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1.
Lupus ; 21(7): 764-5, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22635226

RESUMEN

Antibodies against ß(2)-glycoprotein I (anti-ß(2)GPI) are one of the hallmarks of the antiphospholipid syndrome (APS). However, they are heterogenic regarding their epitope specificity, pathogenic mechanisms and their avidity. In the current study we present some outstanding issues about avidity of anti-ß(2)GPI antibodies. Our results confirmed that high avidity anti-ß(2)GPI are associated with thrombosis and APS, while in low avidity anti-ß(2)GPI group non-APS (predominantly systemic lupus erythematosus) patients prevailed.


Asunto(s)
Afinidad de Anticuerpos , Síndrome Antifosfolípido/inmunología , Autoanticuerpos/sangre , beta 2 Glicoproteína I/inmunología , Adulto , Femenino , Humanos , Masculino
2.
Lupus ; 20(11): 1166-71, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21712304

RESUMEN

OBJECTIVE: The objective of this study was to extend the findings of the preliminary study by measuring the avidity of IgG anti-ß2-glycoprotein I antibodies (anti-ß2-GPI) on a larger group of patients with primary or secondary antiphospholipid syndrome (APS) and anti-ß2-GPI positive patients without APS in the frame of the European Forum on antiphospholipid antibodies (aPL). METHODS: Serum from 137 patients with primary APS, APS associated with autoimmune diseases, and patients with autoimmune diseases other than APS from five EU rheumatology centres were tested for anti-ß2-GPI antibodies. The 109 patients who were sera positive for anti-ß2-GPI by the in-house anti-ß2-GPI enzyme-linked immunosorbent assay (ELISA) at the Immunology Laboratory, UMC Ljubljana were selected for further testing on avidity with chaotropic anti-ß2-GPI ELISA. RESULTS: High, low and heterogeneous avidity IgG anti-ß2-GPI was found in 32/109, 17/109 and 60/109 patients respectively. Significantly more patients with APS were in the high avidity than in the low avidity anti-ß2-GPI group, while the opposite was observed for non-APS (both p < 0.001). The most common clinical feature among patients with high avidity anti-ß2-GPI was thrombosis, mainly due to venous thrombosis (p < 0.01 and p < 0.001, versus low avidity anti-ß2-GPI group). CONCLUSION: Patients with or without APS had anti-ß2-GPI of high, low or heterogeneous avidity. High avidity anti-ß2-GPI was associated with thrombosis and APS, while in the low avidity anti-ß2-GPI group non-APS (predominantly SLE) patients prevailed. Determination of anti-ß2-GPI avidity should be considered in the analytical strategies for further differentiation of patients with anti-ß2-GPI antibodies.


Asunto(s)
Anticuerpos Antifosfolípidos/sangre , Síndrome Antifosfolípido/inmunología , Autoanticuerpos/sangre , beta 2 Glicoproteína I/inmunología , Adolescente , Adulto , Anciano , Afinidad de Anticuerpos , Niño , Europa (Continente) , Femenino , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Adulto Joven
3.
Lupus ; 19(13): 1515-9, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20647249

RESUMEN

Increased levels of serum prolactin have been reported in patients with various autoimmune diseases and have been associated with lupus disease activity. Currently, there is a lack of data regarding hyperprolactinaemia in patients with the antiphospholipid syndrome. Hence, this study was carried out in order to evaluate the prevalence and clinical significance of hyperprolactinaemia in antiphospholipid syndrome. A total of 172 European patients with antiphospholipid syndrome and 100 geographically and sex-matched healthy controls were included in the study; none had obvious causes of hyperprolactinaemia. All patients underwent clinical assessment for disease manifestations, in addition to laboratory assessment for serum prolactin, antiphospholipid antibodies and some other biomarkers of autoimmune diseases. The tests were performed utilizing the LIAISON® Analyzer (DiaSorin, Sallugia Italy). Hyperprolactinaemia was detected in 21/172 patients with antiphospholipid syndrome and 0/100 controls (p < 0.001). This significant difference was present in both genders and was obvious even after subgrouping the patients into primary and secondary antiphospholipid syndrome. When clinical features were compared, hyperprolactinaemia was associated with reproductive failure, including early and late pregnancy loss (p < 0.05), as well as intrauterine growth retardation (p < 0.05). Hyperprolactinaemia was negatively related to arthralgias, venous thrombosis, pulmonary microthrombosis, pulmonary hypertension in both primary antiphospholipid syndrome and antiphospholipid syndrome secondary to other diseases, and to neurological manifestations in primary antiphospholipid syndrome (p<0.05). The data indirectly imply that prolactin may play a role in the pathogenesis of antiphospholipid syndrome, especially antiphospholipid syndrome-related reproductive failure.


