Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02749 (beta2-glycoprotein I)
 836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the clinical significance of IgG beta 2-glycoprotein I (GPI)-dependent anticardiolipin antibodies (aCL) in rheumatic diseases. Three hundred and seventeen patients were entered. They consisted of 133 patients with SLE, 60 with RA, 45 with SSc, 37 with PM, 23 with overlap syndrome (overlap), and 19 with unclassified connective tissue disease (UCTD). IgG beta 2-GPI-dependent aCL were examined by ELISA. While IgG beta 2-GPI-dependent aCL were detected in 13% of patients with SLE, these aCL were positive in two patients with SSc, two with overlap and 14 with UCTD. A significant association between IgG beta 2-GPI-dependent aCL and thrombosis was found. Clinical manifestations were studied in 32 patients with secondary APS based on SLE and 14 with primary APS (PAPS). Incidence of malar rash, arthritis, renal disorder, leucopenia, immunological disorders and hypocomplementemia were significantly less frequent in patients with PAPS. IgG beta 2-GPI-dependent aCL were detected in all patients with PAPS and in 34% of secondary APS. This difference was significant. These data suggest that IgG beta 2-dependent aCL are useful for identifying a subset in patients with APS.
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PMID:Disease distribution of beta 2-glycoprotein I-dependent anticardiolipin antibodies in rheumatic diseases. 775 7

Antiphospholipid antibodies are a wide family of antibodies, dominated by lupus anticoagulant (LA) and anti-cardiolipin antibodies (aCL), encountered in various circumstances. Unnecessary laboratory tests can be avoided by carefully weighing the indications, especially regarding patient age. Three steps are required to demonstrate LA: screening, mixing studies, then confirmation by neutralization tests. Two coagulation tests at least should be performed aCL are detected with ELISA kits using plates coated with cardiolipin. Due to the large number of kits available and to the lack of agreement on cut-off values, all laboratories must indicate their own standards. Other kits use plates coated with a mixture of phospholipids. Recent data suggest that pathogenic aPL are more specifically directed against phospholipid-associated proteins rather than towards phospholipids. In the future, tests for aCL might be replaced by tests for beta 2-glycoprotein I. The presence of aPL requires a specific treatment only in patients presenting clinical manifestations thought to be aPL-induced (thromboses, fetal losses). Long term warfarin aimed at an INR of 3-3.5 is effective for the secondary prevention of thrombosis. In primary APS, prevention of recurrent miscarriages is frequently achieved by a combination of subcutaneous heparin plus aspirin.
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PMID:[Antiphospholipid antibody/cofactors. What are they? Why, when and how to search for them? Is treatment justified?]. 909 60

aPL antibodies are a wide and heterogeneous family of autoantibodies, formerly believed to be directed at anionic phospholipids. In recent years they have been shown to be directed at plasma proteins bound to suitable (phospholipid) anionic surface: beta 2-GPI and prothrombin are the best known and characterized antigens, which are recognized by aCL antibodies and most Lupus Anticoagulants, respectively. The presence of these antibodies has been associated with arterial and venous thrombosis, recurrent miscarriages and thrombocytopenia in the so-called "Antiphospholipid Syndrome". Retrospective and "cross-sectional" studies have established the role of aCL antibodies and Lupus Anticoagulants as risk factors for both venous and arterial thrombosis, the most common clinical manifestations of APS. Prospective studies performed in different patients' populations have validated the association between aCL antibodies and Lupus Anticoagulants with venous and, possibly, arterial thrombosis. Along with the concept of the heterogenity of aPL antibodies there is the observation that among Lupus Anticoagulants aCL-type A, but not LA antibodies, appear to represent a risk factor for thrombosis. However, informations on the predictive value of the various laboratory tests with respect to thrombosis are still rather limited. It is, therefore, necessary to continue the development and standardization of assays that selectively identify aPL antibodies associated with an increased risk of thrombosis, in order to help the clinicians to establish the most appropriate therapeutic strategies for the prevention of the thromboembolic complication of APS.
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PMID:Antiphospholipid antibodies: predictive value of laboratory tests. 919 31

