Heritable Thrombophilia Research Articles

Heritable Thrombophilia and Increased Risk for Venous Thromboembolism Despite Thromboprophylaxis After Pelvis or Acetabulum Fracture.

Individuals with pelvic and acetabular fractures are at high risk of venous thromboembolism (VTE). The purpose of this study was to determine whether serum markers for thrombophilia and rapid thromboelastography (r-TEG) values correlate with increased VTE risk among patients with pelvic and acetabular fractures. . Prospective observational study. Two urban academic level 1 trauma centers. Adult patients with isolated pelvis and/or acetabulum fractures (OTA/AO 61 and 62) treated surgically placed on a standardized VTE chemoprophylaxis regimen with enoxaparin over a 5-year period were included. Serum r-TEG, coagulation laboratory values, and markers for heritable thrombophilia were drawn postoperatively and after completion of a 6-week course of enoxaparin. The primary outcome was VTE event (either deep venous thrombosis or pulmonary embolism) diagnosed using a Duplex ultrasound, chest computed tomography angiogram, or lung ventilation-perfusion ordered based on clinical suspicion of a VTE event. Laboratory markers and values were then compared between patients who went on to have a VTE event and those who did not and patients with and without markers of thrombophilia. One hundred thirty-three adult patients with isolated operative pelvic and/or acetabular fractures were enrolled in this study. The average age of patients at time of injury was 48.3 years (range 18-91). Sixty-seven percent of patients in the study were (n = 90) males. Sixty-three percent of patients (n = 84) completed both clinical and laboratory follow-up. Forty-one percent of patients (n = 54) had 1 or more markers of heritable thrombophilia. Twelve percent (n = 10) of patients who completed follow-up were diagnosed with VTE. Age, sex, and smoking status were not associated with VTE. Patients who developed VTE had a higher body mass index (P = 0.04). Having more than 1 marker of heritable thrombophilia (P = 0.004) and an r-TEG mean amplitude greater than 72 mm postoperatively was positively associated with VTE (P = 0.02). Among patients treated surgically for isolated pelvic and acetabular fractures who received enoxaparin prophylaxis, the presence of more than 1 marker of heritable thrombophilia or r-TEG mean amplitude value greater than 72 mm postoperatively was associated with an increased risk of VTE. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Prioritisation of early pregnancy risk factors for stillbirth: An international multistakeholder modified e-Delphi consensus study

ObjectiveTo identify and prioritise early pregnancy risk factors for stillbirth to inform prognostic factor and model research. Study designWe used a modified e-Delphi method and consultation meeting to achieve consensus. Risk factors for early, late and stillbirth at any gestation identified from an umbrella review of risk factors for stillbirth were entered into a two-stage online Delphi survey with an international group of stakeholders made up of healthcare professionals and researchers.The RAND/ University of California at Los Angeles appropriateness method was used to evaluate consensus. Responders voted on a scale of 1–9 for each risk factor in terms of importance for early, late, and stillbirth at any gestation. Consensus for inclusion was reached if the median score was in the top tertile and at least two thirds of panellists had scored the risk factor within the top tertile. ResultsTwenty-six risk factors were identified from an umbrella review and presented to stakeholders in round 1 of our e-Delphi survey. Round 1 was completed by 68 stakeholders, 79% (54/68) of whom went on to complete the second round. Seventeen risk factors were discussed at the consensus meeting. From the twenty-six risk factors identified, fifteen of these were prioritised for stillbirth at any gestation, eleven for early stillbirth, and sixteen for late stillbirth, across three domains of maternal characteristics, ultrasound markers and biochemical markers. The prioritised maternal characteristics common to early, late, and stillbirth at any gestation were: maternal age, smoking, drug misuse, history of heritable thrombophilia, hypertension, renal disease, diabetes, previous stillbirth and multiple pregnancy. Maternal BMI, access to healthcare, and socioeconomic status were prioritised for late stillbirth and stillbirth at any gestation. Previous pre-eclampsia and previous small for gestational age baby were prioritised for late stillbirth. Of the ultrasound markers, uterine artery Doppler pulsatility index and congenital fetal anomaly were prioritised for all. One biochemical marker, placental growth factor, was prioritised for stillbirth at any gestation. ConclusionsOur prioritised risk factors for stillbirth can inform formal factor-outcome evaluation of early pregnancy risk factors to influence public health strategies on prevention of such risk factors to prevent stillbirth.

Acquired Thrombophilic Hypercoagulable States Seen in Patients with Liver Cirrhosis: A Single Center Study

