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1.
Arthritis Rheumatol ; 68(11): 2728-2739, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27332042

RESUMO

OBJECTIVE: Antiphospholipid antibodies (aPL) constitute a diagnostic criterion of systemic lupus erythematosus (SLE), and aPL have been functionally linked to liver disease in patients with SLE. Since the mechanistic target of rapamycin (mTOR) is a regulator of oxidative stress, a pathophysiologic process that contributes to the development of aPL, this study was undertaken in a mouse model of SLE to examine the involvement of liver mitochondria in lupus pathogenesis. METHODS: Mitochondria were isolated from lupus-prone MRL/lpr, C57BL/6.lpr, and MRL mice, age-matched autoimmunity-resistant C57BL/6 mice as negative controls, and transaldolase-deficient mice, a strain that exhibits oxidative stress in the liver. Electron transport chain (ETC) activity was assessed using measurements of oxygen consumption. ETC proteins, which are regulators of mitochondrial homeostasis, and the mTOR complexes mTORC1 and mTORC2 were examined by Western blotting. Anticardiolipin (aCL) and anti-ß2 -glycoprotein I (anti-ß2 GPI) autoantibodies were measured by enzyme-linked immunosorbent assay in mice treated with rapamycin or mice treated with a solvent control. RESULTS: Mitochondrial oxygen consumption was increased in the livers of 4-week-old, disease-free MRL/lpr mice relative to age-matched controls. Levels of the mitophagy initiator dynamin-related protein 1 (Drp1) were depleted while the activity of mTORC1 was increased in MRL/lpr mice. In turn, mTORC2 activity was decreased in MRL and MRL/lpr mice. In addition, levels of aCL and anti-ß2 GPI were elevated preceding the development of nephritis in 4-week-old MRL, C57BL/6.lpr, and MRL/lpr mice. Transaldolase-deficient mice showed increased oxygen consumption, depletion of Drp1, activation of mTORC1, and elevated expression of NADH:ubiquinone oxidoreductase core subunit S3 (NDUFS3), a pro-oxidant subunit of ETC complex I, as well as increased production of aCL and anti-ß2 GPI autoantibodies. Treatment with rapamycin selectively blocked mTORC1 activation, NDUFS3 expression, and aPL production both in transaldolase-deficient mice and in lupus-prone mice. CONCLUSION: In lupus-prone mice, mTORC1-dependent mitochondrial dysfunction contributes to the generation of aPL, suggesting that such mechanisms may represent a treatment target in patients with SLE.


Assuntos
Anticorpos Antifosfolipídeos/biossíntese , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Mitocôndrias Hepáticas/metabolismo , Complexos Multiproteicos/metabolismo , Estresse Oxidativo/imunologia , Consumo de Oxigênio/imunologia , Serina-Treonina Quinases TOR/metabolismo , Animais , Anticorpos Anticardiolipina/biossíntese , Anticorpos Anticardiolipina/efeitos dos fármacos , Anticorpos Anticardiolipina/imunologia , Anticorpos Antifosfolipídeos/efeitos dos fármacos , Anticorpos Antifosfolipídeos/imunologia , Formação de Anticorpos/efeitos dos fármacos , Formação de Anticorpos/imunologia , Western Blotting , Modelos Animais de Doenças , Dinaminas/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Feminino , Imunossupressores/farmacologia , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Camundongos Knockout , Mitocôndrias Hepáticas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Sirolimo/farmacologia , Transaldolase/genética , beta 2-Glicoproteína I/imunologia
2.
Arch Dermatol Res ; 305(2): 173-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22836779

RESUMO

Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis and is known as an immunoglobulin (Ig) A related immune complex-mediated disease. However, the molecular mechanisms in the development of HSP are not yet fully understood. Herein, we investigated the serum levels of Interleukin (IL)-33 and soluble ST2 (sST2) in HSP patients and their association with disease severity and IgA autoantibodies production. The serum levels of IL-33 and sST2 were measured by double antibody sandwich enzyme-linked immunosorbent assay (ELISA) in the serum of 33 patients with HSP and 22 controls. Serum levels of IgA anti-endothelial cell antibodies (AECA) and IgA anticardiolipin antibodies (ACA) in HSP patients were detected by double antigen sandwich ELISA. Our results indicated that serum levels of IL-33 but not sST2 were significantly elevated in patients with HSP in acute stage and restored to normal levels in convalescent stage. Moreover, serum IL-33 levels were correlated with the severity of HSP and serum concentrations of AECA-IgA and ACA-IgA. Taken together, we show firstly that serum IL-33 is abnormally elevated in HSP patients. IL-33 might be associated with the IgA autoantibodies production in the pathogenesis of HSP.


