C677T gene mutation was detected in 3 subjects. The results indicate that FV Leiden prevalence is quite high and coexistence of FV Leiden with other hereditary causes of thrombosis such as prothrombin G20210A mutation and MTHFR enzyme defect is not rare in healthy population of Aegean region of Turkey.

Clinical Performance of the 1st American Academy of Orthopaedic Surgeons Clinical Guideline on Prevention of Symptomatic Pulmonary Embolism after Total Knee Arthroplasty in Korean Patients

We sought to document the clinical performance of the 1st American Academy of Orthopaedic Surgeons (AAOS) guideline on the prevention of symptomatic pulmonary embolism (PE) after total knee arthroplasty (TKA) in Korean patients, in terms of the proportions of the each risk-stratified group, efficacy and safety. Consecutive 328 patients underwent TKA were preoperatively assessed for the risks of PE and bleeding and categorized into 4 groups: 1) standard risk, 2) high risk for PE, 3) high risk for bleeding, and 4) high risks both for PE and bleeding. One of three options was administered according to the groups (aspirin in group 1 or 4; enoxaparin and following aspirin in group 2; antithrombotic stocking in group 3). Incidences of symptomatic deep vein thrombosis (DVT) and PE, and major or minor bleeding complications were evaluated. Majority of the patients (86%) were assessed to be with standard risks both for PE and bleeding. No patient experienced symptomatic DVT or PE and major bleeding. Eleven percent of the patients discontinued chemoprophylaxis because of bleeding-related wound complication. In conclusion, the 1st AAOS guideline functions successfully in Korean patients undergoing TKA in terms of prevention of symptomatic DVT and PE while avoiding major bleeding complications.

Prothrombotic risk factors and antithrombotic therapy in children with ischemic stroke

OBJECTIVE

Congenital and acquired prothrombotic disorders have been highlighted in a recent series of cerebrovascular stroke (CVS), with a controversial role in pathogenesis. The aim is to study some prothrombotic risk factors [activated protein C (APC) resistance, von Willebrand factor (vWF), anticardiolpin (ACL) antibodies and plasma homocysteine] in children with ischemic stroke, and to evaluate the role of aspirin and low molecular weight heparin (LMWH) in its management in relation to outcome.

METHODS

A total of 37 cases aged from 1 month to 15 years ( mean ± standard deviation 26.2 ± 35.7 months), diagnosed as ischemic stroke (>24 hours) were recruited. Complete blood count, prothrombin time and concentration, partial thromboplastin time, serum electrolytes, random blood sugar, C-reactive protein, electrocardiogram and echocardiography were done. Levels of APC resistance, vWF, ACL antibodies [immunoglobulin G (IgG) and immunoglobulin M (IgM)] and plasma homocysteine were estimated. A total of 25 cases received aspirin 3-5 mg /kg/d and 12 patients received LMWH as initial dose at 75 international units (IU)/kg subcutaneously (SC) then 10-25 IU/kg/day for 15 days in a nonrandomized fashion.

RESULTS

The levels of APC resistance, vWF, ACL antibodies (IgG and IgM) and plasma homocysteine were significantly higher in stroke cases than in controls. There was no significant difference between cases treated with aspirin and those with LMWH in all prothrombotic factors. Significant positive correlations were found between vWF and ACL antibodies (IgG and IgM) levels before treatment. Significant decrease in cognitive function was detected between cases treated with LMWH and those treated with aspirin.

CONCLUSION

Ischemic CVS in children is multifactorial. Thrombophilia testing should be performed in any child with CVS. Early use of aspirin improves the prognosis and has less effect on cognitive function.

The 3'end prothrombin gene variants in patients with different thrombotic events

BACKGROUND

Prothrombin (FII) A19911G and C20221T gene variants are associated with increased prothrombin levels and potentially represent thrombotic risk factors.

OBJECTIVE

To determine the frequency of A19911G and C20221T FII gene variants in patients with thrombotic disorders and in women who have experienced pregnancy loss (PL).

METHODS

We determined the frequency of these variants in 133 patients with deep venous thrombosis (DVT), 80 patients with isolated pulmonary embolism (PE), 101 patients with idiopathic PL, and 180 control individuals.