Asunto(s)
Anticuerpos Antifosfolípidos/sangre , Síndrome Antifosfolípido/fisiopatología , Hiperprolactinemia/fisiopatología , Prolactina/sangre , Aborto Espontáneo/epidemiología , Aborto Espontáneo/etiología , Adulto , Síndrome Antifosfolípido/etiología , Estudios de Casos y Controles , Europa (Continente) , Femenino , Retardo del Crecimiento Fetal/epidemiología , Retardo del Crecimiento Fetal/etiología , Humanos , Hiperprolactinemia/epidemiología , Masculino , Persona de Mediana Edad , Embarazo
4.
J Rheumatol ; 37(7): 1488-501, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20551097

RESUMEN

OBJECTIVE: To determine the prevalence of and independent factors associated with joint involvement in a large population of patients with systemic sclerosis (SSc). METHODS: This study was cross-sectional, based on data collected on patients included in the European League Against Rheumatism (EULAR) Scleroderma Trials and Research (EUSTAR) registry. We queried this database to extract data regarding global evaluation of patients with SSc and the presence of any clinical articular involvement: synovitis (tender and swollen joints), tendon friction rubs (rubbing sensation detected as the tendon was moved), and joint contracture (stiffness of the joints that decreased their range of motion). Overall joint involvement was defined by the occurrence of synovitis and/or joint contracture and/or tendon friction rubs. RESULTS: We recruited 7286 patients with SSc; their mean age was 56 +/- 14 years, disease duration 10 +/- 9 years, and 4210 (58%) had a limited cutaneous disease subset. Frequencies of synovitis, tendon friction rubs, and joint contractures were 16%, 11%, and 31%, respectively. Synovitis, tendon friction rubs, and joint contracture were more prevalent in patients with the diffuse cutaneous subset and were associated together and with severe vascular, muscular, renal, and interstitial lung involvement. Moreover, synovitis had the highest strength of association with elevated acute-phase reactants taken as the dependent variable. CONCLUSION: Our results highlight the striking level of articular involvement in SSc, as evaluated by systematic examination in a large cohort of patients with SSc. Our data also show that synovitis, joint contracture, and tendon friction rubs are associated with a more severe disease and with systemic inflammation.


Asunto(s)
Ensayos Clínicos como Asunto , Bases de Datos Factuales , Inflamación , Artropatías , Esclerodermia Localizada/patología , Esclerodermia Sistémica , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Inflamación/etiología , Inflamación/patología , Inflamación/fisiopatología , Artropatías/etiología , Artropatías/patología , Artropatías/fisiopatología , Articulaciones/patología , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular , Esclerodermia Localizada/etiología , Esclerodermia Sistémica/complicaciones , Esclerodermia Sistémica/patología , Esclerodermia Sistémica/fisiopatología , Sinovitis/etiología , Sinovitis/patología , Tendones/patología
5.
Lupus ; 19(8): 949-56, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20375124

RESUMEN

An inception cohort of patients with systemic lupus erythematosus from 14 European centres was followed for up to 5 years in order to describe the current early disease course. At inclusion patients (n = 200, 89% female, mean age 35 years, 97% Caucasian, mean SLEDAI 12.2) fulfilled a mean of 6.5 ACR classification criteria. The most prevalent criteria were antinuclear Ab presence (97%) followed by anti-dsDNA Ab (74%), arthritis (69%), leukocytopenia (54%) and malar rash (53%), antiphospholipid Ab (48%) and anti-synovial membrane Ab (21.6%). Clinical signs of lupus nephritis (LN) were present in 39% with biopsy-confirmed LN seen in 25%. Frequent additional findings were hypocomplementaemia (54%), anti-SSA Ab (49%), alopecia (26%) and Raynaud's phenomenon (31%). There were few regional differences in disease presentation and management. One and 5-year survival rates were 99% and 97% respectively. During the mean follow-up of 4.1 years 25% entered a state of early disease quiescence by global physician assessment, but the overall risk of subsequent flare was 60%. Maximum SLEDAI scores decreased over time, but 45% of patients accrued damage (SDI >or=1) for which baseline presence of proteinuria and persistent disease activity were independent predictors. The results indicate minor differences in SLE presentation and treatment within various regions of Europe and a high diagnostic reliance on anti-dsDNA Ab. Despite early reductions in disease activity and improved mortality, the risk for disease flare and damage development is, however, still substantial, especially in patients not entering an early remission.


