The effect of the plasminogen activator inhibitor-1 4G/5G polymorphism on the thrombotic risk

Inherited Disorders of the Fibrinolytic Pathway: Pathogenic Phenotypes and Diagnostic Considerations of Extremely Rare Disorders

Fibrinolysis is initiated by the activation of plasminogen to plasmin via tissue-plasminogen activator (tPA) and urokinase-plasminogen activator (uPA); plasmin then converts fibrin to fibrin degradation products (FDPs). The antifibrinolytics counterbalancing this system include plasminogen activator inhibitor-1 (PAI-1), which inhibits tPA and uPA, α-2 antiplasmin (α2AP), which inhibits plasmin, and thrombin activatable fibrinolysis inhibitor, which inhibits the conversion of fibrin to FDP. Inherited disorders of the fibrinolytic pathway are rare and primarily have hemorrhagic phenotypes in humans: PAI-1 deficiency, α2AP deficiency, and Quebec platelet disorder. Patients with these disorders are usually treated for bleeds or receive prophylaxis to prevent bleeds in the surgical setting, with pharmacological antifibrinolytics such as aminocaproic acid and tranexamic acid. Disorders of the fibrinolytic pathway with fibrin deposition are extremely rare, mostly noted in patients with plasminogen deficiency, who have more recently benefited from advances in human plasma-derived plasminogen concentrates administered intravenously or locally. These disorders can be very difficult to diagnose using conventional or even specialized coagulation testing, as testing can be nonspecific or have low sensitivity. Testing of the corresponding protein's activity and antigen (where applicable) can be obtained in specialized centres, and routine laboratory measures are not diagnostic. Genetic testing of the pathogenic mutations is recommended in patients with a high suspicion of an inherited disorder of the fibrinolytic pathway.

The Multifaceted Complexity of Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS): A Case Report Highlighting Atypical Gastrointestinal Manifestations

BACKGROUND

Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) is an autosomal dominant autoinflammatory disorder stemming from mutations in the TNFRSF1A gene affecting the tumor necrosis factor receptor (TNFR)-1. These mutations lead to dysregulated inflammatory responses, primarily mediated by augmented interleukin (IL)-1β release.

CASE PRESENTATION

We present the case of a 29-year-old woman with a history of recurrent febrile episodes, abdominal pain, and joint manifestations, eventually diagnosed with TRAPS following genetic testing revealing a heterozygous R92Q mutation in TNFRSF1A. Further genetic examinations unveiled additional clinically significant mutations, complicating the clinical picture. Our patient exhibited delayed colonic transit time and right colonic amyloidosis, a rare complication. Surgical intervention was required for overwhelming intestinal obstruction, revealing mucosal atrophy and dense lymphocytic infiltrates on histological examination.

DISCUSSION

Gastrointestinal involvement in TRAPS is common but can present diagnostic challenges. Following colon resection, histological examination revealed amyloid deposition, underscoring the importance of a comprehensive evaluation of these patients. Isolated colic amyloidosis has significant diagnostic and prognostic implications, warranting cautious monitoring and tailored management strategies. Treatment of TRAPS typically involves anti-inflammatory agents such as IL-1 inhibitors, with our patient experiencing clinical improvement on anakinra and canakinumab.

CONCLUSION

This case report emphasizes the diverse manifestations of TRAPS and the importance of recognizing gastrointestinal complications, particularly isolated colic amyloidosis. Comprehensive evaluation, including histological examination, is crucial for identifying atypical disease presentations and guiding management decisions. Continued research is needed to elucidate the underlying mechanisms and optimize treatment strategies for TRAPS and its associated complications.

Association of single nucleotide polymorphisms (4G/5G) of plasminogen activator inhibitor-1 and the risk factors for placenta-related obstetric complications

BACKGROUND

Placenta-related obstetric complications (PROCs) such as miscarriage, fetal growth restriction, preeclampsia, and preterm birth are the major causes of maternal and fetal morbidity and mortality. The objective of this study was to search the relevance of plasminogen activator inhibitor-1 (PAI-1) polymorphisms and co-morbidities and the risk factors for PROCs such as miscarriage, fetal growth restriction, preeclampsia, and preterm birth.

METHOD

This retrospective study analyzed the PAI-1 genotype in a cohort of 268 multiparous women with poor obstetric history. Poor obstetric history was defined as the presence of at least one of the PROCs and/or poor gestational outcomes at the previous pregnancy/pregnancies.

RESULTS

5G allele frequency was higher than the 4G allele frequency in the cohort (0.767 vs. 0.233). The frequencies of having at least one risk factor are relatively similar among the different PAI-1 genotypes ( P  > 0.05). However, the presence of MTHFR polymorphisms (homozygous and compound heterozygous forms of C677T and A1298G) and hereditary thrombophilia (Factor V Leiden and prothrombin G20210A gene mutations, and FXIII deficiency) were found to be associated with PAI 4G/4G ( P  = 0.048) and 5G/5G ( P  = 0.022) genotypes, respectively. Significant differences were not observed in other risk factors and co-morbidities such as autoimmune disorders, chronic inflammatory diseases, history of venous thromboembolism, carbohydrate metabolism disorders, hyperlipidemia, cardiovascular and cerebrovascular diseases depending on PAI-1 genotypes ( P  > 0.05).

CONCLUSION

MTHFR polymorphisms were found to be associated with PAI 4G/4G genotype, while 5G/5G genotype was observed more frequently in hereditary thrombophilia cases.

Fibrinolysis Shutdown and Hypofibrinolysis Are Not Synonymous Terms: The Clinical Significance of Differentiating Low Fibrinolytic States

Low fibrinolytic activity has been associated with pathologic thrombosis and multiple-organ failure. Low fibrinolytic activity has two commonly associated terms, hypofibrinolysis and fibrinolysis shutdown. Hypofibrinolysis is a chronic state of lack of ability to generate an appropriate fibrinolytic response when anticipated. Fibrinolysis shutdown is the shutdown of fibrinolysis after systemic activation of the fibrinolytic system. There has been interchanging of these terms to describe critically ill patients in multiple settings. This is problematic in understanding the pathophysiology of disease processes related to these conditions. There is also a lack of research on the cellular mediators of these processes. The purpose of this article is to review the on and off mechanisms of fibrinolysis in the context of low fibrinolytic states to define the importance in differentiating hypofibrinolysis from fibrinolysis shutdown. In many clinical scenarios, the etiology of a low fibrinolytic state cannot be determined due to ambiguity if a preceding fibrinolytic activation event occurred. In this scenario, the term "low fibrinolytic activity" or "fibrinolysis resistance" is a more appropriate descriptor, rather than using assumptive of hypofibrinolysis and fibrinolysis shutdown, particularly in the acute setting of infection, injury, and surgery.