RESULTS

The FII A19911G variant was more prevalent in patients with DVT and with PL compared with controls; however, these differences were not statistically significant. The 19911GG genotype was associated with increased risk of PE (odds ratio, 1.91; 95% confidence interval, 1.04-3.51). We did not detect carriers of the FII C20221T gene variant in this study.

CONCLUSIONS

This is the first study, to our knowledge, that demonstrates the FII 19911GG genotype may represent a risk factor for isolated PE. Also, our results show that the FII C20221T is a rare variant in this population and therefore, routine thrombophilia screening should not include screening for this genotype.

Genetic predictors of response to photodynamictherapy

In Western countries, therapeutic management of patients affected by choroidal neovascularization (CNV) secondary to different typologies of macular degeneration represents a major health care problem. Age-related macular degeneration is the disease most frequently associated with CNV development. Schematically, CNVs can be distinguished into classic and occult subtypes, which are characterized by variable natural history and different responsiveness to some therapeutic procedures. At present, the dramatic vision loss due to CNV can be mainly treated by two interventional strategies, which are utilizable in either single or combined modalities: photodynamic therapy with verteporfin (PDT-V), and intravitreal administration of drugs acting against vascular endothelial growth factor. The combined use of PDT-V and anti-angiogenic drugs represents one of the most promising strategies against neovascular macular degeneration, but it unavoidably results in an expensive increase in health resource utilization. However, the positive data from several studies serve as a basis for reconsidering the role of PDT-V, which has undergone a renaissance prompted by the need for a more rational therapeutic approach toward CNV. New pharmacogenetic knowledge of PDT-V points to exploratory prospects to optimize the clinical application of this intriguing photothrombotic procedure. In fact, a Medline search provides data regarding the role of several single nucleotide polymorphisms (SNPs) as genetic predictors of CNV responsiveness to PDT-V. Specifically, correlations between SNPs and different levels of PDT-V efficacy have been detected by examining the gene variants influencing (i) thrombo-coagulative pathways, i.e. methylenetetrahydrofolate reductase (MTHFR) 677C>T (rs1801133), factor V (F5) 1691G>A (rs6025), prothrombin (F2) 20210G>A (rs1799963), and factor XIII-A (F13A1) 185G>T (rs5985); (ii) complement activation and/or inflammatory processes, i.e. complement factor H (CFH) 1277T>C (rs1061170), high-temperature requirement factor A1 (HTRA1) promoter -512G>A (rs11200638), and two variants of the C-reactive protein (CRP) gene (rs2808635 and rs876538); and (iii) production and bioavailability of vascular endothelial growth factor (VEGFA -2578C>A [rs699947] and rs2146323). This article critically evaluates both the clinical plausibility and the opportunity to utilize the most important SNP-response interactions of PDT-V for an effective upgrade of the current anti-CNV therapeutic scenario. In addition, the pharmacogenetics of a very severe post-PDT-V adverse event, i.e. a decrease in acute vision, is briefly discussed. A comprehensive appraisal of the findings reviewed in this article should be carefully considered to design future trials aimed at verifying (after proper genotypic stratification of the enrolled patients) whether these innovative pharmacogenetic approaches will be able to improve the multifaceted interventional management of neovascular macular degeneration.

Prevalence of angiotensin-converting enzyme, methylenetetrahydrofolate reductase, Factor V Leiden, prothrombin and apolipoprotein E gene polymorphisms in Morocco

BACKGROUND

Evidence of the influence of genetic risk factors on cardiovascular diseases is more or less established. These genetic factors are involved in several pathways affecting blood pressure regulation, blood coagulation, homocysteine and lipid metabolisms.

AIM

We evaluated frequencies of five genetic polymorphisms to assess their informativeness as markers for prospective clinical studies.

SUBJECTS AND METHODS

182 healthy Moroccan subjects were genotyped for ACE I/D by amplification alone and by amplification followed by enzymatic digestion for other polymorphisms.

