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)

To investigate prevalence of anticardiolipin antibodies (aCL) in patients with Behcet's disease (BD) and to determine whether they are related to anti-beta2-glycoprotein I antibodies (aGPI), we measured aCL and aGPI in 47 patients of BD and 14 patients of systemic lupus erythematosus (SLE). The levels of aCL and aGPI were determined by conventional enzyme immunoassay for both IgG and IgM classes. Twelve (25.5%) patients with BD were positive for IgG or IgM aCL and no patient was positive for aGPI. Eleven (78.6%) patients with SLE were also positive for aCL and among them, 8 (72.7%) patients were positive for aGPI. Positive IgG aCL patients with BD showed lower level of IgG aCL than those with SLE (15.7+/-7.3 vs 34.1+/-16.0 GPL, p<0.05). There was no relation between the presence of aCL in BD and either dinical activity or clinical features. In the patients with BD, aCL are found but it would not be associated with aGPI as they are in patients with SLE. In patients with BD, aCL seem to be authentic aCL unlike those in patients with SLE and may not be related with vascular complications in BD.
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PMID:Anticardiolipin and anti-beta2-glycoprotein I antibodies in Behcet's disease. 974 45

Many of the autoantibodies in antiphospholipid syndrome (APS) are directed against beta2-glycoprotein I (beta2-GPI). Recent studies from our laboratories have indicated that the immunodominant binding epitope(s) for high titer, affinity purified antibodies from 11 APS patients are localized to the amino terminal domain (domain 1) of beta2-GPI. The present study employed surface plasmon resonance to localize the immunodominant domain in serum samples from a large cohort of patients with GPL values ranging from 21 to 230 units (n = 106 patients). Eighty-eight percent of patients showed > or = threefold selectivity for beta2-GPI containing domain 1 relative to the domain deletion mutant that lacked domain 1. The domain 1 binding activity in patient serum was abolished by removing the IgG fraction from the serum and the binding activity could be fully reconstituted with the IgG fraction. Thus, analysis of serum samples from a large cohort of APS patients indicates that the immunodominant binding epitope(s) for anti-beta2 antibodies are localized to the amino terminal domain of beta2-GPI.
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PMID:Beta2-glycoprotein I-dependent anticardiolipin antibodies preferentially bind the amino terminal domain of beta2-glycoprotein I. 1152 8

Atherosclerosis is an autoimmune/inflammatory disease associated with infectious, inflammatory, and autoimmune factors. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and/or progression of atheromatous lesions. Heat-shock protein (hsp), oxidized low-density lipoprotein (LDL), and beta2-GPI have been reported to elicit humoral and cellular immune response in both experimental animals and humans. These autoantigens are expressed within atherosclerotic lesions. Immunization with the given autoantigens elicits an immune response that influences lesion progression. Atherosclerosis susceptibility can be transferred by autoantigen-sensitized lymphocytes from immunized animals. Patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) have a high risk for atherosclerotic cardiovascular events. The traditional risk factors fail to fully account for accelerated atherosclerosis in SLE and APS. Immunological alterations, such as antibodies to oxidized LDL, antiphospholipid antibodies (aPL), antibodies to beta-2 Glycoprotein (anti-beta2-GPL), anti-prothrombin antibodies, may play a role in premature atherosclerosis in SLE and APS. Paraoxonase (PON1) is an enzyme with antioxidant activity attached to the circulating high-density lipoprotein (HDL) in plasma. Its function is to prevent oxidation of LDL, thereby accounting for the antioxidant properties and the atherosclerotic protective effects of HDL. The relationship between PON1 and aPL has been recently suggested. IgG anti-HDL and IgG anti-beta2-GPI antibodies were associated with reduced PON1 activity in patients with SLE and primary APS. The determination of classic and new factors, together with specific autoantibody titers and the use of Doppler carotid ultrasound, are useful methods to detect early atherosclerosis in SLE and PAPS. Therapeutic strategies, including early control of disease and other risk factors, are essential to reduce morbidity and mortality.
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PMID:Atherosclerosis and antiphospholipid syndrome. 1279 63