Highlights on Genetic Polymorphism Associated with Thromboembolic Risk; Implications in Ophthalmic and Autoimmune Disorders—A Review

The present paper explores genetic polymorphism and its association with thromboembolic retinal venous disorders, such as central/hemi-retinal vein occlusion, as well as possible correlations with other ocular findings, such as closed angle glaucoma, but also with autoimmune general disorders. In this review, we are highlighting the importance of establishing a correspondence between all of the above, since they all have complex etiopathogeneses; sometimes, when all coexist together, they could generate effects that may be very difficult to manage. There are studies supporting that genetic polymorphism, such as the variant MTHFR A1298C, may increase the risk for developing glaucoma, especially in the heterozygote model. Being aware of all these aspects may prove to be useful in patients with several associated diseases, as a combined effort between several medical specialties may prove to the benefit of these patients. Our review, completed with an exemplifying clinical case, shows that it is necessary to raise awareness of all aspects of a complex medical situation, including the genetic one, of a patient being at risk for thromboembolic episodes, for preventing them or managing them promptly and properly in the future.

Plasminogen activator inhibitor 1 is not a major causative factor for exacerbation in a mouse model of SARS-CoV-2 infection

Coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a global pandemic. Although several vaccines targeting SARS-CoV-2 spike proteins protect against COVID-19 infection, mutations affecting virus transmissibility and immune evasion potential have reduced their efficacy, leading to the need for a more efficient strategy. Available clinical evidence regarding COVID-19 suggests that endothelial dysfunction with thrombosis is a central pathogenesis of progression to systemic disease, in which overexpression of plasminogen activator inhibitor-1 (PAI-1) may be important. Here we developed a novel peptide vaccine against PAI-1 and evaluated its effect on lipopolysaccharide (LPS)-induced sepsis and SARS-CoV-2 infection in mice. Administration of LPS and mouse-adapted SARS-CoV-2 increased serum PAI-1 levels, although the latter showed smaller levels. In an LPS-induced sepsis model, mice immunized with PAI-1 vaccine showed reduced organ damage and microvascular thrombosis and improved survival compared with vehicle-treated mice. In plasma clot lysis assays, vaccination-induced serum IgG antibodies were fibrinolytic. However, in a SARS-CoV-2 infection model, survival and symptom severity (i.e., body weight reduction) did not differ between vaccine- and vehicle-treated groups. These results indicate that although PAI-1 may promote the severity of sepsis by increasing thrombus formation, it might not be a major contributor to COVID-19 exacerbation.

A Comprehensive Review of Risk Factors for Venous Thromboembolism: From Epidemiology to Pathophysiology

Venous thromboembolism (VTE) is the third most common cause of death worldwide. The incidence of VTE varies according to different countries, ranging from 1-2 per 1000 person-years in Western Countries, while it is lower in Eastern Countries (<1 per 1000 person-years). Many risk factors have been identified in patients developing VTE, but the relative contribution of each risk factor to thrombotic risk, as well as pathogenetic mechanisms, have not been fully described. Herewith, we provide a comprehensive review of the most common risk factors for VTE, including male sex, diabetes, obesity, smoking, Factor V Leiden, Prothrombin G20210A Gene Mutation, Plasminogen Activator Inhibitor-1, oral contraceptives and hormonal replacement, long-haul flight, residual venous thrombosis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, trauma and fractures, pregnancy, immobilization, antiphospholipid syndrome, surgery and cancer. Regarding the latter, the incidence of VTE seems highest in pancreatic, liver and non-small cells lung cancer (>70 per 1000 person-years) and lowest in breast, melanoma and prostate cancer (<20 per 1000 person-years). In this comprehensive review, we summarized the prevalence of different risk factors for VTE and the potential molecular mechanisms/pathogenetic mediators leading to VTE.

Septic Superior Ophthalmic Vein Thrombosis in a Prothrombotic Adolescent Patient

A 14-year-old boy presented to the emergency room with 5 days of fever and periorbital edema and erythema refractory to 4 days of augmentin and clindamycin. Examination revealed normal visual acuity, mild left periorbital edema and erythema, and a (-)1 supraduction deficit, concerning for orbital cellulitis. CT imaging revealed pansinusitis, orbital cellulitis with subtle orbital fat stranding, and a dilated superior ophthalmic vein with concern for thrombosis. This was confirmed on subsequent magnetic resonance venography. He was treated with intravenous antibiotics and enoxaparin with significant improvement in 24 hours. Standard hypercoagulable workup revealed positive lupus anticoagulant and cardiolipin of unclear significance; on genetic sequencing, he was found to have a homozygous mutation of the 4G variant of plasminogen activator inhibitor-1. Plasminogen activator inhibitor-1 homozygosity is a rare predisposing hypercoagulable state. This case highlights the importance of hematologic and genetic studies in adolescent patients with superior ophthalmic vein thrombosis, particularly those with mild presentation.

Endothelial nitric oxide synthase polymorphism and venous thromboembolism: A meta-analysis of 9 studies involving 3993 subjects

BACKGROUND

Endothelial nitric oxide synthase (eNOS) polymorphism may influence the risk of venous thromboembolism (VTE). However, data from published studies with low statistical power are inconclusive. The present meta-analysis aimed to assess the relationship between eNOS polymorphism and the risk of VTE.

METHOD

Case-control studies evaluating the association between the eNOS polymorphism and VTE were searched in PubMed, Embase, Web of Science, Google Scholar, Wanfang, Chinese National Knowledge Infrastructure (CNKI), the Chongqing VIP Chinese Science and Technology Periodical Database (VIP), and Chinese Biomedical Literature Database (CBM).

RESULTS

A total of 1588 cases and 2405 controls from 9 studies were included in the analysis. The results showed that eNOS G894T polymorphism was related to VTE susceptibility and the difference was statistically significant [T vs G: OR = 1.41, 95% CI (1.13, 1.75), P = 0.002; TT + GG vs TG: OR = 0.71, 95% CI (0.60, 0.84), P = 0.000; TT + TG vs GG: OR = 1.45, 95% CI (1.23, 1.70), P = 0.000]. Additionally, eNOS Intron 4 VNTR polymorphism was related to VTE susceptibility and the difference was statistically significant [4b4b vs 4a4a + 4a4b: OR = 2.77, 95% CI (1.01, 7.61), P = 0.048].

CONCLUSION

ENOS G894T and eNOS Intron 4 VNTR polymorphisms were associated with VTE susceptibility, especially in Asian populations. However, multicenter studies with larger samples should be conducted to further clarify this association and verify our findings.

Relationship between thrombomodulin gene polymorphism and susceptibility to venous thromboembolism: A protocol for systematic review and meta-analysis

BACKGROUND

Previous studies displayed that thrombomodulin gene polymorphisms are closely associated with venous thromboembolism (VTE), while the results are inconsistent. Therefore, we conducted a meta-analysis to accurately determine the association between thrombomodulin gene polymorphism and the risk of VTE.

METHODS

Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, the Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, EmBase, and Web of Science databases were searched, and the time to build the database was set until January 2021. The association between thrombomodulin gene polymorphism and the risk of VTE was evaluated. Meta-analysis was performed with STATA 16.0 software, and the odds ratio and its 95% confidence interval were applied to estimate the relationship between thrombomodulin gene polym'orphism and the risk of VTE.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This meta-analysis will summarize the relationship between thrombomodulin genepolymorphism and VTE risk.