Assuntos
Vasculite por IgA/diagnóstico , Interleucinas/sangue , Adolescente , Adulto , Anticorpos Anticardiolipina/biossíntese , Anticorpos Anticardiolipina/sangue , Autoanticorpos/biossíntese , Autoanticorpos/sangue , Criança , Progressão da Doença , Feminino , Humanos , Vasculite por IgA/sangue , Vasculite por IgA/imunologia , Imunoglobulina A/biossíntese , Imunoglobulina A/sangue , Proteína 1 Semelhante a Receptor de Interleucina-1 , Interleucina-33 , Masculino , Receptores de Superfície Celular/sangue , Adulto Jovem
3.
J Thromb Haemost ; 4(10): 2210-4, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16856974

RESUMO

BACKGROUND: Recent reports show an apparent large number of individuals with low to moderate titers of anticardiolipin antibodies (ACA), particularly of the IgM isotype with no clinical signs of antiphospholipid syndrome (APS). The significance of these results is unknown. This study examined the prevalence of low positive titers of IgM ACA antibodies in a large number (n = 982) of normal blood donors (Group 1) and in a group of 159 individuals > 60 years of age (Group 2). The effect of re-defining the currently used cut-off values for the IgM ACA tests was also examined. METHODS: IgM ACA antibodies were tested in three ELISA assays: the Bindazyme Anti-IgM Cardiolipin EIA kit (assay A), an 'in-house' ACA test (assay B), and the APhL ELISA kit (assay C). RESULTS: THE normal range cut-offs were re-calculated using the 95th percentile of the data for Group 1 (12.4 MPL U mL(-1) for assay A, 5.4 MPL U mL(-1) for assay B and 9.5 MPL U mL(-1) for assay C) and Group 2 (9.9 MPL U mL(-1) for assay A, 5.5 MPL U mL(-1) for assay B and 13.2 MPL U mL(-1) for assay C). These values were not significantly different from the current cut-off values for each assay. The prevalence of low positive results in Group 1 relative to the re-defined cut-off for that group were: 1.0%, 1.1% and 0.9% in assay A, B and C; and in Group 2: 0.6%, 0.6% and 0.6%, respectively. An indeterminate zone (between the 95th and 99th percentile) was then established for the two groups. The prevalence in Group 1 was 3.8%, 3.9% and 3.9% for assays A, B and C, respectively, and for Group 2: 4.4% in all three assays. CONCLUSIONS: The data confirm that the current cut-off point for each of the three assays is correct. We suggest based on this study that the low positive range is re-assigned 'indeterminate' and recommend that samples falling in this category should be retested to confirm positivity at a later date.


Assuntos
Anticorpos Anticardiolipina/biossíntese , Anticorpos Anticardiolipina/imunologia , Síndrome Antifosfolipídica/sangue , Síndrome Antifosfolipídica/diagnóstico , Síndrome Antifosfolipídica/imunologia , Química Clínica/normas , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina M/química , Adolescente , Adulto , Idoso , Autoanticorpos/química , Testes de Coagulação Sanguínea , Química Clínica/métodos , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Reprodutibilidade dos Testes
4.
Clin Exp Immunol ; 142(2): 377-80, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16232227

RESUMO

This study was undertaken to evaluate the possible role of hepatitis B recombinant vaccine inducing the synthesis of IgG and IgM anti-cardiolipin antibodies (aCL), antibodies against beta(2)GPI (anti-beta(2)GPI), lupus anti-coagulant (LA), anti-nuclear antibodies and antibodies against extractable nuclear antigens (anti-ENA). The study population consisted of 85 healthy students (63 female, 22 male; mean age 20.8 years), vaccinated with three doses of recombinant DNA hepatitis B vaccine. One month after vaccination with the first dose of hepatitis B vaccine a minority of vaccinated individuals showed changes in IgG or IgM aCL or anti-beta(2)GPI or LA activity (P < 0.001). Among subjects in whom changes of IgG anti-beta(2)GPI were observed, a significantly higher number of increased (8/85) than decreased (2/85) values were found (P < 0.01). Analyses of paired data showed that differences in aCL or anti-beta(2)GPI levels before vaccination or 1 month later did not reach statistical significance. In two people aCL transitorily reached medium positivity after the first dose of hepatitis B vaccine with a drop 5 months later. Similar evident anti-beta(2)GPI fluctuation was also observed in one person. Another participant was initially low positive for IgG anti-beta2GPI and the levels were increasing after vaccination. Two participants became positive for anti-nuclear antibodies during 6 months' follow-up. There were no sex-dependent differences in tested antibodies observed and no associations between levels of aPL and levels of anti-HBV antibodies. We conclude that HBV can induce aPL, although rarely. In genetically susceptible individuals or together with some other triggers such combination might confer the risk of developing a continuous autoimmune response in an individual.


Assuntos
Anticorpos Antifosfolipídeos/biossíntese , Vacinas contra Hepatite B/imunologia , Vacinas Sintéticas/imunologia , Adulto , Anticorpos Anticardiolipina/biossíntese , Autoimunidade , Feminino , Glicoproteínas/imunologia , Humanos , Esquemas de Imunização , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Inibidor de Coagulação do Lúpus/biossíntese , Masculino , Vacinação , beta 2-Glicoproteína I
5.
Thromb Haemost ; 93(5): 867-71, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15886801

RESUMO

From 1998 to 2003, 133 Caucasian women aged 17-40 years (median 29 years) suffering from unexplained recurrent miscarriage (uRM) were consecutively enrolled. In patients and 133 age-matched healthy controls prothrombotic risk factors (factor V (FV) G1691A, factor II (FII) G20210A, MTHFR T677T, 4G/5G plasminogen activator inhibitor (PAI)-1, lipoprotein (Lp) (a), protein C (PC), protein S (PS), antithrombin (AT), antiphospholipid/anticardiolipin (APA/ACA) antibodies) as well as associated environmental conditions (smoking and obesity) were investigated. 70 (52.6%) of the patients had at least one prothrombotic risk factor compared with 26 control women (19.5%; p<0.0001). Body mass index (BMI; p=0.78) and smoking habits (p=0.44) did not differ significantly between the groups investigated. Upon univariate analysis the heterozygous FV mutation, Lp(a) > 30 mg/dL, increased APA/ACA and BMI > 25 kg/m(2) in combination with a prothrombotic risk factor were found to be significantly associated with uRM. In multivariate analysis, increased Lp(a) (odds ratio (OR): 4.7/95% confidence interval (CI): 2.0-10.7), the FV mutation (OR:3.8/CI:1.4-10.7), and increased APA/ACA (OR: 4.5/CI: 1.1-17.7) had independent associations with uRM.