Asunto(s)
Progresión de la Enfermedad , Lupus Eritematoso Sistémico/patología , Lupus Eritematoso Sistémico/fisiopatología , Adulto , Anticuerpos Antinucleares/sangre , Estudios de Cohortes , Europa (Continente) , Femenino , Humanos , Inmunosupresores/uso terapéutico , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/terapia , Masculino , Persona de Mediana Edad , Mortalidad , Adulto Joven
6.
Lupus ; 18(13): 1149-53, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19880561

RESUMEN

Antiphospholipid syndrome is characterized by thrombosis and pregnancy loss. Infections are generally associated with autoimmune diseases, but in the setting of antiphospholipid syndrome this link has been suggested as having a pathogenic role. In this study, 98 patients with antiphospholipid syndrome were screened for antibodies directed to several infectious agents. The main finding in this study is the significantly higher prevalence of IgM antibodies to toxoplasma and rubella. This novel finding suggests that these infections might be associated with antiphospholipid syndrome. As autoimmune diseases and, in particular, antiphospholipid syndrome are associated with infections, mainly the catastrophic type of the syndrome, this finding implies that a current infection with these agents, i.e. toxoplasma and rubella, might either be related to the pathogenesis of antiphospholipid syndrome or alternatively to its manifestations.


Asunto(s)
Síndrome Antifosfolípido , Infecciones , Trombosis/fisiopatología , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Síndrome Antifosfolípido/inmunología , Síndrome Antifosfolípido/fisiopatología , Femenino , Humanos , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Infecciones/complicaciones , Infecciones/epidemiología , Embarazo , Rubéola (Sarampión Alemán)/inmunología , Toxoplasma/inmunología
7.
J Thromb Haemost ; 7(11): 1767-73, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19694946

RESUMEN

BACKGROUND: Diagnosis of the antiphospholipid syndrome (APS) is difficult as a result of limited specificity of existing assays for detecting clinically relevant antiphospholipid antibodies. Anti-beta2-glycoprotein I (beta 2GPI) antibodies play a central role in the disease process of APS. OBJECTIVES: We have investigated the relation between antiphospholipid antibodies with specificity for domain I of beta 2GPI and thrombosis/pregnancy morbidity in an international multicenter study. PATIENTS/METHODS: Four hundred and seventy-seven patients derived from nine different centres met the inclusion criterion of having anti-beta 2GPI antibodies in their plasma/serum. Clinical data and results of tests for lupus anticoagulant, anti-cardiolipin antibodies and anti-beta 2GPI antibodies were established at the different centres of inclusion. After being re-tested for the presence of IgG and/or IgM anti-beta 2GPI antibodies, the samples were tested for the presence of IgG-directed against domain I of beta 2GPI and results were correlated with the thrombotic and obstetric history. RESULTS: Re-testing for the presence of anti-beta 2GPI antibodies resulted in inclusion of 442/477 patients. IgG class anti-domain I antibodies were present in plasma of 243/442 patients (55%). 201/243 (83%) had a history of thrombosis. This resulted in an odds ratio of 3.5 (2.3-5.4, 95% confidence interval) for thrombosis. Anti-domain I IgG antibodies were also significantly correlated with obstetric complications [odds ratio: 2.4 (1.4-4.3, 95% confidence interval)]. CONCLUSION: In this multicenter study, the detection of IgG antibodies that are directed against domain I of beta 2GPI proved to be more strongly associated with thrombosis and obstetric complications than those detected using the standard anti-beta 2GPI antibody assay.