ETHICS AND DISSEMINATION

Ethical approval was not required for this study. The systematic review will be published in a peer-reviewed journal, presented at conferences, and shared on social media platforms. This review would be disseminated in a peer-reviewed journal or conference presentations.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/UEHJP.

Bivalirudin and Alteplase for Pulmonary Embolism Requiring Veno-Arterial Extracorporeal Membrane Oxygenation in an Adolescent

Saddle pulmonary embolism (PE) remains a challenge to diagnose and manage in pediatric patients. Current literature encourages early consideration of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in high-risk PE patients with impending right ventricular failure. We present a 17-year-old patient who was admitted to a pediatric cardiac intensive care unit with saddle PE requiring emergent VA-ECMO support because of cardiovascular collapse. Despite anticoagulation with bivalirudin and receiving systemic thrombolysis with alteplase, the clot burden was persistent with minimal improvement in right ventricular function. We proceeded to catheter thrombolysis while on VA-ECMO. This ultimately led to a successful resolution of the PE and allowed for weaning off VA-ECMO. PE is rare in children compared with adults, and pediatricians may be unaware of therapies becoming increasingly used in adults such as the use of VA-ECMO, with systemic and local thrombolysis. The concurrent use of a direct thrombin inhibitor for ECMO anticoagulation alongside the thrombolysis is a novel combination in this condition and age-group.

Association between the 4G/5G polymorphism of plasminogen activator inhibitor-1 (PAI-1) gene and sudden sensorineural hearing loss in Caucasian population: a meta-analysis

PURPOSE

To clarify the association between the 4G/5G polymorphism of plasminogen activator inhibitor-1 (PAI-1) and sudden sensorineural hearing loss (SSNHL).

METHODS

A systematic literature search of related studies up to August 30, 2019 in the PubMed and Embase databases was performed, and the results were displayed by odds ratios (ORs), and their 95% confidence intervals (CIs) were assessed using the STATA12.0 software using an allele model and a recessive model.

RESULTS

Three eligible studies covering 519 subjects (241 cases, 278 controls) were identified. No statistically significant association was detected between the 4G/5G polymorphism and SSNHL in any model (allele model: 5G vs. 4G, OR = 0.952, 95% CI = 0.765-1.185, P = 0.662; recessive model: 5G/5G vs. 4G/5G + 4G/4G, OR = 0.841, 95% CI = 0.415-1.704, P = 0.631).

CONCLUSIONS

There is no statistically significant association between the 4G/5G polymorphism of PAI-1 gene and SSNHL in the Caucasian population, and well-designed studies covering more patients and institutions should be conducted.

Effects of Long-term Thrombin Inhibition (Dabigatran Etexilate) on Spontaneous Thrombolytic Activity during the Progression of Atherosclerosis in ApoE-/--LDLR-/- Double-Knockout Mice

Background and Objectives

Atherosclerosis is characterized by a hypercoagulable state, during which coagulation and fibrinolytic factors are activated simultaneously. However, details regarding the thrombolytic pathway in this context remain unknown. Here we investigated how direct long-term inhibition of thrombin influenced spontaneous thrombolytic activity during atherosclerotic progression in apolipoprotein E (ApoE)^–/^––low density lipoprotein receptor (LDLR)^–/^– double-knockout mice.

Methods

All mice received either standard chow (placebo group) or dabigatran-containing chow for 22 weeks, after which we evaluated them. The amount of atherosclerosis was estimated as the ratio of the atherosclerotic area to the total aortic intimal area. In addition, we used immunohistochemistry to analyze the expression of tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), thrombin activatable fibrinolysis inhibitor (TAFI), and endothelial nitric oxide synthase (eNOS) in atherosclerotic regions. To evaluate thrombolysis, we used a He–Ne laser to induce thrombosis in vessels of the cremaster muscle and then measured the thrombus volume over time.

Results

The atherosclerotic area was smaller and thrombolytic activity greater in the dabigatran-treated group than in the placebo group. Furthermore, according to the thrombolysis model, spontaneous thrombolytic activity was increased in the dabigatran-treated mice compared with the placebo mice. In support of these results, immunohistochemistry demonstrated decreased expression of PAI-1 and TAFI but increased expression of eNOS in the dabigatran group compared with the placebo group. However, t-PA expression did not differ between groups.

Conclusions

Direct long-term inhibition by dabigatran etexilate of thrombin led to an increase in spontaneous thrombolytic activity decreasing the expression of PAI-1 and TAFI.

Immunohistochemical expression of plasminogen activator inhibitor-1 in subcutaneous versus omental adipose tissue in patients after elective abdominal surgery

Plasminogen activator inhibitor-1 (PAI-1) is a biomarker of thrombosis. Adipose and vascular tissues are among the major sources of PAI-1 production. Previous studies indicated that fat deposits mediate increased cardiovascular risk among obese individuals. We investigated the immunohistochemical (IHC) expression of PAI-1 in adipose and vascular tissues from the omentum and the subcutaneous tissue. The pathology samples were selected from 37 random patients who underwent elective abdominal surgery between 2008-2009. PAI-1 expression was semi-quantitatively scored and compared between the groups. Significant differences were noted in the IHC expression of PAI-1 between the omental and the subcutaneous adipose tissues (1.1 ± 0.8 versus 0.8 ± 0.6, respectively (p=0.05)). Adipose tissue displayed higher IHC expression of PAI-1 compared to vascular wall tissue in both omentum and subcutaneous sections (1.1 ± 0.8 versus 0.5 ± 0.9 (p=0.004), and 0.8 ± 0.6 versus 0.4 ± 0.6 (p=0.003), respectively). In conclusion, our study compared PAI-1 expression in the omentum versus the subcutaneous tissue and adipose versus vascular tissues. IHC expression of PAI-1 level was significantly higher in the omental adipose tissue compared to the subcutaneous adipose tissue. Adipose tissue displayed significantly higher PAI-1 expression than vascular tissue. The study elucidates the biological differences of adipose and vascular tissue from subcutaneous versus omental sections.

Soy isoflavones reduce asthma exacerbation in asthmatic patients with high PAI-1-producing genotypes

BACKGROUND

The 4G4G genotype of plasminogen activator inhibitor 1 (PAI-1) is associated with increased plasma PAI-1 levels and poor asthma control. Previous studies suggest that soy isoflavones can reduce PAI-1 levels.

OBJECTIVE

We sought to investigate PAI-1 genotype-specific differences of the soy isoflavone response in asthma outcomes.

METHODS

A PAI-1 functional polymorphism (rs1799768, 4G5G) was characterized in subjects with poorly controlled asthma enrolled in a randomized clinical trial of soy isoflavones (n = 265). Genotype-specific treatment responses on asthma outcomes were compared between soy isoflavones and placebo. Normal human bronchial epithelial cells were cultured with or without TGF-β1, genistein, or both, and PAI-1 levels were measured.

