31 resultados para Autoantibodies


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Anti-neutrophil cytoplasmic antibodies (ANCA) are autoantibodies against enzymes present in primary granules of neutrophils and lysosomes of monocytes detected in systemic vasculitis and in other diseases, including infections, ANCA are markers of active Wegener granulomatosis, which presents some anatomo-pathologic and immune response features similar to those of leprosy. Thus, we raised the hypothesis that ANCA may be present in leprosy as markers specifically linked to the presence of vasculitis. The aim of this study was to determine the presence of ANCA in leprosy and its correlation with the clinical forms of the disease. Sera from 60 normal individuals and from 59 patients with different clinical forms of leprosy were studied. The patients were also allocated into reactional and nonreactional groups. By indirect immunofluorescence, ANCA were positive, an atypical pattern A-ANCA, in 28.8% of the patient sera. A-ANCA predominated, although not significantly (p >0,05), in the reactional groups (37.9% vs 20.0%), and in those at the lepromatous pole (41.6% vs 20.0%). There was no correlation between ANCA positivity and either disease duration, disease activity, or therapeutic regimen (p >0.05), An interesting finding was the correlation between ANCA and gender: 94.1% of ANCA-positive patients were males (p <0.01), a feature that so far has not been reported in ANCA-related diseases and for which there is no explanation at the moment. By ELISA, the sera of the lepromatous leprosy patients did not show activity against either PR3, MPO, HLE, the most common ANCA antigens. Because A-ANCA are nonspecific, this finding requires further investigation for the determination of the responsible antigen(s), in conclusion, A-ANCA are present in 28.8% of leprosy patients but are not related to vasculitis in the erythema nodosum leprosum reaction and are not a marker of a specific clinical form.

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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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Objective. Juvenile localized scleroderma (JLS) includes a number of conditions often grouped together. With the long-term goal of developing uniform classification criteria, we studied the epidemiological, clinical and immunological features of children with JLS followed by paediatric rheumatology and dermatology centres. Methods. A large, multicentre, multinational study was conducted by collecting information on the demographics, family history, triggering environmental factors, clinical and laboratory features, and treatment of patients with JLS. Results. Seven hundred and fifty patients with JLS from 70 centres were enrolled into the study. The disease duration at diagnosis was 18 months. Linear scleroderma (LS) was the most frequent subtype (65%), followed by plaque morphea (PM) (26%), generalized morphea (GM) (7%) and deep morphea (DM) (2%). As many as 15% of patients had a mixed subtype. Ninety-one patients (12%) had a positive family history for rheumatic or autoimmune diseases; 100 (13.3%) reported environmental events as possible trigger. ANA was positive in 42.3% of the patients, with a higher prevalence in the LS-DM subtype than in the PM-GM subtype. Scl70 was detected in the sera of 3% of the patients, anticentromere antibody in 2%, anti-double-stranded DNA in 4%, anti-cardiolipin antibody in 13% and rheumatoid factor in 16%. Methotrexate was the drug most frequently used, especially during the last 5 yr. Conclusion. This study represents the largest collection of patients with JLS ever reported. The insidious onset of the disease, the delay in diagnosis, the recognition of mixed subtype and the better definition of the other subtypes should influence our efforts in educating trainees and practitioners and help in developing a comprehensive classification system for this syndrome. © 2006 Oxford University Press.

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Sjögren's syndrome is an autoimmune disease characterized by sialoadenitis and elevated titers of autoantibodies. To assess whether it is possible to induce inflammatory changes in salivary gland tissues, a series of immunizations in Balb/c mice have been undertaken, using salivary gland extract, modified or not, added to several adjuvants. Mice's humoral immune response to salivary gland antigens was monitored by ELISA. Inflammatory cells infiltrating gland tissue were seen 3 months after immunization with salivary gland extract modified with pepsin (AgGp) and metaperiodate (AgGMp). Although pathological progression was not observed, the histopathological picture was similar to the initial phase of Sjögren's syndrome. In addition, a monoclonal antibody reactive with 3 gland polypeptides and anhydrase carbonic II was rescued among B cells from immunized mice. Thus, immunizations with modified autoantigens were able to initiate pathological damage to glandular tissue and stimulate the proliferation of auto-reactive B cells.

