Endothelial dysfunction biomarkers in sickle cell disease: is there a role for ADMA and PAI-1?

Within the spectrum of sickle cell disease (SCD) are sickle cell anemia (SCA), presence of hemoglobin SS (HbSS), hemoglobin SC disease (HbSC), and sickle cell ß-thalassemia (Sß-thal). Asymmetric dimethylarginine (ADMA) competitively inhibits the binding of arginine to NOS, reducing NO production. In patients with HbSS, increased levels of ADMA have been reported, as well as changes in many hemostatic biomarkers, including the plasminogen activator inhibitor type 1 (PAI-1). We hypothesized that high levels of ADMA and PAI-1 may be associated with more severe SCD. Thus, ADMA and PAI-1 levels were determined in 78 individuals including 38 adult patients with SCD and 40 control subjects. Higher levels of ADMA were shown in HbSS and Sß-thal patients compared to controls. Concerning PAI-1, all patients showed high levels of PAI-1 compared to controls. As a role of NO in the pathogenesis of SCD has already been established, we concluded that high levels of ADMA should compromise, at least in part, NO synthesis, resulting in endothelial dysfunction. Elevated plasma levels of PAI-1 in all patients may indicate not only endothelial dysfunction but also a hypofibrinolytic state favoring thrombotic complications. Finally, high levels of ADMA and PAI-1 may be associated with more severe SCD.

Hemostasis and oxidative stress in chronic kidney disease in children and adolescents.

Chronic kidney disease (CKD) can be defined as the progressive loss of renal function, characterized by a decreased glomerular filtration rate (GFR). The etiology of CKD in childhood is mainly associated with congenital anomalies of the kidneys and urinary tract (CAKUT) and with glomerular diseases. The goal of this study was to investigate the hemostasis and oxidative stress in pediatric CKD of different etiologies. Fifty-four CKD children and adolescents and 52 controls were enrolled in this study. The evaluation of hemostasis was carried out by determination of D-dimer (D-Di) and plasminogen activator inhibitor (PAI-1) plasma levels, while oxidative stress was evaluated by thiobarbituric acid reactive substance (TBARS) levels, protein carbonyl content, plasma antioxidant capacity (MTT), and ascorbate. The D-Di was increased in CAKUT stage 3 or 4 patients compared with those with glomerular disease. PAI-1 was increased in patients with glomerular disease compared with CAKUT. Carbonyl protein content was higher in the control group compared with glomerular disease stage 3 or 4 patients. Our findings showed that the reduction in GFR is associated with a state of hypercoagulability. The analysis of integrated networks showed an expansion of connections among hemostatic and oxidative stress markers in CKD children and adolescents compared with controls.

ADAMTS-13-VWF axis in sickle cell disease patients.

Sickle cell disease (SCD) comprises a group of genetic disorders characterized by the presence of the hemoglobin (Hb) S in homozygosis or in heterozygosis with some other Hb variant or in interaction with thalassemia. SCD is characterized by a very complex pathophysiology, which determines a wide variability of clinical manifestations, including a chronic state of hypercoagulability responsible for the increased risk of thromboembolic events. ADAMTS13 and von Willebrand factor (VWF) play an important role in arterial and venous thrombosis. Thus, the aim of this study was to understand how the ADAMTS13-VWF axis behaves in sickle cell disease, as well as whether there is an association of these markers with the use of hydroxyurea (HU). This is a cross-sectional study conducted with 40 patients diagnosed with SCD and 40 healthy individuals. The analysis of the ADAMTS13-VWF axis was comparatively performed between groups of patients and controls and, afterwards, between patients with SCD who were users and non-users of HU. ADAMTS13 activity, ADAMTS13 activity/VWF:Ag, and ADAMTS13:Ag/VWF:Ag ratios were significantly lower and VWF:Ag levels significantly higher in SCD patients when compared to the controls. There was no statistically significant difference in ADAMTS13:Ag and VWF collagen binding (VWF:CB) levels between the groups evaluated. Among the categories of HU use, there was no statistically significant difference in any of the evaluated markers. As a conclusion, we could observe that the ADAMTS13-VWF axis is altered in SCD when compared to healthy individuals and that there is no association between these markers and the use of HU.

