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 anti-phospholipid syndrome (APS) is a systemic autoimmune disease characterized by an adaptive immune response against self phospholipid (PL)--binding proteins. Although APS is considered as an autoantibody-mediated disease, there is now evidence that anti-phospholipid antibodies (aPL) are necessary but not sufficient to trigger some of the clinical manifestations of the syndrome. For example, mediators of the innate immunity are recognized to be additional second hits able to induce the thrombotic events in the presence of aPL. Finally, environmental agents - in particular infectious ones - were reported to act as triggers for the production of autoantibodies cross-reacting with PL-binding proteins as well as inflammatory stimuli that potentiate the aPL thrombogenic effect. Altogether, these findings suggest a role for the innate immunity in APS pathogenesis. Toll-like receptors (TLR) are receptors that induce prompt inflammatory responses and mediate functional activation in immune effector cells. There is evidence that aPL, and in particular anti-beta(2) glycoprotein I (beta(2)GPI) antibodies, may activate endothelial cells and monocytes through TLR-4-dependent signalling. Whether or not TLR may behave as surface receptors for beta(2)GPI is still matter of research. Drugs or molecules able to interfere with TLR involvement may represent new therapeutic approaches for APS.
Lupus 2008 Oct
PMID:Toll-like receptors: another player in the pathogenesis of the anti-phospholipid syndrome. 1882 59

Antiphospholipid antibodies (aPL), the majority of which are directed against beta(2)-glycoprotein I (beta(2)GPI), are associated with an increased incidence of venous and arterial thrombosis. The pathogenesis of antiphospholipid/anti-beta(2)GPI-associated thrombosis has not been defined, and is likely multifactorial. However, accumulating evidence suggests an important role for endothelial cell activation with the acquisition of a procoagulant phenotype by the activated endothelial cell. Previous work demonstrated that endothelial activation by antiphospholipid/anti-beta(2)GPI antibodies is beta(2)GPI-dependent. We extended these observations by defining annexin A2 as an endothelial beta(2)GPI binding site. We also observed that annexin A2 plays a critical role in endothelial cell activation induced by anti-beta(2)GPI antibodies, and others have described direct endothelial activation by anti-annexin A2 antibodies in patients with aPL . Similar findings have been reported using human monocytes, which also express annexin A2. Because annexin A2 is not a transmembrane protein, how binding of beta(2)GPI/anti-beta(2)GPI antibodies, or anti-annexin A2 antibodies, to endothelial annexin A2 causes cellular activation is unknown. Recent studies, however, suggest an important role for the Toll-like receptor family, particularly TLR4. In this article, we review the role of these interactions in the activation of endothelial cells by aPL . The influence of these antibodies on the ability of annexin A2 to enhance t-PA-mediated plasminogen activation is also discussed.
Lupus 2008 Oct
PMID:Annexin A2: biology and relevance to the antiphospholipid syndrome. 1882 60

Antiphospholipid syndrome is considered to be associated with a hypercoagulable state that leads to stroke and other ischemic events, and is currently diagnosed based on the modified Sapporo criteria that was proposed in 2006. Antiphospholipid antibodies (aPL) comprise a heterogeneous group of autoantibodies. Among them, the level of beta2-glycoprotein I-dependent anticardiolipin antibody, lupus anticoagulant (LA), and IgG anticardiolipin antibody are commonly measured. Recently, phosphatidylserine dependent anti-prothrombin antibody has been suggested to be closely related to LA. aPL is an independent risk factor for a first-ever ischemic stroke, especially in young female patients. It is still debatable whether aPL is a marker for recurrent stroke risk. The precipitating factors for the occurrence of stroke are beta2-GPI-dependent aCL, aGPL, and aCL levels of greater than 40, and the simultaneous presence of LA. Several mechanisms are considered to be involved in the thrombotic process in patients with antiphospholipid antibodies. Activation of protein C is impaired in patients with aPL. Beta2-GPI has simultaneous procoagulant and anticoagulant effects. Cardiac valvular involvement, which could be the cause of cardiogenic embolism, is prevalent in patients with aCL. In addition, the presence of aPL is associated with the development of atherosclerosis. Recently, it has been proposed that endothelial cells, monocytes, and platelets were reported to be activated by beta2-GPI: further, p38 mitogen-activated protein kinase has been reported to be phosphorylated. Several therapeutic options are available for the prevention of ischemic stroke in patients with aPL. For cases of cryptogenic ischemic stroke and positive aPL antibodies, antiplatelet therapy is reasonable. Oral anticoagulation with a target international normalized ratio (INR) of 2 to 3 is reasonable for patients with ischemic stroke who meet the criteria for antiphospholipid syndrome with venous and arterial occlusive disease in multiple organs.
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PMID:[Ischemic stroke with antiphospholipid antibody]. 1897 2

