Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0024141 (systemic lupus erythematosus)
44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antiphospholipid syndrome (APS) is characterized by clinical manifestations such as venous and arterial thrombosis, thrombocytopenia and/or recurrent pregnancy loss, as well as the persistent presence of laboratory markers of antiphospholipid (aPL) antibodies detected in laboratory assays. Though it is generally accepted that aPL antibodies, such as anticardiolipin (aCL), anti-beta2 glycoprotein I (anti-beta2GPI), and lupus anticoagulants (LA) contribute to the pathogenesis of APS, precise mechanism(s) are yet to be fully described. It is probable that aPL antibodies bind to a range of cellular targets (e.g., platelets, endothelial cells, and monocytes), leading to thrombosis and obstetric complications. There is now increasing evidence that alterations to the tissue factor (TF) pathway of blood coagulation contribute toward hypercoagulability in patients with aPL antibodies. This article reviews current evidence that suggests changes and/or interference to the major pathway of blood coagulation may represent a novel mechanism that contributes to the development of APS.
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PMID:Novel considerations in the pathogenesis of the antiphospholipid syndrome: involvement of the tissue factor pathway of blood coagulation. 1872 Mar 4

Fetal loss in patients with antiphospholipid antibodies (aPL) has been ascribed to thrombosis of placental vessels. However, we have shown that inflammation, specifically complement activation with generation of the anaphylotoxin C5a, is an essential mediator of fetal injury. We have analysed the role of tissue factor (TF) in a mouse model of aPL-induced pregnancy loss. TF is the major cellular activator of the coagulation cascade but also has cell signaling activity. Mice that received aPL-IgG showed strong TF staining throughout the decidua and on embryonic debris. This TF staining was not associated with either fibrin staining or thrombi in deciduas. The absence of fibrin deposition and thrombi suggests that TF-dependent activation of coagulation does not mediate aPL-induced pregnancy loss.We found that either blockade of TF with a monoclonal antibody in wild type mice or a genetic reduction of TF prevented aPL-induced inflammation and pregnancy loss indicated a pathogenic role for TF in aPL-induced pregnancy complications. In response to aPL-generated C5a, neutrophils express TF potentiating inflammation in the deciduas and leading to miscarriages. Importantly, we showed that TF in myeloid cells, but not fetal-derived cells (trophoblasts), was associated with fetal injury, suggesting that the site for pathologic TF expression is neutrophils. We found that TF expression in neutrophils contributes to respiratory burst and subsequent trophoblast injury and pregnancy loss induced by aPL. The identification of TF, acting as an important pro-inflammatory mediator in aPL-induced fetal injury, provides a new target for therapy to prevent pregnancy loss in the aPL syndrome.
Lupus 2008 Oct
PMID:Tissue factor in antiphospholipid antibody-induced pregnancy loss: a pro-inflammatory molecule. 1882 58

Antiphospholipid (aPL) antibodies are clinically important acquired risk factors for thrombosis and pregnancy loss and are thought to have a direct prothrombotic effect in vivo. Data suggest that a major mechanism by which aPL antibodies contribute to thrombophilia is the upregulation of tissue factor (TF) (CD142) on blood cells and vascular endothelium. TF is the physiological trigger of normal blood coagulation and thrombosis in many hypercoagulable conditions. This article reviews the physiology of TF, the molecular regulation of TF expression and the effects of aPL antibodies on intravascular TF regulation and expression. Inhibition of TF and the pathways by which aPL antibodies induce TF expression are potentially attractive therapeutic targets in the antiphospholipid syndrome.
Lupus 2008 Oct
PMID:Tissue factor in the antiphospholipid syndrome. 1882 61

Microparticles are submicron vesicles shed from plasma membranes in response to cell activation, injury, and/or apoptosis. The measurement of the phospholipid content (mainly phosphatidylserine; PSer) of microparticles and the detection of proteins specific for the cells from which they are derived has allowed their quantification and characterization. Microparticles of various cellular origin (platelets, leukocytes, endothelial cells) are found in the plasma of healthy subjects, and their amount increases under pathological conditions. Endothelial microparticles (EMP) not only constitute an emerging marker of endothelial dysfunction, but are also considered to play a major biological role in inflammation, vascular injury, angiogenesis, and thrombosis. Although the mechanisms leading to their in vivo formation remain obscure, the release of EMP from cultured cells can be caused in vitro by a number of cytokines and apoptotic stimuli. Recent studies indicate that EMP are able to decrease nitric-oxide-dependent vasodilation, increase arterial stiffness, promote inflammation, and initiate thrombosis at their PSer-rich membrane, which highly co-expresses tissue factor. EMP are known to be elevated in acute coronary syndromes, in severe hypertension with end organ damage, and in thrombotic thrombocytopenic purpura, all conditions associated with endothelial injury and pro-thrombotic state. The release of EMP has also been associated with endothelial dysfunction of patients with multiple sclerosis and lupus anticoagulant. More recent studies have focused on the role of low shear stress leading to endothelial cell apoptosis and subsequent EMP release in end-stage renal disease. Improved knowledge of EMP composition, their biological effects, and the mechanisms leading to their clearance will probably open new therapeutic approaches in the treatment of atherothrombosis.
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PMID:Endothelial microparticles in diseases. 1898 4

