Another gastroenteritis?

Portal vein thrombosis (PVT) is an important, but often delayed or missed differential diagnosis in patients presenting with abdominal pain. In this case report we present a previously healthy 42-year-old patient with persistent upper abdominal pain for five days. Being a common complication in patients suffering from liver cirrhosis, PVT is an unusual finding in healthy individuals. However, gene mutation leading to a hypercoagulable state can be associated with thrombotic events in the portal venous system. Investigation for underlying disorders such as myeloproliferative neoplasm (MPN), paroxysmal nocturnal hemoglobinuria (PNH), antiphospholipid antibody syndrome are crucial.

Thrombophilic risk of individuals with rare compound factor V Leiden and prothrombin G20210A polymorphisms: an international case series of 100 individuals

The risk of thrombosis in individuals with rare compound thrombophilias, homozygous factor V Leiden (FVL) plus heterozygous prothrombin G20210A (PTM), homozygous PTM plus heterozygous FVL, and homozygous FVL plus homozygous PTM, is unknown. We identified, worldwide, individuals with these compound thrombophilias, predominantly through mailing members of the International Society on Thrombosis and Haemostasis. Physicians were sent a clinical questionnaire. Confirmatory copies of the genetic results were obtained. One hundred individuals were enrolled; 58% were female. Seventy-one individuals had a venous thrombosis (includes superficial and deep vein thrombosis, and pulmonary embolism), 4 had an arterial thrombosis and 6 had both. Nineteen individuals had never had a thrombotic event. Thrombosis-free survival curves demonstrated that 50% of individuals had experienced a thrombotic event by 35 yrs of age, while 50% had a first venous thromboembolic event (VTE; includes all venous thrombosis except superficial thrombosis) by 41 yrs of age; 38.2% of first VTEs were unprovoked. 37% of patients had at least one VTE recurrence. Seventy percent of first pregnancies carried to term and not treated with anticoagulation were thrombosis-free. In conclusion, patients with these rare compound thrombophilias are not exceedingly thrombogenic, even though they have a substantial risk for VTE.

Association of factor V Leiden, Janus kinase 2, prothrombin, and MTHFR mutations with primary Budd-Chiari syndrome in Egyptian patients

BACKGROUND AND AIM

Budd-Chiari syndrome (BCS) is defined as obstruction of hepatic venous outflow anywhere from the small hepatic veins to the suprahepatic inferior vena cava. The pathogenesis of BCS is still not fully understood. This study aimed to evaluate the association of factor V Leiden (FVL), Janus kinase 2 (JAK2), prothrombin, and methylene tetrahydrofolate reductase (MTHFR) mutations with primary BCS.

METHODS

The study was carried out on 35 patients with primary BCS and 15 age and gender matched healthy individuals as a control group. Genotyping of FVL, prothrombin, and MTHFR mutations was determined by GENEQUALITY AB-THROMBO TYPE kit based on the reverse hybridization principle. JAK2 mutation was determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

There was a statistically significant difference between patients and controls regarding FVL, MTHFR C677T, and MTHFR A1298C mutations with odds ratio of 1.83, 2.0, and 1.79, respectively. Hetero MTHFR C677T, hetero FVL, and hetero MTHFR A1298C were the most common etiological factors being responsible for 57.1, 42.9, and 42.9% of primary BCS cases, respectively.

CONCLUSION

It could be concluded that BCS is a multifactorial disease; in the current study, MTHFR C677T mutation was the most common cause of disease. Identification of one cause of BCS should not eliminate investigations for detection of other etiological factors.

Factor V Leiden, Prothrombin and MTHFR Mutation in Patients with Preeclamsia, Intrauterine Growth Restriction and Placental Abruption

BACKGROUND

Factor V Leiden, Prothrombin and MTHFR gene mutation, could have an influence in pregnancy with adverse outcome Preeclamsia, IUGR and Placental abruption.

AIM

The aim of this study is to investigate the presence of above mentioned inherited thrombophilias and its statistical significance, distribution among the complicated and normal pregnancy, and relative risk for carrier of mutation to develop preeclampsia, IUGR and placental abruption.

MATERIAL AND METHODS

Prospective cohort study is implemented at University Clinic for Obstetric and Gynecology in Skopje, Republic of Macedonia. The study included 109 delivered patients: 40 with preeclapmsia, 22 with IUGR, 17 with placental abruption and 30 as control group with normal pregnancy. The amount of 3 ml venous blood has been used for detection of these point mutations using ThromboStrip -Opegen, QIAGEN kit manufactured for thrombotic risk.