The aim of this study was to characterize the antigen specificity and to evaluate the diagnostic and prognostic value of anti-mitochondrial M5 type antibodies (AMA M5). Fifty-eight patients selected on the basis of their AMA M5 positivity were investigated in relationship to their clinical and serological profile. Cross-absorption studies, Western blotting and immunoprecipitation analysis were carried out for AMA M5 antigen specificity characterization. Most patients had a diagnosis of systemic lupus erythematosus (SLE) (65.5%) or of primary anti-phospholipid syndrome (PAPS) (24%); all the patients were positive for IgG or IgM anti-cardiolipin (anti-CL) antibodies and 49% of them also displayed lupus anticoagulant (LA) activity. Anti-beta2-glycoprotein I (beta2-GPI) IgG were detectable in 30/38 sera (78.9%) and IgM in 34/38 (89.4%). While anti-CL and anti-beta2-GPI IgG antibodies were significantly associated with history of thrombosis and fetal loss, AMA M5 displayed a statistical association only for thrombocytopenia and recurrent fetal loss. Absorption with human beta2-GPI both in free solution or in solid phase as well as with CL liposomes or CL/beta2-GPI liposome complexes did not affect AMA M5 fluorescence. While AMA M5 activity is absorbed by whole mitochondrial preparations, no specific reactivities against several human, bovine and rat mitochondrial proteins could be detected in Western blotting and immunoprecipitation studies. AMA M5 appear to be detectable in both primary and secondary APS, displaying a strong association with the presence of thrombocytopenia and fetal loss. Although strictly related to anti-phospholipid antibodies, AMA M5, anti-CL and anti-beta2-GPI antibodies represent distinct serological markers of the APS.
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PMID:Anti-mitochondrial M5 type antibody represents one of the serological markers for anti-phospholipid syndrome distinct from anti-cardiolipin and anti-beta2-glycoprotein I antibodies. 956 3

The clinical associations of antiphospholipid antibodies (aPL) are well recognized but the mechanism(s) causing the production of these antibodies are not yet known. We demonstrated the induction of pathogenic aPL antibodies that caused intrauterine fetal death and transverse myelopathy due to spinal cord infarction in mice by immunization with foreign beta2GPI. We also induced aPL and anti-beta2-GPI in mice by immunization with PL-binding viral peptides and hypothesized that in APS patients, aPL may be induced by beta2GPI-like-PL-binding products of common human bacteria and viruses.
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PMID:Origin of antiphospholipid antibodies: induction of aPL by viral peptides. 981 74

We studied 99 patients with systemic autoimmune disease (5 males, 94 women; mean age 37 year, range 16-72): 28 Primary Antiphospholipid Syndrome, 67 Systemic lupus Erythematosus, 1 Mixed Connective Tissue Disease, 2 Undifferentiated Connective Tissue Disease and 1 Discoid Lupus. Based on the observation that native PT shows conformational changes in presence of Ca++ ions and discloses new epitopes available for binding with phospholipids, we performed 3 different methods for the detection of aPT in presence and absence of Ca++, finding a different incidence of specific autoantibodies, associated with clinical features of APS (aPT in presence of Ca++) or non associated (aPT in absence of Ca++). The presence of aPT was significantly associated also with the presence of Lupus Anticoagulant (LAC). The detection of aPT (in presence of Ca++) significantly enhances diagnostic sensibility of APS allowing the identification of a subset of patients (6/99) with clinical features of APS, but with negative LAC, aCL and a beta2-GPI; in fact (limited to thrombotic episodes) the sensibility rises from 56.2% with one test (LAC) to 81.1% with the application of LAC, aCL, a(beta)2GPI and aPT.
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PMID:[Role of anti-prothrombin in antiphospholipid syndrome]. 1240 33

The antiphospholipid (Hughes) syndrome (APS) includes systemic and central nervous system (CNS) pathology associated with antibodies to a complex of phospholipids and beta2-glycoprotein I (beta2-GPI). Beta2-GPI immunized mice develop systemic manifestations of APS and we presently examined CNS manifestations in this APS model. Female BALB/c mice were immunized once with beta2-GPI in complete Freund's adjuvant (CFA) or with CFA alone (controls). A staircase test and a T-maze alternation test were performed to test behavior and cognition in independent groups of mice 6, 12 and 18 weeks following the immunization. The APS mice developed elevated levels of antibodies against negatively charged phospholipids and beta2-GPI. Neurological impairment was detected only 18 weeks after the induction of the APS and consisted of both cognitive (53 +/- 4 vs 71 +/- 3% correct choices in the T-maze alternation for APS vs control mice, P < 0.001) and behavioral changes (higher number of rears (18 +/- 2 vs 11 +/- 1, P < 0.006) and higher number of stairs climbed (12 +/- 2 vs 7 +/- 1, P < 0.02). This is the first report of cognitive deficits in this APS model and demonstrates the time course for the development of previously described behavioral changes. The mechanism involved in these CNS manifestations remains to be elucidated.
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PMID:Behavioral and cognitive deficits occur only after prolonged exposure of mice to antiphospholipid antibodies. 1247 4