Assuntos
Aborto Habitual/sangue , Lipoproteína(a)/química , Trombose/sangue , Aborto Habitual/diagnóstico , Adolescente , Adulto , Anticorpos Anticardiolipina/biossíntese , Anticorpos Antifosfolipídeos/sangue , Anticoagulantes/farmacologia , Antitrombinas/biossíntese , Índice de Massa Corporal , Estudos de Casos e Controles , Fator V/biossíntese , Feminino , Seguimentos , Heterozigoto , Humanos , Lipoproteína(a)/biossíntese , Modelos Logísticos , Metilenotetra-Hidrofolato Desidrogenase (NAD+)/biossíntese , Análise Multivariada , Mutação , Razão de Chances , Inibidor 1 de Ativador de Plasminogênio/biossíntese , Proteína C/biossíntese , Proteína S/biossíntese , Protrombina/biossíntese , Fatores de Risco , Trombose/diagnóstico
6.
J Thromb Haemost ; 3(5): 929-34, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15869586

RESUMO

BACKGROUND: In recent years there has been a significant increase in the diagnosis of sudden sensorineural hearing loss (SSHL) in western, countries with an incidence of 20 of 100,000 people affected every year. No clear causes for this disease have been found thus far, but cochlear ischemia has been hypothesized in patients in whom an infectious episode or acoustic neurinoma have been excluded. OBJECTIVES: The aim of this case-control study was to investigate a number of acquired and inherited thrombophilic risk factors [antithrombin, protein C and S; factor V (FV) Leiden, FII polymorphism; lupus anticoagulant (LA); anticardiolipin (aCL) antibodies; fasting homocysteine (Hcy); lipoprotein(a) (Lp(a)); plasminogen activator inhibitor-1 (PAI-1)] in addition to cardiovascular risk factors in patients with idiopathic SSHL (ISSHL). PATIENTS AND METHODS: We investigated 155 patients (67 male/88 female; age: 55 (range 19-79 years) with a diagnosis of ISSHL within 30 days from the onset of symptoms, and 155 controls (67 male/88 female; age 54 (range 19-78 years). Fasting Hcy levels were significantly higher in patients than in controls [11.6 (6.7-60) micromol/L vs. 8.7 (5.0-24) micromol/L] as well as PAI-1 levels [19 (2-95) mg/dL vs. 14.5 (4.0-87) mg/dL]. Lupus anticoagulant was present in 13 of 155 (8.4%) patients; 20 patients (12.9%) had positivity of aCL (four IgM and 16 IgG). In no patient was a deficiency of physiological clotting inhibitors antithrombin, protein C and protein S found. No significant differences between patients and controls were observed for Lp(a) plasma levels [111 (1-1146) mg/L vs. 103 (11-695) mg/L] and for the presence of FV Leiden (4.5% vs. 4.5%) and FII variant G20210A (3.8% vs. 3.2%). RESULTS AND CONCLUSIONS: Independent risk factors for ISSHL at the multivariate analysis (adjusted for age, sex and the traditional cardiovascular risk factors) were the positivity of aCL: OR 5.6 (95% CI 2.0-15.3); cholesterol levels within the second and third tertiles (with respect to the first tertile): T2 = OR 4.8 (95% CI 1.9-12.6)/T3 = OR 19 (95% CI 7-50.1); PAI-1 and Hcy levels within the third tertile (with respect to the first tertile): OR 20 (95% CI 7.8-78) and OR 4.0 (95% CI 2.0-8.1), respectively. These preliminary data suggest that hypercholesterolemia, hyperhomocysteinemia, elevated PAI-1 levels and anticardiolipin antibodies are associated with ISSHL, so indirectly supporting the hypothesis of a vascular occlusion in the pathogenesis of the disease.


Assuntos
Perda Auditiva Neurossensorial/diagnóstico , Trombofilia/diagnóstico , Adulto , Idoso , Anticorpos Anticardiolipina/biossíntese , Antitrombinas/biossíntese , Estudos de Casos e Controles , Fator V/genética , Feminino , Perda Auditiva Neurossensorial/complicações , Homocisteína/biossíntese , Humanos , Hipercolesterolemia/complicações , Hiper-Homocisteinemia/complicações , Lipoproteína(a)/biossíntese , Inibidor de Coagulação do Lúpus/biossíntese , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Inibidor 1 de Ativador de Plasminogênio/biossíntese , Proteína C/biossíntese , Proteína S/biossíntese , Fatores de Risco , Fatores de Tempo
7.
AIDS Patient Care STDS ; 18(6): 333-40, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15294083

RESUMO

There is a high incidence of antiphospholipid antibodies, detected by assays for anticardiolipin or lupus-like anticoagulant, in HIV disease. However, a link to the antiphospholipid syndrome, with clinical thrombosis, is tenuous. We report a case of a 25-year-old man with undetermined risk factors for HIV presenting with possible antiphospholipid syndrome manifesting as necrotic skin lesions as the initial clinical presentation for HIV. We also review the literature exploring the association between HIV and antiphospholipid syndrome.