RESULTS

The 4G4G/4G5G genotype was associated with a greater risk for allergy-related worsened asthma symptoms and eczema at baseline compared with the 5G5G genotype. There was a significant interaction between the genotype and soy isoflavone intervention on oral corticosteroid use for asthma exacerbation (P = .005). In a subgroup analysis soy isoflavones significantly reduced the use of oral corticosteroids (number of events/person-year) by 4-fold compared with placebo in the 4G4G/4G5G genotype (0.2 vs 0.8; relative risk, 0.28; P < .001) but not in the 5G5G genotype. Soy isoflavones reduced plasma PAI-1 levels compared with placebo. Genistein treatment reduced TGF-β1-induced PAI-1 production in normal human bronchial epithelial cells.

CONCLUSIONS

This study demonstrates that soy isoflavone treatment provides a significant benefit in reducing the number of severe asthma exacerbations in asthmatic patients with the high PAI-1-producing genotype. PAI-1 polymorphisms can be used as a genetic biomarker for soy isoflavone-responsive patients with asthma.

Rare thrombophilic conditions

Thrombophilia, either acquired or inherited, can be defined as a predisposition to developing thromboembolic complications. Since the discovery of antithrombin deficiency in the 1965, many other conditions have been described so far, which have then allowed to currently detect an inherited or acquired predisposition in approximately 60-70% of patients with thromboembolic disorders. These prothrombotic risk factors mainly include qualitative or quantitative defects of endogenous coagulation factor inhibitors, increased concentration or function of clotting proteins, defects in the fibrinolytic system, impaired platelet function, and hyperhomocysteinemia. In this review article, we aim to provide an overview on epidemiologic, clinic and laboratory aspects of both acquired and inherited rare thrombophilic risk factors, especially including dysfibrinogenemia, heparin cofactor II, thrombomodulin, lipoprotein(a), sticky platelet syndrome, plasminogen activator inhibitor-1 apolipoprotein E, tissue factor pathway inhibitor, paroxysmal nocturnal haemoglobinuria and heparin-induced thrombocytopenia.

Can components of the plasminogen activation system predict the outcome of kidney transplants?

Proteolytic and antiproteolytic enzymes play a critical role in the physiology and pathology of different stages of human life. One of the important members of the proteolytic family is the plasminogen activation system (PAS), which includes several elements crucial for this review: the 50 kDa glycoprotein plasminogen activator inhibitor 1 (PAI-1) that inhibits tissue-type (tPA) and urokinase-type plasminogen activator (uPA). These two convert plasminogen into its active form named plasmin that can lyse a broad spectrum of proteins. Urokinase receptor (uPAR) is the binding site of uPA. This glycoprotein on the cell surface facilitates urokinase activation of plasminogen, creating high proteolytic activity close to the cell surface. PAS activities have been reported to predict the outcome of kidney transplants. However, reports on expression of PAS in kidney transplants seem to be controversial. On the one hand there are reports that impaired proteolytic activity leads to induction of chronic allograft nephropathy, while on the other hand treatment with uPA and tPA can restore function of acute renal transplants. In this comprehensive review we describe the complexity of the PAS as well as biological effects of the PAS on renal allografts, and provide a possible explanation of the reported controversy.

Local Production of Soluble Urokinase Plasminogen Activator Receptor and Plasminogen Activator Inhibitor-1 in the Coronary Circulation Is Associated With Coronary Endothelial Dysfunction in Humans

Background Soluble urokinase plasminogen activator receptor (su PAR ) is a proinflammatory biomarker associated with immune activation and fibrinolysis inhibition. Plasminogen activator inhibitor ( PAI -1) is associated with excessive fibrin accumulation, thrombus formation, and atherosclerosis. The relationship between cross-coronary su PAR and PAI -1 production and endothelial dysfunction remains unknown. Methods and Results Seventy-nine patients (age 53±10 years, 75% women) with angina and normal coronary arteries or mild coronary artery disease (<40% stenosis) on angiogram underwent acetylcholine assessment of epicardial endothelial dysfunction (mid-left anterior descending coronary artery diameter decrease >20% after acetylcholine) and mircovascular endothelial dysfunction (coronary blood flow change <50% after acetylcholine). Simultaneous left main and coronary sinus su PAR and PAI -1 levels were measured in each patient before acetylcholine administration, and cross-coronary su PAR and PAI -1 production rates were calculated. Patients' characteristics, except for age (51±10 versus 57±9, P=0.02), and resting coronary hemodynamics were not significantly different between patients with (26%) versus without (74%) epicardial endothelial dysfunction. Patients' characteristics and resting coronary hemodynamics were not significantly different between those with (62%) and those without (38%) mircovascular endothelial dysfunction. Patients with mircovascular endothelial dysfunction demonstrated local coronary su PAR production versus su PAR extraction in patients with normal microvascular function (median 25.8 [interquartile range 121.6, -23.7] versus -12.7 [52.0, -74.8] ng/min, P=0.03). Patients with epicardial endothelial dysfunction had higher median coronary PAI -1 production rates compared with those with normal epicardial endothelial function (1224.7 [12 940.7, -1915.4] versus -187.4 [4444.7, -4535.8] ng/min, P=0.03). Conclusions su PAR is released in coronary circulation of patients with mircovascular endothelial dysfunction and extracted in those with normal microvascular function. Cross-coronary PAI -1 release is higher in humans with epicardial endothelial dysfunction.

Re: "Plasminogen Activator Inhibitor-1 and Pericardial Fat in Individuals with Type 2 Diabetes Mellitus" by Bayomi et al. (Metab Syndr Relat Disord 2017;15:269-275)

Plasminogen activator inhibitor-1 (PAI-1) is a member of the serine protease inhibitor (serpin) superfamily, which inactivates tissue plasminogen activator (tPA); therefore, increased level of PAI-1 antigen counteracts the anticoagulant effect of tPA and facilitates the fibrin clot formation. Plasma PAI-1 antigen and activity levels are associated with increased body mass index and with features of the insulin resistance syndrome like obesity and diabetes. Visceral adipose tissue produces more PAI-1 than subcutaneous adipose tissue: This increased production of PAI-1 from the visceral adipose tissue is one important link between visceral obesity and cardiovascular disease. Besides visceral adipose tissue, there is mounting evidence that epicardial adipose tissue may be an important source of PAI-1, especially in patients with type 2 diabetes.

Vehicle-dependent Effects of Sphingosine 1-phosphate on Plasminogen Activator Inhibitor-1 Expression

Aim: Sphingosine 1-phosphate (S1P) has been suggested to be a positive regulator of plasminogen activator inhibitor 1 (PAI-1) in adipocytes, while some studies are not consistent with this prothrombotic property of S1P. Since S1P is bound to apolipoprotein M (apoM) on HDL or to albumin in plasma, we compared the properties of these two forms on the PAI-1 induction.