To study the antigenic and epitope specificities of anti-phospholipid Ab in detail, we investigated 177 patients without (62 with APS-related systemic clinical symptoms, 115 with microangiopathies) and 164 patients with connective tissue diseases (CTD). Ab associated with primary APS (pAPS) seem to show a restricted specificity (phospholipid/beta2-GPI-complexes), whereas those in secondary APS (sAPS) react additionaly with pure beta2-GPI. Simultaneously, beta2-GPI-independent Ab were also frequently present in both conditions (50% of all Ab-positive sera). In CTD patients, the reactivity profile "pure beta2-GPI + phospholipid/beta2-GPI-complexes" is significantly associated with clinically manifest sAPS. Comparing cardiolipin and phosphatidylserine as antigenic target, the overall concordance (crossreactivity?) between both assays was lower than expected (52%), being highest in pAPS (87%) and sAPS (65%). Based on these results, a two-step procedure for reliable serological diagnosis of APS could be recommended: Ab-screening using a mix of phospholipids complexed with beta2-GPI (sensitivity > 90% for Ab concentrations above 20 U/ml) followed by an assay allowing the simultaneous detection of all relevant antigenic and epitope specificities.
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PMID:Reactivity profiles of autoantibodies to different phospholipids and the phospholipid-binding protein beta2-glycoprotein I in patients with clinical symptoms related to thromboembolic and/or vasculopathic events with or without connective tissue diseases. 1290 34

Antiphospholipid syndrome (APS, Hughes' syndrome) is a systemic autoimmune disorder characterized by arterial and/or venous thrombosis and recurrent foetal loss, accompanied by mild to moderate thrombocytopaenia and elevated titres of antiphospholipid antibodies (aPLs): lupus anticoagulant (LAC) and/or anticardiolipin (aCL) antibodies. APS was defined originally in 1983 in systemic lupus erythematosus (SLE) patients, but later it was found that APS can be primary or secondary to other autoimmune diseases or malignancy. During the past 20 years many organs have been reported to be involved in this syndrome and the clinical manifestations are seen in every medical field. Moreover, many aPLs have been found in APS besides aCLs and LACs, which bind to the autoantigen beta-2-glycoprotein I (beta2GPI). Treatment for APS, based on antiplatelet and anticoagulation drugs, is dependent on various parameters, including whether SLE is also present, classical vs non-classical manifestations of the diseases, women with APS based on pregnancy morbidity, the presence of elevated aCL antibody titres in the absence of clinical manifestations, and catastrophic APS.
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PMID:The systemic nature of the antiphospholipid syndrome. 1579 93

Antiphospholipid syndrome is characterized by arterial or venous thrombosis, and the presence of antiphospholipid antibodies (aPL). APL are considered to be a cause of an acquired hypercoagulable state leading to stroke and transient ischemic attack (TIA). We examined the causes in 50 young patients with ischemic stroke. The most prevalent cause was atherosclerosis and the incidence of APS was 12.5%. APL comprise a heterogeneous group of autoantibodies, such as beta2-glycoprotein I dependent anticardiolipin antibody (beta2-GPIaCL), lupus anticoagulant (LA), and other antiphospholid-protein antibodies. We examined the incidence and the pathogenic role of antiphospholipid protein antibodies. The subjects comprised 250 patients (155 male, 95 females) with ischemic stroke, aged 26 to 92 years (mean 72 years). We measured beta2-GPI aCL, IgG aCL, LA, phosphatidyserine dependent antiprothrtombin antibody (PS-PT), antiphosphatidyl-serine antibody (PS), antiphosphatidyl-inositol antibody (PI) in each patient. The incidence of beta2-GPI aCL, IgG aCL, LA, phosphatidyserine, PS-PT, PS, and PI was 2.8%, 12%, 9.2%, 7.2%, 9.6%, and 8.8%, respectively. The incidence of young stroke patients under 50 years was 5.2%. Among 13 young stroke patients, 5 had SLE. Among 23 patients with LA., 18 (78%) patients had PS-PT. Anti-PS-PT antibody is closely related to LA. Antinuclear antibody was detected in 79% of the patients with aPS and/or aPI. We compared the carotid ultrasonographic findings in positive aPI or aPS patients with those in negative ones. Increased IMT, plaque score and carotid stenosis were more common in aPI and aPS-positive patients than in negative ones Three of 5 patients who showed positive beta2-GPI, aCL and LA, simulataneously, had sysyemic lupus erythematosus as an immulological background. Two of 3 patients with PI and/or PS and beta2-GPI and/or LA were patients with SLE. Antiphospholipid antibody was considered to be a risk factor of stroke, especially in SLE and/or young female patients. The incidence of lupus anticoagulant is more common than beta2-GPI aCL in ischemic stroke. In SLE patients with stroke, multi-antiphospholipid-protein antibodies was inclined to be present. LA is closely related to ant-PS-PT and aPI and aPS are associated with anti-nuclear antibody and precipitation of atherosclerosis.
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PMID:[Antiphospholipid syndrome and stroke]. 1644 44


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