To study sensitivity and specificity of antibodies to beta 2-glycoprotein I (B2GP-I) and antibodies to cardiolipin (CL) in diagnosis of antiphospholipid syndrome (APS), we examined 19 patients with primary antiphospholid syndrome (PAPS), 23 patients with secondary APS (SAPS) and systemic lupus erythematosus (SLE) and 73 patients with SLE. Antibodies to B2GP-I and CL of IgG isotype were measured at enzyme immunoassay. The levels of IgG aCL and IgG aB2GP-I in the serum of PAPS patients were 69.9 +/- 116.0 GPL, 74.1 +/- 117.4 SGU, respectively; of SAPS and SLE patients 60.5 +/- 68.9 GPL and 66.2 +/- 88.3 SGU, respectively. These values were significantly higher than in SLE patients (19.5 +/- 27.6 GPL, p = 0.0025 and p = 0.0012; 14.5 +/- 41.9 SGU, p = 0.0001, respectively) and donors (3.9 +/- 3.8 GPL, p = 0.0001; 5.7 +/- 1.2 SGU, p = 0.001). By IgG aCL and IgG-aB2GP-I, PAPS and SAPS patients differed insignificantly (p > 0.05), but these values correlated positively (r = 0.85; p < 0.0005 for PAPS and r = 0.9, p < 0.005 for SAPS). Simultaneous detection of IgG aCL and IgG aB2GP-I occurred in 36.8% in PAPS, 52.4% in SAPS and 12.3% in SLE. 10.5% PAPS patients were positive by IgG aCL as well as 9.5% with SAPS and 13.4% with SLE. Isolated rise of IgG aB2GP-I concentration was observed in 21.1% patients with PAPS, in 9.5% patients with SAPS and 9.6% patients with SLE. Of 43 patients with a history of thrombosis, 46.5% were positive by IgG aCL and IgG aB2GP-I, 7.0% positive only by IgG aCL and 11.6% only by IgG aB2GP-I. Levels of IgG aCL and IgG aB2GP-I in patients with thrombosis (64.7 +/- 87.5 GPL and 66.0 +/- 94.8 SGU, respectively) were significantly higher than in patients without them (19.6 +/- 3.8 GPL, p = 0.009 and 16.4 +/- 52.2 SGU, p = 0.0001). In venous thrombosis IgG aCL and IgG aB2GP-I were higher than in arterial thrombosis (p < 0.004). For diagnosis of APS sensitivity and specificity of IgG aB2GP-I and IgG aCL were 60.0 and 83.8%; 57.1 and 73.5% (p > 0.05), respectively. As to thrombosis, the sensitivity and specificity were 58.1 and 84.6%; 54.5 and 72.7% (p > 0.005), respectively. Thus, IgG aB2GP-I is an essential additional marker of APS. In the presence of APS symptoms, but in negative results of APS test it is justified to confirm APS diagnosis by aB2GP-I test results. To make APS diagnosis more accurate, it is valid to make simultaneous measurements of aCL using standard B2GP-I dependent enzyme immunoassay and aB2GP-I.
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PMID:[Antibodies to beta2-glycoprotein I and antibodies to cardiolipin in antiphospholipid syndrome: analysis of sensitivity and specificity]. 1459 87

Antiphospholipid syndrome is considered to be a cause of an acquired hypercoagulable state leading to stroke and transient ischemic attack. Antiphospholipid antibodies (aPL) comprise a heterogeneous group of autoantibodies. Among them, lupus anticoagulant (LA) and beta 2-glycoprotein I dependent anticardiolipin antibody (beta 2-GPI aCL) are important and commonly measured. Recently, LA has been considered to be closely related to phosphatidylserine anti-prothrombin antibody. APL is an independent risk factor for first-ever ischemic stroke and a prognostic marker of recurrent stroke. The precipitating factors for the occurrence of stroke are the presence of beta 2-GPI-dependent aCL, a GPL aCL level of more than 40, and the simultaneous presence of lupus anticoagulant. Several mechanisms are believed to be involved in the thrombotic process in patients with antiphospholipid antibodies. Human activated protein C functions as a potent anticoagulant in human plasma by inhibiting the activity of coagulation cofactors Va and VIIIa. Activation of protein C is impaired in patients with aPL. Recently, the presence of aPL has been considered to be contributory factor for the development of atherosclerotic lesions. Transgenic mouse lacking the LDL receptor develop accelerated arteriosclerosis upon immunization with beta 2-GPL Several therapeutic options are available for the prevention of ischemic stroke in patients with aPL, such as antiplatelet, anticoagulant, and immunosuppressive therapy. The rate of recurrence in patients undergoing antiplatelet and anticoagulation combination therapy was found to be lower than that in patients receiving other forms of therapy. The WARSS-APASS collaborative study showed that there was no difference in the recurrence rate between aPL patients receiving antiplatelet or anticoagulation therapy alone. APL has been investigated in other neurological disorders such as multiple sclerosis, chorea, migraine and convulsion. The association of aPL with multiple sclerosis remains debatable. APL could be a contributory factor for the development of convulsion, but not for migraine.
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PMID:[Neurological aspects in antiphospholipid syndrome]. 1515 54

