Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antiphospholipid antibodies (aPL) are defined by anticardiolipin antibody (aCL) ELISA and prolongation of phospholipid dependent coagulation assays (lupus anticoagulant; LAC). For the binding of aCL to cardiolipin a cofactor, beta 2-glycoprotein I (beta 2-GPI), is necessary. We have investigated whether the same cofactor is essential for LAC activity. Plasma from 6 LAC positive patients and 3 controls was depleted from beta 2-GPI by means of affinity chromatography. From the 6 LAC positive plasmas, 4 became LAC negative (tested with dRVVT) when beta 2-GPI was depleted and became positive again when purified beta 2-GPI (200 micrograms/ml) was added. A dose response curve showed that addition of 50 micrograms/ml beta 2-GPI to beta 2-GPI deficient patient plasma, led to a positive dRVVT. Depletion of, and addition of beta 2-GPI to plasma from controls had no effect on the dRVVT. Measurement of beta 2-GPI plasma levels in 19 LAC positive patients, 40 LAC negative patients and 15 controls showed no difference in beta 2-GPI levels. These results show that a combination of aPL and beta 2-GPI is essential not only for binding to cardiolipin, but also for LAC activity and imply that low beta 2-GPI levels (less than 50 micrograms/ml) can lead to false negative LAC tests. These observations may lead to new insights in the pathophysiological complications associated with aPL.
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PMID:Lupus anticoagulant activity is frequently dependent on the presence of beta 2-glycoprotein I. 151 7

The case history of a 31-year-old woman is described. She had a history of thrombosis; in the past there had been an arterial embolus of the left superficial femoral artery and venous thrombosis of the right leg. The patient was admitted to hospital because of fever of unknown origin. During the hospital stay the diagnosis of probable SLE was made. She died of myocardial infarction. At autopsy, thrombosis of the small arterioles of the heart was found without sclerosis of the coronary arteries. A lupus anticoagulant could be demonstrated in her blood and seems to have been the cause of this rare complication. Treatment with anticoagulants is advised for patients with LAC and a history of thrombosis.
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PMID:A patient with probable systemic lupus erythematosus, lupus anticoagulant and myocardial infarction. 263 86

We serially measured the plasma thrombomodulin (TM) levels in systemic lupus erythematosus (SLE) patients and assessed them clinically. The patients who responded to medical treatment experienced a decrease in plasma TM levels. Patients who developed exacerbations of SLE, thrombotic thrombocytopenic purpura or thrombosis, displayed increased plasma TM levels. There was no significant difference between the plasma TM levels of the lupus anticoagulant-positive (LAC-positive) patients and the LAC-negative patients or between the plasma TM levels of the anticardiolipin antibody-positive (aCL-positive) patients and the aCL-negative patients. While LAC and aCL titers did not always coincide with improvement in the patients' clinical course or with aggravation of the disease, the TM values correlated well with the patients' clinical condition. Plasma TM values may be used to evaluate disease activity and may predict the occurrence of thrombosis in SLE.
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PMID:Plasma thrombomodulin as an indicator of thromboembolic disease in systemic lupus erythematosus. 773 45

To determine whether young patients who suffered a stroke in the past, have a higher prevalence of ACA of LAC as compared to healthy controls, we evaluated 44 stroke patients and 46 controls in a case-control study for the presence of ACA and LAC. All the patients had had a stroke under the age of 50 yr and the stroke date was less than 5 yr ago (mean 2.5 yr). Stroke was defined as an ischaemic cerebral infarction and was confirmed by angiography, CT-scan or MRI. An age- and sex-matched group of healthy volunteers served as controls. The mean age of the patients was 41.4 yr (range 22-52 yr), and of the controls 36.8 yr (range 24-50 yr). Serum and plasma from both groups was examined for IgM- and IgG-ACA and LAC. One patient was positive for both IgG- and IgM-ACA, whereas 3 controls were found positive for IgG-ACA. For 2 patients and 5 controls an equivocal result was obtained for IgG-ACA or IgM-ACA. None of the patients or controls were positive for LAC. The differences between the patient and control group were statistically not significant. In conclusion, no difference was found in the prevalence of cardiolipin antibodies in sera from patients with a stroke within the last 5 yr and an age- and sex-matched control group. There was no correlation either between the presence of lupus anticoagulant and the occurrence of a stroke in the past.
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PMID:Cardiolipin antibodies and lupus anticoagulant in young patients with a cerebrovascular accident in the past. 831 30