Among the common hemostatic issues of the patients of liver cirrhosis, deep venous thrombosis, pulmonary embolism, and intrahepatic thrombus development are more often ignored. With an estimated frequency ranging from 0.6 to 26 percent, portal venous thrombosis is another potentially dangerous consequence of liver cirrhosis. Objectives: To determine the frequency of various acquired thrombophilic / hypercoagulable states seen in patients with liver cirrhosis. Study design: Descriptive, cross sectional. Settings: Department of Medicine, Allied Hospital, Faisalabad Study duration: 30th June 2019 to 29th December 2019 Materials & Methods: Cirrhosis cases ranging in age from 25 to 75 years old and of both genders were included in the study. Patients with HCC, heritable thrombophilias such as the Factor V leiden mutation, congenital budd chiari, and cholestatic liver disorders such as primary biliary cirrhosis (PBC) and primary sclerosing cholangitis were also eliminated. To assess for hepatic decompensation, ultrasonography, LFTs, and other baseline procedures were performed. Doppler USG was performed in each case with the assistance of the Radiology Department of Allied Hospital Faisalabad to assess for DVT, Budd-Chiari syndrome, and Portal venous thrombosis. Results: Mean age of the patients enrolled was 52.08 ± 10.47 years. Among these 840 patients, 461 (54.88%) were male and 379 (45.12%) were females (ratio 1.2 : 1). Mean AST levels were 77.49 ± 8.93 units/liter. Mean ALT levels were 88.51 ± 9.17 units/liter. Mean total bilirubin levels were 8.33 ± 1.65 mg/dl. Frequency of various acquired thrombophilic / hypercoagulable states seen in patients with liver cirrhosis were as follows; portal vein thrombosis in 136 (16.19%) patients, budd chiari syndrome in 102 (12.14%), deep vein thrombosis in 96 (11.43%) and pulmonary embolism in 108 (12.86%) patients. Conclusion: This study concluded that frequency of various acquired thrombophilic / hypercoagulable states seen in patients with liver cirrhosis is quite high. Keywords: liver cirrhosis, hypercoagulable states, portal vein thrombosis.

Heritable Thrombophilia in Venous Thromboembolism in Northern Pakistan: A Cross-Sectional Study.

Background Venous thromboembolism (VTE) is referred to as formation of clots in a deep vein or lodging of thrombus towards the lungs which could be fatal yet preventable. The risk of developing VTE can be increased by various factors. Where there are innumerable acquired causes, the possibility of inherited thrombophilia cannot be ignored. In view of this, we have evaluated all patients with venous thromboembolism for inherited thrombophilia. Objective To evaluate the frequencies of antithrombin (AT) deficiency, protein C and S deficiencies, Factor V Leiden, and prothrombin gene mutations in patients harboring venous thromboembolism. Materials and Methods A study comprising of 880 patients who were presented with manifestations of venous thromboembolism was conducted from July 2016 to June 2017. A blood sample collected from patients was screened for thrombophilia defects encompassing AT, protein C and S deficiencies, Factor V Leiden, and prothrombin gene mutations. All acquired causes of thrombosis were excluded. Results Of 880 patients who underwent screening for thrombophilia, 182 patients demonstrated VTE history. Their age ranged from 1 to 58 years. Males constituted a predominant group. About 45 (24.7%) patients had evidence of heritable thrombophilia. Of these, 20 (10.9%) had AT deficiency, 9 (4.9%) had Factor V Leiden mutation, 6 (3.2%) had protein C deficiency, whereas protein S deficiency and prothrombin gene mutation both were found in 5 (2.7%) patients. Conclusion Our study illustrated the highest frequency of antithrombin deficiency among other investigated thrombophilia defects.

Clinical Impact of Heritable Thrombophilia on Neonatal-Onset Thromboembolism: A Nationwide Study in Japan

To clarify the incidence and genetic risk of neonatal-thromboembolism, we conducted a nationwide study exploring the impact of thrombophilia on neonatal-thromboembolism in Japan. A questionnaire survey was conducted for perinatal centers in Japan, focusing on the clinical expression, genotype, treatment, and outcome of patients who developed thromboembolism within 28days of birth from 2014 to2018. The estimated incidence of neonatal-thromboembolism was 0.39 cases per 10 000 live births. Intracranial lesions and purpura fulminans occurred in 66 and 5 of 77 patients, respectively. Fifty-eight (75.3%) infants presented within 3days after birth. Four (5.2%) died, and 14 (18.2%) survived with disability. At the diagnosis, <20% plasma activity of protein C was noted in 16 infants, protein S (in 2), and antithrombin (in 1). Thirteen genetic tests identified 4 biallelic and 5 monoallelic protein C-variants but no protein S- or antithrombin-variants. Protein C-variants had purpura fulminans (P<.01), ocular bleeding (P<.01), positive-family history (P=.01), and death or disability (P=.03) more frequently than others. Protein C-variants were independently associated with disability (OR 5.74, 95% CI 1.16-28.4, P=.03) but not death. Four biallelic variants had serious thrombotic complications of neurologic disability, blindness, and/or amputation. Three monoallelic variants survived without complications. The only protein C-variant death was an extremely preterm heterozygote infant. Monoallelic protein C-variants had a higher incidence of neonatal-thromboembolism than biallelic variants. Thrombophilia genetic testing should be performed in the setting of neonatal-thromboembolism and low protein C to identify the underlying genetic defect.

Referral for Thrombophilia Testing in an Obstetric Patient Population: A Tertiary Centre Experience