RESULTS

Allele frequencies of ACE ID, MTHFR C677T were 76.6%, 26.9% for D and T alleles, respectively. APOE polymorphism showed 11.3%, 78.6% and 10.2% for the alleles E2, E3 and E4, respectively. The frequency for FII G20210A polymorphism was around 2.7% for A allele. Our data showed an absence of FVL mutation. Using allele frequencies, genetic distances between Moroccan and other populations revealed an independent variability of these polymorphisms.

CONCLUSION

These values appear to be influenced by findings in European and African peoples, and may be considered in assessing the clinical significance of a predisposition to cardiovascular disease.

Venous thromboembolism in African-Americans: a literature-based commentary

Among the cardiovascular diseases and after ischemic heart disease and stroke, venous thromboembolism (VTE) is the third leading cause of death in the U.S. (3). Although VTE is seen across most ethnic groups in the U.S. as well as throughout the world, the rate varies. In the U.S., American Indians/Alaskan Natives as well as Asians have been reported to have a significantly lower rate of deep vein thrombosis (DVT) and pulmonary embolism (PE) as compared to blacks and whites. In sharp conrast blacks appear to have much higher rates than whites. Although these rate differences are thought in part by some to be attributable to disparities in diagnosis and care as well as genetics, it nevertheless is important to define as well as to understand the true incidence and impact so that both public health and clinical resources can be maximally utilized. The purpose of this commentary is to review the VTE burden in the U.S. with respect to ethnicity in terms of clinical demographics and genetics with particular emphasis on blacks.

High Incidence of Factor V Leiden and Prothrombin G20210A in Healthy Southern Italians

Factor V Leiden (FVL) and G20210 prothrombin (FII G20210A) mutations are risk factors for thromboembolism. In Europe, FVL is more prevalent in the north (7%) than in the south (3%), whereas FII G20210A is more common in the south (3% to 7%) than in the north (2% to 5%). In Italy, the prevalence is 2% to 3% for both. The aim of this study was to assess if these polymorphisms could be more frequent in the south than in the rest of Italy. In 105 blood donors in southern Italy, the prevalence of FVL and FIIG20210A was 9.5% and 5.7%, respectively. These prevalence data are higher when compared with published data. The results of this study are as high as those observed in Greece and the Middle East. The diffusion of FVL and FII G20210A in the Mediterranean, consequent to Phoenician and Greek colonization, could be a reason for the high prevalence observed.

Thrombophilic polymorphisms in Israel

Three thrombophilic polymorphisms, FV G1691A, FII G20210A and MTHFR C677T were investigated in Israeli populations by FRET, (fluorescence resonance energy transfer) real-time PCR. We observe extensive variability in the frequencies of each of the polymorphisms, as has been observed in the study of other polymorphisms in these populations. Very high allele frequencies for FV G1691A (the highest 0.087 in Turkish and Greek Jews) and FII G20210A (the highest 0.061 in Georgian Jews) in some of the Israeli populations justify a clinical investigation to assess their risk for venous thrombosis. Principal Coordinates Analysis demonstrates that the Jewish populations are interspersed among the non-Jewish populations. The resemblance of some Jewish populations to certain non-Jewish populations coincides with findings based on classical markers.

Genetic variations and their influence on risk and treatment of venous thrombosis

Venous thrombosis (VT) is a highly prevalent disease. Risk factors can be genetic or acquired. The well-established genetic polymorphisms predisposing to thrombophilic disorders can be divided into rare 'loss-of-function mutations' in anticoagulant proteins and common 'gain-of-function mutations' in procoagulant proteins, which are weaker risk factors. In addition to functional polymorphisms, defects in common pathways affecting biosynthesis or clearance of plasma coagulation factors and their relations to VT risk have been detected. Recently, investigations regarding genetic variations and response to drug treatment, relevant for the pathogenesis as well as therapy of venous thromboembolism have been performed. The methodical advances in genetic research have led to the identification of a number of new variants with still unclear association to VT. This review aims to discuss the established genetic risk factors as well as some candidate predictors of VT. Further, the recent developments in pharmacogenomics are reviewed.