RESULTS

The highest frequency was found: in the group with preeclampsia 35% were MTHFR homozygous, IUGR -MTHFR heterozygous 45%, Placental abruption- 52.9% MTHFR heterozygous, and in the control group without thrombophilia 56.7%. There were combined thrombophilia in 3 patients. There aren`t statistical significance in presence of thrombophilia among groups (p > 0.05). Statistical significance (p < 0.05) was found between carriers of MTHFR homozygous in preeclampsia and group with placental abruption and control group. Relative risk in IUGR group for MTHFR homozygous was 5.54 (1.37

CONCLUSION

The presence of mutation MTHFR homozygous could increase the risk for development of IUGR and mutation of Factor V Leiden for placental abruption. Further investigations with more patients are warranted.

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Key Words

• IUGR
• MTHFR
• factor V Leiden
• placental abruption
• preeclampsia
• prothrombin

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MESH Headings Collapse

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Factor V Leiden and Cardiopulmonary Bypass

We present a case of a patient with factor V Leiden with an antithrombin III activity of 67% who received a successful aortic valve replacement supported by cardiopulmonary bypass (CPB). A safe level of anticoagulation was achieved by monitoring activated clotting time (ACT) and heparin concentration ensuring adequate anticoagulation throughout the procedure. Results from ACT, heparin dose response, heparin protamine titration, and thrombelastography are given. Factor V Leiden patients can be safely anti-coagulated using heparin for CPB procedures when monitored with ACT, heparin protamine titration, and thrombelastography. Postoperative chest tube losses were 360 mL, less than half our institutional average. Anticoagulation for the pre-and post-operative phase is also discussed.

Thrombophilia in 67 Patients With Thrombotic Events After Starting Testosterone Therapy

We compared thrombophilia in 67 cases (59 men and 8 women) with thrombotic events after starting testosterone therapy (TT) versus 111 patient controls having unprovoked venous thrombotic events without TT. In the 67 patients, thrombosis (47 deep venous thrombosis-pulmonary embolism, 16 osteonecrosis, and 4 ocular thrombosis) occurred 6 months (median) after starting TT. Cases differed from controls for factor V Leiden heterozygosity (16 of the 67 [24%] vs 13 [12%] of the 111, P = .038) and for lupus anticoagulant (9 [14%] of the 64 vs 4 [4%] of the 106, P = .019). After a first thrombotic event and continuing TT, 11 cases had a second thrombotic event, despite adequate anticoagulation, 6 of whom, still anticoagulated, had a third thrombosis. Screening for thrombophilia before starting TT should identify men and women at high risk for thrombotic events with an adverse risk-benefit ratio for TT. When TT is given to patients with familial and acquired thrombophilia, thrombosis may occur and recur in thrombophilic men despite anticoagulation.

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.

Seeing through thick and through thin: Retinal manifestations of thrombophilic and hyperviscosity syndromes

The presence of retinal vasculopathy in the absence of typical predisposing factors should suggest a possible underlying hematologic abnormality. In such cases, a systemic investigation may reveal a potentially fatal hypercoagulability or hyperviscosity syndrome. Retinal vein occlusion is the most commonly encountered ophthalmic finding in such syndromes; however, abnormalities of the arterial system, the choroid, and the macula are also possible. Visual symptoms may be the only manifestation of the underlying process, making timely diagnosis by the ophthalmologist critical for both treatment and thrombotic prophylaxis. Moreover, as newer ophthalmic diagnostic technologies arise, there is an increasingly important role for eye physicians in the management of such syndromes.

Renal transplantation experience in a patient with factor V Leiden homozygous, MTHFR C677T heterozygous, and PAI heterozygous mutation

Vascular complications are important causes of allograft loss in renal transplantation. A two and a half-month-old boy was diagnosed with posterior urethral valve and progressed to end-stage renal disease at eight yr of age. During the HD period, a central venous catheter was replaced three times for repeated thrombosis. The boy was found to be homozygous for FVL and heterozygous for both MTHFR (C677T) and PAI. At the age of 12, renal transplantation was performed from a deceased donor. Postoperative anticoagulation therapy was initiated with continuous intravenous administration of heparin at the dose of 10 IU/kg/h. HD was performed for the first three days. By the fourth day of transplantation, his urine output had increased gradually. Heparin infusion was continued for 18 days during hospitalization at the same dosage. Thereafter, he was discharged with LMWH. On the third month after transplantation, his serum creatinine level was 1.1 mg/dL and eGFR was 75.7 mL/min/1.73 m(2). He has still been using LMWH, and his eGFR was 78.7 mL/min/1.73 m(2) eight months after transplantation. Postoperative low-dose heparin treatment is a safe strategy for managing a patient with multiple thrombotic risk factors.

Survival advantage of heterozygous factor V Leiden carriers in murine sepsis

BACKGROUND

The high allelic frequency of the prothrombotic Leiden polymorphism in human blood coagulation factor V (FV) has been speculated to reflect positive selection during evolution. Heterozygous Leiden carriers enrolled in the placebo arm of the PROWESS sepsis trial and heterozygous Leiden mice challenged with endotoxin both showed reduced mortality, whereas homozygous Leiden mice were not protected from lethal endotoxemia. Follow-up analyses of clinical outcomes and of mouse models of infection with various pathogens remained inconclusive.