Assuntos
Anticorpos Antifosfolipídeos/biossíntese , Síndrome Antifosfolipídica/virologia , Infecções por HIV/complicações , Infecções por HIV/imunologia , Adulto , Anticorpos Anticardiolipina/biossíntese , Humanos , Masculino , Necrose , Dermatopatias/imunologia , Dermatopatias/patologia , Dermatopatias/virologia , Trombose/imunologia , Trombose/patologia , Trombose/virologia
8.
J Lab Clin Med ; 140(5): 336-41, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12434135

RESUMO

Antiphospholipid antibodies (aPLs) are a heterogeneous family of antibodies found in autoimmune disorders, infectious diseases, and other situations. The presence of different aPLs has been associated with various clinical manifestations of the antiphospholipid syndrome (APS). The objective of this study was to investigate the prevalence of aPLs in a group of 90 Chilean patients with systemic lupus erytematosus (SLE) and 90 healthy controls. We measured anticardiolipin antibodies (aCLs), antiphosphatidylserine antibodies (aPSs), anti-beta(2) glycoprotein I antibodies (anti-beta(2)GPIs), and antiprothrombin antibodies (aPTs) with an enzyme-linked immunosorbent technique using "in-house" assays. Fifty-four of 90 SLE patients (60.0%) had some type of aPL. Forty of 90 (44.4%) were positive for aCLs, 9 of 61 (14.8%) had aPSs, 21 of 90 (23.3%) had anti-beta(2)GPIs, and 18 of 90 (20.0%) had aPTs. In the control group, prevalences were as follows: aCLs, 3.3%; aPSs, 1.1%; anti-beta(2)GPIs, 1.1%; aPTs, 2.2%. In most cases, values were in the low-positive range. Of all aPL detected, 29.5% was of the IgG isotype, 37.5% IgM, and 33.0% IgA. We observed a correlation between aCLs and aPSs and of these antibodies with anti-beta(2)GPIs and aPTs but not between anti-beta(2)GPIs and aPTs. Our results show a high prevalence of aPLs in SLE patients. An association between different specificities and isotypes of aPLs was also observed.


Assuntos
Anticorpos Antifosfolipídeos/biossíntese , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Anticorpos Anticardiolipina/biossíntese , Chile , Ensaio de Imunoadsorção Enzimática , Feminino , Glicoproteínas/imunologia , Humanos , Isotipos de Imunoglobulinas/biossíntese , Masculino , Fosfatidilserinas/imunologia , beta 2-Glicoproteína I
9.
J Immunol ; 168(6): 2689-94, 2002 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11884434

RESUMO

Infection with Mycobacterium tuberculosis induces Abs against a vast array of mycobacterial lipids and glycolipids. One of the most prominent lipid Ags recognized is cardiolipin (CL). The kinetics of the generation of anti-CL Abs during infection reveals that IgM titers to CL increase over time. Interestingly, at day 30 postinfection CL-specific IgG1 appears, an isotype usually dependent on T cell help. Using an immunization schedule with CL/anti-CL Ab complexes, which induces antiphospholipid syndrome in mice, we show that the generation of IgG1 to CL requires IL-4 and that optimal production is T cell dependent. IgG1 production to CL was impaired in nude (nu/nu) mice devoid in conventional T cells, but was not affected in mice deficient for either alphabeta TCR(+), gammadelta TCR(+), CD4(+), CD8(+), or NK1.1(+) T cells. We conclude that IgG1 production to CL depends on T cell help and IL-4, which can be provided by different T cell populations. This is the first report that IL-4 is indispensable for the induction of IgG1 Abs to lipid Ags.


Assuntos
Anticorpos Anticardiolipina/biossíntese , Imunoglobulina G/biossíntese , Interleucina-4/fisiologia , Subpopulações de Linfócitos T/fisiologia , Animais , Anticorpos Anticardiolipina/sangue , Complexo Antígeno-Anticorpo/administração & dosagem , Complexo Antígeno-Anticorpo/imunologia , Cardiolipinas/administração & dosagem , Cardiolipinas/imunologia , Feminino , Soros Imunes/metabolismo , Esquemas de Imunização , Switching de Imunoglobulina/genética , Injeções Subcutâneas , Metabolismo dos Lipídeos , Lipídeos/imunologia , Linfopenia/genética , Linfopenia/imunologia , Linfopenia/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Mycobacterium tuberculosis/imunologia , Subpopulações de Linfócitos T/patologia , Linfócitos T Auxiliares-Indutores/fisiologia , Tuberculose/imunologia
10.
Am J Pathol ; 159(5): 1957-69, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11696457

