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.

Association among ACE, ESR1 polymorphisms and preeclampsia in Brazilian pregnant women.

BACKGROUND: Genetic, immune and environmental factors are involved in preeclampsia (PE) etiopathogenesis. Considering that hypertension and poor placental perfusion are important features in PE, polymorphisms in the angiotensin-converting enzyme (ACE) and estrogen nuclear receptor 1 (ESR1) genes could be involved in the predisposition and/or development of the disease. The aim of this study was to evaluate if polymorphisms in ACE and ESR1 genes were associated with PE occurrence. MATERIAL AND METHODS: This case-control study included 209 Brazilian pregnant women (107 with severe PE and 102 normotensive controls). The polymorphisms were investigated by polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis. RESULTS: No significant difference between PE versus normotensive pregnant women, as well as early versus late PE, was observed when compared the allelic and genotypic frequencies of insertion/deletion polymorphism in intron 16 of the ACE gene and the single nucleotide polymorphisms (SNPs - rs2234693 and rs9340799) of the ESR1 gene. CONCLUSION: This pioneer study involving Brazilian women showed no association among the studied polymorphisms and PE, which suggests that ins/del ACE and SNPs ESR1 do not contribute to this disease occurrence in Brazil.

Higher levels of circulating TIMP-4 in preeclampsia is strongly associated with clinical parameters and microRNA.

BACKGROUND: Preeclampsia results in maternal and fetal complications and some studies have reported the role of MMPs and TIMPs in its pathophysiology. Therefore, the aim of this study was to compare plasma TIMP-4 levels in preeclampsia and healthy pregnant; and to correlate these levels with clinical parameters and expression of Let7a-5p (3´UTR post-transcriptionally regulation) Methods: TIMP-4 was measured by ELISA and miR-Let7a-5p expression by qPCR. RESULTS: Elevated plasma TIMP-4 levels in preeclampsia compared to healthy pregnant was found 1450 ± 411 vs. 775 ± 210 pg/mL, respectively (p < 0.0001); these levels are correlated positively with serum liver enzymes (ALT, r = 0.84, p = 0.004; and AST, r = 0.51, p = 0.02); and negatively with newborn weight (r = -0.45, p = 0.04) in preeclampsia. Regarding Let7a-5p a negative but not significant correlation was found (r = -0.39, p = 0.06, including both healthy and preeclampsia). CONCLUSIONS: Preeclampsia present elevated levels of circulating TIMP-4 compared to healthy pregnant and these levels are correlated with clinical parameters of disease.

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.

Polymorphisms in endothelial nitric oxide synthase gene in early and late severe preeclampsia.

Preeclampsia (PE) is characterized by hypertension and proteinuria, occurring after the 20th week of pregnancy in women who have had no previous symptoms. The disease progresses with generalized vasoconstriction and endothelial dysfunction. Clinically, it is important to diagnose the severe form of the disease (sPE), in which blood pressure and proteinuria are much higher. Recently, the gestational age (GA) of the onset of PE has led to the classification of this disease as early (GA <34 weeks) and late (GA ≥34 weeks). Several genetic polymorphisms affecting endothelial nitric oxide synthase (eNOS) levels or function were described, including G894T (Glu298Asp), VNTR b/a (variable-number 27-bp tandem repeat) and T-786C (promoter) polymorphisms. Thus, the aim of this study was to compare the distribution of G894T, VNTR b/a and T-786C polymorphisms and their haplotypes in Brazilian early and late sPE, as well as in normotensive pregnant. A total of 201 women were evaluated, 53 with early sPE, 45 with late sPE and 103 as normotensive pregnant women. The frequency of 894T allele was higher in late sPE vs normotensive pregnant, and 894TT genotype was higher in late sPE vs early sPE and normotensive pregnant. For VNTR b/a polymorphism, higher frequencies of aa genotype and a allele were observed in early sPE vs late sPE and normotensive pregnant. Besides, the frequency of haplotype T-b-C was higher in late sPE vs early sPE and normotensive pregnant. Considering the results found for eNOS polymorphisms, it is possible to suggest that the functional alterations induced by these two polymorphisms may influence the time of severe PE onset, although both alterations are putatively associated with low NO bioavailability. However, other studies are necessary to validate these findings and clarify this issue.