Methods: We investigated the associations of S1P, apoM, and PAI-1 concentrations in the plasma of normal coronary artery (NCA), stable angina pectoris (SAP), and acute coronary syndrome (ACS) subjects (n = 32, 71, and 38, respectively). Then, we compared the effects of S1P with various vehicles on the PAI-1 expression in 3T3L1 adipocytes. We also investigated the modulation of the PAI-1 levels in mice infected with adenovirus coding apoM.

Results: Among ACS subjects, the PAI-1 level was positively correlated with the S1P level, but not the apoM level. In adipocytes, S1P bound to an apoM-rich vehicle induced PAI-1 expression to a lesser extent than the control vehicle, while S1P bound to an apoM-depleted vehicle induced PAI-1 expression to a greater extent than the control vehicle in 3T3L1 adipocytes. Additionally, apoM overexpression in mice failed to modulate the plasma PAI-1 level and the adipose PAI-1 expression level. S1P bound to albumin increased PAI-1 expression through the S1P receptor 2-Rho/ROCK-NFκB pathway.

Conclusion: S1P bound to albumin, but not to apoM, induces PAI-1 expression in adipocytes, indicating that S1P can exert different properties on the pathogenesis of vascular diseases, depending on its vehicle.

Link between plasminogen activator inhibitor-1 and cardiovascular risk in chronic hepatitis C after viral clearance

The pathophysiological implications of plasminogen activator inhibitor-1 (PAI-1) in HCV infection remain obscure. This prospective study evaluated 669 HCV patients, of whom 536 had completed a course of anti-HCV therapy and had pre-, peri- and post-therapy measurements of various profiles, including PAI-1 levels. Multivariate analysis demonstrated, before anti-HCV-therapy, platelet count and PAI-1-rs1799889 genotype were associated with PAI-1 levels. Among patients with a sustained virological response (SVR, n = 445), platelet count was associated with PAI-1 level at 24 weeks post-therapy. GEE analysis showed that PAI-1-rs-1799889 and interferon-λ3-rs12979860 genotypes affected PAI-1 levels early and late in therapy, respectively. At 24 weeks post-therapy, higher lipid, brain natriuretic peptide, homocysteine and PAI-1 levels and PAI-1 activity were noted only in SVR patients compared with pre-therapy levels. Within 24 weeks post-therapy, 2.2% of the SVR (mean age: 57.8 yr; 8 smoking males; the 2 females had pre-therapy hypercholesteremia or cardiovascular family history of disease) and 0% of the non-SVR patients experienced a new cardiovascular event. Platelet counts consistently correlated with PAI-1 levels regardless of HCV infection. PAI-1-rs-1799889 and interferon-λ3-rs12979860 genotypes mainly affected PAI-1 levels longitudinally. Within 24 weeks post-anti-HCV therapy, the SVR patients showed increasing PAI-1 levels with accelerating cardiovascular risk, especially the vulnerable cases.

[Role of polymorphic markers for the genes of hemostasis and platelet receptors in liver fibrosis progression in patients with chronic hepatitis C]

AIM

to estimate the clinical and prognostic value of the carriage of different allele variants of the gene polymorphisms of the coagulation system and platelet receptors in the progression of liver fibrosis (LF) in patient with chronic hepatitis C (CHC).

SUBJECTS AND METHODS

The investigation enrolled 177 patients with CHC and liver cirrhosis at its outcome who were divided into 2 groups according to the rate of LF progression: 1) 89 patients with rapid (rapid fibrosis) and 2) 88 patients with slow (slow fibrosis) progression. The polymorphism of the study genes was studied using a real-time polymerase chain reaction and a melting curve analysis.

RESULTS

In CHC patients, the FV 1691G/A genotype was more often in the rapid progressors than that in the slow progressors (10.11% vs 1.14%; p=0.011). The A allele of the 1691 G/A FV gene was more common in the rapid fibrosis group than that in the slow fibrosis group (1.7% vs 5.56%, odd ratio 9.787; p=0.139). In our investigation, the polymorphic marker GA in the FII 20210 G/A gene, as well as the 4G allele (5G4G + 4G4G genotypes) and the 4G allele of PAI-I -675 5G/4G were more often seen in the rapid fibrosis group than that in the slow fibrosis group; the detection rate was only at the trend level (p=0.118, p=0.112, and p=0.117 respectively). There were no significant differences between the groups in the spread of variant genotypes and alleles of other study genes. Integral model construction by coding «profibrogenic» genotypes (FV 1691 G/A, FII 20210 G/A, PAI-I -675 5G/4G) showed that the fibrosis progression rate expressed as fibrosis units annually also increased with higher total scores (p=0.039), indicating the combined effect of these genes.

CONCLUSION

The carriage of mutant genotypes of FV 1691 G/A, FII 20210 G/A, and PAI-I -675 5G/4G genes is a prognostic factor for rapid CHC progression.

Atherosclerotic and thrombotic genetic and environmental determinants in Egyptian coronary artery disease patients: a pilot study

BACKGROUND

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Multiple genetic variants in combination with various environmental risk factors have been implicated. This study aimed to investigate the association of twelve thrombotic and atherosclerotic gene variants in combination with other environmental risk factors with CAD risk in a preliminary sample of Egyptian CAD patients.

METHODS

Twenty three consecutive CAD patients undergoing diagnostic coronary angiography and 34 unrelated controls, have been enrolled in the study. Genotyping was based on polymerase chain reaction and reverse multiplex hybridization. Five genetic association models were tested. Data distribution and variance homogeneity have been checked by Shapiro-Wilk test and Levene test, respectively; then the appropriate comparison test was applied. Spearman's rank correlation coefficient was used for correlation analysis and logistic regression has been performed to adjust for significant risk factors. Clustering the study participants according to gene-gene and gene-environment interaction has been done by Detrended Correspondence Analysis (DCA).

RESULTS

The univariate analysis indicated that the five variants; rs1800595 (FVR2; factor 5), rs1801133 (MTHFR; 5,10-methylenetetrahydrofolate reductase), rs5918 (HPA-1; human platelet antigen 1), rs1799752 (ACE; angiotensin-converting enzyme), and rs7412 and rs429358 (ApoE; apolipoprotein E) were significantly associated with CAD susceptibility under different genetic models. Multivariate analysis revealed clustering of the study population into three patient groups (P) and one control group. FVR2 was the most variant associated with CAD patients, combined with the factor V Leiden (FVL) variant in P1 cluster and with both ACE and MTHFR 667C > T in P2. Whereas, P3 was mostly affected by both MTHFR 667C > T and FXIII (factor 13) V89L mutations. When combined with traditional risk factors, P1 was mostly affected by dyslipidemia, smoking and hypertension, while P2 was mostly affected by their fasting blood sugar levels and ApoE variant.

CONCLUSIONS

Taken together, these preliminary results could have predictive value to be applied in refining a risk profile for our CAD patients, in order to implement early preventive interventions including specific antithrombotic therapy. Further large scale and follow-up studies are highly recommended to confirm the study findings.

PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q, and Prothrombin 20210A in Splanchnic Vein Thrombosis: Analysis of Individual Patient Data From Three Prospective Studies

BACKGROUND

There are no univocal opinions on the role of genetic thrombophilia on splanchnic vein thrombosis (SVT). We defined genetic thrombophilia the presence of one of these thrombophilic genetic factors (THRGFs): PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q, and prothrombin 20210A.

OBJECTIVES

To evaluate the frequencies of these THRGFs in SVT patients, we analyzed individual data of 482 Caucasian patients, recruited from 2000 to 2014 in three prospective studies. SVT was defined as the presence of thrombosis of portal (PVT), mesenteric (MVT), splenic (SPVT), cava (CT), and hepatic vein (Budd Chiari syndrome, BCS). Pre-hepatic SVT (pre-HSVT) was defined as PVT with or without MVT/SPVT, without BCS. Post-hepatic SVT (post-HSVT) was BCS with or without PVT/MVT/SPVT.

METHODS

We compared 350 patients with liver cirrhosis (LC), 47 hepatocellular carcinoma (HCC), 37 myeloproliferative neoplasm (MPN), 38 associated disease (AD), 10 without any associated disease (WAD), vs 150 healthy controls (HC); 437 patients showed pre-HSVT and 45 post-HSVT.

RESULTS

Thrombophilia was present in 294/482 (60.9%) patients: 189/350 LC (54.0%), 31/47 (66.0%) HCC, 29/39 (74.4%) MPN, 35/38 AD (92.1%), and 10/10 (100%) WAD, and 54/150 (36.0%) in HC. In the total group, we found 175 PAI-1 4G-4G, 130 MTHFR 677TT, 42V Leiden 506Q, and 27 prothrombin 20210A; 75 patients showed presence of >1 TRHGF; the more frequent association was PAI-1 4G-4G/MTHFR 677TT, in 36 patients. PAI-1 4G-4G and MTHFR 677TT were significantly more frequent in patients with SVT (P values <0.005), whereas V Leiden Q506 and prothrombin G20210A were not. PAI-1 4G-4G and MTHFR 677TT distributions deviated significantly from that expected from a population in Hardy-Weinberg equilibrium. Thrombophilia was significantly less frequent in patients with pre-HSVT (250/437, 57.2%) than in patients with post-HSVT (44/45, 97.8%).

CONCLUSIONS

Our study shows the significant prevalence of PAI-1 4G-4G and MTHFR 677TT in SVT, mainly in post-HSVT.

What causes intracerebral bleeding after thrombolysis for acute ischaemic stroke? Recent insights into mechanisms and potential biomarkers

The overall population benefit of intravascular recombinant tissue plasminogen activator (rtPA) on functional outcome in ischaemic stroke is clear, but there are some treated patients who are harmed by early symptomatic intracranial haemorrhage (ICH). Although several clinical and radiological factors increase the risk of rtPA-related ICH, none of the currently available risk prediction tools are yet useful for practical clinical decision-making, probably reflecting our limited understanding of the underlying mechanisms. Finding new methods to identify patients at highest risk of rtPA-related ICH, or new measures to limit risk, are urgent challenges in acute stroke therapy research. In this article, we focus on the potential underlying mechanisms of rtPA-related ICH, highlight promising candidate risk biomarkers and suggest future research directions.

The Effect of PAI-1 4G/5G Polymorphism and Clinical Factors on Coronary Artery Occlusion in Myocardial Infarction

Objective. Data on the impact of PAI-1-675 4G/5G genotype for fibrinolysis during myocardial infarction are inconsistent. The aim of our study was to evaluate the association of clinical and genetic (PAI-1-675 4G/5G polymorphism) factors with coronary artery occlusion in patients with myocardial infarction. Materials and Methods. PAI-1-675 4G/5G detection was achieved by using Sanger sequencing in a sample of patients hospitalized for stent implantation due to myocardial infarction. We categorized the patients into two groups: patients with coronary artery occlusion and patients without coronary artery occlusion according to angiographic evaluation. Results. We identified n = 122 (32.4%) 4G/4G, n = 186 (49.5%) 4G/5G, and n = 68 (18.1%) 5G/5G PAI-1 genotype carriers. Univariate and multivariate analysis showed that only the 4G/5G genotype was associated with coronary artery occlusion (OR: 1.656 and 95% CI: 1.009–2.718, p = 0.046). Conclusions. Our results showed that carriers of PAI-1 4G/5G genotype with myocardial infarction have increased odds of coronary artery occlusion more than 1.6 times in comparison to the carriers of homozygous genotypes.

The role of hypercoagulability in ischemic colitis

OBJECTIVE

The aim of this study is to evaluate the role of thrombophilia-hypercoagulability in ischemic colitis (IC).

MATERIAL AND METHODS

Thrombophilia and fibrinogen were evaluated in 56 cases of IC and 44 controls with known predisposing factors but no evidence of IC. Thrombophilic factors tested were: protein C (PC), protein S, antithrombin (AT), resistance to activated protein C (APCR), lupus anticoagulant (LA), factor V G1691A mutation (FV Leiden), prothrombin G20210A mutation, methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C mutations and plasminogen activator inhibitor-1 (PAI-1) gene 5G/4G and 4G/4G polymorphisms.

RESULTS

In IC group were recorded: i) low levels of PC and AT (p = 0.064 and p = 0.022, respectively); ii) low levels of APCR (normal: >2, p = 0.008); iii) high levels of fibrinogen (p = 0.0005); iv) higher number of homozygotes for MTHFR A1298C and C677T mutations (p = 0.061 and p = 0.525 (Pearson chi-square), respectively); v) greater prevalence of 5G/4G and 4G/4G polymorphisms (p = 0.031 (Pearson chi-square)) and vi) higher incidence of LA-positive individuals (p = 0.037, Fischer's exact test). Multivariate analysis was performed to determine the effects of prothrombotic factors in IC. 5G/4G polymorphism of PAI-1 gene (odds ratio (OR) 12.29; 95% confidence interval (CI) 2.26-67.00), APCR (OR 0.089; 95% CI 0.011-0.699) and fibrinogen (OR 1.013; 95% CI 1.003-1.023) were determined as predictors of IC.

CONCLUSIONS

This study suggests that hypercoagulability, hereditary or acquired, plays an essential role in the manifestation of IC.

Fibrinolysis and the control of blood coagulation

Fibrin plays an essential role in hemostasis as both the primary product of the coagulation cascade and the ultimate substrate for fibrinolysis. Fibrinolysis efficiency is greatly influenced by clot structure, fibrinogen isoforms and polymorphisms, the rate of thrombin generation, the reactivity of thrombus-associated cells such as platelets, and the overall biochemical environment. Regulation of the fibrinolytic system, like that of the coagulation cascade, is accomplished by a wide array of cofactors, receptors, and inhibitors. Fibrinolytic activity can be generated either on the surface of a fibrin-containing thrombus, or on cells that express profibrinolytic receptors. In a widening spectrum of clinical disorders, acquired and congenital defects in fibrinolysis contribute to disease morbidity, and new assays of global fibrinolysis now have potential predictive value in multiple clinical settings. Here, we summarize the basic elements of the fibrinolytic system, points of interaction with the coagulation pathway, and some recent clinical advances.