RESUMO

Bovine thrombin is used as an aid to hemostasis in medical and surgical procedures. At least 500,000 Americans are exposed to this therapeutic annually and reports suggest that exposure is associated with the development of autoreactive antibodies. To determine whether bovine thrombin can induce pathological autoimmunity we exposed nonautoimmune-prone galactose-alpha1-3-galactose-deficient mice to the two bovine thrombin preparations currently approved for use in the United States. We found that, like humans exposed to bovine thrombin, mice developed an immune response against the therapeutic and the xenogeneic carbohydrate galactose-alpha1-3-galactose, and some mice developed autoantibodies against clotting factors. Further, unexpectedly, a single exposure to this therapeutic also induced autoimmunity with features characteristic of systemic lupus erythematosus including antibodies against nuclear antigens, native DNA, double-stranded DNA, and cardiolipin. High levels of these autoantibodies correlated with glomerulonephritis in all mice evaluated. This autoimmune syndrome was detected in mice 15 weeks after a secondary exposure to bovine thrombin and female mice were found to develop the syndrome at a significantly greater frequency than males. Thus, these studies indicate that exposure to bovine thrombin preparations can induce a pathological systemic autoimmune syndrome with lupus-like serology.


Assuntos
Autoimunidade/imunologia , Trombina/administração & dosagem , Trombina/imunologia , Administração Tópica , Animais , Anticorpos/imunologia , Anticorpos Anticardiolipina/biossíntese , Anticorpos Antinucleares/análise , Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Doenças Autoimunes/psicologia , Comportamento Animal , Bovinos , DNA/imunologia , DNA de Cadeia Simples/imunologia , Feminino , Galactosiltransferases/genética , Galactosiltransferases/imunologia , Masculino , Camundongos , Camundongos Knockout/genética , Microscopia Eletrônica , Fatores de Tempo
11.
Blood ; 98(6): 1760-4, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11535509

RESUMO

The pathogenetic role and the clinical importance of the presence of antiphospholipid antibodies (APAs) in patients with immune thrombocytopenic purpura (ITP) are not clear. In this study, the prevalence and clinical significance of APAs were investigated in patients with ITP. Eighty-two newly diagnosed ITP patients were prospectively studied. They were evaluated for the presence of lupus anticoagulant (LA) and immunoglobulin G/M anticardiolipin antibodies (ACAs). Thirty-one patients (37.8%) were APA positive at diagnosis. No statistically significant differences were found between the APA-positive and APA-negative groups regarding gender, initial platelet counts, or response to methylprednisolone therapy. After 5 years of follow-up, cumulative thrombosis-free survival of APA-positive (n = 31) and APA-negative (n = 51) ITP patients was 39% and 97.7%, respectively. A significant difference was found between these groups by log-rank test (P =.0004). In addition, LA was an important risk marker for the development of thrombosis in ITP patients. After a median follow-up of 38 months, 14 ITP patients (45%) who had APA positivity developed clinical features (thrombosis or fetal losses) of antiphospholipid syndrome (APS). There were no differences between the APA-positive patients with and without APS regarding the initial platelet counts, response to the therapy, or ACA positivity. The positivity rate for LA was significantly higher in those patients with ITP who developed APS (chi(2): P =.0036; relative risk 7.15; 95% confidence interval, 1.7-47). In conclusion, this study indicates that a significant proportion of patients initially presenting with ITP and APA positivity developed APS. In patients with ITP, the persistent presence of APAs is an important risk factor for the development of APS.


Assuntos
Anticorpos Anticardiolipina/biossíntese , Síndrome Antifosfolipídica/diagnóstico , Síndrome Antifosfolipídica/imunologia , Inibidor de Coagulação do Lúpus/biossíntese , Púrpura Trombocitopênica Idiopática/diagnóstico , Adolescente , Adulto , Idoso , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Trombose/diagnóstico
12.
Clin Exp Immunol ; 125(2): 211-5, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11529911

RESUMO

The two main entities of open-angle glaucoma are primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). Both diseases may be associated with autoimmune processes. Therefore, IgG and IgM antibodies to phospholipids (APL) and their subspecies cardiolipin (ACL), phosphatidylserine (APS) and beta2-glycoprotein (beta2GP) were determined in 43 NTG patients, 40 POAG patients and 40 healthy controls in a prospective study. The most prominent observation was the increase in APS concentrations in NTG patients (IgG 20.6 +/- 2.7 U/ml, IgM 24.4 +/- 3.4 U/ml) compared with POAG patients (IgG 8.8 +/- 1.2 U/ml, IgM 11.0 +/- 1.7), and controls (IgG 7.7 +/- 1.3 U/ml, IgM 12.8 +/- 1.5 U/ml). APS may be important due to their binding specificity to phosphatidylserine molecules which become accessible during apoptosis; this in turn may lead to local thrombosis.