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.

Early and late-onset preeclampsia: effects of DDAH2 polymorphisms on ADMA levels and association with DDAH2 haplotypes.

Objective: To examine whether the DDAH2 promoter polymorphisms -1415G/A (rs2272592), -1151A/C (rs805304) and -449G/C (rs805305), and their haplotypes, are associated with PE compared with normotensive pregnant women, and whether they affect ADMA levels in these groups. Methods: A total of 208 pregnant women were included in the study and classified as early-onset (N=57) or late-onset PE (N =49), and as normotensive pregnant women (N = 102). Results: Pregnant with early-onset PE carrying the GC and GG genotypes for the DDAH2 -449G/C polymorphism had increased ADMA levels (P=0.01). No association of DDAH2 polymorphisms with PE in single-locus analysis was found. However, the G-C-G haplotype was associated with the risk for late-onset PE. Conclusion: It is suggested that DDAH2 polymorphisms could affect ADMA levels in PE, and that DDAH2 haplotypes may affect the risk for PE.

Cytokines signatures in short and long-term stable renal transplanted patients.

Despite the evidences showing the relevance of regulatory immune-mediated mechanisms to guarantee the stable graft function in renal transplanted patients, studies focusing on the immune response observed over a long-term period after renal transplantation are still limited. Several efforts have been done to establish novel biomarkers with relevant predictive values that could be used as prognostic laboratorial tools to monitor the complex network triggered through time after kidney transplantation. In this study, we have evaluated the pro-inflammatory and regulatory patterns of plasma cytokines in a group of 120 renal transplanted patients with stable graft function ranging from 1 to 160 months. Our data demonstrated an overall predominance of regulatory cytokines short-term after renal transplantation (1-24 months) with peaks of IL-4, IL-5 and IL-10. Moreover, a slight peak of TNF-α was observed 25-60 months after renal transplantation. Following a gap of stable cytokine profile (61-120 months), peaks of pro-inflammatory cytokines IL-8, IL-6, IL1ß, TNF-α and IL-12 were observed later on (>120 months) after renal transplantation. Additionally, the categorical analysis of "low" or "high" cytokine producers re-enforce the occurrence of an overall regulatory status early-after stable renal graft function with a predominant pro-inflammatory pattern later on long-term renal transplantation. Taken together, our data suggest that IL-5 is a good biomarker associated with short-term stable renal function, whereas IL-12 seems to be a relevant pro-inflammatory element in long-term renal transplanted patients.

Assessment of L-arginine asymmetric 1 dimethyl (ADMA) in early-onset and late-onset (severe) preeclampsia.

Preeclampsia (PE) is characterized by hypertension and proteinuria. It has been classified in early or late according to gestational age at the onset of disease. Endothelial dysfunction plays a crucial part in its pathogenesis. NO is a potent vasodilator and ADMA is its endogenous inhibitor. We have assessed maternal ADMA levels. ADMA were increased in early [0.66 µmol/L] versus late sPE [0.47 µmol/L] (P=0.001) and versus normotensive pregnant [0.48 µmol/L] (P=0.001). Our findings suggest that high ADMA levels in early sPE could compromise NO synthesis contributing to endothelial dysfunction, leading to impaired placentation and the onset of this disease.

Preeclampsia and ABO blood groups: a systematic review and meta-analysis.

Preeclampsia (PE) is a multifactorial pregnancy-specific syndrome which represents one of the leading causes of maternal mortality worldwide. Inherited thrombophilia have been investigated as risk factor for the development of PE and it is currently known that ABO blood group may impact haemostatic balance, having the non-O blood groups (A, B or AB) subjects increased risk for thrombus formation, as compared to those of group O. We performed a systematic review of the literature for published studies investigating whether ABO blood groups could influence PE developing. A sensitive search of four databases identified 45 unique titles. The retrieved papers were assessed independently by authors and a rigorous process of selection and data extract was conduct. Methodological quality of the included studies was also evaluated. Two studies met eligibility criteria. As a main finding of our systematic review, an association between the AB blood group and the occurrence of PE was detected based on two original studies. Considering the role of ABO blood groups on the hemostatic process and thrombus formation, special attention should be given to pregnant patients carrying the AB blood group in order to prevent the syndrome and improve prognosis.