The 2007 John Charnley Award. Factors leading to low prevalence of DVT and pulmonary embolism after THA: analysis of genetic and prothrombotic factors

We evaluated 136 hips (104 patients) to determine the prevalence of and contributing factors in deep vein thrombosis (DVT) and pulmonary embolism (PE) in those who were not given thromboprophylaxis when undergoing primary cementless total hip arthroplasty (THA). We performed coagulation assays, a full blood count, blood typing, and serum chemical profile tests for all patients on three separate occasions. Molecular genetic testing was performed preoperatively to detect the genetic traits involving DVT. DVT was diagnosed by roentgenographic venography, and PE was diagnosed by perfusion lung scanning. Our patients had a low prevalence of DVT and no patient had PE. Patients with bilateral THA had similar rates (p = 0.158; CI, -0.134-0.125) of venographic DVT as patients with unilateral THA (16 of 65 or 25% versus 12 of 72 or 17% respectively). We observed a relationship between DVT and factor V Leiden mutation, antithrombin-III level, and prothrombin promoter G20210A mutation. We saw no relationship between DVT and coagulation or thrombophilic data. We conclude combinations of absent thrombophilic polymorphisms with low clinical prothrombotic risk factors led to low prevalence of DVT and virtually absent PE after THA in the current series of patients, who had not received any form of prophylactic or therapeutic treatment for DVT.

Factors leading to decreased rates of deep vein thrombosis and pulmonary embolism after total knee arthroplasty

We evaluated a total of 473 knees (264 patients) to determine the prevalence of deep vein thrombosis and pulmonary embolism (PE) in those who were not given thromboprophylaxis after total knee arthroplasty (TKA). Deep vein thrombosis was diagnosed by roentgenographic venography, and PE was diagnosed by perfusion lung scanning. In patients with bilateral TKA, 47 (11%) of 418 venograms showed positive findings for thrombi, whereas in patients with unilateral TKA, 11 (20%) of 55 venograms showed positive findings for thrombi (P = .758). No patient had symptoms of PE, and findings for the perfusion lung scans were negative in all patients. We neither treat our patients for deep vein thrombosis and PE prophylactically nor therapeutically unless patient has a symptomatic PE.

The scientific basis for evaluation and management of thrombotic disorders

The hemostatic mechanisms at work in the body involve a complex series of interactions between platelets, the endothelium, and the coagulation cascade. Much has been learned regarding the molecular mechanisms governing these intricate processes. The hypercoagulable state involves a disruption of the normal homeostatic equilibrium. This state may be either inherent or acquired. The prevention of associated thromboembolic complications requires therapeutic anticoagulation. A broader understanding of the factors contributing to these prothrombotic tendencies and the subtleties involved in their management provides the surgeon with another weapon in the armamentarium to promote better and safer patient outcomes.

Cerebral venous sinus thrombosis as a recurrent thrombotic event in a patient with heterozygous prothrombin G20210A genotype after discontinuation of oral anticoagulation therapy: How long should we treat these patients with warfarin?

BACKGROUND

Cerebral venous sinus thrombosis is an uncommon condition with many clinical manifestations, and hereditary prothrombotic conditions such as factor Leiden V, deficiency of protein S, protein C and antithrombin III, as well as prothrombin gene mutation, may account for 10-15% of cases. To date, conflicting results have been reported for recurrent venous thrombosis in the patients with factor V Leiden and prothrombin G20210A mutation, since some studies have shown a higher risk for recurrent venous thrombosis in carriers of these two mutations than in non-carriers, and the last study showed higher risk only for carriers of double defect (homozygous or double heterozygous for this mutations).

METHODS

Case report is presented.

RESULTS

We report a case of cerebral sinus thrombosis as a recurrent thrombotic event in a patient with heterozygous prothrombin G20210A genotype after discontinuation of oral anticoagulation therapy.

CONCLUSION

Since many facts are controversial, the use of secondary prophylaxis for thrombosis in these patients is still a matter of debate without clear consensus recommendation. Data on the risk of recurrent thrombotic events in thrombophilic patient is insufficient. The main unclear question concerning these patients is: how long and whom should we treat with long-term anticoagulant therapy as secondary prophylaxis of DVT? The problem for practitioner is that we do not have guidelines and precise recommendations for secondary thromboprophylaxis in this or similar cases. This case is remarkable for its favorable and quick outcome and its rarity, because CSVT is an uncommon condition and heterozygous prothrombin G20210A genotype was only found predisposing factor for CSVT. Further studies of risk of recurrent venous thrombosis in patients with heterozygous prothrombin G20210A genotype with the larger sample size are required.