The antiphospholipid syndrome is characterized by the occurrence of vascular thrombosis combined with the presence of antiphospholipid antibodies in plasma of patients. It has been published that antibeta2-glycoprotein I (beta2-GPI) antibodies, with lupus anticoagulant activity (LAC), highly correlate with thrombosis. Resistance related to antiphospholipid antibodies against activated protein C (APC) is one of the proposed mechanisms responsible for thrombosis. We investigated a possible correlation between a beta2-GPI-dependent LAC (titration of cardiolipin into an activated partial thromboplastin time-based assay) and increased APC resistance in a population of 22 plasma samples with LAC activity. Eleven plasma samples that displayed a beta2-GPI-dependent LAC also showed increased APC resistance. In contrast, only one of the 11 plasma samples with a beta2-GPI-independent LAC displayed increased APC resistance. In addition, a monoclonal antibeta2-GPI antibody and patient-purified immunoglobulin G (both with LAC activity) were diluted in plasma with/without protein C. Both antibodies only displayed a beta2-GPI-dependent LAC in plasma in the presence of protein C. This indicates that the principle of the beta2-GPI LAC-assay was based on increased resistance against protein C. Surface plasmon resonance analysis was used to investigate binding between APC and beta2-GPI. We observed that beta2-GPI was able to bind APC directly, especially in the presence of a monoclonal antibeta2-GPI antibody. In conclusion, our observations show a direct correlation between a major clinical symptom of antiphospholipid syndrome (thrombosis), a diagnostic assay (beta2-GPI-dependent LAC) and a potential mechanism responsible for thrombosis in the antiphospholipid syndrome (increased APC resistance).
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PMID:Correlation between the potency of a beta2-glycoprotein I-dependent lupus anticoagulant and the level of resistance to activated protein C. 1900 41

The objective of this retrospective study was to evaluate the potential ability of diluted Russell viper-venom time (dRVVT) to identify antiphospholipid syndrome (APS) in a lupus anticoagulant (LA)-positive patient population, already selected by other LA clotting tests. Our cohort of positive LA patients was first identified in our outpatients population by the following sensitive LA-detecting tests: Rosner index, diluted prothrombin time (dPT) and Rosove index. Then the 227 consecutive LA-positive patients were tested for dRVVT with the same blood sample. Anticardiolipin (aCL) and anti-beta(2)-glycoprotein-I (beta(2)GPI) autoantibodies assays were also performed. APS using Sapporo clinical criteria revised at Sydney, was found in 116 of these 227 consecutive LA-positive patients. Results of the different tests were analysed statistically. Using univariate analysis, dRVVT, dPT, IgG aCL and IgG anti-beta(2)GPI autoantibodies were significantly associated with APS. The receiver operating-characteristics (ROC) curve defined the best cut-off value for dRVVT ratio at 1.61 with a good specificity (78%) and a lower sensitivity (53%). A multivariate analysis using a binary logistic procedure, retained the dRVVT ratio (> or = 1.61) and IgG anti-beta(2)GPI autoantibodies (> 15 USG) as being associated with APS (p = 0.018; odds ratio [OR] 2.39; 95% confidence interval [CI] 1.2-4.7, and p = 0.0001; OR 3.2; 95% CI 1.5-6.5, respectively). To conclude, these results agree with the need for LA criteria favouring specificity over sensitivity. The use of a threshold around 1.6 for dRVVT ratio should help discriminate APS from non-APS patients.
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PMID:Diluted Russell viper-venom time improves identification of antiphospholipid syndrome in a lupus anticoagulant-positive patient population. 1927 23

The antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy morbidity associated with the presence of laboratory criteria such as antibodies directed towards cardiolipin or beta(2)-GPI and lupus anticoagulant. Recently, the term "seronegative APS " has been proposed to define patients with the typical clinical manifestations but with negative serologies. One explanation for such a context could be that some APS patients may only have antiphospholipid antibodies (aPL) other than the admitted laboratory criteria. This review is focused on antibodies directed against phosphatidylethanolamine (aPE) and underlines the interest of their investigation in the different clinical manifestations of APS.
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PMID:Clinical significance of antiphosphatidylethanolamine antibodies in the so-called "seronegative antiphospholipid syndrome". 1930 51

The antiphospholipid syndrome (APS) is characterised by a great clinical variability, with diverse clinical presentations such as venous thromboembolism, preeclampsia, arterial thrombosis and renal and cerebral small vessel thrombosis. Given this wide spectrum of manifestations, it is very important to make an early diagnosis in order to start adequate medical therapy before irreversible damage ensues. Persistent positivity of lupus anticoagulant (LA), anticardiolipin antibodies (aCL) at high levels or the combined triple positivity of LA, aCL and anti-ss(2)GPI make the diagnosis of APS likely in the adequate clinical setting. The treatment of APS is based on antiaggregant and anticoagulant drugs. The optimal approach is still debated; however, indefinite anticoagulation is warranted. We recommend high intensity anticoagulation in patients with arterial and/or recurrent events, as well as a strict control of vascular risk factors. Pregnant women with APS should be best attended in combined medical-obstetric clinics. Low dose aspirin should be given to every pregnant woman with antiphospholipid antibodies, with the addition of low molecular weight heparin in those with previous thrombosis, previous fetal death or failure of monotherapy with aspirin.
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PMID:[The antiphospholipid syndrome in the 21st century]. 1937 17

The objective of this study is to evaluate the prevalence of antiphospholipid antibodies, mainly anti-beta(2)-glycoprotein I (anti-beta(2)-GPI), and their possible clinical and laboratory relevance in mixed connective tissue disease (MCTD). This study included 39 consecutive patients with MCTD (Kasukawa's criteria) from January, 2005, to March, 2007, and compared them with 21 age- and sex-matched healthy controls. IgG and IgM anticardiolipin (aCL) and anti-beta(2)-GPI were measured by ELISA. Lupus anticoagulant (LA) was detected by functional coagulation tests. Medium to high titres of aCL and anti-beta(2)-GPI antibodies were found in sera from four (10.2%) MCTD patients. One of these patients was found to be positive for IgM aCL, IgM anti-beta(2)-GPI and LA antibodies simultaneously. Additionally, this patient had a previous history of foetal loss in the second trimester and new-onset pulmonary arterial hypertension (PAH). The other three patients had none of the manifestations of antiphospholipid syndrome (APS) or PAH. The mean value of IgG anti-beta(2)-GPI was higher among those MCTD patients with PAH than in the group without PAH (34.2 +/- 46.8 vs 12.3 +/- 9.1, P = 0.018). None of the controls were positive for antiphospholipid antibodies. High to moderate titres of anti-beta(2)-GPI as well as APS were rare in MCTD, and these antibodies may be correlated with the development of PAH in these patients.
Lupus 2009 Jun
PMID:The frequency of anti-beta2-glycoprotein I antibodies is low and these antibodies are associated with pulmonary hypertension in mixed connective tissue disease. 1943 62

