379 resultados para AUTOANTIBODIES


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Chronic urticaria (daily or almost daily symptoms lasting for more than six weeks) is characterized by wheals and erythema, with or without itching. A few case reports have shown chronic autoimmune urticaria at the beginning of systemic lupus erythematosus (SLE), particularly in adults. However, the prevalence of this manifestation in a lupus paediatric population was not studied. During 27 consecutive years, 5419 patients were followed up at our University Hospital and 271 (5%) had juvenile SLE (American College of Rheumatology criteria). Two of them (0.7%) had chronic and painless autoimmune urticaria as the first manifestation of juvenile SLE, and were reported herein. One case was a five-year old female with continuous widespread urticaria (duration 120 days), antinuclear antibodies (ANA) 1:640 (dense fine speckled pattern) and elevated complement levels. The juvenile SLE diagnosis was established after one year. The other case was a 13-year old female who had chronic widespread urticaria (lasting 45 days), ANA 1:160 (fine speckled pattern) and normal complement levels. The juvenile SLE diagnosis was established after three years. In conclusion, chronic autoimmune urticaria is very rare and may be the first lupus manifestation, particularly associated with the presence of autoantibodies. This study reinforces the importance of a rigorous follow-up in children and adolescents suffering from autoimmune urticaria due to the possibility of connective tissue disorders, such as paediatric lupus. Lupus (2011) 20, 763-766.

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The objective of this study is to investigate the presence of anti-nucleosome (anti-NCS) and anti-chromatin (anti-CRT) antibodies in patients with cutaneous lupus erythematosus (CLE) compared with active and inactive systemic lupus erythematosus (SLE). A total of 154 subjects were evaluated: 54 patients presenting CLE, 66 patients with active SLE and 34 with inactive SLE. Lupus activity was assessed using the disease activity index (SLEDAI). Anti-NCS and anti-CRT antibodies were detected by enzyme-linked immunosorbent assay ( ELISA). Only one of 54 patients with CLE tested positive for both anti-NCS and anti-CRT antibodies. The prevalence of anti-CRT antibodies was significantly higher in active SLE (84.8%) when compared with inactive SLE (26.4%) and CLE (1.8%) ( P < 0.001). Anti-NCS antibodies were also more prevalent in active SLE patients (74.2%) than inactive SLE (11.7%) and CLE patients ( 1.8%) ( P < 0.001). The presence of anti-CRT and anti-NCS antibodies was correlated to disease activity in patients with SLE (r = 0.4937, r = 0.5621, respectively). Furthermore, the detection of both antibodies was correlated with disease activity in patients with SLE who tested negative for anti-dsDNA antibodies ( r = 0.4754 for anti-NCS and r = 0.4281 for anti-CRT). The presence of these two auto-antibodies was strongly associated with renal damage in patients with SLE ( OR = 13.1, for anti-CRT antibodies and OR = 25.83, for anti-NCS antibodies). The anti-NCS and anti-CRT antibodies were not found in CLE. In patients with SLE, there is a correlation of these antibodies with disease activity and active nephritis. When compared with anti-dsDNA antibodies, anti-NCS and anti-CRT antibodies were more sensitive in detecting disease activity and kidney damage in lupus patients. Lupus (2009) 18, 223-229.

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A genetic polymorphism of the beta 2-glycoprotein I (beta 2-GPI) is recognized by antiphospholipid antibodies (aPL) and may even play a role in the development of antiphospholipid syndrome (APS). The objectives of this study were to determine a Val/Leu SNP at position 247 of the beta 2-GPI gene in Brazilian patients with APS and to compare these data with clinical and laboratory manifestations. Polymorphism assignment was performed by PCR followed by Rsa I restriction endonuclease. The titration of anti-beta 2-GPI antibodies was detected by ELISA. The results showed significantly higher frequencies of the V-encoding allele and the homozygous VV genotype in patients with APS than in control subjects (OR = 1.781, P = 0.0068; and OR = 6.413, P < 0.0001, respectively). The frequency of this genotype was also significantly higher in patients with arterial and venous thrombosis than in the control group (52% and 44%, respectively, versus 13%). Anti-beta 2-GPI-positive patients had significantly higher frequencies of the VV genotype than the controls subjects (OR = 8.179, P < 0.0001). These results suggest that the V-encoding allele and the homozygous VV genotype at position 247 of the beta 2-GPI gene may play a role in the generation of anomalous beta 2-GPI, with consequent auto-antibody production, and in phenotype expression of arterial and venous thrombosis in APS patients.