Introduction:Thrombophilias augment the risk of pregnancy related morbidity, increasing the likelihood of adverse events such as fetal loss [1,2]. Current guidelines recommend women be tested for antiphospholipid antibodies when they present with recurrent miscarriage (3 or more consecutive pregnancy losses before 24 weeks) or with a late miscarriage (loss between 12-24 weeks) [1]. Inherited thrombophilia testing (including factor V Leiden, prothrombin gene mutation and protein S) is also recommended for women with 2nd trimester miscarriage [1]. Controversy exists around the benefit of universal thrombophilia screening given the low relative increase in risk of pregnancy events and the lack of evidence surrounding interventions such as low molecular weight heparin (LMWH) and aspirin in most thrombophilias [2,3].Our aim was to evaluate our own testing for thrombophilia in pregnancy related events. We aimed to assess the frequency of positive results and evaluate whether testing resulted in a change in management for our cohort of women.Methods:Data was collected retrospectively on 151 thrombophilia screens requested for obstetric reasons from July 2016 to July 2017 at Waikato Hospital. The tests comprised antiphospholipid antibodies (APL) including lupus anticoagulant (LA), factor V Leiden (FVL), protein C and S levels, antithrombin III (ATIII) and prothrombin (PT) gene mutations. Data pertaining to request information, outcome of current and previous results were included. Cost analysis was done using NZ $300 (US $223) for a full thrombophilia screen and NZ $30 (US $22) for protein S alone. GraphPad Prism 7 software was used for all data interpretation.Results:The mean patient age was 31 years (range 18-48 years). The commonest reason for referral for testing was recurrent miscarriage (49/151) (Figure 1) and the majority of requests were from the obstetrics department (79/151) (Figure 2).83% (126/151) of tests requested were for a full thrombophilia screen; the remainder (25/151) were for single tests or a combination. The majority were being tested for the first time; 16.5% (25/151) had previous testing done. Of those with previous tests 52% (13/25) had no abnormality found; the others had low protein S levels or ATIII deficiency, or both.With the current test, almost two thirds of patients (62%, 94/151) had no abnormality found. Of the others, low protein S levels made up the majority of positive tests (26/57) (Figure 3). Of these 4/26 tests were repeated with 1 ongoing low result representing a likely true protein S deficiency. The laboratory cost of negative tests was estimated to be NZ $28,200 (US $20,992); while the cost of testing for protein S, including repeat testing due to low levels likely associated with pregnancy, was estimated at NZ $879 (US $648).Results that could potentially change management (APL antibodies, presence of VTE with positive inherited thrombophilia result) were few (6/151).Conclusion:In our tertiary centre, the majority of thrombophilia testing done for obstetric reasons over a 12 month period was negative. Most positive results (low protein S) were likely attributable to recent pregnancy, with a lack of repeat testing undertaken. There was a potential change in management for only 6 patients. Our results are in line with the literature which shows a scarcity of evidence supporting thrombophilia screens in pregnancy related morbidity. These tests are not only costly but for the majority provide no clinical benefit. Our next step is to disseminate these results locally and we aim to educate our colleagues on the utility of thrombophilia testing in pregnancy related events and when it is clinically helpful. We await with interest the results of ongoing randomised controlled trials assessing the role of LMWH and aspirin in thrombophilia in pregnancy.[1] Royal College of Obstetricians and Gynaecologists (RCOG) Green-top guideline No 7. The investigation and treatment of couples with recurrent first-trimester and second-trimester miscarriage. April 2011.[2] Baglin T, Gray E, Graves M, et al . Clinical guidelines for testing for heritable thrombophilia. Br J Haematol 2010; 149(2): 209-20[3] de Jong PG, Kaandorp S, Di NM, et al . Aspirin and/or heparin for women with unexplained recurrent miscarriage with or without inherited thrombophilia. Cochrane Database Syst Rev . 2014;7:CD004734 [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Genomic Analysis for the Detection of Bleeding and Thrombotic Disorders.

The development of high-throughput sequencing technologies has ushered in a new era of genomic testing in clinical medicine. This has greatly enhanced our diagnostic repertoire for hemostatic diseases particularly for milder or rarer bleeding disorders. New genetic causes for heritable platelet disorders have been discovered along with the recognition of clinical manifestations outside hemostasis, such as the association of leukemia with RUNX1 variation. Genome-wide association studies in heritable thrombophilia have demonstrated that some of the genetic variants that are commonly included in thrombophilia testing are of no clinical relevance, while uncovering new variants that should potentially be included. The implementation of new technology has necessitated far-reaching changes in clinical practice to deal with incidental findings, variants of uncertain significance, and genetic disease modifiers. Mild bleeding disorders that were previously considered to have a monogenic basis now appear to have an oligogenic etiology. To harness these advances in knowledge large databases have been developed to capture the new genomic information with phenotypic features on a population-wide scale. The use of this so-called "big data" requires new bioinformatics tools with the promise of delivering precision medicine in the foreseeable future. This review discusses the use of these technologies in clinical practice, the benefits of genomic testing, and some of the challenges associated with implementation.

Retinal Vein Apoplexy: Pathogenesis, Risk Factors Hematological Disorders and Treatment

Retinal vein impediment (RVO) is the most common retinal vascular sickness after diabetic retinopathy. Attributable to its multifactorial nature, notwithstanding, the board of this condition remains a test. Of the two fundamental kinds of RVO, branch retinal vein impediment (BRVO) is more pervasive than central retinal vein impediment (CRVO). Most patients create the disease at an older age, and the greater parts of them have associated foundational messes (for example hypertension, hyperlipidemia and/or diabetes mellitus). There is no proof to suggest routine testing for heritable thrombophilia’s in patients with RVO. The fundamental driver of the visual debilitation is macular edema, while neovascularization of the retina and optic plate are the most genuine inconveniences prompting glassy hemorrhage, retinal separation and neovascular glaucoma. Macular grid laser photocoagulation is an effective treatment for macularedema in patients with BRVO and a visual keenness of 20/40 or less. Other treatment choices for decreasing the edema are intra vitreal steroids, against VEGF medications and vitrectomy. The recently presented intra vitreal use of steroids and against VEGF medications might end up being a superior methodology for improving visual keenness. At long last, dissipate pan retinal laserphotocoagulationcan effectively treat neovascularization and its secondary complications.