The association of prothrombin A19911G polymorphism with plasma prothrombin activity and venous thrombosis: results of the MEGA study, a large population-based case-control study

BACKGROUND

Prothrombin (FII) G20210A mutation and elevated plasma prothrombin activity are known risk factors for venous thrombosis. The risk of venous thrombosis among 19911G carriers of the prothrombin A19911G polymorphism has not been extensively investigated.

OBJECTIVES AND METHODS

We assessed prothrombin activity, FIIG20210A, and FIIA19911G polymorphisms in a large population-based case-control study, the Multiple Environmental and Genetic Assessment (MEGA) study of risk factors for venous thrombosis. Four thousand three hundred and sixty-five consecutive patients with a first episode of deep vein thrombosis of the leg or pulmonary embolism were included. The control group (n = 4779) consisted of partners of patients or persons gathered using a random-digit dialing method. We studied the effect of FIIA19911G polymorphism on prothrombin activity and thrombosis risk, also in combination with factor V Leiden.

RESULTS

Among FII20210-GG control subjects, FII19911-GG carriers had 7.1% [95% confidence interval (CI): 5.7-8.5] higher mean prothrombin activity than FII19911-AA carriers and the risk for GG carriers was 1.43-fold increased compared to AA carriers [odds ratio (OR) 1.43; 95% CI: 1.27-1.61]. Among FII20210-GA control carriers, the mean prothrombin activity in both FII19911-AA and -AG carriers was nearly equivalent [131.7% and 133.4%; mean difference (95% CI) = 1.7% (-7.2-10.7)]. Because of genetic linkage, FII19911-GG carriers were very rare on a FII20210-GA background, as only one FII20210A carrier had FII19911-GG. In FII20210-GA carriers, the OR increased from 3.05 (95% CI: 2.17-4.27) in subjects with FII19911-AA to 3.33 (2.28-4.85) in subjects with FII19911-AG, compared to those with FII20210-GG and FII19911-AA.

CONCLUSIONS

The FIIA19911G polymorphism is associated with mildly elevated prothrombin activity and is a risk factor for venous thrombosis.

Phenotypic Heterogeneity in Patients with Homozygous Prothrombin 20210AA Genotype. A paper from the 2005 William Beaumont Hospital Symposium on Molecular Pathology

Venous thromboembolic events (VTEs) affect an estimated 1 in 1000 people annually, resulting in approximately 50,000 deaths, with prevalence increasing with age. The genetic contributors to thrombosis have been described and further explored within the last 15 years as molecular diagnostic techniques have become more widely used. The prothrombin G20210A mutation is the second most common inherited thrombotic risk factor after factor V Leiden. Generally present in less than 5% of the population, the mutation's prevalence varies greatly with ethnicity. The G20210A mutation confers a mildly increased thrombotic risk that is compounded by the presence of other risk factors. One striking characteristic of the G20210A mutation is the phenotypic heterogeneity of the rare homozygous cases. Forty percent of the reported homozygous cases are asymptomatic. Many of the symptomatic patients have additional risk factors that might compound the thrombotic risk. We present here a review of the literature for the homozygous prothrombin G20210A mutation and describe additional cases that exemplify the heterogeneous nature of this entity.

Thrombophilic gene polymorphisms in puerperal cerebral veno-sinus thrombosis

Puerperal cerebral veno-sinus thrombosis (PCVT) is a common form of stroke in young women in India, which is associated with high morbidity and mortality. The frequency of PCVT in India is 10 to 12 times more compared to western population. As yet, the etiology of this condition is unclear. Our aim was to study the prevalence and the role of the common genetic polymorphisms associated with thrombophilia such as factor V Leiden, prothrombin G20210A and methylene tetrahydrofolate reductase (MTHFR) C677T, in aseptic PCVT. We investigated 86 women with PCVT and 86 age-matched women with no post-partum complications. Polymerase chain reaction (PCR)/restriction fragment length polymorphism analysis was used to identify their genotypes. The frequency of the three polymorphisms in cases and controls were: factor V Leiden, 2.3% versus 1.2% (OR 0.49, 95% CI=0.02-7.12, p=1.000) and MTHFR C677T, 16.3% versus 17.4% (OR 0.92, 95% CI=0.39-2.19, p=0.838). The prothrombin G20210A variant was not detected in either patients or controls. The clinical characteristics of the PCVT patients with the polymorphisms did not differ significantly from those without them. In our series of PCVT patients, the risk associated with the established thrombophilic risk factors is insignificant. Exploration of these gene polymorphisms seems to be of limited value in the investigation of PCVT in south Indian women.

