An Unexpectedly High Rate of Thrombophilia Disorders in Patients with Superficial Vein Thrombosis of the Lower Extremities.

BACKGROUND: Superficial vein thrombosis (SVT) is a common venous condition. Recent studies have shown that SVT is associated with high frequency of thromboembolic complications: from 22-37% for deep venous thrombosis and up to 33% for pulmonary embolism. Our goal was to assess the prevalence of major hereditary and acquired thrombophilic factors in patients with SVT. METHODS: Sixty-six patients presenting with primary SVT underwent evaluation for thrombophilia: molecular testing for the factor V Leiden and factor II G20210 A (prothrombin) mutations, protein C, protein S, antithrombin deficiency, presence of lupus anticoagulant, as well as anticardiolipin antibody titers. Patients aged less than 18 years, with confirmed deep vein thrombosis, and pregnant women were excluded. RESULTS: 95.5% were Caucasian, and 62.1% were female gender. Age ranged from 21-88 years. Molecular testing showed that 34.2% of patients were heterozygous for factor V Leiden, 23.6% were heterozygous for the factor II mutation, 7.8% had antithrombin deficiency, 2.6% had protein S deficiency, and 2.1% had protein C deficiency. CONCLUSIONS: Our study showed that hereditary and acquired thrombophilias are higher than previously expected and reported.

Production of recombinant coagulation factors: Are humans the best host cells?

The main treatment option for Hemophilia A/B patients involves the administration of recombinant coagulation factors on-demand or in a prophylactic approach. Despite the safety and efficacy of this replacement therapy, the development of antibodies against the coagulation factor infused, which neutralize the procoagulant activity, is a severe complication. The production of recombinant coagulation factors in human cell lines is an efficient approach to avoid such complication. Human cell lines can produce recombinant proteins with post translation modifications more similar to their natural counterpart, reducing potential immunogenic reactions. This review provides a brief overview of the most important characteristics of recombinant FVIII and FIX products available on the market and the improvements that have recently been achieved by the production using human cell lines.

CoagVDb: a comprehensive database for coagulation factors and their associated SAPs.

The current state of the art in medical genetics is to identify and classify the functional (deleterious) or non-functional (neutral) single amino acid substitutions (SAPs), also known as non-synonymous SNPs (nsSNPs). The primary goal is to elucidate the mechanisms through which functional SAPs exert their effects, and ultimately interrogating this information for association with complex phenotypes. This work focuses on coagulation factors involved in the coagulation cascade pathway which plays a vital role in the maintenance of homeostasis in the human system. We developed an integrated coagulation variation database, CoagVDb, which makes use of the biological information from various public databases such as NCBI, OMIM, UniProt, PDB and SAPs (rsIDs/variant). CoagVDb enriched with computational prediction scores classify SAPs as either deleterious or tolerated. Also, various other properties are incorporated such as amino acid composition, secondary structure elements, solvent accessibility, ordered/disordered regions, conservation, and the presence of disulfide bonds. This specialized database provides integration of various prediction scores from different computational methods along with gene, protein, and disease information. We hope our database will act as a useful reference resource for hematologists to reveal protein structure-function relationship and disease genotype-phenotype correlation.

CoagVDb: a comprehensive database for coagulation factors and their associated SAPs

The current state of the art in medical genetics is to identify and classify the functional (deleterious) or non-functional (neutral) single amino acid substitutions (SAPs), also known as non-synonymous SNPs (nsSNPs). The primary goal is to elucidate the mechanisms through which functional SAPs exert their effects, and ultimately interrogating this information for association with complex phenotypes. This work focuses on coagulation factors involved in the coagulation cascade pathway which plays a vital role in the maintenance of homeostasis in the human system. We developed an integrated coagulation variation database, CoagVDb, which makes use of the biological information from various public databases such as NCBI, OMIM, UniProt, PDB and SAPs (rsIDs/variant). CoagVDb enriched with computational prediction scores classify SAPs as either deleterious or tolerated. Also, various other properties are incorporated such as amino acid composition, secondary structure elements, solvent accessibility, ordered/disordered regions, conservation, and the presence of disulfide bonds. This specialized database provides integration of various prediction scores from different computational methods along with gene, protein, and disease information. We hope our database will act as a useful reference resource for hematologists to reveal protein structure-function relationship and disease genotype-phenotype correlation.

Genetic factors of the hemostatic system in young patients with myocardial infarction.