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The Japanese Brazilian population has one of the highest prevalences of diabetes worldwide. Despite being non-obese according to standard definitions, their body fat distribution is typically central. We investigated whether a subset of these subjects had autoantibodies that would suggest a slowly progressive form of type 1 diabetes. A total of 721 Japanese Brazilians (386 men) in the 30- to 60-year age group underwent clinical examination and laboratory procedures, including a 75-g oral glucose tolerance test and determinations of serum autoantibodies. Antibodies to glutamic acid decarboxylase (GADab) were determined by radioimmunoassay and to thyroglobulin (TGab) and thyroperoxidase (TPOab) by flow-cytometry assays. Mean body mass index was 25.2 ± 3.8 kg/m2, but waist circumference was elevated according to the Asian standards. Diabetes, impaired glucose tolerance, and impaired fasting glycemia were found in 31%, 22%, and 22%, respectively, and 53% of the subjects had metabolic syndrome. Glutamic acid decarboxylase (GADab) was positive in 4.72%, TGab in 9.6%, and TPOab in 10% of the whole sample. When participants were stratified according to the presence of thyroid antibodies, similar frequencies of GADab were found in positive and negative groups. The prevalence rates of glucose metabolism disturbances did not differ between GADab positive and negative groups. Our data did not support the view that autoimmune injury could contribute to the high prevalence of diabetes seen in Japanese Brazilians, and the presence of co-morbidities included in the spectrum of metabolic syndrome favors the classification as type 2 diabetes.

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Autoimmune bullous dermatoses are diseases in which blisters and vesicles are the primary and fundamental types of skin lesion. Their classification is based on the location of the blister: intraepidermal and subepidermal. Patients produce autoantibodies against self-specific structures of the skin detectable by immunofluorescence techniques, immunoblotting and ELISA. Recent advances in molecular and cellular biology have brought to knowledge these self-antigens, against which patients are sensitized, and which are found in epidermis or in the dermo-epidermal junction. These are low incidence, but high morbidity diseases that may be fatal. The aim of this article is to review and describe the progress of four autoimmune vesiculobullous disorders: endemic pemphigus foliaceous (wild fire), pemphigus vulgaris, bullous pemphigoid and dermatitis herpetiformis. ©2009 by Anais Brasileiros de Dermatologia.

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Introduction: The autologous serum skin test (ASST) may suggest an autoimmune etiology in chronic urticaria (CU). A new laboratory technique called basophil activation test (BAT) has been currently employed for its diagnosis. Objective: To analyze ASST in relation to BAT as well as to evaluate interleukin 3 (IL3) receptors (CD123) and non-specific immunoglobulin G (IgG) autoantibodies bound to basophils in patients with chronic urticaria. Methods: We studied 33 adults with CU and mean age of 42.5 + 14 years. After stimulation by serum from patients with CU, CD63 expression on basophils from one atopic donor was analyzed by flow cytometry. Furthermore, we investigated CD123 and IgG autoantibody expressions. Results: The odds ratio (OR) between ASST and BAT was 1.00 (95% confidence interval [CI]: 0.22 to 4.5). The ASST for autoimmune CU diagnosis showed an accuracy of 54.5%, sensitivity of 66%, specificity of 33%, positive predictive value of 63%, and negative predictive value of 36%. There was no statistical difference between the studied groups as to mean non-specific IgG and CD123 expressions (for a p < 0.05). Discussion: This study demonstrated that ASST has low accuracy in the diagnosis of autoimmune CU. Concerning other analyzed aspects, there was no statistical difference between positive ASST and negative ASST. Conclusions: Due to insufficient studies in this area and the relevance of this issue, further investigation is required.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Patologia - FMB