Inpatient Hypercoagulable Work-up in a Community Teaching Hospital: A Preventable Cost with No Added Benefit

Background: Thrombophilia testing in hospitalized patients is often inaccurate and rarely clinically useful especially in acute settings. Testing for inherited thrombophilia is often done in the setting of recurrent unprovoked venous thromboembolism (VTE). Several prospective studies have shown that heritable thrombophilia status is not statistically associated with recurrent VTE. Additionally, such testing may be confounded by ongoing disease or treatment. The cost per thrombophilia panel testing range anywhere between $1100 to $2400 based on estimation of charges billed by a large commercial laboratory. We aim to identify patterns and costs involved in inpatient thrombophilia testing in a community teaching hospital. Methods: The study was conducted as a part of our quality improvement initiative in a community teaching hospital. We performed a retrospective chart review of patients above the age of 18 years who had a clinically and radiologically confirmed diagnosis of venous thromboembolism during the year of 2016 and performed descriptive analysis. Institutional IRB was obtained and data was collected by reviewing the electronic medical records . Results: A total of 395 patients with the diagnosis of VTE were included (mean age 68.5, 54.2% female). At least one thrombophilia test was ordered in 66 of the 395 patients (16.7%). Around 38 (9.6%) patients were already on anticoagulation for atrial fibrillation/flutter, deep venous thrombosis (DVT) and pulmonary embolism (PE) among whom 5/38 (13.2%) patients underwent thrombophilia testing. Number of patients with a prior history of DVT or PE or both were 67/395(20%). Out of these, 26/67 (38.8%) patients were on anticoagulation and 14/67 (20.9%)patients underwent thrombophilia testing during their hospital stay. Only 11/395 (2.8%) patients had a family history of DVT/PE among whom 4 were tested. The approximate cost of the testing was $132,000 considering roughly $2000 per test on an average for a total of 66 tests. Discussion: Thrombophilia testing in hospitalized patients adds little if at all any value to their acute management. However, it does add a significant unnecessary avoidable cost to the hospital. Although inpatient thrombophilia testing is not supported by current guidelines for inherited thrombophilia evaluation, the testing is often done in hospitalized patients with recurrent thromboembolism. Learning the pattern of thrombophilia testing in hospitalized patients will help us implement measures to prevent unnecessary testing and the significant costs associated with it. Conclusion: With the increasing emphasis on value-based health care, thrombophilia testing should be considered only if it affects overall patient management and preferably in an outpatient setting with appropriate indications. Disclosures No relevant conflicts of interest to declare.

Association of Thrombophilic Factors in Pathogenesis of Osteonecrosis of Femoral Head in Indian Population.

Role of heritable blood clotting disorders, both thrombophilias and hypofibrinolysis in causing avascular necrosis (AVN) of femoral head have been studied in regions like Europe and U.S.A. This study was done to investigate the role of heritable thrombophilias in ethnic Indian population. A case control study of 150 patients (100 cases and 50 age and sex matched controls) of Indian Ethnicity with clinico-radiographically documented idiopathic AVNof femoral head was done after ethics committee approval. DNA was extracted from the blood and PCR analysis was used to study heritable thrombophilic gene mutation (G1691A Factor V Leiden). Enzyme-linked immunosorbent assay (ELISA)-based assays, were utilized to measure antigen levels of protein C, antithrombin III levels and protein S. Nine cases out of 100 showed deficiency of Protein C (9%) while no control showed deficiency of Protein C (p value: 0.028-significant, Odds ratio: 9.791) Ten cases showed deficiency of Protein S (10%) in study population as compared to one case (2%) in control population (p value: 0.038-significant, Odds ratio: 5.44). ATIII deficiency was more prevalent in control group i.e. 22% compared to 11% in study group. Factor V mutation was present in 3% cases as compared to one (2%) in control group. (p value is 0.393-not significant). Difference in thrombophilic mutations in various populations indicates possible effect of ethnicity on genetic profile in the development of AVN. This risk stratification will enable in near future early diagnosis and possible role of antithrombotics in disease prevention.

Association between factor V Leiden mutation and recurrent pregnancy loss in the middle east countries: a Newcastle-Ottawa meta-analysis.

Heritable thrombophilia is a category of genetic disorders of the coagulation cascade with the increasing risk of thrombus formation and recurrent pregnancy loss (RPL). Factor V Leiden (FVL) (R506Q) mutation is the most common genetic cause of deep venous thrombosis, but its association with RPL has been inconsistent in studies arising from non-Western countries. The present metanalysis was aimed to determine whether an association exists between FVL and RPL in the Middle East. We searched PubMed, MEDLINE Web of Science, Scopus, and Embase, evaluating the association between the FVL and RPL. The Middle East countries (Bahrain, Cyprus, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, The State of Palestine, Syria, Turkey, TheUnited Arab Emirates, and Yemen) were evaluated in succession. Raw data were extracted, and 19 case-control studies were included in our final analysis. Overall, 2513 cases and 1836 controls in the Middle East showed a prevalence of FVL mutation as 12.6% and 4.9% in patients and controls, respectively. To evaluate the relationship between FVL mutation and RPL, we used Forest plot (random effect model) with the overall random OR of 2.37 (CI 95%: 1.50-3.75). FVL mutation was associated with a higher risk of RPL. In Iran, the OR was 1.90 (95% CI 1.04-3.45), and in Turkey, the OR was 3.01 (95% CI 1.10-8.23). The results of our study support an association between FVL mutation status and RPL in women of the Middle East countries. It is recommended that specific policies include comprehensive testing for FVL mutation as a standard of care in women of the Middle East region with unexplained RPL.