Lupus anticoagulants (LA) are immunoglobulins which interfere with in vitro phospholipid-dependent coagulation tests. Its presence is associated with thromboembolic events. Laboratory recognition of these inhibitors is therefore of increasing clinical importance. A variety of tests has been introduced to detect LAs. In this study, 'IL Test LAC Screen/LAC Confirm', a new sensitive LA test, is evaluated on 23 LA-positive and 70 LA-negative plasmas. In this procedure, a dilute Russell's viper venom is served as a screening test with addition of phospholipids as a confirmatory test. A correct sensitivity for LAs is observed. This new approach for biological LA diagnosis may contribute to an accurate LA recognition in association with one or more phospholipid-dependent coagulation tests.
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PMID:[Evaluation of the reagent "IL Test LAC Screen/IL Test LAC Confirm" for the biological diagnosis of circulating lupus anticoagulants]. 895 26

Antiphospholipid antibodies (aPL) characterize patients at risk for both arterial and venous thrombotic complications. Recently it has been recognized that the presence of plasma proteins such as beta 2-glycoprotein I(beta 2 GPI) and prothrombin are essential for the binding of aPL to phospholipids and that these proteins are probably the real target of aPL. The discovery of these new antigens for aPL introduces the possibility of new assays to detect the presence of aPL. However, it is not known whether these assays improve the identification of patients at risk for thrombosis. In this retrospective study we compared the value of the classic assays LAC (lupus anticoagulant) and ACA (anticardiolipin antibodies) to detect aPL associated with thrombotic complications, with new assays which are based on the binding of aPL to the plasma proteins prothrombin and beta 2GPI. To do so, we have used these assays in a group of 175 SLE patients and correlated the positivity of the different assays with the presence of a history of venous and arterial thrombosis. Control groups were patients without SLE but with LAC and/or ACA and thrombosis (n = 23), patients with thrombosis without LAC and ACA (n = 40) and 42 healthy controls. In the univariate analysis, in which no distinction has been made between high and low antibody levels, we confirmed LAC and ACA to be related to both arterial and venous thrombosis. Anti-beta 2GPI- and anti-prothrombin-antibodies, both IgG and IgM correlate with venous thrombosis and anti-beta 2GPI-IgM with arterial thrombosis. Multivariate analysis showed that LAC is the strongest risk factor (OR 9.77; 95% CI 1.74-31.15) for arterial thrombosis. None of the other factors is a significant additional risk factor. For venous thrombosis LAC is the strongest risk factor (OR 6.55; 95% CI 2.36-18.17), but ACA-IgM above 20 MPL units also appeared to be a significant (p = 0.0159) risk factor (OR 3.90; 95% CI 1.29-11.80). Furthermore, the presence of anti-beta 2GPI- and/or anti-prothrombin-antibodies in LAC positive patients (n = 60) does not increase the risk for thrombosis. The results showed that (i) the LAC assay correlates best with a history of both arterial and venous thrombosis and (ii) neither the anti-beta 2GPI ELISA nor the anti-prothrombin ELISA gives additional information for a thrombotic risk in SLE patients.
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PMID:Lupus anticoagulant is the strongest risk factor for both venous and arterial thrombosis in patients with systemic lupus erythematosus. Comparison between different assays for the detection of antiphospholipid antibodies. 926 10

We examined thrombophilic mechanisms and outcome in 54 patients with deep-vein thrombosis (DVT), who were otherwise apparently healthy and aged < or = 50 years. Patients were followed up 6 years (median) after a confirmed first DVT between 1987-1992 with no known predisposing illnesses. Patients were traced through the hospital registry and compared with 25 matched controls. Tested thrombophilic mechanisms were either genetic (activated protein C [APC] resistance; anti-thrombin III deficiency [ATIII]; protein C or protein S deficiency [PC, PS]) or acquired (lupus anti-coagulant [LAC]/anti-cardiolipin antibodies [ACA]; subsequent diagnosis of cancer). Twenty-nine DVT patients attended for full studies. The remaining 25 were interviewed by phone and none had a reported neoplastic disease, confirmed by their hospital records and the National Cancer Registry. These patients' demographics, risk factors and subsequent course were similar in all respects to the studied group. In the control group, APC resistance was the only coagulopathy found (1/25, 4%), and it was also the most common abnormality among DVT patients (8/29, 28%) (p = 0.009). Three DVT patients had LAC/ACA (10%) and one each, ATIII, PC and PS deficiencies (3.3% each). No malignancy was encountered during a follow-up of 7.9 +/- 5.7 years. Circumstantial risk factors were found in 52% of the patients, 21% had a family history of DVT, and 41% had recurrent DVT. These characteristics were not significantly different when DVT patients with and without coagulopathy were compared.
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PMID:Causes and outcome of deep-vein thrombosis in otherwise-healthy patients under 50 years. 930 63