Asunto(s)
Autoanticuerpos/sangre , Epítopos/inmunología , Trombosis/inmunología , beta 2 Glicoproteína I/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antifosfolípidos , Síndrome Antifosfolípido/diagnóstico , Síndrome Antifosfolípido/inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Embarazo , Complicaciones del Embarazo/inmunología , Trombosis/diagnóstico , Adulto Joven
8.
Lupus ; 18(10): 894-9, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19671789

RESUMEN

In recent years, antiphospholipid syndrome (APS) has been increasingly recognised in various paediatric autoimmune and nonautoimmune diseases, but the relatively low prevalence and heterogeneity of APS in childhood made it very difficult to study in a systematic way. The project of an international registry of paediatric patients with APS (the Ped-APS Registry) was initiated in 2004 to foster and conduct multicentre, controlled studies with large number of paediatric APS patients. The Ped-APS Registry is organised as a collaborative project of the European Forum on Antiphospholipid Antibodies and Juvenile Systemic Lupus Erythematosus Working Group of the Paediatric Rheumatology European Society. Currently, it documents a standardised clinical, laboratory and therapeutic data of 133 children with antiphospholipid antibodies (aPL)-related thrombosis from 14 countries. The priority projects for future research of the Ped-APS Registry include prospective enrollment of new patients with aPL-related thrombosis, assessment of differences between the paediatric and adult APS, evaluation of proinflammatory genotype as a risk factor for APS manifestations in childhood and evaluation of patients with isolated nonthrombotic aPL-related manifestations.


Asunto(s)
Síndrome Antifosfolípido/epidemiología , Sistema de Registros , Síndrome Antifosfolípido/complicaciones , Niño , Humanos , Trombosis/etiología
10.
Clin Exp Rheumatol ; 27(2): 229-36, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19473562

RESUMEN

OBJECTIVES: Glutathione S-transferases (GST); GST-mu1 (GSTM1), GST-pi1 (GSTP1) and GST-theta1 (GSTT1) have peroxidase activity towards cytotoxic metabolites produced in inflammatory reactions, the main feature of rheumatoid arthritis (RA). Genetic polymorphisms in GSTM1, GSTP1 and GSTT1 modify the enzyme conjugation capacity and may be associated with the activity of RA. METHODS: A genotyping approach was used to analyze GSTM1-0, GSTT1-0 and GSTP1 Ile105Val and Ala114Val polymorphisms in 213 RA patients. Disease activity was assessed by the disease activity score of 28 joint counts (DAS28) twice for each patient and mean DAS28 values were calculated. RESULTS: The patients with GSTT1-0 genotype had a higher risk for developing high activity RA than the patients with GSTT1 genes present (p=0.028, OR=2.761, 95% CI=1.114-6.843). An interaction between the GSTT1 polymorphism and smoking was observed. In the group of smokers, the carriers of a homozygous deletion GSTT1 had an 8.5-fold higher risk for developing high disease activity than the patients with the GSTT1-1 genotype (p=0.004, OR=8.640, 95% CI=1.995-37.426). GSTM1 and GSTP1 polymorphisms were not associated with the disease activity. CONCLUSION: Our results suggest that the presence of the GSTT1-0 genotype contributed to higher disease activity in RA patients. The risk for developing highly active RA was the highest in smokers with the GSTT1-0 genotype.


Asunto(s)
Artritis Reumatoide/genética , Glutatión Transferasa/genética , Polimorfismo de Nucleótido Simple , Fumar/genética , Anciano , Femenino , Genotipo , Gutatión-S-Transferasa pi/genética , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Fumar/efectos adversos
11.
Lupus ; 18(1): 53-60, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19074169

RESUMEN

The main objective of these meetings is to promote international collaboration in various clinical and research projects. This paper is the summary of the 2007 Ljubljana meeting, and offers an overview of the proposed projects. The technical and methodological details of the projects will be published on the forum's web site (http://www.med.ub.es/MIMMUN/FORUM/STUDIES.HTM).