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To determine the relation between neutrophil function and the clinical characteristics of systemic lupus erythematosus ( SLE), the superoxide anion (O(2)(-)) production by neutrophils, mediated by Fc gamma R and Fc gamma R/CR cooperation, was studied in 64 SLE patients classified according to their prevalent clinical manifestations. Three clinically distinct patterns were designated: ( 1) manifestations associated with the occurrence of cytotoxic antibodies ( SLE-I group); ( 2) manifestations associated with circulating immune complexes ( IC; SLE-II group), and ( 3) manifestations associated with IC and cytotoxic antibodies ( SLE-III group). O(2)(-) production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with ICIgG opsonized or not with complement. No difference in O(2)(-) production was observed when neutrophil responses from healthy controls were compared to the unclassified patients. However, when the SLE patient groups were considered, the following differences were observed: ( 1) SLE-I neutrophils showed lower O(2)(-) production mediated by the IgG receptor ( Fc gamma R) with the cooperation of complement receptors ( Fc gamma R/ CR) than observed in the SLE-II, SLE-III, and healthy groups; ( 2) neutrophils from the SLE-II group showed a decreased O(2)(-) production mediated by Fc gamma R/ CR compared to the SLE-III group, ( 3) SLE-III neutrophils produced more O(2)(-) than neutrophils from the SLE-II and control groups, and ( 4) CR showed inefficiency in mediating the O(2)(-) production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence ( CL; T(max) and CL(max)) disclosed differences only for the SLE- I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by Fc gamma R/ CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.

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Impaired DNA repair efficiency in systematic lupus erythematosus (SLE) patients has been reported ill some studies, mainly regarding the repair of oxidative damage, but little is known about repair kinetics towards primarily single-stranded DNA breaks. In the present study, we aimed to investigate: (a) the efficiency of SLE peripheral blood leucocytes in repairing DNA damage induced by ionizing radiation and (b) the association of DNA repair gene (XRCC1 Arg399Gln, XRCC3 Thr241Met and XRCC4 Ile401Thr) polymorphisms in SLE patients, considering the whole group, or stratified sub-groups according to clinical and laboratory features. A total of 163 SLE patients and 125 healthy control were studied. The kinetics of DNA strand break repair was evaluated by the comet assay, and genotyping for DNA repair genes was performed by PCR-RFLP. Compared with controls. SLE leucocytes exhibited decreased efficiency of DNA repair evaluated at 30 min following irradiation. A significant association with DNA repair gene polymorphisms was not observed for the whole group of SLE patients; however, the XRCC1Arg399Gln polymorphism was associated with the presence of anti-dsDNA antibody. The concomitance of two DNA repair polymorphic sites was associated with the presence of neuropsychiatric manifestations and antiphospholipid antibody syndrome. Taken together, these results indicated that SLE leucocytes repair less efficiently the radiation-induced DNA damage, and DNA repair polymorphic sites may predispose to the development of particular clinical and laboratory features. Lupus (2008) 17, 988-995.

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Heat-shock proteins (HSPs) are currently one of the most promising targets for the development of immunotherapy against tumours and autoimmune disorders. This protein family has the capacity to activate or modulate the function of different immune system cells. They induce the activation of monocytes, macrophages and dendritic cells, and contribute to cross-priming, an important mechanism of presentation of exogenous antigen in the context of MHC class I molecules, These various immunological properties of HSP have encouraged their use in several clinical trials. Nevertheless, an important issue regarding these proteins is whether the high homology among HSPs across different species may trigger the breakdown of immune tolerance and induce autoimmune diseases. We have developed a DNA vaccine codifying the Mycobacterium leprae Hsp65 (DNAhsp65), which showed to be highly immunogenic and protective against experimental tuberculosis. Here, we address the question of whether DNAhsp65 immunization could induce pathological autoimmunity in mice. Our results show that DNAhsp65 vaccination induced antibodies that can recognize the human Hsp60 but did not induce harmful effects in 16 different organs analysed by histopathology up to 210 days after vaccination. We also showed that anti-DNA antibodies were not elicited after DNA vaccination. The results are important for the development of both HSP and DNA-based immunomodulatory agents.