Prothrombin 20210G>A is an ancestral prothrombotic mutation that occurred in whites approximately 24 000 years ago

Prothrombin 20210G>A and factor V Leiden are common prothrombotic mutations in whites for which founder effects have been established. In this study, we analyzed the frequencies of 5 single nucleotide polymorphisms (SNPs) and 9 microsatellites flanking the prothrombin gene (F2) in 88 homozygotes for 20210A and 66 homozygotes for 20210G. For estimating the age of the prothrombin 20210G>A mutation, we used the DMLE+2.0 program, which analyzed linkage disequilibria between the mutation and the multiple markers that had been assessed. This analysis yielded an age estimate of 23 720 years (95% credible set, 19 080-31 340 years). A similar analysis by the DMLE+2.0 program was performed on 5 SNPs from previously studied homozygotes for factor V Leiden and controls that yielded an age estimate of 21 340 years (95% credible set, 16 880-29 480 years). The occurrence of the 2 mutations in whites toward the end of the last glaciation and their presently wide distribution in whites suggest selective evolutionary advantages for which some evidence was reported (diminished blood loss) or is controversial (protection against infections).

Iliofemoral Deep Vein Thrombosis in Childhood; Developing a Management Protocol

OBJECTIVE

To develop an evidence-based protocol for the management of iliofemoral deep vein thrombosis (IDVT) in childhood.

METHODS

A search of the literature was undertaken. All publications pertaining to IDVT in childhood were analysed and then categorised according to their level of evidence. Recommendations were then made on the basis of this.

RESULTS

The commonest presenting symptoms were pain and swelling in the affected limb (evidence level II). Predisposing risk factors of special significance in children included the recent use of a venous access device, malignancy, prothrombotic disorders, infection, surgery and congenital venous anomalies (evidence level II). The most frequently described imaging modalities were B-mode ultrasonography, duplex, venography, and helical CT (evidence level III). The mainstay of treatment was anticoagulation with LMWH alone or followed by warfarin (evidence level I). Early clot removal through catheter-directed thrombolysis or surgical thrombectomy has been shown to be beneficial (evidence level II/III). There is little evidence for the benefit of early mobilisation and compression therapy in childhood.

CONCLUSION

Level I evidence relating to IDVT in childhood is sparse. The possibility of IDVT should be considered when examining a child with a swollen and painful limb. Imaging should be with duplex ultrasound, followed by spiral CT to include assessment of the IVC. A thrombophilia screen should be taken prior to anticoagulation with LMWH (and warfarin). Thrombolysis should be considered in cases of extensive IDVT.

The prothrombin 20209 C-->T mutation in Jewish-Moroccan Caucasians: molecular analysis of gain-of-function of 3' end processing

BACKGROUND

Mutations of the 3' end mRNA-processing signal of the prothrombin (F2) gene have been reported to cause elevated F2 plasma concentrations, thrombosis, and complications of pregnancy. Whereas the common F2 20210*A mutation is almost exclusively found in Caucasians, the F2 20209*T mutation has been reported in Afro-Americans and Afro-Caribbeans only.

PATIENTS AND METHODS

Using LightCycler technology, three unrelated Jewish-Moroccan patients tested for obstetric complications were found to be carriers of the F2 20209*T allele. A detailed molecular analysis was performed to identify the functional impact of this mutation.

RESULTS

We report three unrelated women of Jewish-Moroccan origin with a F2 20209*T mutation and fetal loss or infertility. The functional analysis revealed that the F2 20209*T mutation stimulates 3' end processing and up-regulates prothrombin protein expression as assessed by a highly sensitive luminescence-based reporter system.