Asunto(s)
Anticuerpos Anticardiolipina/metabolismo , Síndrome Antifosfolípido/fisiopatología , Animales , Síndrome Antifosfolípido/diagnóstico , Síndrome Antifosfolípido/terapia , Ensayos Clínicos como Asunto , Modelos Animales de Enfermedad , Humanos , Factores de Riesgo
12.
Clin Exp Rheumatol ; 26(5): 807-13, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19032812

RESUMEN

OBJECTIVE: To analyze the epithelial cell-basement membrane attachment, in particular in the secretory end pieces (responsible for secretion of saliva) and in Sjögren's syndrome (SS) characterized by acinar cell failure. METHOD: Immunohistochemistry with laminin receptor chain-specific monoclonal antibodies to integrin (Int) subunits, Lutheran blood group antigen and alpha-dystroglycan. RESULTS: Only acinar cells contained Int alpha1 and alpha2 subunits. This staining was interrupted but strong in controls, but very weak in SS. Both acinar and ductal cells contained Int alpha3, alpha6, b1 and b4 and Lutheran blood group antigen and ductal cells also contained alpha-dystroglycan. These staining patterns were similar in SS and controls. CONCLUSIONS: Binding of the acinar and ductal cells to the basement membrane laminins seems to be mediated by Int alpha3b1, alpha6b1 and alpha6b4 integrin-receptors and Lutheran blood group antigen and alpha-dystroglycan non-integrin receptors. This structure-supporting system is intact in SS, compatible with the maintenance of the tubuloalveolar architecture of the SS glands. The irregular staining pattern of the acinus-specific Int alpha1b1 and alpha2b1 was compatible with a regulated signaling role, which was apparently impaired in SS. Indeed, their laminin counterparts (Lm -1/111 and -2/211) are also aberrant in SS revealing this as the central cell-matrix defect in the syndrome.


Asunto(s)
Glándulas Salivales Menores/fisiología , Transducción de Señal/fisiología , Síndrome de Sjögren/fisiopatología , Membrana Basal/fisiología , Estudios de Casos y Controles , Células Epiteliales/fisiología , Humanos , Integrina alfa1beta1/fisiología , Integrina alfa2beta1/fisiología
13.
Autoimmun Rev ; 7(7): 523-9, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18625440

RESUMEN

AIMS: Oxidation reactions can modify protein activity or specificity. Recently, a novel redox-reactive family of autoantibodies was described, which indicated involvement of altered antibodies (beside altered antigens) into autoimmune reactions. The aim of our study was to determine the binding capacity alterations of electro-oxidized blood donors' IgGs, and to evaluate their effects on released proinflammatory interleukin 6 in HUVEC. RESULTS: We found out that 1.) Isolated blood donor IgGs bound after electro-oxidation to beta2-glycoprotein I, cardiolipin, citrullinated cyclic peptide and protein 3 by enzyme-linked immunosorbent assay, extractable nuclear antigens by counterimmuno-electrophoresis, and cell antigens by indirect immunofluorescence; 2.) Alterations in immunoreactivity of IgGs due to oxidation highly depend on electric current, time of exposure and the presence of antioxidants, 3.) Treatment of HUVEC with oxidized IgGs resulted in changed cell morphology, accompanied by an increase in released interleukin-6. CONCLUSIONS: Our data suggest repeatable transformation of antibodies present in the blood of healthy persons and patients. Inter-individual differences in chemical stability of antibodies, patient's antioxidant status, and the microenvironmental changes at the cellular level may influence the range of antibody alterations and their involvement in pathophysiological autoimmune processes.


Asunto(s)
Autoanticuerpos/inmunología , Inmunoglobulina G/inmunología , Interleucina-6/biosíntesis , Especificidad de Anticuerpos , Antioxidantes/farmacología , Autoanticuerpos/sangre , Autoanticuerpos/metabolismo , Donantes de Sangre , Endotelio Vascular/citología , Endotelio Vascular/inmunología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/metabolismo , Mediadores de Inflamación/metabolismo , Interleucina-6/genética , Cinética , Oxidación-Reducción , ARN Mensajero/metabolismo
14.
Ann Rheum Dis ; 67(9): 1282-6, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18063672