Association between dyslipidemia and CCL2 in patients undergoing hemodialysis.

INTRODUCTION: Hemodialysis (HD) is associated with high risk for cardiovascular diseases including acute myocardial infarction, stroke and congestive heart failure. C-C Motif Chemokine Ligand 2 (CCL2), also known monocyte chemotactic protein-1 (MCP-1) can be produced by a variety of cells, reaching increased levels in dyslipidemic chronic kidney disease (CKD) patients undergoing HD treatment. The main of this study was to evaluate the association between of CCL2 plasma levels and dyslipidemia in CKD patients undergoing HD. METHODS: A cross-sectional study enrolled 160 Brazilian HD patients. CCL2 plasma levels were measured by capture ELISA. The association between CCL2 levels and dyslipidemia was investigated using linear regression, adjusted for classic and non-classical CVD risk factors. RESULTS: A significant association was observed between CCL2 levels and dyslipidemia (P = 0.029), even after adjustment for possible confounding variables, such as age, gender, body mass index, diabetes mellitus, HD time, urea pre-hemodialysis and interdialytic weight gain (P = 0.045). CONCLUSION: Our findings show that CCL2 levels are associated with dyslipidemia, which suggests a role of this cytokine in the pathogenesis of cardiovascular disease in HD patients. A better understanding of this pathogenesis could contribute to the discovery of new therapeutic targets that would reduce cardiovascular complications in these patients.

The dual effect of C-peptide on cellular activation and atherosclerosis: Protective or not?

C-peptide is a cleavage product of proinsulin that acts on different type of cells, such as blood and endothelial cells. C-peptide biological effects may be different in type 1 and type 2 diabetes. Besides, there are further evidence for a functional interaction between C-peptide and insulin. In this way, C-peptide has ambiguous effects, acting as an antithrombotic or thrombotic molecule, depending on the physiological environment and disease conditions. Moreover, C-peptide regulates interaction of leucocytes, erythrocytes, and platelets with the endothelium. The beneficial effects include stimulation of nitric oxide production with its subsequent release by platelets and endothelium, the interaction with erythrocytes leading to the generation of adenosine triphosphate, and inhibition of atherogenic cytokine release. The undesirable action of C-peptide includes the chemotaxis of monocytes, lymphocytes, and smooth muscle cells. Also, C-peptide was related with increased lipid deposits and elevated smooth muscle cells proliferation in the vessel wall, contributing to atherosclerosis. Purpose of this review is to explore these dual roles of C-peptide on the blood, contributing at one side to haemostasis and the other to atherosclerotic process.

Duffy blood group system: New genotyping method and distribution in a Brazilian extra-Amazonian population.

Duffy blood group system is of interest in several fields of science including transfusion medicine, immunology and malariology. Although some methods have been developed for Duffy polymorphism genotyping, not all of them have been sufficiently described and validated, and all present limitations. At the same time, the frequency of Duffy alleles and antigens in some densely populated regions of the world are still missing. In this study we present new tests for genotyping the major alleles of the Duffy blood system and describe Duffy alleles and antigens in blood donors and transfusion-dependent patients in Minas Gerais, Brazil. A simple and reproducible strategy was devised for Duffy genotyping based on real-time PCR that included SNPs rs12075 and rs2814778. No significant differences between the allele frequencies were observed comparing blood donors and patients. Among the blood donors, the phenotype Fy(a-b+) was the most common and the Fy(a-b-) phenotype, associated with populations of African descent, was remarkably less common among subjects who self-identified as black in comparison to other ethnoracial categories. However, the African ancestry estimated by molecular markers was significantly higher in individuals with the allele associated to the Duffy null phenotype. The genotyping method presented may be useful to study Duffy genotypes accurately in different contexts and populations. The results suggest a reduced risk of alloimmunization for Duffy antigens and increased susceptibility for malaria in Minas Gerais, considering the high frequency of Duffy-positive individuals.

ABO blood group polymorphisms and risk for ischemic stroke and peripheral arterial disease.