Heritable thrombophilia test utilization and cost savings following guideline-based restrictions: An interrupted time series analysis

ObjectiveExisting guidelines provide indications for appropriate heritable thrombophilia (HT) testing but testing practices often do not conform to these guidelines. The Canadian province of Newfoundland and Labrador (NL) implemented a new ‘hard-stop’ guideline-based approach to HT testing whereby tests ordered outside specific guidelines were rejected. The objective of this study was to evaluate the effectiveness of this intervention and the associated cost savings. MethodsUsing data on number of HT tests ordered and performed in NL between December 1, 2014 and February 28, 2018, we conducted interrupted time series analyses to analyze changes in number of HT tests ordered and performed following the intervention. Cost savings were estimated by comparing cost of tests actually performed after enforcement of guidelines with the cost of counterfactual number of tests that would have been performed without guidelines. ResultsGuideline-based restrictions on HT testing were associated with a 86–98% decline in the number of tests performed (p < 0.05). Contrary to previous softer, educational approaches to restricting HT testing, number of Protein C and Factor V Leiden/Prothrombin G20210A tests ordered also declined post-guideline implementation (p < 0.05). Annual cost savings associated with reductions in tests performed were estimated to be $205,154 for NL from a societal perspective. We estimated that if this model was expanded across Canada, annual cost savings could be as large as $14.2 million from a societal perspective. ConclusionsA ‘hard-stop’ guideline-based approach to restricting HT testing is associated with significant reductions in HT testing and meaningful cost savings.

Protein C deficiency; PROC gene variants in a Danish population

IntroductionProtein C deficiency is a heritable thrombophilia caused by numerous different genetic alterations in the protein C (PROC) gene. We aimed to identify variants causing protein C deficiency in a Danish population. Material and methodsSanger sequencing of the PROC gene was performed in 20 probands and 26 relatives. In total, 30participants were previously diagnosed with protein C deficiency. Protein C activity was measured by a chromogenic substrate method (N = 40) and antigen level by an enzyme-linked immunosorbent assay (N = 26). ResultsTen different single nucleotide variants were detected in 13 probands (65%) and in seven of the relatives previously diagnosed with protein C deficiency. Five variants were novel. The median protein C activity level was lower in participants with an identified variant (50% (range: 38–75%)) than in protein C deficient participants without a variant (65% (range: 36–73%); P = 0.18). A protein C activity of 57% resulted in the highest detection rate (12/13 (92%)). Likewise, the median antigen level was lower in participants with detectable variants than in participants without (49% (range: 35–99%) vs 70% (range: 41–101%); P = 0.09). No difference was found in venous thromboembolism (VTE) prevalence comparing participants with (12/20 (60%)) and without (7/10 (70%)) a variant (P = 0.59). ConclusionIn a Danish population, a PROC gene variant was identified in 67% of participants previously diagnosed with protein C deficiency. Five variants were novel. The study confirmed an association between biochemical severity and the presence of a PROC gene variant. The VTE risk did not seem to differ between protein C deficient participants with and without a variant.

Inferior Vena Cava Atresia: Characterisation of Risk Factors, Treatment, and Outcomes.

To characterise (1) the risk factors associated with inferior vena cava (IVC) atresia, (2) the radiographic and clinical presentations of deep vein thrombosis (DVT) in patients with IVC atresia, and (3) the treatment and outcome of DVT in patients with IVC atresia. The electronic medical record was systematically reviewed for thrombotic risk factors in patients who presented with lower-extremity DVT (n = 409) at a single centre between 1996 and 2017. Patients with IVC atresia were identified based on imaging and chart review. Differences in demographics and thrombotic risk factors between patients with and without IVC atresia were statistically assessed. Extent and chronicity of DVT on imaging, clinical presentation, treatment, and outcomes were evaluated for all patients with IVC atresia. 4.2% of DVT patients (17/409) were found to have IVC atresia; mean age at diagnosis was 25.5 ± 9.4years. The rate of heritable thrombophiliawas significantly higher in patients with IVC atresia compared to patients without IVC atresia (52.9% vs. 17.9%, p < 0.0001). There were bilateral DVT in 70.6% of IVC atresia patients; DVT was chronic in 41.2% and acute on chronic in 58.8%. Pre-intervention Villalta scores were 13.9 ± 9.8 in the left limb and 8.5 ± 7.0 in the right limb. DVT in IVC atresia patients was typically treated with catheter-directed thrombolysis followed by stent placement, achieving complete or partial symptom resolution in 78.6% of cases. Thrombotic risk factors such as heritable thrombophilia are associated with IVC atresia. IVC atresia patients can experience high burdens of lower-extremity thrombotic disease at a young age which benefit from endovascular treatment. Level 4.