RESUMEN

OBJECTIVES: To determine the prevalence of anti-Ku antibodies in 625 patients with systemic sclerosis (SSc) from six European rheumatological centres and to evaluate their clinical and serological characteristics. METHODS: Sera of 625 consecutive patients with either limited cutaneous or diffuse cutaneous SSc were tested for antibodies to Ku antigen together with other extractable nuclear antigens by counterimmunoelectrophoresis. A case-control design with calculation of bootstrap 95% confidence intervals derived from anti-Ku negative control patients was used to evaluate clinical associations of anti-Ku antibodies. Sera from anti-Ku positive patients with SSc and a control group were additionally tested by immunofluorescence on Hep-2 cell substrates and line immunoassay. RESULTS: Anti-Ku antibodies were found in the sera of 14/625 (2.2%) patients with SSc. Of 14 anti-Ku positive patients with SSc, 10 had no other anti-extractable nuclear antigen (ENA) antibodies detected by counterimmunoelectrophoresis. Using a case-control study design, anti-Ku antibodies were significantly associated with musculoskeletal manifestations such as clinical markers of myositis, arthritis and joint contractures. In addition, a significant negative correlation of anti-Ku antibodies was found with vascular manifestation such as fingertip ulcers and teleangiectasias. There was a striking absence of anti-centromere antibodies as well as anti- polymyositis (PM)/scleroderma (Scl) antibodies in patients that were anti-Ku positive. As expected, anti-Scl70 and punctate nucleolar immunofluorescence patterns were present only in single cases. CONCLUSION: This is the largest cohort to date focusing on the prevalence of anti-Ku antibodies in patients with SSc. The case-control approach was able to demonstrate a clinically distinct subset of anti-Ku positive patients with SSc with only relative clinical differences in skeletal features. However, the notable exceptions were signs of myositis. This shows the importance of anti-Ku antibody detection for the prediction of this specific clinical subset.


Asunto(s)
Antígenos Nucleares/inmunología , Autoanticuerpos/sangre , Proteínas de Unión al ADN/inmunología , Esclerodermia Sistémica/inmunología , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Autoantígeno Ku , Masculino , Persona de Mediana Edad , Esclerodermia Difusa/inmunología , Esclerodermia Limitada/inmunología
15.
Autoimmun Rev ; 6(8): 547-52, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17854747

RESUMEN

In order to elucidate beta2-GPI at the DNA level and characterize its polymorphisms, mRNA expression, protein levels and clinical significance at each of these steps, a molecular review of beta2-GPI literature was performed. The human beta2-GPI complete nucleotide sequence has been reported and it consists of 8 exons separated by large introns. The beta2-GPI gene is polymorphic with four alleles. The distribution of point mutations can be significantly different between various racial populations. DNA variation studies of the beta2-GPI gene identified a total of 151 single-nucleotide polymorphisms, 26 of which are within regions with potential clinical significance. Southern blot analysis indicated the presence of one gene product only. An atypical TATA box and a hepatic nuclear factor-1 element are both essential for beta2-GPI promoter activity. Transcription factor binding sites for STAT, CREB, C/EBPbeta, NF-1, AP-1, NFAT, HNF-3beta and HNF-1 have been identified in the promoter region of the beta2-GPI gene by computer analysis. The beta2-GPI transcriptional signal of 1.5 kb was detected in Northern blot analysis and its 326-amino-acid sequence was found to be one of the most proline-rich eukaryotic proteins. Amino acid substitutions have been shown to be associated with loss of phospholipid binding, development and recognition of antiphospholipid antibodies.


Asunto(s)
beta 2 Glicoproteína I/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Estudios de Cohortes , Predisposición Genética a la Enfermedad , Humanos , Polimorfismo de Nucleótido Simple , beta 2 Glicoproteína I/biosíntesis , beta 2 Glicoproteína I/sangre
16.
Lupus ; 16(5): 309-17, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17576731