BACKGROUND: Coronary artery disease (CAD) is the first cause of death worldwide and represents a public health issue in our country. Acute myocardial infarction (AMI) represents the main thrombotic complication of CAD. Approximately 9% of the new events of MI occur in patients <45 years of age. DISCUSSION: AMI is produced by development of a thrombus at the site of an atherosclerotic plaque that initiates abrupt arterial occlusion, with ischemia and cell death. AMI results from the interaction of gene-environment factors. There are several modifiable factors such as hypertension, diabetes, smoking, obesity, and hypercholesterolemia associated with AMI. However, in a large number of patients with AMI, modifiable risk factors are not present. In the last decade, several genetic variants (polymorphisms) have been identified associated with AMI in genes related to coagulation proteins, fibrinolytic system, platelet receptors, homocysteine metabolism, endothelial dysfunction, abnormal blood flow and oxidative stress. CONCLUSIONS: Identifying the genes associated with CAD will allow us to develop more efficacious treatment strategies and will also help to identify at-risk subjects, thereby enabling the introduction of early preventive measures. Thus, many research efforts continue to address the identification of acquired and inherited risk factors of this complex disease.

Factores genéticos del sistema hemostático en pacientes jóvenes con infarto agudo del miocardio / Genetic factors of the hemostatic system in young patients with myocardial infarction

La enfermedad arterial coronaria (EAC) es la primera causa de muerte en todo el mundo y representa un problema de salud pública en México. El infarto agudo del miocardio (IAM) representa la principal complicación trombótica de la EAC. Aproximadamente 9 % de los nuevos casos está constituido por sujetos menores de 45 años. El IAM se produce por el desarrollo de un trombo en el sitio de la placa aterosclerosa, generando oclusión arterial súbita con isquemia y muerte celular. El IAM resulta de la interacción entre factores genéticos y ambientales. Existen diversos factores de riesgo modificables como la hipertensión arterial, la diabetes mellitus, el tabaquismo, la obesidad y la hipercolesterolemia asociados con el IAM. Sin embargo, numerosos pacientes con IAM no presentan factores de riesgo modificables. En la última década se han identificado variantes genéticas en las proteínas relacionadas con los sistemas de coagulación y fibrinólisis, receptores plaquetarios, disfunción endotelial, flujo sanguíneo anormal, metabolismo de la homocisteína, estrés oxidativo, los cuales se asocian a desarrollo del IAM. La identificación de los polimorfismos asociados a la enfermedad arterial coronaria permitirá desarrollar mejores estrategias de tratamiento e identificación de individuos con alto riesgo para EAC y medidas preventivas en etapas tempranas.

BACKGROUND: Coronary artery disease (CAD) is the first cause of death worldwide and represents a public health issue in our country. Acute myocardial infarction (AMI) represents the main thrombotic complication of CAD. Approximately 9% of the new events of MI occur in patients <45 years of age. DISCUSSION: AMI is produced by development of a thrombus at the site of an atherosclerotic plaque that initiates abrupt arterial occlusion, with ischemia and cell death. AMI results from the interaction of gene-environment factors. There are several modifiable factors such as hypertension, diabetes, smoking, obesity, and hypercholesterolemia associated with AMI. However, in a large number of patients with AMI, modifiable risk factors are not present. In the last decade, several genetic variants (polymorphisms) have been identified associated with AMI in genes related to coagulation proteins, fibrinolytic system, platelet receptors, homocysteine metabolism, endothelial dysfunction, abnormal blood flow and oxidative stress. CONCLUSIONS: Identifying the genes associated with CAD will allow us to develop more efficacious treatment strategies and will also help to identify at-risk subjects, thereby enabling the introduction of early preventive measures. Thus, many research efforts continue to address the identification of acquired and inherited risk factors of this complex disease.