Recent studies have demonstrated association between ABO blood system and thrombosis, indicating that individuals belonging to non-O blood groups (A, B or AB) present an increased risk of venous thrombosis, heart disease, and ischemic stroke (IS) as compared to O blood group carriers. In this study, we investigated the frequency of ABO blood group polymorphisms and its association with IS and peripheral arterial disease. Significant differences were observed for O1 (OR 0.57, 95% CI 0.35-0.95, p < 0.05) and O2 (OR 3.47, 95% CI 1.15-10.28, p < 0.05) alleles among IS patients while significant differences were observed for B phenotype (26.3 vs 9.5%, OR 3.42, 95% CI 1.32-8.76, p = 0.01, patients vs controls, respectively) and alleles A1 (OR 0.31, 95% CI 0.11-0.84, p < 0.05), O2 (OR 4.61, 95% CI 1.59-13.23, p < 0.01) and B (OR 3.42, 95% CI 1.62-7.13, p < 0.001) alleles for PAD patients. O1 allele was an independent variable (OR 0.27, 95% CI 0.12-0.57, p < 0.001) for IS patients. These data suggest the relationship of non-O blood groups in pathogenesis of thrombosis events and a possible protective effect of O blood group.

Pediatric chronic kidney disease: blood cell count indexes as inflammation markers.

INTRODUCTION: Chronic kidney disease (CKD) is defined as a progressive decline of kidney functions. In childhood, the main triggering factors are congenital anomalies of the kidneys and urinary tract (CAKUT) and glomerulopathies. Inflammatory responses present challenges for diagnosis and staging, which justifies studies on biomarkers/indexes. AIM: To define blood cell count indexes and verify their association with pediatric CKD etiology and staging. The included indexes were: Neutrophil-Lymphocyte Ratio (NLR), Derived Neutrophil-Lymphocyte Ratio (dNLR), Lymphocyte-Monocyte Ratio (LMR), Systemic Inflammation Response Index (SIRI), Aggregate Index of Systemic Inflammation (AISI), and Systemic Immune-Inflammation Index (SII). METHODS: We determined the indexes in 52 pediatric CKD patients and 33 healthy controls by mathematical calculation. CKD patients were separated in five groups based on the etiology and staging: Group IA: glomerulopathies at stage 1 or 2; IB: glomerulopathies at stage 3 or 4; IIA: CAKUT at stage 1 or 2; IIB: CAKUT at stage 3 or 4; and III: stages 3 or 4 of other etiologies. In addition, we combined all patients with CKD in one group (IV). Group V was a healthy control group. RESULTS: Lower values of LMR were observed for groups IB and IIB compared to group V (p = 0.047, p = 0.031, respectively). Increased values of SIRI were found for group III versus group V (p = 0.030). There was no difference for other indexes when the groups were compared two by two. CONCLUSION: The LMR and SIRI indexes showed promising results in the evaluation of inflammation, as they correlated with CKD etiologies and specially staging in these patients.

Plasminogen activator inhibitor-1 4G/5G promoter polymorphism and PAI-1 plasma levels in young patients with ischemic stroke.

The 4G/5G polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene, has been associated with arterial disease. In this study, we investigated the association of IS in young patients with CRP and PAI-1 levels and frequency of insertion-deletion polymorphism of PAI-1 gene. The plasma levels of PAI-1 and CRP and the frequency of 4G/5G polymorphism were analyzed in 127 Brazilian young patients that presented IS and in 201 healthy and unrelated control subjects. The levels of CRP (P < 0.001) and PAI-1 (P < 0.001) were significantly higher in patients when compared with control group. Only PAI-1 plasma levels were independently associated with risk of IS (OR 3.40; 95% CI 1.49-7.74; P = 0.001) after adjustments for lifestyles covariates. The 4G/4G genotype was significantly more frequent among control subjects as compared to patients (OR 0.41; 95% CI 0.24-0.68; P < 0.001). Although increased PAI-1 plasma levels are associated with development of IS in Brazilian young patients, they are not influenced by the 4G/5G PAI-1 polymorphism.

Longitudinal assessment of leukotriene B4, lipoxin A4, and resolvin D1 plasma levels in pregnant women with risk factors for preeclampsia.