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O diagnóstico de doença hepática autoimune em doentes com patologia hepática implica a exclusão de outras causas de lesão hepática como vírica, alcoólica, tóxica, devido a alterações genéticas ou metabólicas, esteatose hepática não alcoólica e uma criteriosa avaliação de dados clínicos, bioquímicos, histológicos e colangiográficos especificas destas patologias (Invernizzi et al 2007) O diagnóstico e tratamento precoces destas patologias são fundamentais para a prevenção da alta morbilidade e mortalidade associada a estes doentes. O despiste de patologia hepática autoimune assenta na utilização de testes serológicos para a deteção de autoanticorpos associados a estas patologias. O conhecimento destes testes e a interpretação dos resultados obtidos revelam-se fundamentais para o diagnóstico ou exclusão destas doenças (Beuers 2005). Deste modo, foi objetivo deste trabalho a pesquisa e identificação de autoanticorpos em uso clínico: ANA, AMA, AML, ANCA, Anti-SLA/LP, anti-LKM, anti-LC1 e anti-actina F, em doentes com suspeita de HAI e CBP em que foi excluída causa vírica, alcoólica e tóxica. O trabalho incidiu particularmente na comparação dos resultados do perfil de autoanticorpos de pedidos feitos ao exterior com os resultados obtidos recorrendo à utilização de um novo kit de imunoblot, e assim determinar a relevância da introdução da pesquisa dos novos autoanticorpos e avaliar a relação custo/benefício da implementação do kit BlueDot liver da D-tek® na rotina laboratorial do serviço de Patologia Clínica do Hospital Pedro Hispano. Os resultados encontrados foram de 100% de concordância entre os métodos de imunofluorescência indireta e imunoblot, e Elisa e Imunoblot. Deste modo seria uma boa estratégia a implementação desta última técnica na rotina laboratorial uma vez que proporciona uma rápida disponibilização dos resultados para o clínico, antecipando desta forma o diagnóstico e o início rápido do tratamento em benefício do doente. Por outro lado, quando analisámos a relação custo/beneficio, seria vantajosa a implementação desta técnica uma vez que o laboratório dispõe de capacidade técnica, e o custo de aquisição do kit não excede o valor praticado atualmente correspondendo a uma poupança de 51%.

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Celiac disease is a gluten-induced autoimmune enteropathy characterized by the presence of tissue tranglutaminase (tTG) autoantibodies. A disposable electrochemical immunosensor (EI) for the detection of IgA and IgG type anti-tTG autoantibodies in real patient’s samples is presented. Screen-printed carbon electrodes (SPCE) nanostructurized with carbon nanotubes and gold nanoparticles were used as the transducer surface. This transducer exhibits the excellent characteristics of carbon–metal nanoparticle hybrid conjugation and led to the amplification of the immunological interaction. The immunosensing strategy consisted of the immobilization of tTG on the nanostructured electrode surface followed by the electrochemical detection of the autoantibodies present in the samples using an alkaline phosphatase (AP) labelled anti-human IgA or IgG antibody. The analytical signal was based on the anodic redissolution of enzymatically generated silver by cyclic voltammetry. The results obtained were corroborated with a commercial ELISA kit indicating that the electrochemical immunosensor is a trustful analytical screening tool.

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Antibodies against gliadin are used to detect celiac disease (CD) in patients. An electrochemical immunosensor for the voltammetric detection of human anti-gliadin antibodies (AGA) IgA and AGA IgG in real serum samples is proposed. The transducer surface consists of screen-printed carbon electrodes modified with a carbon nanotube/gold nanoparticle hybrid system, which provides a very useful surface for the amplification of the immunological interactions. The immunosensing strategy is based on the immobilization of gliadin, the antigen for the autoantibodies of interest, onto the nanostructured surface. The antigen–antibody interaction is recorded using alkaline phosphatase labeled anti-human antibodies and a mixture of 3-indoxyl phosphate with silver ions (3-IP/Ag+) was used as the substrate. The analytical signal is based on the anodic redissolution of the enzymatically generated silver by cyclic voltammetry. The electrochemical behavior of this immunosensor was carefully evaluated assessing aspects as sensitivity, non-specific binding and matrix effects, and repeatability and reproducibility. The results were supported with a commercial ELISA test.