OBJECTIVE

To establish whether activated protein C resistance of FV Leiden modifies the outcome of bacterial infection in murine sepsis models.

METHODS

Homozygous and heterozygous FV Leiden mice were subjected to gram-positive (S. aureus) or gram-negative (Y. pestis; E. coli) septic peritonitis or polymicrobial, focal septic peritonitis induced by cecal ligation and puncture. The effect of FV Leiden on 7-day survival and bacterial dissemination was assessed. Outcomes were compared with the sepsis survival of mice with genetically impaired hemostasis (hemophilia A, thrombocytopenia, thrombin receptor PAR4 [protease activated receptor 4] deficiency, endothelial protein C receptor [ProcR/EPCR] deficiency).

RESULTS

Heterozygous, but not homozygous, Leiden mice were protected from lethal infection with highly virulent S. aureus and Y. pestis strains. FV Leiden did not affect the outcome of sepsis induced by cecal ligation and puncture, staphylokinase-deficient S. aureus, Pla-deficient Y. pestis, or E. coli. Thrombocytopenia, deficiency of PAR1 or PAR4 did not affect S. aureus sepsis survival, whereas hemophilia A increased mortality. ProcR deficiency selectively abolished the survival advantage of heterozygous Leiden mice.

CONCLUSIONS

In mice, heterozygous FV Leiden carriers are protected from sepsis mortality after infection with clinically relevant human bacterial pathogens.

Why is factor V Leiden so rare in the Basques?

Factor V Leiden is the most common inherited trait in Caucasians that predisposes individuals to venous thrombosis. However, it is almost absent amongst the Basque people that live in the south western part of Europe. To explain this finding, we speculate upon the putative contribution of various evolutionary forces through which the Basque genome may have been shaped.

Diagnostic ramifications of ocular vascular occlusion as a first thrombotic event associated with factor V Leiden and prothrombin gene heterozygosity

AIM

This study aimed to assess the diagnostic ramifications of vascular occlusion of the ocular vein and artery as a first thrombotic event associated with factor V Leiden (FVL) and/or prothrombin gene (PTG) heterozygosity.

METHODS

Patients with ocular vein (n=191) and artery (n=74) occlusion, free of cardioembolic etiologies, were sequentially referred from vitreoretinal specialists for measurement of thrombophilia-hypofibrinolysis and compared to 110 healthy normal controls.

RESULTS

Of the 265 patients, 29 (11%; 17 women, 12 men) of all referred ocular vascular occlusion (OVO) cases were found to be heterozygous for FVL and/or PTG, including 16 with FVL, 12 with PTG, and 1 with both. Of the 29 cases, 16 had central retinal vein occlusion (CRVO), 2 branch retinal vein occlusion (BRVO), 5 nonarteritic anterior ischemic optic neuropathy (NA-AION), 3 retinal artery occlusion (RAO), 2 amaurosis fugax (AF), and 1 had both CRVO and RAO. Of the 16 FVL cases, 15 (94%) had OVO as a first thrombotic event without prior deep venous thrombosis (DVT) or pulmonary embolism (PE); 6 (38%) also had other thrombotic events, including recurrent miscarriage, osteonecrosis, ischemic stroke, and/or ischemic colitis; and 5 (31%) had immediate family members with previous venous thromboembolism (VTE). Of the 12 PTG cases, 9 (75%) had OVO as a first thrombotic event, 5 (42%) experienced VTE other than DVT or PE, and 6 (50%) had immediate family members with VTE. In one patient with both FVL and PTG, DVT occurred before BRVO. Of the 17 women with FVL and/or PTG mutations, 7 (41%) experienced ≥1 miscarriage, 6 (35%) were on estrogen therapy, and 1 (6%) was on clomiphene.

CONCLUSION

Of the 265 patients with OVO, 29 (11%) had FVL and/or PTG, and 83% of these 29 cases presented with OVO as their first thrombotic event. By diagnosing thrombophilia as an etiology for OVO, the ophthalmologist opens a window to family screening and preventive therapy.

The relationship between coagulation state and inflammatory bowel disease: current understanding and clinical implications

Inflammatory bowel disease (IBD) is associated with a hypercoagulable state and subsequently with an increased risk for venous thromboembolism (VTE). VTE in IBD is characterized by a high recurrence rate and is associated with the disease activity. Acquired endothelial dysfunction, abnormalities of platelets, activation of coagulation system and impaired fibrinolysis are the main changes in the coagulation state in IBD. The development of VTE in IBD has been considered to be the result of multiple interactions between acquired and inherited risk factors. The treatment of VTE in IBD patients is recommended to be similar and to follow the same protocols as for non-IBD patients. In the clinical practice, the management of IBD patients and especially the hospitalized patients should include thromboprophylaxis.