Whole-Exome Sequencing in Evaluation of Thrombophilia: Characterization of Novel Genetic Variants

Abstract Venous thromboembolism (VTE), defined as deep venous thrombosis and pulmonary embolism, is a cause of significant morbidity and mortality worldwide, with an overall incidence of about 10,000,000 cases per year. The majority of VTE is attributable to genetic factors, yet the five major heritable thrombophilias of factor V Leiden, prothrombin gene mutation, antithrombin deficiency, protein C deficiency, and protein S deficiency comprise only a minority of VTE cases, suggesting that further genetic factors must contribute to VTE risk. We performed whole-exome sequencing (WES) in 106 patients with VTE, focusing our analysis on a 55-gene extended thrombophilia panel comprising genes previously reported in next-generation sequencing studies to be associated with VTE. In our cohort, we identified a probable disease-causing genetic variant or variant of unknown significance (VUS) in approximately 60% of study patients. We then selected several novel VUS involving genes with known roles in hemostasis for further characterization to determine their biological and pathological significance in thrombophilia. Multiple sequence alignment analysis showed that several nonsynonymous variants produced amino acid substitutions in highly conserved regions of proteins relevant to hemostasis and thrombosis, including thrombomodulin (TM), heparin cofactor II, ADAMTS13, and von Willebrand factor (vWF). To evaluate the theoretical effects of selected VUS on thrombosis susceptibility, we visualized proteins using PyMol and performed in silico mutagenesis modeling to evaluate for structural alterations that can predict functional and physiological consequences. Our analyses showed that several variants caused conformational changes predicted to either result in a deleterious effect on enzymatic activity or prevent substrate binding to the active site. For example, variants in TM (P401L and V454A) are predicted to decrease thrombin binding and protein C activation, whereas a C668R variant in the spacer domain of ADAMTS13 is predicted to prevent binding to vWF, resulting in ultra-large vWF multimers. We plan to use these results in combination with clinical laboratory-based coagulation testing and family studies to determine pathogenicity of specific variants in thrombosis and thrombophilia. Overall, these findings indicate that WES is a potentially useful tool for inherited thrombophilia and can provide insight into the genetic factors contributing to VTE.

Pregnancy and delivery in a patient with a 40-year history of type 1 diabetes mellitus and antiphospholipid syndrome

Type 1 diabetes mellitus is a condition associated with an increased risk of adverse perinatal outcomes such as spontaneous abortions, preterm birth, placental insufficiency, congenital malformations, and perinatal mortality. Diabetes mellitus combined with cardiovascular diseases in women during pregnancy often leads to hypertensive disorders and pre-eclampsia. The severity of the microvascular diabetic complications and frequency of hypoglycemic episodes, particularly in early pregnancy, are related to the risk of pre-eclampsia. We report the case of pregnancy and delivery of a live newborn in a 42-year-old woman with type 1 diabetes mellitus, pre-existing hypertension, heritable thrombophilia, and antiphospholipid syndrome. She had a 40-year history of type 1 diabetes mellitus with well-controlled diabetic nephropathy and retinopathy. The woman had been receiving continuous subcutaneous insulin therapy for the last five years, which allowed maintaining an appropriate glycemic control during pregnancy. Multidisciplinary supervision of course of pregnancy was carried out from the pre-gravidity stage until delivery and postpartum. In spite of the severe pre-eclampsia and preterm delivery by cesarean section at 36 weeks, she and newborn could avoid the intensive unit care and discharge from perinatal center without any complications.

Whole Exome Sequencing and Extended Thrombophilia Testing in Patients with Venous Thromboembolism

Introduction: Venous thromboembolism (VTE), defined as deep venous thrombosis (DVT) and pulmonary embolism (PE), is a cause of significant morbidity and mortality worldwide, with an overall incidence of about 10,000,000 cases per year. The majority of VTEs are believed to be attributable to genetic factors. Yet, the five established heritable thrombophilias of factor V Leiden (FVL), prothrombin (PT) gene mutation, antithrombin (AT) deficiency, protein C (PC) deficiency, and protein S (PS) deficiency comprise only a small portion of VTEs, suggesting that further genetic factors contributing to VTE risk are unrecognized. In our previously published study, we performed whole exome sequencing (WES) in 64 patients with VTE and developed a 55-gene extended thrombophilia panel which identified 40 pathogenic or likely pathogenic variants or variants of uncertain significance (VUS) involving 22 different genes. Here, we present updated data from an expanded patient cohort.Methods: Blood was obtained from 101 patients with VTE. Genomic DNA was extracted and WES performed; mean coverage of the exome was 100x with 98% of the exome covered >/= 20 times. Variants were filtered for an allele frequency of 7% in the GnomAD database. A targeted analysis of the 55 genes in the extended thrombophilia panel was then performed. Variants in these genes were classified according to ACGM criteria as pathogenic, likely pathogenic, VUS, benign or likely benign. The number of patients with pathogenic or likely pathogenic variants and VUS in VTE patients was compared to a control population of 237 patients who had WES performed for reason other than VTE. The results of WES were also compared to those of traditional laboratory-based thrombophilia testing. Further, 17 VUS underwent in silico protein modeling to evaluate structural modifications.Results: Of the 101-patient study population, 46 were men and 55 women; 62% were Caucasian, 22% African American and 5% Hispanic; 15% had unprovoked VTE, 71% had provoked, 12% had both; and 55% had first degree family members with VTE. WES and extended thrombophilia testing identified a pathogenic or likely pathogenic variant or VUS in 69/101 (68%) VTE patients compared to 6/237 (2.5%) controls, a statistically significant difference (p-value <0.001). 86 patients underwent traditional laboratory-based thrombophilia testing; of these, 35 patients had a positive laboratory abnormality, with 31/35 (89%) also demonstrating a variant on WES. Among these 35 patients, in instances when laboratory-based thrombophilia testing did not correlate with WES, the abnormal lab was usually a borderline low PC or PS level that was not interpretable due to the clinical scenario (e.g. warfarin use). 51 patients had negative laboratory-based thrombophilia testing, of whom 30/50 (58%) had a variant on WES.A total of 72 genetic variants (26 previously published and 46 novel) were identified in 30 genes in the extended thrombophilia panel. 18 variants were categorized as pathogenic or likely pathogenic and 54 as VUS. 32 patients had pathogenic or likely pathogenic variants in one or more of the major thrombophilia genes, with FVL being the most common, and AT and PS deficiency being more common than PT gene mutation (FVL, n=15; PT gene mutation, n=3; AT deficiency, n=5; PC deficiency, n=3; PS deficiency, n=6). Of pathogenic variants in major thrombophilia genes, 15 were previously reported in literature, while 13 were novel. Of the 52 VUS, 17 were subjected to in silico analysis, including protein modeling, which suggested impaired protein folding in 14 variants.Conclusions: WES and extended thrombophilia testing reveal a high frequency of pathogenic or likely pathogenic variants or VUS in VTE patients compared to controls. These variants demonstrate good concordance with traditional laboratory-based thrombophilia testing. Several novel pathogenic or likely pathogenic variants were identified. In silico studies and protein modeling suggest that many VUS identified by this approach are likely to be deleterious to protein function. The results may underlie a strong genetic component to VTE. Next steps include further characterization of VUS using protein modeling, biochemical analysis, and epidemiological and familial studies to understand potential roles these variants may play in thrombosis. [Display omitted] DisclosuresCamire:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spark Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy.