Análise da expressão gênica de proteínas associadas à coagulação sanguínea na neoplasia maligna de esôfago / Analysis of gene expression of proteins associated with blood coagulation in malignant esophageal neoplasm

Estudos recentes indicam que o fator tecidual (TF) participa no crescimento tumoral, metástase e angiogênese através de uma via independente da coagulação sanguínea. A superexpressão do TF em células tumorais contribui para o estado pró-trombótico em pacientes com câncer. Adicionalmente, uma família de receptores acoplados à proteína G, conhecidos como receptores ativados por proteases (PARs), tem sido associada à biologia do tumor. Estes receptores podem ser ativados por proteases da coagulação como a trombina, o fator VIIa (FVIIa) e o fator FXa (FXa), mediando assim a sinalização celular e podendo levar a um aumento da expressão de IL-8 em vários tipos celulares. O objetivo deste estudo foi analisar a expressão do RNAm de TF, PAR-1, PAR-2 e IL-8 em pacientes com câncer de esôfago. Amostras de tecidos foram obtidas de 35 pacientes submetidos a esofagectomia ou endoscopia em 3 hospitais das regiões Sul e Sudeste do Brasil: Hospital Universitário Pedro Ernesto (HUPE-UERJ), na cidade do Rio de Janeiro, Hospital de Clínicas (HCPA-UFRGS), na cidade de Porto Alegre - Rio Grande do Sul e o Hospital de Clínicas - Gastrocentro (HC-UNICAMP), na cidade de Campinas - São Paulo. Amostras de tecido esofágico tumoral e da mucosa normal adjacente ao tumor, foram obtidas de cada paciente e o diagnóstico foi confirmado através da análise histopatológica do tecido adjacente. O RNA total foi então extraído e analisado por transcrição reversa e reação em cadeia da polimerase (RT-PCR) e por PCR em tempo real (qPCR). Nossos resultados demonstraram um aumento significativo, nas amostras tumorais quando comparadas as amostras normais, da expressão de TF (4,2 +- 5,3, SE=0,9), PAR-1 (6,1 +- 4,7, SE=0,9) e IL-8 (18,2 +- 14,4, SE=3,9), o mesmo porém não foi encontrado para o PAR-2 (1,6 +- 0,8, SE=0,2). Nossos dados sugerem que TF, PAR-1 e IL-8 podem ter um importante papel na biologia dos tumores de esôfago. Na busca por esclarecimentos de como as proteínas analisadas...

A number of studies indicate that Tissue Factor (TF) might participate in tumor growth, metastasis and angiogenesis through a pathway that is independet of blood coagulation. TF overexpression by tumor cells contributes to a pro-thrombotic status in cancer patients. Also, a family of G protein-coupled receptors known as protease-activated receptors (PARs) has been implicated in tumor biology. These receptors may be activated by blood coagulation proteases including thrombin, FVIIa and FXa, thus eliciting cell signalling which might lead to interleukin-8 (IL-8) expression by a variety of cells. The aim of this study was to compare the expression of TF, PAR-1, PAR-2 and IL-8 mRNAs in patients with esophageal cancer. Tissue samples were obtained from 35 patients submitted to esophagectomy or endoscopy in three hospitals from south and southeast regions of Brazil: Hospital Universitário Pedro Esnesto (HUPE-UERJ), located at Rio de Janeiro, Hospital de Clínicas (HCPA-UFRGS), located at Porto Alegre, Rio Grande do Sul, and Hospital de Clínicas - Gastrocentro (HC-UNICAMP), located at Campinas, São Paulo. Tumor samples and the corresponding normal mucosa were obtained from each patient and the diagnosis was confirmed by histopathological analysis of adjacent tissues. Total RNA was extracted and further analyzed by reverse transcriptase (RT)-PCR and Real Time PCR. Our results showed a significant increased expression of TF (4,2 +- 5,3, SE=0,9), PAR-1 (6,1 +- 4,7, SE=0,9) and IL-8 (18,2 +- 14,4, SE=3,9) in tumor samples, but not of PAR-2 (1,6 +- 0,8, SE=0,2). Our data indicate that TF, PAR-1 and IL-8 might play an important role in esophageal cancer. To analyze the role of this proteins in oesophageal cancer patients, we used "in vitro" models with TE-1 cell line. Our results demonstrated that TE-1 cells express TF, PAR-1 and PAR-2 and display potent procoagulant activity. In this context, we will further investigate whether the activation of PAR receptors induces...

Impact of screening on thrombophilia for patients with venous thrombosis.