Maternal genotype and severe preeclampsia: a HuGE review

Severe preeclampsia is a common cause of maternal and perinatal morbidity worldwide. The disease clusters in families; however, individual genetic studies have produced inconsistent results. We conducted a review to examine relationships between maternal genotype and severe preeclampsia. We searched the MEDLINE and Embase databases for prospective and retrospective cohort and case-control studies reporting associations between genes and severe preeclampsia. Four reviewers independently undertook study selection, quality assessment, and data extraction. We performed random-effects meta-analyses by genotype and predefined functional gene group (thrombophilic, vasoactive, metabolic, immune, and cell signalling). Fifty-seven studies evaluated 50 genotypes in 5,049 cases and 16,989 controls. Meta-analysis showed a higher risk of severe preeclampsia with coagulation factor V gene (proaccelerin, labile factor) (F5) polymorphism rs6025 (odds ratio = 1.90, 95% confidence interval: 1.42, 2.54; 23 studies, I(2) = 29%), coagulation factor II (thrombin) gene (F2) mutation G20210A (rs1799963) (odds ratio = 2.01, 95% confidence interval: 1.14, 3.55, 9 studies, I(2) = 0%), leptin receptor gene (LEPR) polymorphism rs1137100 (odds ratio = 1.75, 95% confidence interval: 1.15, 2.65; 2 studies, I(2) = 0%), and the thrombophilic gene group (odds ratio = 1.87, 95% confidence interval: 1.43, 2.45, I(2) = 27%). There were no associations with other gene groups. There was moderate heterogeneity between studies and potential for bias from poor-quality genotyping and inconsistent definition of phenotype. Further studies with robust methods should investigate genetic factors that might potentially be used to stratify pregnancies according to risk of complications.

Rivaroxaban for the Long-term Treatment of Spontaneous Ovarian Vein Thrombosis Caused by Factor V Leiden Homozygosity

OBJECTIVE

To report a case where rivaroxaban was used in the management of an ovarian vein thrombosis and to briefly review the literature, pathophysiology, and clinical implications therein.

CASE SUMMARY

A 30-year-old previously healthy woman was diagnosed with acute, spontaneous, left-ovarian vein thrombosis (OVT) with proximal extension into the renal vein. After initial catheter-directed thrombolysis with tPA, angioplasty of the left renal vein, and heparinoid treatment, rivaroxaban was begun for long-term anticoagulation. Three months after her index event she was symptom free, with complete resolution of her thrombosis and no adverse effects or bleeding complications from rivaroxaban. To our knowledge, this is the first report of OVT successfully treated with rivaroxaban.

DISCUSSION

OVT is a rare but potentially fatal cause of abdominal pain that may pose diagnostic and therapeutic dilemmas. Factor V Leiden (FVL) homozygosity, an uncommon but severe inherited thrombophilia, increases the risk of thrombosis by approximately 50- to 80-fold. This case report and accompanying literature review highlight important clinical pearls related to the diagnosis and management of OVT and inherited thrombophilias.

CONCLUSIONS

This clinical vignette adds to the published literature suggesting that novel oral anticoagulants, such as rivaroxaban, may eventually emerge as an alternative to vitamin K antagonists for the treatment of extra-axial thromboses. Reporting these cases is important because their prevalence is low outside of specialized referral centers, and thus, dissemination of these experiences may help other providers in treating their patients.

Factor V Leiden does not have a role in cryptogenic ischemic stroke among Iranian young adults

BACKGROUND

Different risk factors have been suggested for ischemic stroke in young adults. In a group of these patients despite of extensive diagnostic work-up, the primary cause remains unknown. Coagulation tendency is accounted as a possible cause in these patients. Previous studies on factor V Leiden (FVL) as the main cause of inherited thrombophilia for clarifying the role of FVL in stroke have resulted in controversial findings. The current study investigates the role of this factor in ischemic stroke among Iranians.

MATERIALS AND METHODS

This case-control study was performed between September 2007 and December 2008 in Isfahan, Iran. The case group comprised of 22 patients of which 15 were males and 7 were females with age range of ≤50 years, diagnosed as ischemic stroke without classic risk factors and the control group consisted of 54 healthy young adults. After filling consent form, venous blood samples were obtained and sent to the laboratory for genetic examination.

RESULTS

No FVL mutation was found in the case group. There was one carrier of the mutation as heterozygous in the control group (relative frequency = 1.85%).

CONCLUSIONS

Based on our study, FVL might not be considered as an independent risk factor for ischemic stroke in Iranian individuals who are not suffering from other risk factors of ischemic stroke.