Functional stability of plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), and a major regulator of the fibrinolytic system. PAI-1 plays a pivotal role in acute thrombotic events such as deep vein thrombosis (DVT) and myocardial infarction (MI). The biological effects of PAI-1 extend far beyond thrombosis including its critical role in fibrotic disorders, atherosclerosis, renal and pulmonary fibrosis, type-2 diabetes, and cancer. The conversion of PAI-1 from the active to the latent conformation appears to be unique among serpins in that it occurs spontaneously at a relatively rapid rate. Latency transition is believed to represent a regulatory mechanism, reducing the risk of thrombosis from a prolonged antifibrinolytic action of PAI-1. Thus, relying solely on plasma concentrations of PAI-1 without assessing its function may be misleading in interpreting the role of PAI-1 in many complex diseases. Environmental conditions, interaction with other proteins, mutations, and glycosylation are the main factors that have a significant impact on the stability of the PAI-1 structure. This review provides an overview on the current knowledge on PAI-1 especially importance of PAI-1 level and stability and highlights the potential use of PAI-1 inhibitors for treating cardiovascular disease.

Association between the plasminogen activator inhibitor-1 4G/5G polymorphism and risk of venous thromboembolism: a meta-analysis

INTRODUCTION

The plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism was considered to be associated with risk of venous thromboembolism (VTE), while evidence remains inadequate. To provide a more accurate estimation of this relationship, we performed an updated meta-analysis of all eligible studies.

MATERIALS AND METHODS

A systematical search was performed in PubMed, EMBASE, Wanfang, China National Knowledge Infrastructure (CNKI) and Cqvip databases to identify relevant studies published before March 6(th) 2014. The odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the fixed/random-effects model using Review Manager 5.1 and STATA 12.0.

RESULTS

A total of 34 studies with 3561 cases and 5693 controls were analyzed. Overall, significant association between the PAI-1 4G/5G variant and VTE risk in total population (dominant model: OR=1.32, 95%CI: 1.13-1.54) was observed. And this variant was also related to the deep vein thrombosis risk (dominant model: OR=1.60, 95%CI: 1.24-2.06, P=0.0003). In the subgroup analyses on ethnicity, significant results were obtained in both Asians (dominant model: OR=2.08, 95%CI: 1.29-3.35, P=0.003) and Caucasians (dominant model: OR=1.31, 95%CI: 1.10-1.56, P=0.003). However, no significant association was found in patients with provoked VTE. In terms of subgroup analyses on co-existence of other thrombotic risk factors, the PAI-1 4G/5G polymorphism was significantly associated with VTE risk in patients with factor V Leiden mutation (dominant model: OR=1.72, 95%CI: 1.17-2.53), but not in patients with cancer or surgery.

CONCLUSION

Our findings demonstrate the role of PAI-1 4G/5G polymorphism being a risk candidate locus for VTE susceptibility, especially in patients with other genetic thrombophilic disorders.

Thrombophilic Mutations as Risk Factor for Retinal Vein Occlusion

Background:

Retinal vein occlusion (RVO) is the second most common retinal vein disease and an important cause of blindness and visual morbidity. Many conditions are associated with RVO but the real role of the thrombophilic mutations is still unclear.

Aim:

To evaluate the potential role of thrombophilic mutations in RVO.

Methods:

We have evaluated 113 patients with RVO and compared with 104 volunteer controls. The controls were all healthy blood donors without previous venous thromboembolism episode or arterial thromboembolism episode. All patients were tested for 5 gene variants (here all named as mutations): factor V ( FV) Leiden (G1691A), factor II ( FII; G20210A), 5,1-methylenetetra-hydrofolate reductase ( MTHFR; C677T), plasminogen activator inhibitor 1 ( PAI-1; 4G/5G), and angiotensin-converting enzyme ( ACE; Del/Ins). Statistical analysis were performed by the 2-tailed chi-square test.

Results:

Statistical test showed that TT homozygous patients of the MTHFR C677T mutation ( P = .017) and heterozygous GA patients of the FII G20210A mutation ( P = .018) were significantly higher than that in controls. For FV Leiden, even if the values were higher in patients than in controls, P value was not statistically significant. Conversely, for the ACE (Ins/Del) and PAI-1 (4G/5G) mutations, no difference was observed among genotypes of patients with RVO and control participants.

Conclusions:

In our study, the FII G20210A and the MTHFR C677T mutations resulted significantly higher in patients than in controls; in contrast, thrombophilic mutation of FV, ACE, and PAI-1 genes was not statistically correlated with RVO. In spite of having found an association between some thrombophilic mutations and RVO, more studies with a major number of patients are necessary to determine the final role of these gene variants.

The study of t-PA, u-PA and PAI-1 genes polymorphisms in patients with abdominal aortic aneurysm

The most important feature of abdominal aortic aneurysm (AAA) pathogenesis is an enzymatic degradation of elastic lamellae and extracellular matrix proteins particularly with participation of matrix metalloproteinases. Plasmin, which is responsible for the dissolution of fibrin in blood vessels, plays also a key role in the cascade for activation of the metalloproteinases. The purpose of this study was to evaluate the influence of selected polymorphisms in genes coding for tissue plasminogen activator (−7351 C/T polymorphism), urokinase-type plasminogen activator (1788 C/T polymorphism) and plasminogen activator inhibitor 1 (−675 4G/5G and −844 G/A polymorphism) on the susceptibility to AAA. We performed a case–control study of 153 polish patients hospitalized due to AAA and compared them with matched healthy control subjects. The polymorphisms were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments or through high-resolution melting analysis. In this study we have found lower frequency of wild-type GG genotype of the −844G/A PAI-1 polymorphism in cases than in controls, what may suggest the protective effect of this genotype for the risk of AAA development. None of the remaining polymorphisms tested were associated with AAA occurrence.