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A diabetes mellitus do tipo 1 (DM1) é o distúrbio endócrino-metabólico mais frequente em crianças. É uma doença autoimune resultado da destruição selectiva das células beta pancreáticas. A velocidade de destruição das células beta pode ser rápida em algumas pessoas e lenta em outras; esta última é típica de adulto é conhecido como diabetes autoimune latente em adulto (LADA). A sua etiologia envolve factores ambientais e genéticos, dos genes envolvidos a maior contribuição vem da região do genoma onde estão localizados os genes do Complexo Principal de Histocompatibilidade (MHC). A combinação de diferentes alelos do sistema de antigénio leucocitário humano tipo II (HLAII) esta associada a susceptibilidade da doença e as principais molécula envolvidas são a DQ e DR. O estágio pré-clínico da doença se caracteriza pela presença de auto-anticorpos, sendo o anti-GAD o mais sensível nesta patologia. OBJECTIVO: Analizar a frequência dos polimorfismos HLA-DR/DQ em angolanos portadores de diabetes tipo 1, residentes em Luanda. O tipo de estudo adotado foi casocontrolo num universo de voluntários provenientes da consulta externa de hospitais e clínicas locais no período de outubro de 2012 a outubro 2013. A amostra biológica utilizada foi sangue total, tendo sido processada no laboratório LABGENE, da Faculdade de Medicina (FM) da Universidade Agostinho Neto (UNA). Os auto-anticorpos, anti-GAD, foram doseados pelo método de ELISA. O ADN genómico foi extraído à partir de sangue total periférico e tipagem genética foi realizada mediante PCR-SSP.O alelo DQB1*02 (DQ2/DQ2) (p=0,033, OR= 4, IC (1,2-13,3) foi associado a susceptibilidade da DM1; os alelos DQB1*06 (DQ6/DQ6) (p=0,000, OR=0,30, IC (0,17-0,54); *11 (p=0,011, OR=0,14, IC=0,032-0,62); *13 (p=0,006, OR=0,13, IC=0,049-0,588) e *15 (p=0,001, OR=0,044, IC=0,005-0,39) foram associados a proteção. Foi encontrado 29,2% de positividade para o anti-GAD, não houve associação significativa (p=0,69) entre a resposta positiva do anti-GAD e a idade. Não foi encontrada associação significativa (p=0,39) entre o tempo de diagnóstico e resposta humoral. Observou-se associação significativa entre os alelos de risco DQB1*02 (p=0.000) e resposta positiva para anti-GAD; da mesma maneira houve uma associação significativa para os alelos DQB1*06 (p=0,002), DRB1*11 (p=0,048); *13 (p=0,004) e *15 (p=0,021) e a resposta negativa do anti-GAD.Os dados demostram o forte envolvimentos do gene HLA-II (DQ) com a suceptibilidade a DM1 e sugere que a autoimunidade se desenvolve na presença de susceptibilidade genética, quer dizer, em associação com alelos HLA-II específicos.

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Inflammatory reaction has been associated with dilated cardiomyopathy. In this context, cardiac autoantibodies and inflammatory cell infiltration have been studied during the last two decades towards the understanding of their origin and the underlying pathogenic mechanisms. Recent research has increasingly focused on the development of an etiological therapeutic approach. Immunoadsorption has shown to improve clinical, echocardiographic, haemodynamic and laboratory parameters in patients with inflammatory dilated cardiomyopathy. In this article we review recent literature concerning this subject, including classification, pathophysiological mechanisms and therapy.

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Hashimoto's thyroiditis (HT) has been characterized for many years as a well-defined clinicopathologic entity, but is now considered a heterogeneous disease. IgG4-related HT is a new subtype characterized by thyroid inflammation rich in IgG4-positive plasma cells and marked fibrosis. It may be part of the systemic IgG4-related disease. We report a case of a 56-year-old Portuguese man who presented with a one-month history of progressive neck swelling and dysphagia. Laboratory testing revealed increased inflammatory parameters, subclinical hypothyroidism and very high levels of thyroid autoantibodies. Cervical ultrasound (US) demonstrated an enlarged and heterogeneous thyroid gland and two hypoechoic nodules. US-guided fine needle aspiration cytology was consistent with lymphocytic thyroiditis. The patient was submitted to total thyroidectomy and microscopic examination identified typical findings of HT, marked fibrosis limited within the thyroid capsule and lymphoplasmacytic infiltration, with >50 IgG4-positive plasma cells per high-power field and an IgG4/IgG ratio of >40%. After surgery, serum IgG4 concentration was high-normal. Symptoms relief and reduction in laboratory inflammatory parameters were noticed. Thyroid function is controlled with levothyroxine. To our knowledge we report the first case of IgG4-related HT in a non-Asian patient. We also perform a review of the literature regarding IgG4-related disease and IgG4-related HT. Our case highlights this new variant of the well known HT, and helps physicians in recognizing its main clinical features, allowing for proper diagnosis and treatment.