Assuntos
Anticorpos Antifosfolipídeos/biossíntese , Glaucoma de Ângulo Aberto/imunologia , Fosfatidilserinas/imunologia , Idoso , Anticorpos Anticardiolipina/biossíntese , Feminino , Glicoproteínas/imunologia , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Masculino , Pessoa de Meia-Idade , beta 2-Glicoproteína I
14.
Eur J Biochem ; 267(6): 1770-6, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10712609

RESUMO

Apolipoprotein H (apoH, protein; APOH, gene) binds to negatively charged phospholipids, which triggers the production of a subset of autoantibodies against phospholipid in patients with autoimmune diseases. We have demonstrated that two naturally occurring missense mutations in the fifth domain of apoH, Trp316Ser and Cys306Gly, disrupt the binding of native apoH to phosphatidylserine [Sanghera, D. K., Wagenknecht, D. R., McIntyre, J. A. & Kamboh, M. I. (1997) Hum. Mol. Genet. 6, 311-316]. To confirm whether these are functional mutations, we mutagenized APOH cDNAs and transiently expressed them in COS-1 cells. The cardiolipin ELISA of wild-type and mutant recombinant apoH confirmed that the Gly306 and Ser316 mutations are responsible for abolishing the binding of recombinant apoH to cardiolipin. These mutations, however, had no effect on the levels of expression or secretion of recombinant apoH in transfected COS-1 cells. While the Cys306Gly mutation disrupts a disulfide bond between Cys306 and Cys281, which appears to be critical for clustering positively charged amino acids, the Trp316Ser mutation affects the integrity of an evolutionarily conserved hydrophobic sequence at position 313-316 (Leu-Ala-Phe-Trp), which is hypothesized to interact with anionic phospholipid. To test this hypothesis, we exchanged the remaining three hydrophobic amino acids with neutral amino acids by site-directed mutagenesis (Leu313Gly, Ala314Ser and Phe315Ser). Binding of the Leu313Gly and Phe315Ser mutants to cardiolipin was significantly reduced to 25% and 13%, respectively, of that of the wild-type. On the other hand, the Ala314Ser mutation showed normal cardiolipin binding. Taken together with our previous findings, these results strongly suggest that the configuration of the fifth domain of apoH, as well as the integrity of the highly conserved hydrophobic amino acids at positions 313-316, is essential for the binding of apoH to anionic phospholipid.


Assuntos
Cardiolipinas/metabolismo , Glicoproteínas/química , Substituição de Aminoácidos , Animais , Anticorpos Anticardiolipina/biossíntese , Células COS , Fenômenos Químicos , Físico-Química , Chlorocebus aethiops , Códon/genética , DNA Complementar/genética , Ensaio de Imunoadsorção Enzimática , Genótipo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Humanos , Mutagênese Sítio-Dirigida , Fosfatidilserinas/metabolismo , Mutação Puntual , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/metabolismo , Transfecção , beta 2-Glicoproteína I
15.
Lupus ; 7 Suppl 2: S166-9, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9814697

RESUMO

Antiphospholipid syndrome is characterized by a prothrombotic state and the presence of beta2-glycoprotein I (beta2-GPI)-dependent antiphospholipid antibodies. The feasibility of a B cell tolerance-based approach for specific reduction of anti-beta2-GPI antibodies was investigated. Anti-beta2-GPI antibodies isolated from a patient with antiphospholipid syndrome were used to screen peptide libraries expressed in phage, resulting in the identification of a phage that specifically bound anti-beta2-GPI antibodies. The phage-displayed peptide was identified and chemically optimized to generate a synthetic 14-mer peptide with an internal thioether linkage (LJP 685) that retained the binding profile of the original phage. LJP 685 was conjugated to a defined, non-immunogenic organic platform to generate a tetravalent presentation of LJP 685 for use as a toleragen. Tetravalent LJP 685 induced a dose-dependent reduction in antibody levels in mice previously immunized and boosted with LJP 685 coupled to the carrier keyhole limpet hemocyanin. These experiments support the technical feasibility of a tolerance-based approach for reducing anti-beta2-GPI antibodies in vivo.


Assuntos
Anticorpos Anticardiolipina/imunologia , Síndrome Antifosfolipídica/terapia , Autoantígenos/imunologia , Doenças Autoimunes/terapia , Linfócitos B/imunologia , Dessensibilização Imunológica , Epitopos/imunologia , Glicoproteínas/imunologia , Oligonucleotídeos/uso terapêutico , Fragmentos de Peptídeos/imunologia , Peptídeos Cíclicos/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Anticardiolipina/biossíntese , Anticorpos Anticardiolipina/isolamento & purificação , Especificidade de Anticorpos , Síndrome Antifosfolipídica/imunologia , Doenças Autoimunes/imunologia , Bacteriófagos/genética , Cromatografia de Afinidade , Anergia Clonal , Epitopos/isolamento & purificação , Estudos de Viabilidade , Feminino , Vetores Genéticos/genética , Glicoproteínas/química , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Dados de Sequência Molecular , Oligonucleotídeos/química , Oligonucleotídeos/imunologia , Fragmentos de Peptídeos/genética , Peptídeos Cíclicos/genética , beta 2-Glicoproteína I
16.
J Autoimmun ; 11(5): 413-24, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9802924