Оценка протромботического фенотипа у асимптомных носителей мутации G1691A в гене фактора V и/или мутации G20210A в гене протромбина с помощью теста генерации тромбина

Введение. К числу безусловных наследственных детерминант тромбофилии относятся мутации в генах факторов II (G20210A) и V (G1691A). Однако их наличие, особенно в гетерозиготной форме, не всегда приводит к развитию тромботических осложнений, что свидетельствует о целесообразности поиска новых объективных методов выявления протромботического фенотипа у носителей рассматриваемых мутаций. Тест генерации тромбина (ТГТ) отражает состояние гемостаза индивидуума в совокупности взаимодействия прокоагулянтных и антикоагулянтных механизмов и позволяет эффективно выявлять гиперкоагуляцию. Цель исследования: установить целесообразность использования ТГТ для оценки гемостатического потенциала у асимптомных носителей мутаций в генах фактора V (G1691A) и/или протромбина (G20210A). Материалы и методы. Обследовано 42 асимптомных носителя мутации FV G1691A и/или FII G20210A (14 мужчин и 28 женщин, средний возраст — 37,0 ± 15,0 лет). Постановка ТГТ выполнялась в бедной тромбоцитами плазме. В тромбинограмме оценивали следующие показатели: PT (Peak thrombin — максимальное количество тромбина, образующегося в образце), ETP (endogenous thrombin potential — эндогенный тромбиновый потенциал), Lag-time — время инициации свёртывания и V (скорость образования тромбина). Результаты. Согласно полученным данным, гетерозиготное носительство мутаций FV G1691A и/или FII G20210A может ассоциироваться как с протромботическим, так и с нормальным фенотипом. У асимптомных носителей Лейденской мутации повышенные значения ЕТР и РТ обнаружены в 44% случаев, в то время как резистентность к активированному протеину С — в 67%. У большей части носителей мутации в гене протромбина отмечены превышающие норму значения ЕТР и РТ (71% и 57% случаев, соответственно). Скорость генерации тромбина превышала нормальные величины у 57% носителей мутации FV G1691A и у 64% носителей мутации FII G20210A. Значительную часть обследованных можно охарактеризовать как имеющих промежуточный протромботический фенотип, учитывая наличие у них одновременно как нормальных, так и патологических показателей ТГТ. Заключение. ТГТ является перспективным методом в плане создания индивидуального профиля риска для асимптомных носителей мутаций, ассоциированных с наследственной тромбофилией. Introduction. Mutations in genes of factors II (G20210A) and V (G1691A) are well known determinants of hereditary thrombophilia, but their presence, especially in the heterozygous form, does not always lead to the development of thrombotic complications.This indicates the importance of objective methods for the detection of prothrombotic phenotype in carriers of these mutations. Thrombin generation test (TGT) demonstrates the state of individual’s hemostasis in the interaction of procoagulant and anticoagulant mechanisms and allows to detect the hypercoagulability. Aim: to assess the hemostatic potential in asymptomatic carriers of FV G1691A or/and FII G20210A mutations by TGT. Materials and methods. We examined 42 asymptomatic carriers of FV G1691A mutation and/or G20210A prothrombin gene mutation (14 men and 28 women, average age — 37,0 ± 15,0 years). TGT was performed in platelet-poor plasma. In thrombinogram we assessed following parameters: PT (Peak thrombin is the maximum amount of thrombin formed in the sample), ETP (endogenous thrombin potential), Lag-time (coagulation initiation time) and V (thrombin generation rate). Results. According to data obtained, heterozygous carriage of FV G1691A and/or FII G20210A mutations can be associated with both prothrombotic and normal phenotypes. In asymptomatic carriers of Leiden mutation we revealed elevated values of ETP and RT in 44% of cases, while resistance to activated protein C — in 67%. The majority of FII G20210A mutation carriers demonstrated increased values of ETP and PT (71% and 57%, respectively). Thrombin generation rate exceeded normal values in 57% and 64% carriers of FV G1691A and FII G20210A mutations, respectively. The majority of examined patients can be characterized as having intermediate prothrombotic phenotype, taking into account that they had both normal and pathological values of TGT parameters. Conclusion. TGT is a perspective method for creating an individual risk profi le in asymptomatic carriers of mutations associatedwith hereditary thrombophilia.