CONCLUSIONS

This is the first report of 20209*T in Caucasians, and functional analysis demonstrates that F2 20209*T falls into a general category of mutations of the F2 gene, which may possibly contribute to thrombophilia and complications of pregnancy by interfering with a tightly balanced architecture of non-canonical F2 3' end formation signals.

Haemophilia A: from mutation analysis to new therapies

Haemophilia is caused by hundreds of different mutations and manifests itself in clinical conditions of varying severity. Despite being inherited in monogenic form, the clinical features of haemophilia can be influenced by other genetic factors, thereby confounding the boundary between monogenic and multifactorial disease. Unlike sufferers of other genetic diseases, haemophiliacs can be treated successfully by intravenous substitution of coagulation factors. Haemophilia is also the most attractive model for developing gene-therapy protocols, as the normal life expectancy of haemophiliacs allows the side effects of gene therapy, as well as its efficiency, to be monitored over long periods.

Trombophilic screening for nonarteritic anterior ischemic optic neuropathy

BACKGROUND

Nonarteritic anterior ischemic optic neuropathy (NAION) is an ischemic infarction of the optic nerve head, frequently leading to sudden, mostly irreversible loss of vision. In this study blood thrombophilic factors, as well as cardiovascular risk factors were investigated for their relevance to this pathology. Trombophilic risk factors so far not evaluated were included in the study.

PATIENTS AND METHODS

37 NAION patients (4 with sequential second eye involvement) and 81 matched control subjects were examined. From blood, protein C, protein S, antithrombin, von Willebrand antigen levels (vWFAg), and factor V (Leiden) mutation, factor VIIIC level, plasminogen activity, lipoprotein (a) and fibrinogen levels, and presence of anticardiolipin antibodies were investigated. Possibly relevant pathologies [e.g. diabetes mellitus (DM), hypertension, and ischemic heart disease] were also registered.

RESULTS

Elevated Lp(a) and vWFAg levels, DM, F V (Leiden), hypercholesterolemia, and hyperfibinogenemia proved to be significant risk factors associated with NAION. Forward stepwise logistic regression analysis revealed that high Lp(a), DM, and FV (Leiden) were the main predictive components, with odds ratios 16.88 (p=0.012), 5.78 (p=0.022) and 4.44 (p=0.033), respectively.

CONCLUSIONS

Based on our results it appears that thrombophilia is likely to contribute to the development of NAION besides vascular damage due to the presence of cardiovascular risk factors. Further data are needed, however, to justify the suggested use of secondary prophylaxis using anticoagulant/antiplatelet therapy.

Thromboembolic Diseases in Neonates and Children

Acquired and inherited prothrombotic risk factors increase the risk of thrombosis in neonates, infants and children. After suffering thrombosis white paediatric patients should be screened for common gene mutations, i.e. the factor V G1691A, factor II G20210A and MTHFR C677T genotypes, rare inherited prothromboticrisk factors, i.e. deficiencies of protein C,protein S, and antithrombin, plasminogen, probably inherited risk factors, i.e. fibrinogen, factor VIIIC, factor XII, new candidates, i.e. elevation of lipoprotein (a),and fasting homocysteine concentrations (3-6 months after thrombotic onset). Data interpretation is based on age-dependent reference ranges or the identification of causative gene mutations/polymorphisms with respect to individual ethnic backgrounds.

Rapid combined genotyping of factor V, prothrombin and methylenetetrahydrofolate reductase single nucleotide polymorphisms using minor groove binding DNA oligonucleotides (MGB probes) and real-time polymerase chain reaction

Risk factors for cardiovascular diseases and venous thromboembolism involve both acquired and hereditary conditions. Among the latter, mutations in genes coding for coagulation factors (

Genetically Determined Procoagulant States and Heparin Use

The propensity for both arterial and venous thrombotic disorders involves a genetic predetermination that operates In concert with environmental factors or triggers. Appropriate clinical assessment and therapeutic recommendations for patients with thrombosis requires a thorough knowledge of genetic variables that influence this propensity. This review focuses on the pathophysiology, natural history, and molecular biology of defined thrombophilic risk factors relevant to the care of patients with thrombotic disorders.