RESUMEN

Current therapeutic and diagnostic resources have turned systemic lupus erythematosus (SLE) into a chronic disease by reducing mortality rates. The exact contribution of disease activity and disease related damage to mortality is not well studied. The aim of this study was to describe the current causes of death (COD) in a multinational European cohort of patients with SLE in relation to quantified measures of disease activity and damage. Prospective five-year observational study of case fatalities in SLE patients at 12 European centres was performed. Demographics, disease manifestations, interventions and quantified disease activity (by ECLAM and SLEDAI) and damage (by SLICC-DI) at the time of death were related to the various COD. Ninety-one case fatalities (89% females) occurred after median disease duration of 10.2 years (range 0.2-40) corresponding to a annual case fatality of one for each of the participating cohorts. Cumulative mortality correlated linearly with disease duration with nearly 10% of fatalities occurring in the first year and 40% after more than 10 years of disease. Death occurred during SLE remission in one third of cases. In the remaining cases a mixture of disease activity (median ECLAM 5.5, median SLEDAI 15) and accrued damage (median SLICC-DI 5.0) with opposing relationships to disease duration contributed to death. Infections and cardiovascular events were the most frequent COD in both early and late fatalities with no gender differences for type of COD, disease activity, damage or comorbidity. In Europe, case fatalities have become uncommon events in dedicated SLE cohorts. The bimodal mortality curve has flattened out and deaths now occur evenly throughout the disease course with infectious and cardiovascular complications as the main direct COD in both early and late fatalities. Accrued damage supplants disease activity over time as the main SLE specific contributor to death over time.


Asunto(s)
Lupus Eritematoso Sistémico/mortalidad , Lupus Eritematoso Sistémico/patología , Adolescente , Adulto , Anciano , Europa (Continente)/epidemiología , Femenino , Humanos , Lupus Eritematoso Sistémico/etiología , Masculino , Persona de Mediana Edad , Factores de Tiempo
17.
Rheumatology (Oxford) ; 46(1): 81-6, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16820381

RESUMEN

OBJECTIVES: Anti-phospholipid antibodies have been recognized to play a role in vascular thrombosis and pregnancy morbidity. They were first thought to be directed to phospholipids, but it is now known that the majority of pathogenic antibodies recognizes epitopes on phospholipid-binding plasma proteins such as beta2-glycoprotein I (beta2GPI) or possibly also annexin A5 (ANXA5). The mechanism of their prothrombotic action is still not completely understood. The aim of the present study was to observe the effect of antibodies against ANXA5 (aANXA5) and antibodies against beta2GPI (abeta2GPI) on the binding of ANXA5 to the negatively charged phospholipid membrane. METHODS: Giant phospholipid vesicles (GPVs) were used as a simple model of the membrane surface. GPVs composed of phosphatidylserine and phosphatidylcholine were produced in an aqueous medium. A single GPV was transferred to the solution containing ANXA5 conjugated with Alexa Fluor 488 (FANXA5) and (i) aANXA5 or abeta2GPI and (ii) different concentrations of abeta2GPI together with beta2GPI. The emission of the fluorescent light from the GPV surface, as the result of FANXA5 binding, was measured. RESULTS: Beta2GPI together with abeta2GPI reduced the binding of FANXA5 to GPVs. On the contrary, aANXA5 enhanced the binding of ANXA5 to the GPV surface. CONCLUSIONS: Our results point to the competition between FANXA5 and complexes of beta2GPI-abeta2GPI for the same binding sites and therefore support the hypothesis of the disruption of the ANXA5 protective shield on procoagulant phospholipid surface. The influence of increased cell surface ANXA5 concentration in the presence of aANXA5 on coagulation needs to be further studied.


Asunto(s)
Anexina A5/metabolismo , Autoanticuerpos/metabolismo , Fosfolípidos/metabolismo , beta 2 Glicoproteína I/inmunología , Anexina A5/inmunología , Unión Competitiva , Calcio/farmacología , Membrana Celular/metabolismo , Humanos , Inmunoglobulina G/metabolismo , Microscopía Fluorescente , Modelos Biológicos , Fosfolípidos/inmunología
18.
Autoimmun Rev ; 6(1): 21-7, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17110312

RESUMEN

The objectives of this study were (1) to determine how levels of serum amyloid A (SAA), high sensitivity C-reactive protein (CRP) and interleukin-6 (IL-6) correlate to autoimmune diseases in patients with or without thrombosis, and (2) to discuss the parameters that influence the relative SAA values. SAA, CRP and IL-6 concentrations were determined by enzyme linked immunosorbent assay (ELISA). 84 patients with secondary antiphospholipid syndrome (SAPS), primary antiphospholipid syndrome (PAPS), systemic lupus erythematosus with antiphospholipid antibodies (SLE+aPL), SLE, venous thrombosis (VT), arterial thrombosis (AT) were compared to healthy donors (n=60). The percentages of patients above cut-off were highest in the SAPS, SLE and SLE+aPL groups. Significant differences were observed between healthy donors and inflammatory groups of patients (SAPS and SLE+aPL) in all three measured parameters. SAA and CRP were shown to be correlated to a greater extent in SAPS patients than SLE+aPL patients. In summary, this cross-sectional, retrospective, small study and accompanying clinical considerations limit the ability to make definite conclusions. SAA would not serve as a useful marker for venous, arterial thrombosis or PAPS (pro-coagulant events). It could however, be a good predictor of progression from a non-inflammatory thrombotic condition to an inflammatory one.