Thrombophilia Screening

Although controversial, screening for thrombophilia has become common. Testing for antiphospholipid antibodies is indicated in order to guide treatment decisions if there is clinical suspicion for antiphospholipid syndrome. The utility of identifying other thrombophilias in symptomatic venous thromboembolism (VTE) is questionable, as the risk of recurrence does not appear to be increased by an appreciable degree with the most common disorders (heterozygosity for factor V Leiden or prothrombin mutation). Although recurrence appears to be increased in those with homozygous or multiple abnormalities and potentially deficiencies in natural anticoagulants, screening to detect these conditions is difficult to justify based on their rarity. The American College of Chest Physicians' current guidelines note the increased risk of recurrence with idiopathic, proximal events regardless of thrombophilia status. They suggest duration of anticoagulation therapy be based on location and provoking factors rather than whether or not the individual has a thrombophilia. Because routine prophylaxis in asymptomatic individuals with thrombophilia is not recommended, screening of asymptomatic family members is difficult to justify. Screening prior to prescribing combination oral contraceptives is not cost effective, may result in unwanted pregnancies, and may have little effect on the overall rate of VTE.

A Case Series of HIV-Seropositive Patients and Hypercoagulable State-Is It Difficult to Treat Even with Therapeutic Anticoagulation?

Patients with human immunodeficiency virus (HIV) are at risk of developing thrombosis and are 8 to 10 times more likely to develop thrombosis than the general population. Moreover, if they have hypercoagulable state they can have severe thrombosis and life-threatening thrombotic events. The purpose of this retrospective study is to analyze hypercoagulable state in HIV-seropositive patients who have been diagnosed with venous thromboembolism (VTE). This study is a subgroup study of a larger cohort group of HIV-seropositive patients with VTE followed up with our vascular medicine outpatient clinic. The patients included for this study were HIV-seropositive patients with hypercoagulable state, analyzed over the past 3 years, and followed prospectively. HIV-seropositive patients with arterial thrombosis were excluded. These patients had minimum, regular follow-up of 3 months, with a Doppler scan in the beginning and last follow-up. All the patients were analyzed for hypercoagulable state and the patients selected in this study were those who were tested positive for hypercoagulable state. All patients were analyzed for age, gender, race, site of thrombosis, coagulation factors, lipid panel, type of antiretroviral treatment, past or present history of infections or malignancy, CD4 absolute and helper cell counts at the beginning of thrombosis, and response to treatment and outcome. Patients with HIV with arterial thrombosis were excluded. The study was approved by the ethics committee. Five patients were included in this study. The mean age was 47.8 years (range 38 to 58 years). All were male patients with lower limb thrombosis. Most common venous thrombosis was popliteal vein thrombosis, followed by common femoral, superficial femoral, and external iliac thrombosis. Two patients had deficiency of protein S, two had high homocysteine levels, one had deficiency of antithrombin 3, and one had increase in anticardiolipin immunoglobulin G antibody. All the patients were taking nucleoside and nonnucleoside inhibitors but only one patient was taking protease inhibitors. There was no history of malignancy but two patients had past history of tuberculosis. The mean absolute CD4 counts were 244 cells/UL (range 103 to 392 cells/UL) and helper CD4 counts were 19.6 cells/UL (range 15 to 30 cells/UL). All were anticoagulated with warfarin or enoxaparin. There was complete resolution of deep vein thrombosis only in one patient on long-term anticoagulation but there was no resolution of thrombosis in the other four patients despite of therapeutic anticoagulation for more than 6 months. All the patients are alive and on regular follow-up. Thrombosis in HIV patients is seen more commonly in middle aged, community ambulant male patients. The most common hypercoagulable state was noted as deficiency of protein S and hyperhomocysteinemia. Eighty percent of the patients did not respond to therapeutic anticoagulation.

Association between thrombophilia and the post-thrombotic syndrome: a systematic review and meta-analysis

BACKGROUND

The postthrombotic syndrome (PTS) is a frequent chronic complication of deep vein thrombosis (DVT), occurring in 20-40% of patients. Identifying risk factors for PTS may be useful to provide patients with prognostic information and target prevention strategies.

OBJECTIVE

To conduct a systematic review to assess whether, among patients with DVT, inherited and acquired thrombophilias are associated with a risk of PTS.

METHODS

We searched the electronic databases PubMed, EMBASE, Scopus, and Web of Science for studies published from 1990 to 2013 that assessed any thrombophilia in adult DVT patients and its association with the development of PTS. We calculated odds ratios and 95% confidence intervals for PTS according to the presence of thrombophilia. Meta-analysis was performed using the random-effects model.

RESULTS

Sixteen studies were included: 13 assessed factor V Leiden (FVL), 10 assessed prothrombin mutation, five assessed protein S and C deficiencies, three assessed antithrombin deficiency, four assessed elevated FVIII levels, and six assessed antiphospholipid antibodies. None of the meta-analyses identified any thrombophilia to be predictive of PTS. Both FVL and prothrombin mutation appeared protective among studies including patients with both first and recurrent DVT and studies in which more than 50% of patients had an unprovoked DVT.

CONCLUSIONS

Our meta-analysis did not demonstrate a significant association between any of the thrombophilias assessed and the risk of PTS in DVT patients. Other biomarkers in the pathophysiological pathway may be more predictive of PTS.