The HemosIL ThromboPath assay (Instrumentation Laboratory) is a new chromogenic assay designed to globally evaluate the functionality of the protein C (PC) pathway. It is based on the ability of endogenous APC generated after activation of PC by a snake venom extract (Protac) to reduce the thrombin generation induced by a reagent containing tissue factor. The aim of this multicenter study involving three laboratories was to evaluate the test sensitivity to PC pathway abnormalities by retrospectively testing frozen plasma samples obtained in the different laboratories. Test results were significantly lower (p < 0.0001) in subjects who presented with any confirmed PC pathway abnormality than in those without. The cut-off value, defined in each participating center as the mean value minus one standard deviation of test results obtained in 30 normal samples, was found to provide a sensitivity-to-specificity ratio similar to that obtained using ROC-analysis. The assay performed well in carriers of the factor V Leiden mutation (n = 81), patients with PC deficiency (n = 40), combined defects (n = 55) or lupus anticoagulant (n = 44), with test results below the locally defined cut-off values in 97.5%, 95.0%, 100% and 100% of the tested subjects, respectively. The assay sensitivity for PS deficiency (n = 62) was 87.1%. Only 13.6% of the 272 subjects without any PC pathway abnormality had a decreased test result. So, using the locally defined cut-off values, the overall test sensitivity to all tested PC pathway abnormalities was 95.0% (95%CI = 91.8-97.3), its specificity 86.4% (95%CI = 81.8-90.2), its negative predictive value 94.4% (95%CI = 90.8-96.9) and its positive predictive value 87.9% (95%CI = 83.7-91.3).
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PMID:A new chromogenic assay (HemosIL ThromboPath) is sensitive to major prothrombotic risk factors affecting the protein C pathway. Results of a multicenter study. 1915 24

Pregnancy is a pro-inflammatory/hypercoagulable state. Impairment of trophoblastic invasion and placental microthrombi are involved mechanisms in the pathogenesis of recurrent miscarriages (RM). Although in RM related to antiphospholipid antibodies (aPL) non-thrombotic mechanism seems to play an important role as well, we focused this review on the thrombotic mechanisms of RM related to aPL. Thus, in cases of RM related to aPL, placental injury produces inflammatory changes in endothelial cells. Endothelial dysfunction has been shown by increased plasma levels of ICAM-1/VCAM-1 and E-selectin. In RM associated with aPL, the thrombogenic mechanisms included different pathways: protein C inhibition, annexin-5 displacement, blocking of beta(2)GP1 anticoagulant activity and tissue factor upregulation. A new marker/causative agent of RM by itself or in relation to lupus anticoagulant (LA) has risen: circulating microparticles. Microparticles are a heterogeneous group of small, membrane-coated vesicles with a diameter of 0.1-1 microm. Microparticles are released from the cellular membrane during cell activation/apoptosis. Exposition of phospholipids in the outer membrane leaflet could explain the role of microparticles in the thrombotic events. Microparticles have been associated with RM. Microparticles are increased in women with RM when compared with healthy pregnant women. A relationship between aPL and activated endothelial cells (EC) occurs, as well as between EC and circulating microparticles. Interestingly, microparticles induced coagulation in vitro via tissue factor, especially in plasmas with LA. Finally, the relationship between EC, microparticles, LA and RM is revised.
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PMID:Circulating microparticles, lupus anticoagulant and recurrent miscarriages. 1941 Mar 60