RESUMO

The target of many anti-phospholipid autoantibodies (aPL) has been shown to be a complex between anionic phospholipid and the plasma protein beta2-glycoprotein I (beta2GPI) or the protein beta2GPI alone. As aPL binding studies have been performed almost exclusively in vitrothe identity of the natural target and/or immunogen for aPL in vivo remains undetermined. The anionic phospholipids of cell membranes represent an important potential target and immunogen for aPL. Although anionic phospholipids are normally absent from the extracellular surface of cell membranes, they redistribute from the inner to the outer leaflet during apoptosis. We have previously shown that beta2GPI binds selectively to the surface of apoptotic, but not viable, cells, and that binding of beta2GPI to the surface of apoptotic cells generates an epitope recognized by aPL from patients with primary aPL syndrome and systemic lupus erythematosus. We show here that immunization of non-autoimmune mice with beta2GPI combined with, or bound to, apoptotic cells induces aPL and lupus anticoagulant activity. Generation of aPL required heterologous beta2GPI, and occurred upon immunization with apoptotic cells and beta2GPI by three different routes of administration. Importantly, for intravenous immuniz-ations, generation of aPL occurred only when apoptotic cells and beta2GPI were injected together, but not when either was injected alone, suggesting that cell-bound beta2GPI is the true immunogen for production of aPL. Unlike other models of induced aPL, adjuvant was not an absolute requirement. Induced aPL reacted with murine, as well as bovine, beta2GPI, suggesting that heterologous beta2GPI bound to apoptotic cells can break tolerance and induce auto-antibodies reactive with autologous beta2GPI. Combined with our previous data, these results show that apoptotic cells can serve as both immunogens and natural targets for aPL.


Assuntos
Anticorpos Antifosfolipídeos/biossíntese , Apoptose/imunologia , Glicoproteínas/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Animais , Anticorpos Anticardiolipina/biossíntese , Autoimunidade , Bovinos , Glicoproteínas/administração & dosagem , Humanos , Imunização , Técnicas In Vitro , Injeções Intraperitoneais , Injeções Intravenosas , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos BALB C , Especificidade da Espécie , beta 2-Glicoproteína I
17.
J Autoimmun ; 10(2): 115-25, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9185873

RESUMO

Antibodies to cardiolipin, in humans, have been associated with a variety of autoimmune disorders including anti-phospholipid syndrome, systemic lupus erythematosus and Sjögren's syndrome. These antibodies have also been demonstrated in autoimmune-prone MRL-Mp-lpr/lpr (MRL/lpr), BXSB-Mp-(+yaa) (BXSB) and (NZW x BXSB)F1 mice. In previous work, we had shown that gonadectomized or intact male and female non-autoimmune C57BL/6 mice, upon treatment with estrogen, express autoantibodies to cardiolipin. In this study, we extend these findings and show that the expression of these antibodies persists for months even after the exposure to exogenous estrogen has been terminated. These antibodies are of IgM and IgG, but not IgA, isotypes, and the predominant IgG subisotype is IgG2b. Estrogen-induced antibodies to cardiolipin only minimally cross-reacted with DNA, actin or ovalbumin. The binding of antibodies to cardiolipin from autoimmune human patients in general has been shown to depend upon the presence of a cofactor, beta2-glycoprotein I. We found that in estrogen-treated C57BL/6 mice, as well as in SLE-prone MRL/lpr and BXSB mice, the binding of anti-cardiolipin antibodies to cardiolipin was not enhanced, but rather reduced, in the presence of human beta2-glycoprotein I. Further, addition of exogenous human beta2-glycoprotein I to purified immunoglobulin fractions containing anti-cardiolipin antibodies reduces, rather than enhances, the binding to cardiolipin. Together, these data show that persistent detectable levels of IgG and IgM autoantibodies specific for cardiolipin can be induced in normal mice by estrogen treatment alone (i.e. without administration of autoantigens). Further, we characterize these antibodies regarding their kinetics, cross-reactivity, isotype distribution and cofactor (beta2-glycoprotein I) requirements.


Assuntos
Anticorpos Anticardiolipina/química , Doenças Autoimunes/imunologia , Estradiol/farmacologia , Animais , Anticorpos Anticardiolipina/biossíntese , Anticorpos Anticardiolipina/metabolismo , Sítios de Ligação de Anticorpos/efeitos dos fármacos , Cardiolipinas/metabolismo , Reações Cruzadas , Feminino , Glicoproteínas/farmacologia , Humanos , Isotipos de Imunoglobulinas/análise , Imunoglobulinas/isolamento & purificação , Imunoglobulinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Camundongos Mutantes , beta 2-Glicoproteína I
18.
Clin Exp Rheumatol ; 14(4): 359-66, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8871833

RESUMO

OBJECTIVE: The effects of the superantigens (SAgs) Staphylococcal Enterotoxin B (SEB), Toxic Shock Syndrome Toxin-1 (TSST-1) and Mycoplasma Arthritidis Mitogen (MAM) were examined on the induction and on the course of experimental SLE-like disease. METHODS: Immunization of BALB/c mice with human anti-DNA mAb (MIV-7) carrying the pathogenic idiotype 16/6 emulsified in complete Freund's adjuvant (CFA), followed by a boost of MIV-7/PBS 3 weeks later, generated an experimental SLE via an idiotypic dysregulation. RESULTS: After immunization with MIV-7/SAg, replacing the MIV-7 boost by SAg, and then injecting SAg 7 weeks after the regular induction of the SLE-like disease, the mice failed to produce anti-hIgM and dsDNA Ab up to 6 months after the induction. The mice immunized with MIV-7/CFA and boosted with the SAg had high titers of anti-hIgM but no detectable anti-dsDNA Ab. In both experimental groups low titers of anti-CL Abs developed in 25/40 (62%) and 30/38 (79%) of the mice respectively, including the control mice immunized with non-pathogenic human IgM/SAg or PBS/SAg. The mice immunized according to the "classical" protocol showed increased titers of anti-dsDNA Ab (22%) and anti-CL Ab (28%) during 10 weeks of observation. In contrast SEB, TSST-1 and MAM induced a 29%, 1% and 17% reduction in the anti-DNA titers and a 32%, 15% and 12% reduction in the anti-CL titers, respectively. CONCLUSIONS: These data suggest that the SAg tested here cannot replace the effect of CFA in the induction of the primary humoral response. The SAgs TSST-1, SEB and MAM did not induce the SLE-like disease following idiotypic modulation. Moreover, they may have had a suppressive effect on the idiotypic network in our model. The appearance of anti-CL Abs in almost all the experimental groups including the naive mice supports the possibility that microbial SAgs can induce the production of autoantibodies by different mechanisms. The SAgs TSST-1, SEB and MAM reduced autoantibody production in the serologically established idiotypic-induced experimental SLE-like murine model. This beneficial effect may indicate new directions for research on the management of SLE.