AIM: The epidemiologic importance of thrombophilia on venous thromboembolism (VTE) has been extensively studied. We tried to identify the variables that point to the positive test results for thrombophilia and the impact of these results on clinical decisions. METHODS: Thrombophilia screening was applied to 84 consecutive patients with VTE. After test results, two independent observers evaluated, in a case by case basis, the indication of a change on prophylaxis or special attention, in order to modify the period of anticoagulant intake or have a higher medical surveillance before risk situations or for the extension of the research to the first degree relatives. RESULTS: Thrombophilia was found in 41.66% (35/84), and in 32.12% (27/84) it involved a genetic cause. The factor V Leiden was found in 15.47%, followed by the natural anticoagulant dysfunction (11.9%). There was no significative difference of thrombophilia frequency between ages, nor a difference of age in the onset of the first thrombotic event between thrombophilic and non-thrombophilic patients. There was a higher prevalence of thrombophilia in patients with superficial thrombophlebitis of spontaneous onset and in cases of recurrence. The change on prophylaxis resulted in 7.14% (6/84) and special attention in 40.47% (34/84). CONCLUSIONS: Spontaneous superficial thrombophlebitis, occurrence of VTE related to non surgical causes, and recurrence, were the main findings which suggested thrombophilia. The change of prophylaxis was applied to a small percentage of patients. The special attention for risk situations and the extension of the primary prophylaxis to the asymptomatic family members seems to be the best indication for the laboratory research on thrombophilia.

Heritability of hemostasis phenotypes and their correlation with type 2 diabetes status in Mexican Americans.

Hypercoagulation often occurs in type 2 diabetes, suggesting pleiotropy of the genes that influence disease liability and hemostasis-related phenotypes. To better understand the relationship between hemostasis and diabetes, we first used maximum-likelihood methods to estimate the relative contribution of additive genetic, measured environmental, and shared household effects to the normal variance of 16 hemostasis-related traits in 813 individuals participating in the San Antonio Family Heart Study. We estimated moderate to high heritabilities (0.20-0.60) for each phenotype. Von Willebrand factor (VWF), thrombin activatable fibrinolysis inhibitor, activated protein C (APC) ratio, factor V, and prothrombin time had heritabilities greater than 0.50. The correlation between type 2 diabetes status and the hemostasis-related traits was then partitioned into genetic and environmental components using bivariate variance-components methods. Significant (p < or = 0.05) positive genetic correlations (0.37-0.51) occurred with factors II and VIII, VWF, total protein S (tPS), and tissue factor pathway inhibitor. Significant negative genetic correlations were estimated for activated partial thromboplastin time (-0.49) and APC ratio (-0.38). By contrast, significant environmental correlations occurred only with factor II (-0.40) and tPS (-0.31). Our results suggest that genes are important contributors to the normal variation in hemostasis-related traits and that genes influencing hemostasis-related traits pleiotropically influence diabetes risk.

Molecular diseases: The role of genetic factors in venous thrombosis

As doenças multigênicas são aquelas em que o fenótipo clínico é resultante da interação de diferentes mutações em diversos genes. Embora o risco da ocorrência da doença determinado por cada defeito genético isoladamente possa ser baixo, a presença simultânea de várias mutações aumenta o risco da sua ocorrência. As doenças mutigênicas podem também ser vistas como consequentes à interação de uma coleção heterogênia de fatores genéticos e ambientais. O conceito de doença multigênica aplica-se a numerosas condições clínicas como o cancer, hipertensão, diabetes, dislepidemia, obesidade, suscebilidade a infecções, doenças auto-imunes, osteoporose, aterosclerose e tromboembolismo venoso. Como uma grande proporção dos pacientes com trombose venosa ou embolia pulmonar tem uma tendência hereditária a hipercoagulabilidade, o termo "trombofilia" foi introduzido para descrever a predisposição genética aumentada à trombose venosa. Numerosos fatores genéticos que têm uma relação bem estabelecida ou suspeita com trombofilia foram ou estão sendo identificados: Mutações dos genes de antitrombina, de proteína C, proteína S, fatores genéticos em casos individuais permite compreender a tendência hereditária ao tromboembolismo sob uma base mais objetiva e quantificável

Defecto congénito de los factores II, VII, y X / Congenital defect of factors II, VII, and X

Se analizan las principales características clínicas y de laboratorio de las deficiencias aisladas y combinadas de los factores II, VII y X. Se señala la importancia del uso de diferentes reactivos y metodologías para poderlos clasificar, sobre todo las variantes, debido a que en estos casos se presentan niveles inmunológicos normales con niveles disminuidos de actividad funcional o coagulante. Se discute brevemente el diagnóstico diferencial de estos trastornos, asi como se esbozan algunas pautas para el manejo del paciente con estas complicaciones hemorragicas hereditarias