Who are at risk for thromboembolism after arthroplasty? A systematic review and meta-analysis

BACKGROUND

Thromboembolism, including deep venous thrombosis and pulmonary embolism, is a grave threat to patients undergoing total joint replacement. Using a systematic review and meta-analysis we asked whether gene mutations or polymorphisms could be risk factors for thrombosis after arthroplasty.

METHODS

We performed a comprehensive search of Medline, PubMed, Embase, Cochrane databases, China National Knowledge Infrastructure (CNKI), and Google Scholar, and identified 19 studies detailing genetic investigations of patients with thromboembolism following joint replacement.

RESULTS

Our meta-analyses included 5149 patients who underwent arthroplasty surgery. Significant associations with venous thromboembolism were identified for factor G1691A (odds ratio (OR) 1.41, 95% confidence interval (CI) 1.03 - 1.94, p=0.03), prothrombin G20210A (OR 2.16, 95% CI, 1.27- 3.69, p=0.005), and MTHFR/C677T/TT (OR 2.36, 95% CI 1.03 - 5.42, p=0.04) in Caucasian populations. No significant gene mutation was identified in Asian populations.

CONCLUSION

This study suggests a way to identify patients scheduled for arthroplasty who are at higher risk of thrombosis, enabling individualized treatment.

Recurrent unprovoked venous thromboembolism in a young female patient with high levels of homocysteine

Hyperhomocysteinemia is a rare condition which predisposes to atherothrombosis. Recurrent venous thromboembolism (VTE) with hyperhomocysteinemia is known but extremely uncommon. Homocysteine levels of more than 22 umol/L can predispose to VTE in a middle-aged women. We describe a case of a middle-aged woman, community ambulant with recurrent VTE with intermediately high homocysteine levels. She had no other risk factors for recurrent venous thrombosis. In our article, we also discuss hyperhomocysteinemia and its link to VTE.

Large-scale meta-analysis of genetic studies in ischemic stroke: Five genes involving 152,797 individuals

BACKGROUND:

Ischemic stroke descent has a genetic basis. Stroke represents a complex trait, which is assumed to be polygenic. On this topic, the role of a wide number of candidate genes has been investigated in stroke through association studies.

MATERIALS AND METHODS:

We performed a literature-based systematic review of genetic association studies in stroke abound several populations. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for each gene-disease association. Following a review of 300 manuscripts, five candidate gene variants were analyzed among 152,797 individuals (45,433 cases and 107,364 controls).

RESULTS:

For these five candidate genes studied, the prothrombin OR is 1,57 (1,23-2,89), the factor V Leiden OR is 1,43 (0,67-6,24), the mean OR of angiotensin I converting enzyme (ACE) insertion/deletion (I/D) polymorphism is 1,11 (1,02-1,25), the summary OR for the C677T variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) is 1,23 (0,61-1,47) and the pooled OR for the apolipoprotein E (APOE) gene is 0,95 (0,77-1,14) .

CONCLUSION:

These data suggest the genetic associations of some genes with ischemic stroke and it is necessary to compete with other genes. Our findings could represent an epidemiological base and a useful tool to address further molecular investigations and to realize more detailed meta-analyses.

Pharmacogenetic typing for oral anti-coagulant response among factor V Leiden mutation carriers

CONTEXT

Factor V Leiden mutation is the most common inherited predisposition for hypercoagulability and thereby a common genetic cause for initiation of oral anti-coagulation therapy. There is a dearth of knowledge of coumarin response profile in such thrombophilic population.

AIMS

The current pilot study aims to estimate coumarin sensitivity in an Indian cohort with an inherited thrombophilia risk factor (Factor V Leiden mutation carriers) based on the observed frequency of CYP2C9 (*)2, (*)3 and VKORC1-1639G >A genotype combinations.

SETTINGS AND DESIGN

A retrospective study carried out in a tertiary health care center in India.

MATERIALS AND METHODS

Carriers of FVL mutation were genotyped for CYP2C9 ((*)2, F(*)3) and VKORC1 (-1639G >A) variants by PCR-RFLP technique.

STATISTICAL ANALYSIS USED

Chi-square test to analyze difference in expected and observed genotype frequency.

RESULTS

Sixty-one (n = 61) unrelated carriers of FVL mutation were observed in the 13 years study period. The allele frequency of CYP2C9 (*)2, CYP2C9 (*)3, and VKORC1-1639A in this cohort was 0.06, 0.11, and 0.16, respectively. Six (9.7%) individuals had two of the three variant alleles (heterozygous or homozygous), and 28 (45.9%) were heterozygous for at least one polymorphism.

CONCLUSIONS

Pre-prescription genotyping for coumarin drugs, if introduced in Indians with inherited thrombophilia (in whom oral anti-coagulant therapy may be necessary), is likely to identify 9.7% (hypersensitive) subjects in whom the optimum anti-coagulation may be achieved with reduced dosages, 44.3% (normal sensitivity) who may require higher dose and also 55.6% (hyper and moderate sensitivity) subjects who are likely to experience bleeding episodes.