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.

Neuroserpin: A potential biomarker for early-onset severe preeclampsia.

Preeclampsia is a hypertensive disease of pregnancy associated with intense inflammatory and pro-coagulant responses. Neuroserpin is a serine protease inhibitor that has been involved in neurological and immune processes and has not yet been investigated in preeclampsia. Herein, we evaluated neuroserpin levels in association with other inflammatory mediators (IL-17A, IL-33, and CXCL-16) during severe preeclampsia. The mediators' plasma levels were measured by immunoassays in 24 pregnant women with severe preeclampsia (early preeclampsia: N = 17, late preeclampsia: N = 7), 34 normotensive pregnant women, and 32 non-pregnant women. In general, pregnancy was associated with higher levels of neuroserpin, IL-17A, IL-33, and CXCL-16 than the non-pregnant state. However, this increase was attenuated in pregnancies complicated by severe preeclampsia. Although neuroserpin levels did not differ between normotensive pregnant women and pregnant women with severe preeclampsia, neuroserpin levels tended to be lower in early-onset than in late-onset severe preeclampsia. There were positive correlations between neuroserpin and IL-17A, neuroserpin and CXCL-16, and IL-17A and CXCL-16 levels in women with severe preeclampsia. In addition, although the risk for developing severe preeclampsia was higher in older women in this study, maternal age did not significantly influence the mediators' levels, nor their correlations in the preeclampsia group. In summary, our data suggest that neuroserpin might be a potential biomarker for early-onset severe preeclampsia and, that the imbalance among neuroserpin, IL-17A, IL-33, and CXCL-16 levels may be associated with the pathogenesis of preeclampsia, regardless of the maternal age.

Panoramic snapshot of serum soluble mediator interplay in pregnant women with convalescent COVID-19: an exploratory study.

Introduction: SARS-CoV-2 infection during pregnancy can induce changes in the maternal immune response, with effects on pregnancy outcome and offspring. This is a cross-sectional observational study designed to characterize the immunological status of pregnant women with convalescent COVID-19 at distinct pregnancy trimesters. The study focused on providing a clear snapshot of the interplay among serum soluble mediators. Methods: A sample of 141 pregnant women from all prenatal periods (1st, 2nd and 3rd trimesters) comprised patients with convalescent SARS-CoV-2 infection at 3-20 weeks after symptoms onset (COVID, n=89) and a control group of pre-pandemic non-infected pregnant women (HC, n=52). Chemokine, pro-inflammatory/regulatory cytokine and growth factor levels were quantified by a high-throughput microbeads array. Results: In the HC group, most serum soluble mediators progressively decreased towards the 2nd and 3rd trimesters of pregnancy, while higher chemokine, cytokine and growth factor levels were observed in the COVID patient group. Serum soluble mediator signatures and heatmap analysis pointed out that the major increase observed in the COVID group related to pro-inflammatory cytokines (IL-6, TNF-α, IL-12, IFN-γ and IL-17). A larger set of biomarkers displayed an increased COVID/HC ratio towards the 2nd (3x increase) and the 3rd (3x to 15x increase) trimesters. Integrative network analysis demonstrated that HC pregnancy evolves with decreasing connectivity between pairs of serum soluble mediators towards the 3rd trimester. Although the COVID group exhibited a similar profile, the number of connections was remarkably lower throughout the pregnancy. Meanwhile, IL-1Ra, IL-10 and GM-CSF presented a preserved number of correlations (≥5 strong correlations in HC and COVID), IL-17, FGF-basic and VEGF lost connectivity throughout the pregnancy. IL-6 and CXCL8 were included in a set of acquired attributes, named COVID-selective (≥5 strong correlations in COVID and <5 in HC) observed at the 3rd pregnancy trimester. Discussion and conclusion: From an overall perspective, a pronounced increase in serum levels of soluble mediators with decreased network interplay between them demonstrated an imbalanced immune response in convalescent COVID-19 infection during pregnancy that may contribute to the management of, or indeed recovery from, late complications in the post-symptomatic phase of the SARS-CoV-2 infection in pregnant women.