In this study we evaluated the diagnostic accuracy for antiphospholipid syndrome (APS) of new fully automated immunoassays for anticardiolipin (aCL) and anti-beta2 glycoprotein I (anti-beta2-GPI) auto-antibody detection (EliA-Phadia), and compared the results with those obtained with Orgentec and Inova ELISA methods. Sixty-two APS patients and 123 controls (20 syphilis, 33 Lyme disease, 30 HCV infection and cryoglobulinemia, 40 healthy subjects) were studied. Using the 99(th) percentile cutoff, the sensitivity and specificity of EliA aCL IgG, aCL IgM, anti-beta2-GPI IgG, and anti-beta2-GPI IgM were 69.4% and 81.9%, 64.5% and 86.7%, 64.5% and 98.8%, and 53.2% and 92.8%, respectively. Using the Sydney criteria cutoff (>40 GPL/MPL units), sensitivity and specificity of EliA aCL IgG and aCL IgM were 45.2% and 98.8%, and 35.5% and 97.5%, respectively. The best diagnostic efficiency was obtained combining the aCL tests (>40 GPL/MPL units) with the anti-beta2-GPI tests (sensitivity 85.7%, specificity 90.4%). The area under the ROC curves for EliA, Orgentec, and Inova methods were 0.870, 0.940, and 0.850 for aCL IgG; 0.820, 0.820, and 0.820 for aCL IgM; 0.910, 0.960, and 0.920 for anti-beta2-GPI IgG; 0.840, 0.840, and 0.820 for anti-beta2-GPI IgM, respectively. Finally, the overall agreement between EliA assays and the other two ELISA methods ranged from moderate (anti-beta2-GPI IgG EliA versus Orgentec: Cohen's k = 0.426) to good (anti-beta2-GPI IgM EliA vs. Inova: k = 0.841). In conclusion, newly developed EliA methods for antiphospholipid antibody detection perform similarly to other ELISA assays and represent a useful tool for APS laboratory diagnosis in daily practice.
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PMID:Accuracy of the first fully automated method for anti-cardiolipin and anti-beta2 glycoprotein I antibody detection for the diagnosis of antiphospholipid syndrome. 1975 27

Antiphospholipid antibodies (aPL) are considered to be contributory factors in the development of thrombotic events. The objective of the study was to determine if aPL are involved in the pathogenesis of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus. IgG anticardiolipin antibodies (IgG aCL), lupus anticoagulant (LA), and anti-IgG beta2-glycoprotein I antibodies (anti-beta2-GPI) were prospectively tested in 34 patients with DR (group 1), 20 males and 14 females, range of age 52-79 years, mean age 57 +/- 4.6 years, duration of diabetes 8-15 years, as compared to 29 type 2 diabetic patients without DR (group 2), 19 males and 10 females, range of age 54-77 years, mean age 58 +/- 4.8 years, duration of diabetes 10-13 years, and to 31 controls matched for age and sex (group 3). IgG aCL and anti-beta2-GPI were detected by enzyme-linked immunosorbent assay (ELISA) and LA was detected by activated partial thromboplastin time, kaolin clotting time, dilute Russell's viper venom time, dilute prothrombin time. Comparison between patients and controls and patients group were expressed as relative risk with its 95% confidence interval (RR [95%/CI], where a lower limit > 1.0 was considered significant. All values were determined by Fischer's exact test. A value of p < 0.05 was considered statistically significant. The incidence of IgG aCL positive (low 4-15 GPL U IgG aCL titers) in group 1 was 21/34 (62%) vs. 12/29 (41%) in group 2 (RR 1.460 95% CI [0.9052 to 2.382]), p = 0.1330. The incidence of LA positive in group 1 was 27/34 (79%) vs. 8/29 (28%) in group 2 (RR 3.086 95% CI [1.584 to 6.010]), p < 0.0001. The incidence of anti-IgG beta2-GPI positive in group 1 was 29/34 (85%) vs. 6/29 (21%) in group 2 (RR 4.640 95% CI [2.067-10.418]), p < 0.0001. The results suggest the possible participation of anti-beta2-GPI and LA in the pathogenesis of DR, shifting the hemostatic balance toward a pro-thrombotic state increasing the risk of developing thrombosis.
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PMID:Study of antiphospholipid antibodies in type 2 diabetes mellitus with and without diabetic retinopathy. 2044 42