Antiphospholipid antibodies (APA), including lupus anticoagulants (LAC; as detected by in vitro blood clotting tests) and anti-cardiolipin antibodies (ACA; as assayed by solid-phase immunoassay), are strongly associated with recurrent thrombosis, thrombocytopenia, and recurrent fetal loss in some patients with systemic lupus erythematosus (SLE). The combined presence of APA and these clinical manifestations is termed antiphospholipid syndrome (APS). LAC and ACA comprise heterogeneous and somewhat overlapping autoantibody subsets. To date, it is unclear what degree of heterogeneity is present in an individual patient and between patients. To begin to address these issues, we generated three monoclonal LAC antibodies from a patient with SLE and APS. These antibodies were studied for their binding specificities and variable (V) region nucleotide sequences. All three LAC were unreactive with DNA, cardiolipin or other phospholipids. Sequence analysis of these antibodies revealed extensive overlap in their Ig V genes with anti-DNA antibodies and other autoantibodies characteristic of lupus. These data provide the first V gene sequence information on a group of SLE-derived LAC without ACA activity, representative of a similar subset of LAC found in patients with APS.
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PMID:Immunological and molecular analysis of three monoclonal lupus anticoagulant antibodies from a patient with systemic lupus erythematosus. 948 Jul 22

Antiphospholipid antibodies are a heterogeneous group of antibodies, comprising antibodies with different antigen specificity. Prothrombin is one of the antigens which can be detected by antiphospholipid antibodies and therefore anti-prothrombin antibodies belong to the antiphospholipid antibody family. The presence of antiphospholipid antibodies correlates strongly with thromboembolic complications; however a mechanism by which these autoantibodies induce a thrombotic complication in vivo is not understood. The classic assays for the detection of antiphospholipid antibodies (LAC and anticardiolipin ELISAs) aim to measure all the antiphospholipid antibodies present in the samples without making a distinction between the different subspecificities of the antibodies present in one single sample. Moreover, most of the in-vitro studies performed were carried out with total IgGs, which contain a mixture of antibodies. The absence of an accurate characterization of the plasma samples and the lack of specificity of the IgGs used in in-vitro tests makes it difficult to determine the contribution of antiprothrombin antibodies to the thrombotic complications. Here we review and critically analyse the literature regarding the clinical relevance of the presence of antiprothrombin antibodies and the possible participation of these antibodies in the pathogenesis of the thrombotic complications.
Lupus 1998
PMID:Anti-prothrombin antibodies and their relation with thrombosis and lupus anticoagulant. 981 69

We describe two patients whose initial presentation of systemic lupus erythematosus (SLE) was accompanied by haemorrhagic episodes and significant coagulopathy. Further investigation demonstrated positive lupus anticoagulant and decreased Factor II (prothrombin) activity. Both patients were diagnosed with lupus anticoagulant-hypoprothrombinemia syndrome (LAC-HPS) as a result of non-neutralizing antibodies directed against Factor II. LAC-HPS is a rare clinical entity that can occur in association with SLE, transient viral infections, drug reactions or even in healthy individuals. Mixing studies, which can be affected by other coagulation factor inhibitors, play an important role in the diagnosis of LAC-HPS. Factor VII level was decreased in the second patient, a finding that has not previously been reported in association with SLE. In both patients, bleeding stopped promptly and coagulation studies improved significantly with high dose corticosteroids. We discuss the pathogenesis, diagnosis and management of LAC-HPS in patients with SLE.
Lupus 1999
PMID:Lupus anticoagulant-hypoprothrombinemia syndrome associated with systemic lupus erythematosus: report of 2 cases and review of literature. 1048 36


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