Preeclampsia: the role of tissue factor and tissue factor pathway inhibitor.

Preeclampsia (PE) is a multi-system disorder of human pregnancy, whose etiology remains poorly understood. Preeclamptic women are known to have an increased hypercoagulable state that result in excess fibrin deposition in several organs, which compromises their function. Tissue factor (TF) is the main physiological initiator of blood coagulation and its activity is regulated by a specific inhibitor known as Tissue factor pathway inhibitor (TFPI). Based on the important role of TF and TFPI in hemostasis, we hypothesize that their levels may change in the severe PE contributing to exacerbate hypercoagulable state. Some studies have assessed the balance between TF and TFPI in preeclamptic women, but results are inconsistent. Therefore, the aim of this study was to examine these inconsistencies and to assess TF and TFPI plasma levels in three groups of age matched women; pregnant with severe PE (n = 60), normotensive pregnant (n = 50) and normotensive non-pregnant women (n = 50). There was not significantly different among the three groups for TF plasma levels; severe PE women: 338.4 pg/mL (248.1-457.6), normotensive pregnant women: 301.5 pg/mL (216.4-442.9) and normotensive non-pregnant women 393 pg/mL (310.3-522.9). TFPI plasma levels were higher in severe PE comparing to normotensive pregnant women and normotensive non-pregnant women, 115.8 ng/mL (75-149.8); 80.3 ng/mL (59.6-99.7) and 74.5 ng/mL (47.1-98.0), respectively No difference was found between normotensive pregnant women and normotensive non-pregnant women. As for gestational age, a significant difference in TFPI levels was found between severe PE and normotensive pregnant women up to the 33rd week of pregnancy (p = 0.001), and severe PE and non-pregnant women up to the 34th (p = 0.01). In summary, our results indicated that TF plasma levels did not vary in the studied groups, while TFPI plasma levels were significantly increased in severe PE compared to normotensive pregnant and normotensive non-pregnant women. So, our data do not explain the exacerbated hypercoagulability state observed in severe PE. Further studies evaluating genes expression, TF activity and antigen, total and free TFPI and TFPI-2, both in plasma and obstetric tissues, throughout the pregnancy in PE (mild and severe forms) are required.

Relationship between ABO blood groups and von Willebrand factor, ADAMTS13 and factor VIII in patients undergoing hemodialysis.

Several studies have demonstrated that non-O blood groups subjects present an increased VTE risk as compared to those carrying O blood group. The aim of this study was to investigate the ABO blood groups influence on factor VIII (FVIII) activity, von Willebrand factor (VWF), and ADAMTS13 plasma levels in patients undergoing hemodialysis (HD). Patients undergoing HD (N=195) and 80 healthy subjects (control group) were eligible for this cross-sectional study. The ABO blood group phenotyping was performed by the reverse technique. FVIII activity was measured through coagulometric method, and VWF and ADAMTS13 antigens were assessed by ELISA. FVIII activity and VWF levels were significantly higher and ADAMTS13 levels was decreased in HD patients, as compared to healthy subjects (P < 0.001, in three cases). HD patients carrying non-O blood groups showed a significant increase in FVIII activity (P = 0.001) and VWF levels (P < 0.001) when compared to carriers of O blood group. However, no significant difference was observed in ADAMTS13 levels (P = 0.767). In the control group, increased in FVIII activity (P = 0.001) and VWF levels (P = 0.002) and decreased in ADAMTS13 levels (P = 0.005) were observed in subjects carrying non-O blood groups as compared to carriers of O blood group.Our data confirmed that ABO blood group is an important risk factor for increased procoagulant factors in plasma, as FVIII and VWF. Admitting the possible role of kidneys in ADAMTS13 synthesis or on its metabolism, HD patients were not able to increase ADAMTS13 levels in order to compensate the increase of VWF levels mediated by ABO blood groups. Considering that non-O blood groups constitute a risk factor for thrombosis, it is reasonable to admit that A, B and AB HD patients need a careful and continuous follow-up in order to minimize thrombotic events.

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.