Abruptio placentae risk and genetic variations in mitochondrial biogenesis and oxidative phosphorylation: replication of a candidate gene association study

Abruptio placentae is a complex multifactorial disease that is associated with maternal and neonatal death and morbidity. Abruptio placentae's high recurrence rate, high prevalence of heritable thrombophilia among women with abruptio placentae, and aggregation of cases in families of women with the disease support the possibility of a genetic predisposition. Previous genome-wide and candidate gene association studies have identified single nucleotide polymorphisms in mitochondrial biogenesis and oxidative phosphorylation genes that potentially are associated with abruptio placentae risk. Perturbations in mitochondrial biogenesis and oxidative phosphorylation, which results in mitochondrial dysfunction, can lead to the impairment of differentiation and invasion of the trophoblast and to several obstetrics complications that include abruptio placentae. The purpose of this study was to determine whether the results of a candidate genetic association study that indicated a link between DNA variants (implicated in mitochondrial biogenesis and oxidative phosphorylation) and abruptio placentae could be replicated. The study was conducted among participants (507 abruptio placentae cases and 1090 control subjects) of the Placental Abruption Genetic Epidemiology study. Weighted genetic risk scores were calculated with the use of abruptio placentae risk-increasing alleles of 11 single nucleotide polymorphisms in 9 mitochondrial biogenesis and oxidative phosphorylation genes (CAMK2B, NR1H3, PPARG, PRKCA, THRB, COX5A, NDUFA10, NDUFA12, and NDUFC2), which previously was reported in the Peruvian Abruptio Placentae Epidemiology study, a study with similar design and study population to the Placental Abruption Genetic Epidemiology study. Logistic regression models were fit to examine associations of weighted genetic risk scores (quartile 1, <25th percentile; quartile 2, 25-50th percentile; quartile 3, 50-70th percentile, and quartile 4, >75th percentile) with risk of abruptio placentae, adjusted for population admixture (the first 4 principal components), maternal age, infant sex, and preeclampsia. The weighted genetic risk score was also modeled as a continuous predictor. To assess potential effect modification, analyses were repeated among strata that were defined by preeclampsia status, maternal age (≥35 vs 18-34 years), and infant sex. Abruptio placentae cases were more likely to have preeclampsia, shorter gestational age, and lower infant birthweight. Participants in quartile 2 (score, 12.6-13.8), quartile 3 (score, 13.9-15.0) and quartile 4 (score, ≥15.1) had a genetic risk score of 1.45-fold (95% confidence interval, 1.04-2.02; P=.03), a 1.42-fold (95% confidence interval, 1.02-1.98; P=.04), and a 1.75-fold (95% confidence interval, 1.27-2.42; P=7.0E-04) higher odds of abruptio placentae, respectively, compared with those in quartile 1 (score,<12.6; P-for trend=.0003). The risk of abruptio placentae was 1.12-fold (95% confidence interval, 1.05-1.19; P=3.0×1004) higher per 1-unit increase in the score. Among women with preeclampsia, those in quartile 4 had a 3.92-fold (95% confidence interval, 1.48-10.36; P=.01) higher odds of abruptio placentae compared with women in quartile 1. Among normotensive women, women in quartile 4 had a 1.57-fold (95% confidence interval, 1.11-2.21; P=.01) higher odds of abruptio placentae compared with those in quartile 1 (P-for interaction=.12). We did not observe differences in associations among strata defined by maternal age or infant sex. In this study, we replicated previous findings and provide strong evidence for DNA variants that encode for genes that are involved in mitochondrial biogenesis and oxidative phosphorylation pathways, which confers risk for abruptio placentae. These results shed light on the mechanisms that implicate DNA variants that encode for proteins in mitochondrial function that are responsible for abruptio placentae risk. Therapeutic efforts to reduce risk of abruptio placentae can be enhanced by improved biologic understanding of maternal mitochondrial biogenesis/oxidative phosphorylation pathways and identification of women who would be at high risk for abruptio placentae.

Evaluation of stillbirth.

To review current evidence regarding the most useful tests for evaluation of potential causes of stillbirth. Stillbirth remains one of the most devastating obstetric complications. Recent advances include work investigating the highest yield diagnostic tests for determining a cause of death in stillbirths. Placental pathology and fetal autopsy improve the diagnostic yield when combined with maternal clinical history. Additional tools include genetic evaluation, and testing for antiphospholipid antibodies and fetal-maternal hemorrhage based on the clinical scenario. However, routine testing for heritable thrombophilias or infection has not proven to be useful. In cases in which fetal autopsy is not acceptable to patients or possible for logistical reasons, alternative forms of fetal evaluation should be considered. A systematic approach to stillbirth evaluation is useful in identifying a potential cause of death. This should incorporate clinical information as well as placental pathology and fetal autopsy. Based on clinical characteristics further testing may be indicated.