OBJECTIVES: We carried out a longitudinal study to compare leukotriene B4 (LTB4), lipoxin A4 (LXA4), and resolvin D1 (RvD1) levels in pregnant women with risk factors for PE - who did (N = 11) or did not develop (N = 17) this clinical condition. DESIGN & METHODS: For both groups, plasma levels of the lipid mediators were measured using immunoassays at 12-19, 20-29, and 30-34 weeks of gestation. RESULTS: LTB4 tended to be upregulated throughout gestation in women who developed PE. Moreover, this increase was significant at 30-34 weeks. Although LXA4 levels also tended to be higher in the PE group, this difference was not significant for the evaluated gestational periods. Pregnant women with PE had lower RvD1 levels and a low RvD1/LTB4 ratio at 30-34 weeks, compared to those in the normotensive pregnant women. Contrarily, RvD1 levels increased at weeks 12-19 in pregnant women who developed PE. Particularly, LXA4 and RvD1 levels were higher at 30-34 weeks than those at 20-29 weeks considering both groups of women. We observed an interaction between the gestational outcome and the gestational period in case of RvD1. CONCLUSIONS: The imbalance among LTB4, LXA4, and RvD1 levels in these preeclamptic women is consistent with the excessive inflammation that underlies the pathogenesis of PE. Although our data highlight the potential for the use of these lipid mediators as clinical markers for PE development, future longitudinal studies must be carried out to confirm these findings.

Thrombin generation in vivo and ex vivo in sickle cell disease patients.

Activation of coagulation is an important hallmark of sickle cell disease (SCD) and it is believed that hypercoagulability plays a role to the disease pathophysiology. Studies have sought to identify how hemostatic biomarkers are expressed in SCD, however, the results are inconclusive. In this context, our objective was to evaluate the thrombin generation in vivo and ex vivo in SCD patients and the association between these biomarkers and the use of HU. This cross-sectional study was carried out with patients diagnosed with SCD, users or not of Hydroxyurea (HU), and healthy individuals as controls. D dimer (D-Di) was evaluated by ELISA and (TGT) thrombin generation test by CAT method. D-Di plasma levels were significantly higher in SCD patients when compared to the controls. TGT parameters such as peak, ETP and normalized ETP at low TF concentration and time-to-peak, peak, ETP and normalized ETP values at high TF concentration were lower in SCD patients than in controls. In contrast, the normalized activated protein C sensitivity ratio (nAPCsr) was higher in patients compared to controls, indicating resistance to the action of this natural anticoagulant. Regarding the use of HU, comparing users and non-users of this drug, no difference was observed in D-Di levels and in most TGT parameters. Our data analyzed together allow us to conclude that patients with SCD present a state of hypercoagulability in vivo due to the higher levels of D-Di and resistance to APC assessed ex vivo which is consistent with the coagulation imbalance described in SCD patients.

Longitudinal assessment of D-dimer and plasminogen activator inhibitor type-1 plasma levels in pregnant women with risk factors for preeclampsia.

OBJECTIVE: Investigating D-Dimer/D-Di and plasminogen activator inhibitor type-1/PAI-1 levels throughout gestation in women with preeclampsia/PE risk factors. METHODS: D-Di and PAI-1 plasma levels were determined in 28 women at 12-19, 20-29, 30-34 and 35-40 weeks of gestation. RESULTS: D-Di was lower at 12-19 weeks and higher at 30-34 weeks in women who developed PE versus who did not develop it. D-Di increased throughout gestation in both groups, peaking earlier in pregnant women who developed PE versus who did not develop it. PA1-1 increased across gestation, but it didn't differ between groups. CONCLUSION: D-Di was able to discriminate these groups of women at 12-19 and 30-34 weeks of gestation.

Pediatric chronic kidney disease: blood cell count indexes as inflammation markers / Doença renal crônica pediátrica: índices de contagem de células sanguíneas como marcadores de inflamação