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In order to establish if neuropsychiatric systemic lupus erythematosus (NPSLE) can be identified by any characteristic other than those used to diagnose the neuropsychiatric (NP) disease itself, we retrospectively reviewed 98 systemic lupus erythematosus (SLE) patients followed over a mean period of 10 years. NPSLE was identified in 22 patients. Stroke and generalized seizures were the most frequent NP manifestations. The NPSLE and non-NPSLE groups were similar with regard to demographic characteristics, ACR criteria, serum autoantibodies, and frequency of hypertension and hypercholesterolemia. Of note, compared to the non-NPSLE group, NPSLE was associated with a higher frequency of smoking (78 versus 26%), organ damage (73 versus 34%), and cumulative mortality rate (14 versus 7%). The series of patients was further analysed according to the presence of antiphospholipid syndrome (APS). Significantly, the interval between the onset of NP disease and SLE diagnosis was shorter in the APS(-) (0.3 ± 1 years) than in the APS(+) (5 ± 7 years) groups. Recurrence and/or persistence of NP events were only documented in the APS(-) group. Overall cumulative mortality was highest in NPSLE and in APS(+) patients with inadequate anticoagulation control, identifying an aspect that requires improved vigilance and the development of novel therapeutic modalities.

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BACKGROUND: Neuromyelitis Optica (NMO) is an inflammatory demyelinating disease of the CNS. There have been few epidemiologic studies on NMO, none in Portugal. OBJECTIVE: To analyze the clinical, biological and MRI characteristics from a cohort of Portuguese patients who fulfilled the Wingerchuk 2006 NMO/NMOSD criteria. To identify and characterize those who had concomitant autoimmune disease or circulating autoantibodies. METHODS: We performed an observational, retrospective, multicenter study in 5 Hospital Centers in Portugal. RESULTS: Sixty-seven patients fulfilled the inclusion criteria. They were mainly Caucasian, 55 female. Median age at onset was 32.0 years and mean follow-up 7.4±6.0 years. Twenty-one patients were definite NMO and optic neuritis (ON) the most frequent initial presentation. Forty-six were classified as NMO spectrum disorders. The main subtypes were recurrent ON and single longitudinally extensive transverse myelitis. Twenty-four patients had positive AQP4-IgG. Twenty-three had other circulating autoantibodies. Fifteen out of 67 patients had concomitant autoimmune disease. There was a significant correlation between the presence of autoimmune disease and the positivity for AQP4-IgG. Five patients died, all definite NMO. CONCLUSION: This is the first study about this rare disease in Portugal. Demographic features were similar to other studies. The existence of concomitant autoimmune disease was significantly associated with seropositivity for AQP4-IgG.

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Thyroid-stimulating hormone-receptor autoantibodies normally causes hyperthyroidism. However, they might have blocking activity causing hypothyroidism. A 11-year-old girl followed due to type 1 diabetes mellitus, celiac disease and euthyroid lymphocytic thyroiditis at diagnosis. Two years after the initial evaluation, thyroid-stimulating hormone was suppressed with normal free T4; nine months later, a biochemical evolution to hypothyroidism with thyroid-stimulating hormone-receptor autoantibodies elevation was seen; the patient remained always asymptomatic. Chinese hamster ovary cells were transfected with the recombinant human thyroid-stimulating hormone -receptor, and then exposed to the patient's serum; it was estimated a 'moderate' blocking activity of these thyroid-stimulating hormone-receptor autoantibodies, and concomitantly excluded stimulating action. In this case, the acknowledgment of the blocking activity of the serum thyroid-stimulating hormone-receptor autoantibodies, supported the hypothesis of a multifactorial aetiology of the hypothyroidism, which in the absence of the in vitro tests, we would consider only as a consequence of the destructive process associated to lymphocytic thyroiditis.