The Obstetric Medicine Listserv: review of controversies surrounding thrombophilia testing

A woman with no significant personal or family history of thrombosis asked her internist to obtain a thrombophilia work-up prior to starting the combined oral contraceptive for dysmenorrhoea, after another physician advised her to have the test. The case was sent to an international email discussion group where the consensus was that testing should not be done. The responses of the group and review of this controversial topic are presented.

Implantation of left ventricular assist device complicated by undiagnosed thrombophilia

A patient with dilated cardiomyopathy and no history of thromboembolic events received a surgically implanted axial-flow left ventricular assist device. After implantation, transesophageal echocardiography revealed a giant thrombus on the lateral and anterior aspects of the left ventricle. The inflow cannula inserted through the apex of the left ventricle was not obstructed, and the device generated satisfactory blood flow. Laboratory screening for thrombophilia showed protein S deficiency, heterozygous factor V Leiden mutation, and heterozygous MTHFR C667T mutation. During the entire duration of circulatory support, no significant suction events were detected, and the patient was listed for heart transplantation. Ventricular assist device implantation can unmask previously undiagnosed thrombophilia; therefore, it should be necessary to identify thrombophilic patients before cardiac support implantation.

Regional block anesthesia in a patient with factor V Leiden mutation and axillary artery occlusion

Anesthetic management of patients with coagulation disorders presents safety and technical challenges. This case describes a 58-year-old woman with factor V Leiden mutation who required distal saphenous vein harvest and axillo-brachial bypass to treat axillary artery occlusion. The patient underwent surgery with satisfactory anesthesia using infraclavicular brachial plexus block, thoracic paravertebral block, and unilateral subarachnoid block. These three regional anesthetic interventions were performed in lieu of general anesthesia to minimize risks of thrombotic events, pain, and to decrease recovery time. Despite higher failure rates of regional anesthesia, longer time required for procedures, and added discomforts during surgery, the benefits may outweigh risks for selected high-risk patients, including those with factor V Leiden mutations.

A Multiplex Allele Specific Polymerase Chain Reaction (MAS-PCR) for the Detection of Factor V Leiden and Prothrombin G20210A

INTRODUCTION

In order to determine the frequencies of factor V Leiden and prothrombin G20210A point mutations in the Iranian population with Azeri Turkish origin.

MATERIAL AND METHODS

120 unrelated individuals from general population randomly selected and were examined for factor V Leiden and prothrombin G20210A mutations using a multiplex allele specific polymerase chain reaction (MAS-PCR) assayOutcomes: The frequency of prothrombin G20210A mutation was 2.08%, which means 5 chromosomes out of 240 chromosomes had prothrombin G20210A mutation. The distribution of prothrombin 20210 GG, GA, AA genotypes and prothrombin 20210A allele were 37(92.5%), 3(7.5%), 0(0%) and 3(3.75%) in males and 78(97.5%), 2(2.5%), 0(0%) and 2(1.25%) in females, respectively. Factor V Leiden was not found in our tested group (zero chromosomes out of 240 chromosomes). Analysis of the observed frequencies in the studied groups indicates that there is no statistically significant difference between females and males, regarding prothrombin G20210A mutation (p value>0.05).

CONCLUSIONS

This is the first study in its own kind in this population and implies that the frequency of Factor V Leiden G1691A (R506Q, FV-Leiden) allele is extremely low but the prothrombin G20210A mutation is more frequent in the tested group.

Venous thromboembolism and pregnancy

In recent decades, the association between a hypercoagulable state and its causes and adverse pregnancy outcome, in particular recurrent pregnancy loss (RPL) has been studied extensively. Although the first studies were focused only on the association between thrombophilia and RPL, subsequent studies underlined also a potential role of antithrombotic treatment to prevent vascular complication such as venous thromboembolism (VTE) during pregnancy. Thromboprophylaxis should be considered also for pregnant subjects carriers of molecular thrombophilia or that previously experienced VTE, in order to prevent VTE during pregnancy, while antithrombotic treatment for VTE should be performed during all pregnant periods.

Is thrombophilia a major risk factor for deep vein thrombosis of the lower extremities among Lebanese patients?

Aim

Factor V Leiden (R506Q) mutation is the most commonly observed inherited genetic abnormality related to vein thrombosis. Lebanon has one of the highest frequencies of this mutation in the world with a prevalence of 14.4% in the general population. The aim of this study is to define risk factors including inherited genetic abnormalities among Lebanese patients with lower extremity deep vein thrombosis. We report the clinical outcome of patients with thrombophilia.

Methods

From January 1998 to January 2008, 162 patients (61 males and 101 females) were diagnosed with lower extremity deep vein thrombosis. Mean age was 61 years (range: 21 to 95 years).