Today, cardiovascular mortality is the first cause of mortality in systemic lupus erythematosus (SLE). A 40-year-old woman with SLE is over 50 times more likely to have a myocardial infraction than a healthy woman of similar age. The high CV risk has a double origin: an early and progressive atherosclerosis and a prothrombotic propensity. Multiple factors are incriminated, including a higher prevalence of traditional CV risk factors in SLE population, as well as SLE-specific factors. Autoantibodies can modify lipid profile, induce tissue factor synthesis, favour clotting and endothelial apoptosis. Moreover, endothelial dysfunction and permanent chronic inflammation are present. Treatments are occasionally involved. To reduce more efficiently CV risk in SLE patients, we propose to consider SLE has a complete CV risk factor that should be implemented for CV risk management. This medical procedure of CV risk estimation is unusual in young patients. Its implementation in SLE patients requires a modification of medical practices. CV risk management in SLE patients include identification of optimal targets for each traditional risk factor and SLE specific treatments.
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PMID:[High cardiovascular complications in systemic lupus erythematosus: physiopathology and risk management]. 1973 24

Anti-phospholipid syndrome (APS) is defined based on both clinical findings (recurrent arterial and/or venous thrombosis and recurrent fetal loss) and laboratory evidence of persistent anti-phospholipid antibodies (anti-cardiolipin antibodies, anti-beta2 glycoprotein I antibodies, or LA activity). However, the precise mechanism responsible for arterial and/or venous thromboembolic complications in APS patients remains unclear. To clarify the association between the various types of anti phospholipid antibodies (aPLs) and thrombotic complications, we examined the prevalence of seven types of aPLs [anti-cardiolipin/beta2-glycoprotein I antibodies(anti-CL/beta2-GPI), anti-phosphatidylserine/prothrombin antibodies(anti-PS/PT), anti-beta2-glycoprotein I antibodies (anti-beta2-GPI), anti prothrombin antibodies (anti-PT), anti-protein C antibodies (anti-PC), anti-protein S antibodies(anti-PS), and annexin V antibodies(anti-AN)] in 168 patients with systemic lupus erythematosus (SLE). We confirmed that the presence of anti-CL/beta2-GPI, anti-PS/PT, and anti-beta2-GPI is closely related to arterial thrombosis, and that the presence of anti-protein S is closely related to venous thromboembolism. Furthermore, our in-vitro experiment suggests that anti-CL/beta2-GPI and anti-PS/PT may cooperate to promote platelet activation, and may be involved in the pathogenesis of arterial thrombosis. On the other hand, anti-protein S led to APC resistance, which may represent an important mechanism responsible for the development of venous thrombosis. Furthermore, our study showed that anti-CL/beta2-GPI causes a persistently high-level expression of tissue factor on monocytes, and this may increase the risk of atherosclerosis.
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PMID:[Advanced clinical laboratory studies in the graduate school of medicine--studies on pathogenic mechanisms of anti-phospholipid syndrome]. 1976 14

Antiphospholipid syndrome (APS) is an acquired autoimmune disorder defined by the presence of an antiphospholipid antibody (aPL) and the occurrence of at least one associated clinical condition that includes venous thrombosis, arterial thrombosis or pregnancy morbidity. The aPL detected in APS have long been thought to have a direct prothrombotic effect in vivo. However, the pathophysiology underlying their coagulopathic effect has not been defined. Emerging data suggest a role for the procoagulant protein tissue factor (TF). In this review we provide an overview of TF, describe mouse models used in the evaluation of the role of TF in thrombosis, as well as summarize recent work on TF and APS.
Lupus 2010 Apr
PMID:Role of tissue factor in thrombosis in antiphospholipid antibody syndrome. 2035 72

Persistently positive antiphospholipid antibodies in association with thromboses and/or pregnancy morbidity is the hallmark of the antiphospholipid syndrome. The management of antiphospholipid antibody-positive patients has been focused on utilizing anti-thrombotic medications such as heparin or warfarin. Given that our understanding of the molecular mechanisms of antiphospholipid antibody-mediated thrombosis has been growing, it is highly likely that the current 'anti-thrombotic' approach to these patients will be replaced by an 'immunomodulatory' approach in the near future. This review article will address the experimental and/or clinical evidence behind some of these potential 'immunomodulatory' approaches (tissue factor inhibition, P38 mitogen-activated protein kinase inhibition, nuclear factor-kappaB inhibition, platelet glycoprotein receptor inhibition, hydroxychloroquine, statins, inhibition of beta(2)GPI and/or anti-beta(2)GPI binding to target cells, complement inhibition, and B cell inhibition) in antiphospholipid syndrome.
Lupus 2010 Apr
PMID:Antiphospholipid syndrome treatment beyond anticoagulation: are we there yet? 2035 91


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