Thrombophilic Genetic Factors PAI-1, MTHFRC677T, V Leiden 506Q, and Prothrombin 20210A in Noncirrhotic Portal Vein Thrombosis and Budd-Chiari Syndrome in a Caucasian Population

Thrombophilic genetic factors PAI-1, MTHFRC677T, V Leiden 506Q, and Prothrombin 20210A were studied as risk factors in 235 Caucasian subjects: 85 patients with abdominal thrombosis (54 with portal vein thrombosis (PVT) and 31 with Budd-Chiari syndrome (BCS) without liver cirrhosis or hepatocellular carcinoma) and 150 blood bank donors. Seventy-five patients with PVT/BCS showed associated disease or particular clinical status (46 PVT/29 BCS): 37 myeloproliferative neoplasm (20 PVT/17 BCS), 12 abdominal surgery (10 PVT/2 BCS), 10 contraception or pregnancy (6 PVT/4 BCS), 7 abdominal acute disease (6 PVT/1 BCS), and 9 chronic disease (4 PVT/5 BCS); ten patients did not present any association (8 PVT/2 BCS). PAI-14G-4G, MTHFR677TT, and V Leiden 506Q were significantly frequent (OR 95% CI and χ² test with P value) in abdominal thrombosis; in these patients PAI-14G-4G and MTHFR677TT distributions deviated from that expected from a population in the Hardy-Weinberg equilibrium (PAI-1: χ² = 13.8, P < 0.001; MTHFR677: χ² = 7.1, P < 0.01), whereas the equilibrium was respected in healthy controls. V Leiden Q506 and Prothrombin 20210A were in the Hardy-Weinberg equilibrium both in patients with abdominal thrombosis and healthy controls. Our study shows an important role of PAI-14G-4G and MTHFR677TT in abdominal thrombosis without liver cirrhosis or hepatocellular carcinoma.

High prevalence of cerebral venous sinus thrombosis (CVST) as presentation of cystathionine beta-synthase deficiency in childhood: molecular and clinical findings of Turkish probands

Classical homocystinuria is the most commonly inherited disorder of sulfur metabolism, caused by the genetic alterations in human cystathionine beta-synthase (CBS) gene. In this study, we present comprehensive clinical findings and the genetic basis of homocystinuria in a cohort of Turkish patients. Excluding some CBS mutations, detailed genotype-phenotype correlation for different CBS mutations has not been established in literature. We aimed to make clinical subgroups according to main clinical symptoms and discussed these data together with mutational analysis results from our patients. Totally, 16 different mutations were identified; twelve of which had already been reported, and four are novel (p.N93Y, p.L251P, p.D281V and c.829-2A>T). The probands were classified into three major groups according to the clinical symptoms caused by these mutations. A psychomotor delay was the most common diagnostic symptom (n=12, 46.2% neurological presentation), followed by thromboembolic events (n=6, 23.1% vascular presentation) and lens ectopia, myopia or marfanoid features (n=5, 19.2% connective tissue presentation). Pyridoxine responsiveness was 7.7%; however, with partial responsive probands, the ratio was 53.9%. In addition, five thrombophilic nucleotide changes including MTHFR c.677 C>T and c.1298 A>C, Factor V c.1691 G>A, Factor II c.20210 G>A, and SERPINE1 4G/5G were investigated to assess their contributions to the clinical spectrum. We suggest that the effect of these polymorphisms on clinical phenotype of CBS is not very clear since the distribution of thrombophilic polymorphisms does not differ among specific groups. This study provides molecular findings of 26 Turkish probands with homocystinuria and discusses the clinical presentations and putative effects of the CBS mutations.

Elevated plasminogen activator inhibitor type-1 (PAI-1) as contributing factor in pathogenesis of hypercoagulable state in antiphospholipid syndrome

The aim of this study is to explore the role of plasminogen activator inhibitor type 1 (PAI-1) in primary and secondary antiphospholipid syndrome (APS). Thirty patients of APS (24 primary and 6 secondary) were recruited in the study who fulfilled the revised Sapporo criteria. Control groups comprised of age- and sex-matched 10 healthy volunteers and 10 patients each of systemic lupus erythematosus and rheumatoid arthritis without any antecedent thrombotic event and/or APS-related pregnancy morbidity. Serum samples were tested for PAI-1 antigen levels measured by quantitative ELISA. Positivity rate of PAI-1 in patients of primary, secondary as well as total APS patients was significantly higher in relation to age- and sex-matched healthy volunteers (p = 0.010, p = 0.003 and p < 0.001, respectively). Mean ± SEM levels of PAI-1 in primary and secondary as well as total APS patients were significantly higher (p = 0.006, p < 0.001 and p < 0.001) in relation to healthy controls. Correlation of PAI-1 levels (mean ± SEM) with clinical characteristics, that is, thrombosis and pregnancy morbidity, revealed significantly higher levels of PAI-1 (p < 0.001) in patients having thrombosis and APS-related pregnancy morbidity. Elevated PAI-1 level leading to impaired fibrinolysis plays a significant role in producing hypercoagulable state in primary and secondary APS.

Thrombophilic abnormalities in patients with or without pulmonary embolism following elective spinal surgery: a pilot study

BACKGROUND

Significance of the thrombophilic abnormalities in development of venous thromboembolism (VTE) has been studies with total hip arthroplasty and acute traumatic spinal cord injury. However, their role as risk factors for VTE in elective spinal surgery remains to be determined.

QUESTIONS/PURPOSES

To determine the role of thrombophilic abnormalities in the development of pulmonary embolism (PE) following elective spine surgery.

METHODS

Case and control groups were created in patients who had undergone elective spinal surgery for degenerative conditions. The PE group comprised 12 patients whose post-operative course was complicated by development of PE. The control group included 12 patients with an uneventful post-operative course. Demographic data including age, gender and surgical procedures were matched between the PE group and the control group. Both groups were evaluated for thrombophilic and hypofibrinolytic risk factors at 3 months post-operatively or later. Blood tests were performed to measure fasting serum homocysteine, antithrombin III, and protein C. Molecular genetic testing was conducted for detection of the plasminogen activator inhibitor-1 4G/4G, and prothrombin 3 UTR gene mutations.

RESULTS

Heterozygous mutation (G20201A) of prothrombin was detected in two patients (16.7%) in the PE group, whereas no such mutation was noted in the control group. Plasminogen activator inhibitor-1 4G/4G homozygous mutation was seen in three in the PE group and two in the control group. Of homocysteine, antithrombin III and protein C, only one patient in each group showed abnormal levels of homocysteine. In total, there half of the patients in the PE group had at least one thrombophilic abnormality, whereas three (25%) patients showed such abnormality in the control group.

CONCLUSION

These findings suggest the involvement of thrombophilic abnormalities, especially the heterozygous G20201A mutation, in the development of PE in patients undergoing elective spinal surgery.

Genetic markers of cardiovascular disease in rheumatoid arthritis

Cardiovascular (CV) disease is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). It is the result of an accelerated atherosclerotic process. Both RA and atherosclerosis are complex polygenic diseases. Besides traditional CV risk factors and chronic inflammation, a number of studies have confirmed the role of genetic factors in the development of the atherogenesis observed in RA. In this regard, besides a strong association between the HLA-DRB1∗04 shared epitope alleles and both endothelial dysfunction, an early step in the atherosclerotic process, and clinically evident CV disease, other polymorphisms belonging to genes implicated in inflammatory and metabolic pathways, located inside and outside the HLA region, such as the 308 variant (G > A, rs1800629) of the TNFA locus, the rs1801131 polymorphism (A > C; position + 1298) of the MTHFR locus, or a deletion of 32 base pairs on the CCR5 gene, seem to be associated with the risk of CV disease in patients with RA. Despite considerable effort to decipher the genetic basis of CV disease in RA, further studies are required to better establish the genetic influence in the increased risk of CV events observed in patients with RA.