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Pemphigus complex in animals is considered rare, but not so when compared with the occurrence of other autoimmune diseases. Pemphigus Foliaceus in dogs is the most common varieties of pemphigus and is characterized clinically by intraepidermal pustules, starting on the face and ears, pads, groin, and may become multifocal or generalized in six months. As the pustules are very fragile, the lesions usually found are secondary, which may range from dry to collarettes epidermal crusting, and nasal depigmentation. The diagnosis is difficult because presents sintomatology similar to other diseases and laboratory diagnosis more precise through the histopathological examination of pustules integrate (biopsy), which are rarely found. The treatment, although of the individual treatment regimen, is based on treating opportunistic diseases and immunosuppressing the animal in order to decrease the production of autoantibodies. The drugs of choice depend on the clinical presentation, however is usually oral prednisone and azathioprine in the dog and combined immunosuppressive therapy. Should make use daily until the disease is inactive and gradually decrease the dose until have the minimum effective dose, preferably on alternate days for the remission of the disease. Prognosis of pemphigus varies according to disease stage and treatment established. Pemphigus foliaceus is less serious nonetheless might be fatal without treatment

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Background: Autoimmune bullous dermatoses are complex diseases triggered by autoantibodies action against epidermal antigens or the dermoepidermal junction. Blisters and vesicles that evolve with erosion areas characterize them. Although rare, they present high morbidity, affecting the quality of life of patients.Objectives: To assess the magnitude of autoimmune bullous dermatoses on life quality of patients treated in a public university service in countryside of Brazil. Methods: This cross-sectional study was based on an inquiry with autoimmune bullous dermatoses patients assisted at outpatient university referral service. Elements related to quality of life were evaluated by the Dermatology Life Quality Index, as well as clinical and demographic data. Results: The study evaluated 43 patients with pemphigus foliaceus, 32 with pemphigus vulgaris, 6 with bullous pemphigoid and 3 with dermatitis herpetiformis. The average age was 48 +/- 16 years and 34 (40%) were female. The median score (p25-p75) of the Dermatology Life Quality Index was 16 (9-19), classified as "severe impairment" of life quality, in which the greater impact was related to symptoms and feelings, daily and leisure activities. Conclusions: Autoimmune bullous dermatoses inflict severe impairment of quality of life for patients followed by a public outpatient clinic in the countryside of Brazil.

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The potential sequelae of intestinal infection with Yersinia enterocolitica include reactive arthritis, erythema nodosum, Reiter's syndrome and other autoimmune diseases. The role of the immune response in the pathogenesis of these diseases has not been fully defined, but autoimmune manifestations may be a consequence of the increase in autoantibodies as a result of polyclonal B-cell activation induced by Yersinia. We investigated the effects of Y enterocolitica 0:3 derivatives on B lymphocyte activation in vivo. Groups of five specific pathogen free (SPF) Swiss mice were inoculated with bacterial cell extract, Yersinia outermembrane proteins (Yops) or lipopolysaccharide (LPS) obtained from Y enterocolitica 0:3 and their immunoglobulin-secreting spleen cells were detected by isotype-specific protein A plaque assay. The presence of specific anti-Yersinia antibodies and autoantibodies was determined in mouse sera by ELISA. In all experiments a marked increase in the number of secretory cells of different isotypes was observed as early as the third day after inoculation. IgG and IgM anti-Yersinia antibodies were detected in the sera of all inoculated mice, and autoantibodies against myosin in the sera of those inoculated with bacterial cell extract. The sera from animals stimulated with LPS reacted with myelin, actin and laminin, while the sera from mice inoculated with Yops reacted with myelin, thyroglobulin and cardiolipin. These results suggest that SPF Swiss mice inoculated with any one of the Y enterocolitica derivatives tested exhibited polyclonal activation of B lymphocytes as a result of stimulation by various bacterial components and not only LPS stimulation.