Abstract Introduction: Chronic kidney disease (CKD) is defined as a progressive decline of kidney functions. In childhood, the main triggering factors are congenital anomalies of the kidneys and urinary tract (CAKUT) and glomerulopathies. Inflammatory responses present challenges for diagnosis and staging, which justifies studies on biomarkers/indexes. Aim: To define blood cell count indexes and verify their association with pediatric CKD etiology and staging. The included indexes were: Neutrophil-Lymphocyte Ratio (NLR), Derived Neutrophil-Lymphocyte Ratio (dNLR), Lymphocyte-Monocyte Ratio (LMR), Systemic Inflammation Response Index (SIRI), Aggregate Index of Systemic Inflammation (AISI), and Systemic Immune-Inflammation Index (SII). Methods: We determined the indexes in 52 pediatric CKD patients and 33 healthy controls by mathematical calculation. CKD patients were separated in five groups based on the etiology and staging: Group IA: glomerulopathies at stage 1 or 2; IB: glomerulopathies at stage 3 or 4; IIA: CAKUT at stage 1 or 2; IIB: CAKUT at stage 3 or 4; and III: stages 3 or 4 of other etiologies. In addition, we combined all patients with CKD in one group (IV). Group V was a healthy control group. Results: Lower values of LMR were observed for groups IB and IIB compared to group V (p = 0.047, p = 0.031, respectively). Increased values of SIRI were found for group III versus group V (p = 0.030). There was no difference for other indexes when the groups were compared two by two. Conclusion: The LMR and SIRI indexes showed promising results in the evaluation of inflammation, as they correlated with CKD etiologies and specially staging in these patients.

Resumo Introdução: Doença renal crônica (DRC) é definida como um declínio progressivo das funções renais. Na infância, os principais fatores desencadeantes são anomalias congênitas dos rins e trato urinário (CAKUT) e glomerulopatias. Respostas inflamatórias apresentam desafios para diagnóstico e estadiamento, o que justifica estudos sobre biomarcadores/índices. Objetivo: Definir índices de contagem de células sanguíneas e verificar sua associação com etiologia e estadiamento da DRC pediátrica. Os índices incluídos foram: Razão Neutrófilo-Linfócito (NLR), Razão Neutrófilo-Linfócito Derivada (dNLR), Razão Linfócito-Monócito (LMR), Índice de Resposta à Inflamação Sistêmica (SIRI), Índice Agregado de Inflamação Sistêmica (AISI) e Índice de Inflamação Imune Sistêmica (SII). Métodos: Determinamos índices em 52 pacientes pediátricos com DRC e 33 controles saudáveis por cálculo matemático. Pacientes com DRC foram separados em cinco grupos conforme etiologia e estadiamento: Grupo IA: glomerulopatias em estágio 1 ou 2; IB: glomerulopatias em estágio 3 ou 4; IIA: CAKUT em estágio 1 ou 2; IIB: CAKUT em estágio 3 ou 4; e III: estágios 3 ou 4 de outras etiologias. Além disso, combinamos todos os pacientes com DRC em um grupo (IV). Grupo V foi um grupo controle saudável. Resultados: Observamos valores menores de LMR nos grupos IB e IIB comparados ao grupo V (p=0,047; p=0,031, respectivamente). Encontramos valores maiores de SIRI para o grupo III versus grupo V (p=0,030). Não houve diferença para outros índices quando os grupos foram comparados dois a dois. Conclusão: Os índices LMR e SIRI apresentaram resultados promissores na avaliação da inflamação, pois correlacionaram-se com as etiologias da DRC e, principalmente, com o estadiamento desses pacientes.

Thrombin activatable fibrinolysis inhibitor (TAFI): a role in pre-eclampsia?

Pre-eclampsia (P-Ec) is a complex multisystem disorder of unknown aetiology reported to occur in about 6% to 8% of all pregnancies throughout the world. This disease is associated with fibrin deposition and occlusive lesions in placental vessels. Pro-thrombin activatable fibrinolysis inhibitor (pro-TAFI) is a relatively recently described glycoprotein that can be converted into its active form (TAFIa) by thrombin, thrombin-thrombomodulin and plasmin. TAFIa potentially inhibits fibrinolysis by removing C-terminal lysine and arginine residues from fibrin. These residues are required for adsorption of tissue-type plasminogen activator (t-PA) and plasminogen to fibrin. Therefore, TAFIa decreases plasmin formation and protects the fibrin clot against lysis. An increased of pro-TAFI/TAFIa levels has been reported in some clinical conditions associated with thrombotic tendency, as type II diabetes mellitus, deep vein thrombosis and symptomatic artery disease. Few studies have investigated pro-TAFI/TAFIa in normal or complicated pregnancy but contrasting results were reported. Understanding the role of pro-TAFI/TAFIa in the pathogenesis of P-Ec can hold great promise for improving P-Ec management. In this context, a large-scale study evaluating plasma TAFI antigen and activity, its synthesis and metabolism in pre-eclamptic women is required. Recently new selective TAFIa inhibitors have been developed. The design of a new therapy to treat and/or prevent P-Ec, based on successful use of TAFIa inhibitors, may have significant clinical ramifications.