Results

The most frequent risk factors for vein thrombosis were surgery, advanced age, obesity, and cancer. Twenty-five patients had thrombophilia, 16 patients had factor V Leiden (R506Q) mutation, and seven patients had MTHFR C677T mutation. Ninety-two percent of patients screened for thrombophilia were positive. Screening was requested in young patients (16), patients with recurrent (11), spontaneous (8), and extensive (5) venous thrombosis, familial history (5), pregnancy (4), estroprogestative treatment (3), and air travel (1). Nine patients had one, 11 patients had two, and five had three of these conditions. Follow-up (6 to 120 months) of these 25 patients treated with antivitamin K did not reveal recurrences or complications related to venous thromboembolism.

Conclusion

Factor V Leiden mutation followed by MTHFR mutation are the most commonly observed genetic abnormalities in these series. Defining risk factors and screening for thrombophilia when indicated reduce recurrence rate and complications. Recommendations for thrombophilia screening will be proposed.

Etiology of hypercoagulable state in women with recurrent fetal loss without other causes of miscarriage from Southern Italy: new clinical target for antithrombotic therapy

BACKGROUND

Recurrent fetal loss (RPL) is one of the most common cause of sterility. Several studies identified thrombophilia as the principal cause of recurrent pregnancy loss. However, reported studies often do not evaluate other causes of miscarriages in their inclusion and exclusion criteria. So the aim of our study was to investigate the role of inherited thrombophilia in patients with RPL and without other causes of RPL.

PATIENTS AND METHODS

Patients with 2 or more first trimester abortion or with 1 or more late pregnancy loss were considered for this study. In order to evaluate the causes of RPL we looked for chromosomal, endocrine, chronic inflammatory, and infectious alterations. 90 patients affected by unexplained RPL were enrolled and tested for hemostatic alterations. These women were tested for inherited and/or acquired thrombophilia by MTHFR C677T gene polymorphism, factor V Leiden gene polymorphism, PTHRA20210G gene polymorphism, protein S deficiency, protein C deficiency, antithrombin III deficiency, lupus anticoagulant, and anticardiolipin antibodies Ig G and Ig M.

RESULTS

Acquired and/or inherited thrombophilia are strongly associated with RPL when other common causes of miscarriage were excluded. 78% of tested women showed hemostatic abnormalities. Several women with combined thrombophilic defects were also identified by our data.

CONCLUSION

After a thorough evaluation of other causes of miscarriage women affected by RPL should be tested for thrombophilia. Our data demonstrated 78% of women with one or combined thrombophilic conditions. Differences with previous studies should be related to difference in the inclusion and exclusion criteria and ethnic background. Because these patients often also show a hypercoagulable state, it an antithrombotic treatment before and during pregnancy may improve their clinical outcome (ie, secondary prevention of miscarriage and primary thromboprophylaxis).

Genetic thrombophilia has pleiotropic effects in pregnancy

Genetic thrombophilia has been established as a risk factor for pregnancy-associated disorders, such as thrombosis, early and late miscarriage, and pre-eclampsia. Associations between the factor V (F5) Leiden G1691A and the prothrombin/factor II (F2) G20210A SNPs and pre-eclampsia have been evaluated in over 50 association studies. A pooled analysis of 23 and 11 studies demonstrates that carriage of the F5 Leiden G1691A (p < 0.001; odds ratio [OR] 2.0; 95% confidence interval [CI] 1.6-2.5) and the F2 G20210A (p < 0.001; OR 1.8; 95% CI 1.1-2.9) SNPs is significantly associated with pre-eclampsia. Besides pre-eclampsia, genotyping for the F5 Leiden G1691A and the F2 G20210A SNPs is also useful for individual risk assessment regarding pregnancy-associated thrombosis. Carriers of the F5 Leiden G1691A SNP will develop this condition in 6.4% of heterozygotes and in 8.9-16.7% of homozygotes. A total of 6.2% of women with the F2 G20210A SNP and 17.8% of women with simultaneous carriage of the F5 Leiden G1691A and F2 G20210A SNPs will develop pregnancy-associated thrombosis. Both the F5 Leiden G1691A and F2 G20210A SNPs are also risk factors of early recurrent, late recurrent and late spontaneous miscarriage based on a published meta-analysis of 31 studies. These women may benefit from prophylactic heparinization. Six case-control and cohort studies of 687 women with genetic thrombophilia document live birth rates of 82% (181/221) using low-molecular-weight heparin or fractionated heparin compared with 20% (95/466) without therapy (p < 0.001, OR 17.7; 95% CI 12.2-25.5). Based on the data in the literature, including association studies and meta-analyses of these association studies, it can be concluded that genetic thrombophilia due to carriage of the F5 Leiden G1691A and F2 G20210A SNPs is a significant and clinically relevant risk factor for pre-eclampsia, pregnancy-associated thrombosis, and early and late miscarriages.