Asunto(s)
Amiloide/sangre , Anticuerpos Anticardiolipina/sangre , Síndrome Antifosfolípido/inmunología , Trombosis/sangre , Síndrome Antifosfolípido/complicaciones , Síndrome Antifosfolípido/diagnóstico , Humanos , Trombosis/etiología , Trombosis/inmunología
19.
Autoimmun Rev ; 6(1): 28-32, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17110313

RESUMEN

The immune response may be changed due to altered proteins or modifications of immunoglobulins, including oxidative processes. The susceptibility to oxidative modifications depends greatly on amino-acid moiety composition due to chemical characteristics (instability) of their side-chains. Initial steps of oxidation may change the specificity and avidity of immunoglobulins due to chemical alteration of the hypervariable region. The oxidation of antibodies increases the hydrophilic nature of the paratopes and makes them more susceptible for the binding to cationic surfaces even without the strong surface-to-surface fitting. The electro-oxidation of IgG significantly changes the immunoreactivity and specificity of IgG fractions, regardless of the initial immunoreactivity to a specific autoantigen also in healthy persons. Data are presented on changes in the immunoreactivity as well as the avidity of antibodies against beta2-glycoprotein I after being exposed to direct current. ELISA measurements showed increased reactivity of anti-beta2-glycoprotein I antibodies at the beginning and various, fluctuating results after prolonged exposure to electro-oxidation. Inter-individual differences in chemical stability of immunoglobulins and patient's antioxidative status may influence the range of their alterations and their impact on health/disease balance.


Asunto(s)
Afinidad de Anticuerpos/inmunología , Especificidad de Anticuerpos/inmunología , Autoanticuerpos/sangre , Inmunoglobulina G/inmunología , beta 2 Glicoproteína I/inmunología , Reacciones Antígeno-Anticuerpo , Humanos , Oxidación-Reducción
20.
Rheumatol Int ; 27(2): 119-23, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16953396

RESUMEN

Increased mortality due to cardiovascular disease in rheumatoid arthritis (RA) patients was reported. Using B-mode ultrasonography we compared intima-media thickness (IMT) and plaque occurrence (indicators of asymptomatic atherosclerosis) in the carotid arteries in 70 pre-menopausal, female RA patients and 40 controls. Correlations with different risk factors were evaluated. The IMT values were higher in RA patients (0.59 mm vs. 0.47 mm, P < 0.0001) and they had more plaques (P = 0.023). In RA patients higher levels of sensitive CRP (P < 0.0001), ICAM (P < 0.0001), VCAM (P < 0.0001), IL-2 (P < 0.001), IL-6 (P = 0.009) and TNF-alfa (P < 0.01) were found. A correlation between IMT and triglycerides (P = 0.018) and a negative correlation between IMT and HDL cholesterol (P = 0.037) were found. With multiple regression analysis the association between IMT and sensitive CRP (P = 0.027) and presence of plaques and apolipoprotein B (P = 0.028) was established. The results indicate that even pre-menopausal, female RA patients had accelerated atherosclerosis. Chronic systemic inflammation may play an important role in atherogenesis.


Asunto(s)
Artritis Reumatoide/complicaciones , Aterosclerosis/complicaciones , Arterias Carótidas/patología , Premenopausia , Túnica Íntima/patología , Adulto , Aterosclerosis/fisiopatología , Biomarcadores , Proteína C-Reactiva/inmunología , Arterias Carótidas/diagnóstico por imagen , Estudios de Casos y Controles , Femenino , Humanos , Inflamación/complicaciones , Persona de Mediana Edad , Factores de Riesgo , Ultrasonografía
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