Inherited thrombophilias and pre-eclampsia in Brazilian women.

OBJECTIVE: The aim of the present study was to compare the distribution of G1691A, G20210A and C677T mutations in pre-eclamptic Brazilian women and in matched control women with an uncomplicated normal pregnancy. STUDY DESIGN: these mutations were investigated by PCR-RFLP in 83 normal pregnancies (control group) and in 30 pre-eclamptic pregnant women (severe form). RESULTS: G1691A mutation was detected neither in the control group nor in pre-eclamsia women. G20210A mutation was detected in heterozygosis in 3 (3.61%) control subjects, but not in pre-eclampsia group. C677T mutation was detected in homozygosis in 6 (7.23%) control subjects and 2 (6.67%) pre-eclamptic women and in heterozygosis in 31 (37.3%) control subjects and 12 (40%) pre-eclamptic women. Differences in the mutation frequencies detected in the two groups were not statistically significant. CONCLUSION: No correlation was observed between pre-eclampsia and presence of G1691A, G20210A and C677T mutations in Brazilian women.

Economy class syndrome: what is it and who are the individuals at risk?

The term 'economy class syndrome' refers to the occurrence of thrombotic events during long-haul flights that mainly occur in passengers in the economy class of the aircraft. This syndrome results from several factors related to the aircraft cabin (immobilization, hypobaric hypoxia and low humidity) and the passenger (body mass index, thrombophilia, oral contraceptives or hormone replacement therapy, cancer), acting together to predispose to excessive blood coagulation, which can result in venous thromboembolism. Several risk factors, both genetic and acquired, are associated with venous thromboembolism. The most important genetic risk factors are natural anticoagulant deficiencies (antithrombin, protein C and protein S), factor V Leiden, prothrombin and fibrinogen gene mutations and non-O blood group individuals. Acquired risk factors include age, pregnancy, surgery, obesity, cancer, hormonal contraceptives and hormone replacement therapy, antiphospholipid syndrome, infections, immobilization and smoking. People who have these risk factors are predisposed to hypercoagulability and are more susceptible to suffer venous thromboembolism during air travel. For these individuals, a suitable outfit for the trip, frequent walks, calf muscle exercises, elastic compression stockings and hydration are important preventive measures. Hence, it is essential to inform about economic class syndrome in an attempt to encourage Brazilian health and transport authorities to adopt measures, in partnership with the pharmaceutical industry, to prevent venous thromboembolism.

Cytokine Signature in End-Stage Renal Disease Patients on Hemodialysis.

Hemodialysis is a modality of blood filtration in which accumulated toxins and water are removed from the body. This treatment is indicated for patients at the end stage of renal disease. Vascular access complications are responsible for 20-25% of all hospitalizations in dialyzed patients. The occurrence of thrombosis in the vascular access is a serious problem that may severely compromise or even make the hemodialysis impossible, which is vital for the patient. The aim of this study was to investigate inflammatory profile in patients undergoing hemodialysis as well as the association between these alterations and vascular access thrombosis. A total of 195 patients undergoing hemodialysis have been evaluated; of which, 149 patients had not experienced vascular access thrombosis (group I) and 46 patients had previously presented this complication (group II). Plasma levels of cytokines including interleukin (IL-) 2, IL-4, IL-5, IL-10, TNF-α, and IFN-γ were measured by cytometric bead array. Our results showed that patients with previous thrombotic events (group II) had higher levels of the IL-2, IL-4, IL-5, and IFN-γ when compared to those in group I. Furthermore, a different cytokine signature was detected in dialyzed patients according to previous occurrences or not of thrombotic events, suggesting that elevated levels of T-helper 1 and T-helper 2 cytokines might, at least in part, contribute to this complication.