Prothrombin (PT) is a target for antibodies with lupus anticoagulant (LA) activity. Anti-prothrombin antibodies (aPT) were recently identified as antibodies directed toward a phospholipid-binding protein. aPT are a new serologic marker of antiphospholipid syndrome. The objective was to detect aPT in a group of 46 patients with acute ischemic stroke in order to correlate their presence with clinical diagnosis, laboratory and neuroradiological findings. We tested aPT, lupus anticoagulant (LA), anticardiolipin (aCL), and anti-beta2-glycoprotein I antibodies (anti-bbeta2-GPI) in 46 young women with acute ischemic stroke aged 34-45 years and 43 patients with nonischemic neurologic diseases and 141 normal controls. Anti-prothrombin antibodies were detected by calcium-containing aPT ELISA, aCL and anti-beta2-GPI by ELISA. All samples were screened using the activated partial thromboplastin time (aPTT); the dilute Russell viper venous time (dRVV) coagulation test was performed. The results were statistically analyzed. Anti-prothrombin antibodies were found in 26 (57%) of 46 stroke patients. Out of 43 patients with nonischemic neurological disorders, 2 (4.18%) were positive for aPT. aPT were detected in one (0.70%) of the normal controls. Ten stroke patients (21%) were positive for IgG aPT only, 9 stroke patients (18.2%) for IgM aPT only, and 8 stroke patients (16.9%) for both IgG and IgM isotypes of aPT. Two nonischemic neurological disorders patients (4.18%) presented IgM isotype of aPT. Patients with ischemic stroke presented aPT much more frequently than the healthy controls (OR 182.00 [95% CI 23.382-1416.6]. p < 0.0001). Patients with ischemic stroke presented aPT much frequently than the nonischemic neurological disorders patients (OR 26.650 [95% CI 5.743-123.66], p < 0.0001). When IgG or IgM aPT were considered separately, they were more frequently found in patients with ischemic stroke than in healthy control group (OR 38.889 [95% CI 4.817-313.95], p < 0.0001) and (OR 34.054 [95% CI 4.178-277.5], p < 0.0001), respectively. Simultaneous positive titers for both isotypes of aPT (IgG and IgM) were more frequently found in patients with ischemic stroke than in healthy control group (OR 29.474 [95% CI 3.573-243.12], p < 0.0001). Eleven stroke patients (43%) were negative for aCL, LA and anti-beta2-GPI, but positive for aPT (OR 0.03287 [95% CI 0.001794-0.6022], p < 0.001). aCL, LA and anti-beta2-GPI were not found both in nonischemic neurological disorders patients and in healthy controls.
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PMID:Detecting anti-prothrombin antibodies in young women with acute ischemic stroke. 1948 Mar

The possibility of a genetic predisposition to develop antiphospholipid syndrome (APS) and to produce anticardiolipin antibodies and lupus anticoagulant has been addressed by family studies and population studies. Various studies suggest a familial occurrence of anticardiolipin antibodies and lupus anticoagulant, with or without clinical evidence of APS. This familial tendency could be genetically determined. Multiple human leucocyte antigen-DR or -DQ associations with antiphospholipid antibodies have been described. Genetic studies of a representative antigen, beta2-glycoprotein-I (beta(2)GPI), have been carried-out and a particular valine(247)/leucine polymorphism could be a genetic risk for presenting anti-beta(2)GPI antibodies and APS. Many other thrombosis-related genetic factors have been investigated in APS, but no additional risk for thrombosis has been indicated in affected patients. Although the mechanisms and pathophysiology of thrombosis in APS are highly heterogeneous and multifactorial, different genes and acquired factors seem to be involved. In this review, we will focus on those genetic variants that could contribute to the development of thrombosis in APS.
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PMID:Genetic risk factors of thrombosis in the antiphospholipid syndrome. 1965 49


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