Assuntos
Anticorpos Antinucleares/biossíntese , Autoanticorpos/biossíntese , Toxinas Bacterianas , Idiótipos de Imunoglobulinas/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Superantígenos/imunologia , Animais , Anticorpos Anticardiolipina/biossíntese , Antígenos , Antígenos de Bactérias , Autoimunidade/imunologia , Modelos Animais de Doenças , Enterotoxinas/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Adjuvante de Freund/imunologia , Imunização Secundária , Imunoglobulina M/imunologia , Lúpus Eritematoso Sistêmico/induzido quimicamente , Camundongos , Camundongos Endogâmicos BALB C , Mitógenos/imunologia , Proteínas , Staphylococcus aureus/imunologia
19.
Semin Arthritis Rheum ; 25(6): 414-20, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8792513

RESUMO

Whether a genetic predisposition to develop the antiphospholipid syndrome (APS) and to produce anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC) exists has been addressed by family studies and by population studies on primary APS and on aCL in diseases other than primary APS. Various studies suggest a familial occurrence of aCL and LAC, with or without clinical evidence of APS. This familial tendency could be genetically determined, because APS, aCL, and LAC occur in families carrying haplotypes which contain HLA-DR4, -DR7, and -DRw53. Population studies on primary APS also indicate that HLA genes have a role in conferring susceptibility to develop primary APS. Again, DR4, DR7, and DRw53 are the relevant loci. Population studies on aCL in diseases other than primary APS indicate that aCL are associated with DR4, DR7, and DRw53, at least when they are found in patients with systemic lupus erythematosus. Because HLA-DR4, -DR7, and -DRw53 are in linkage disequilibrium, the genetic association of aCL could be with DRw53 and, depending on the regional frequency of DR4 or DR7, it could be linked with either DR4 or DR7. HLA-DR4 seems to be more important in Anglo-Saxons, whereas DR7 emerges in populations of Latin origin. In this report we review our studies and the pertinent literature in this field.


Assuntos
Anticorpos Anticardiolipina/biossíntese , Síndrome Antifosfolipídica/genética , Síndrome Antifosfolipídica/imunologia , Antígenos HLA , Inibidor de Coagulação do Lúpus/biossíntese , Animais , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/epidemiologia , Suscetibilidade a Doenças , Antígenos HLA/análise , Teste de Histocompatibilidade/métodos , Humanos , Lúpus Eritematoso Sistêmico/genética , Complexo Principal de Histocompatibilidade/genética , Camundongos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
20.
Am J Obstet Gynecol ; 173(5): 1410-5, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7503178

RESUMO

OBJECTIVE: Our purpose was to determine whether anticardiolipin antibodies induced by immunization with beta 2-glycoprotein I cause fetal death in mice. STUDY DESIGN: Female BALB/c mice were immunized with beta 2-glycoprotein I in a carbohydrate adjuvant or with carbohydrate adjuvant alone. The mice were mated with BALB/c males and killed on day 11 to 13 of pregnancy, and the fetal status was determined. Posttreatment blood samples were obtained for measurement of anticardiolipin and anti-beta 2-glycoprotein I antibodies and platelet counts. RESULTS: Anticardiolipin and anti-beta 2-glycoprotein I antibodies developed in all mice immunized with beta 2-glycoprotein I. Fetal death occurred in 17 of 145 gestational sacs (12%) in 18 mice immunized with beta 2-glycoprotein I compared with 24 of 177 (14%) sacs in 21 control mice. There were no morphometric or histologic differences between gestational tissues, and platelet counts were similar for each group. CONCLUSIONS: The induction of high levels of anticardiolipin antibodies in BALB/c mice by beta 2-glycoprotein I immunizations did not result in fetal death or thrombocytopenia. These nonpathogenic beta 2-glycoprotein I-induced anticardiolipin antibodies should prove useful in the characterization of clinically relevant epitopes for antiphospholipid syndrome.


Assuntos
Anticorpos Anticardiolipina/biossíntese , Morte Fetal/imunologia , Glicoproteínas/imunologia , Animais , Anticorpos Anticardiolipina/sangue , Apolipoproteínas/imunologia , Feminino , Imunização , Inibidor de Coagulação do Lúpus/sangue , Camundongos , Camundongos Endogâmicos BALB C , Contagem de Plaquetas , Gravidez , Valores de Referência , beta 2-Glicoproteína I
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