Tissue factor and tissue factor pathway inhibitor: a potential role in pregnancy and obstetric vascular complications?

Tissue factor (TF) is the principal cellular initiator of normal blood coagulation. As a result it is considered to be a major regulator of haemostasis and thrombogenesis. In vivo TF activity is regulated by specific circulating inhibitor known as "tissue factor pathway inhibitor (TFPI)". TF is also essential for other cellular processes including embryogenesis and angiogenesis as well as in implantation where it is particularly important in the first trimester. TF is highly expressed in syncytiotrophoblasts (STB) while TFPI is expressed in human umbilical vein endothelial cells (HUVEC). TFPI may be internalized via an endocytic pathway and recycled to the cell surface. The procoagulant tendency of STB may reflect a physiological need for immediate inhibition of hemorrhage in the placental intervillous spaces. Furthermore, the haemostatic balance involving STB and HUVEC may be critical for normal placental function and pregnancy outcome. Homozygous knockouts of both TF and TFPI are generally lethal in fetal mice; heterozygotes survive but with altered coagulation parameters. Despite their apparent association with placental microcirculation-thrombi-formation only few studies have addressed the role of TF and TFPI in the pathogenesis of gestational vascular complications. In this context, detailed studies could provide clinically relevant information.

Factor V Leiden and increased risk for arterial thrombotic disease in young Brazilian patients.

The contribution of mutations in the prothrombin (FII G20210A), methylenetetrahydrofolate reductase (C677T) genes and factor V Leiden (FVL) to the pathogenesis of arterial thrombosis remains controversial. In this study, these polymorphisms were investigated by polymerase chain reaction-restriction fragment length polymorphism in a group of 53 patients that presented arterial thrombosis other than myocardial infarction as a first thrombotic event and 275 control subjects living in the state of Minas Gerais, Brazil. Odds ratio (OR) and chi tests were applied for statistical comparisons. Similar frequencies were detected among patients and control subjects for the C677T mutation. The 20210A mutation was present in 3.6% of the control subjects but was not detected among ischemic stroke patients. Significant differences were detected only for factor V Leiden (odds ratio 7.11; 95% confidence interval 1.55-32.73). Our data indicate that, among these genetic factors, factor V Leiden was identified as an important risk factor for arterial thrombosis in this group of patients. In addition, our results indicate regional differences in the incidence of these genetic factors in Brazil, as compared to the incidences reported in other studies.

Increased Levels of sENG and sVCAM-1 and Decreased Levels of VEGF in Severe Preeclampsia.

BACKGROUND: Preeclampsia (PE) is characterized by hypertension and proteinuria after the 20th week in pregnant women who have had no previous symptoms. Clinically, it is important to diagnose the severe form of the disease, in which blood pressure is much higher. Imbalance between angiogenic and antiangiogenic factors, as well as changes in adhesion molecules seem to contribute to the endothelial dysfunction and PE clinical manifestations. The aim of this study was to assess plasma levels of the angiogenic factors (free vascular endothelial growth factor (VEGF) and soluble endoglin (sEng)) and adhesion molecules (soluble forms of intercellular adhesion molecule-1 (sICAM-1) and soluble forms of vascular cell adhesion molecule-1 (sVCAM-1)) in severe PE (sPE), in order to clarify the circulating profile of these factors. METHODS: Sixty women with sPE (34 with early sPE and 26 with late sPE), and 60 normotensive pregnant were enrolled in this study. Free VEGF, sICAM-1, sVCAM-1, and sEng plasma levels were determined by ELISA. RESULTS: Increased sEng and sVCAM-1 and decreased free VEGF plasma levels were found in women with sPE, compared with normotensive pregnant group. However, no significant difference was observed comparing early and late sPE. CONCLUSION: Our data confirm the imbalance in changes in angiogenic and antiangiogenic factors, as well changes in adhesion molecule (sVCAM-1) in PE. These findings give support to the hypothesis that circulating angiogenic proteins and endothelial dysfunction may have an important biologic role in PE. Data from prospective, longitudinal studies producing serial determinations of these molecules throughout pregnancy are needed to better understanding the relevance of these markers in PE diagnosis and prognosis.