439 resultados para AUTOIMMUNITY
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Background and Objectives: Chronic autoimmune thyroiditis (CAT) remains the most common cause of acquired hypothyroidism There is currently no therapy that is capable of regenerating CAT-damaged thyroid tissue The objective of this study was to gauge the value of applying low-level laser therapy (LLLT) in CAT patients based on both ultrasound studies (USs) and evaluations of thyroid function and thyroid autoantibodies. Study Design/Materials and Methods: Fifteen patients who had hypothyroidism caused by CAT and were undergoing levothyroxine (LT4) treatment were selected to participate in the study Patients received 10 applications of LLLT (830 nm, output power 50 mW) in continuous mode, twice a week, using either the punctual technique (8 patients) or the sweep technique (7 patients), with fluence in the range of 38-108 J/cm(2) USs were performed prior to and 30 days after LLLT USs included a quantitative analysis of echogenicity through a gray-scale computerized histogram index (El). Following the second ultrasound (30 days after LLLT), LT4 was discontinued in all patients and, if required, reintroduced Truodothyronine, thyroxine (T4), free T4, thyrotropin, thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) antibodies levels were assessed before LLLT and then 1, 2, 3, 6, and 9 months after LT4 withdrawal. Results: We noted all patients` reduced LT4 dosage needs, including 7 (47%) who did not require any LT4 through the 9-month follow-up The LT4 dosage used pre-LLLT (96 +/- 22 mu g/day) decreased in the 9th month of follow-up (38 23 mu g/day; P<0.0001) TPOAb levels also decreased (pre-LLLT = 982 +/- 530 U/ml, post-LLLT = 579 454 U/ml, P = 0 016) TgAb levels were not reduced, though we did observe a post-LLLT increase in the EI (pre-LLLT = 0 99 +/- 0.09, post-LLLT= 1.21 +/- 0.19, P=0.001) Conclusion: The preliminary results indicate that LLLT promotes the improvement of thyroid function, as patients experienced a decreased need for LT4, a reduction in TPOAb levels, and an increase in parenchymal echogenicity Lasers Surg. Med. 42:589-596, 2010. (C) 2010 Wiley-Liss, Inc
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Pemphigus refers to a group of human autoimmune blistering diseases involving skin and/or mucous membranes. Endemic pemphigus foliaceus (EPF), or fogo selvagem is an organ-specific autoimmune blistering disease, first reported in the beginning of the 20th century in rural areas of Brazil. The disease follows the course of streams and creeks, and vanishes after urbanization of the endemic areas. The auto-antigen related to EPF is desmoglein 1, a 160 kDa glycoprotein of the desmossomal core, targeted by in situ and circulating IgG autoantibodies, mainly of the IgG4 subclass.
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Pemphigus foliaceus is a life threatening skin disease that is associated with autoimmunity to desmoglein, a skin protein involved in the adhesion of keratinocytes. This disease is endemic in certain areas of South America, suggesting the mediation of environmental factors triggering autoimmunity. Among the possible environmental factors, exposure to bites of black flies, in particular Simulittm nigrimanum has been suggested. In this work, we describe the sialotranscriptome of adult female S. nigrimanum flies. It reveals the complexity of the salivary potion of this insect, comprised by over 70 distinct genes within over 30 protein families, including several novel families, even when compared with the previously described sialotranscriptome of the autogenous black fly, S. vitiation. The uncovering of this sialotranscriptome provides a platform for testing pemphigus patient sera against recombinant salivary proteins from S. nigrimanum and for the discovery of novel pharmacologically active compounds.
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CD40 ligand (CD40-L), a member of the tumor necrosis family of transmembrane glycoproteins, is rapidly and transiently expressed on the surface of recently activated CD4+ T cells. Interactions between CD40-L and CD40 induce B cell immunoglobulin production as well as monocyte activation and dendritic cell differentiation. Since these features characterize rheumatoid arthritis (RA), the expression and function of CD40-L in RA was examined. Freshly isolated RA peripheral blood (PB) and synovial fluid (SF)T cells expressed CD40-L mRNA as well as low level cell surface CD40-L. An additional subset of CD4+ RA SF T cells upregulated cell surface CD40-L expression within 15 min of in vitro activation even in the presence of cycloheximide, but soluble CD40-L was not found in SF. CD40-L expressed by RA T cells was functional, since RA PB and SF T cells but not normal PB T cells stimulated CD40-L-dependent B cell immunoglobulin production and dendritic cell IL-12 expression in the absence of prolonged in vitro T cell activation. In view of the diverse proinflammatory effects of CD40-L, this molecule is likely to play a central role in the perpetuation of rheumatoid synovitis. Of importance, blockade of CD40-L may prove highly effective as a disease modifying therapy for RA.
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Objective: To evaluate interleukin (IL)-12 and IL-18 levels in the serum and peritoneal fluid of women with and without endometriosis. Design: Cross-sectional survey. Setting: University hospital. Patients: Interleukin-12 and IL-18 levels were compared in 105 patients submitted to laparoscopy because of symptoms suggestive of endometriosis (pain and/or infertility). The disease was confirmed in 72 patients (study group), while in 33 patients findings were not compatible with endometriosis (control group). Intevention(s): Blood sample and peritoneal fluid were obtained from patients during videolaparoscopy. Main Outcome Measure(s): The levels of IL-12 and IL-18 in peripheral blood and peritoneal fluid were determined and compared with the stage and site of the disease and histologic classification. Result(s): IL-12 levels measured in peritoneal fluid were higher inpatients with endometriosis compared with the control group. A significant increase in IL-12 levels was found when the more advanced stages of the disease were compared with the initial stages. No statistically significant differences were found in IL-18 levels, either in serum or in peritoneal fluid samples. Conclusion(s): Patients with severe endometriosis have higher IL-12 levels irrespective of IL-18 levels, suggesting that in this disease an alternative pathway is involved in induction of the Th1 immune response. (Fertil Steril (R) 2009;91:320-4. (C)2009 by American Society for Reproductive Medicine.)
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The objective of this study was to evaluate the presence of anti-C1q antibodies Hospital Israelita Albert Einstein Research Institute, Sao Paulo, Brazil in 67 juvenile Systemic lupus erythematosus (JSLE) patients and 26 healthy controls and to assess the association of these antibodies with disease activity, nephritis, and presence of anti-double-stranded (ds)DNA. Anti-C1q antibodies were detected by ELISA. A higher frequency of anti-C1q antibodies was observed in JSLE patients compared to controls (20% vs. 0%, P = 0.016). Specificity of these antibodies was 100% [95% confidence interval (CI) 86.7-100%] and sensitivity was 19.4% (95% CI 10.7-30.8%) for a lupus diagnosis. The median anti-C1q antibodies was higher in JSLE patients compared to controls [median (range) 9.4 (5.5-127) vs. 7.3 (5-20) units, P = 0.004]. Remarkably, a positive Spearman`s coefficient was found between anti-dsDNA and anti-C1q units (r = 0.42, P = 0.0004, 95% CI 0.19-0.60). Our results confirm a low frequency of anti-C1q antibody in our lupus populations, but the presence of anti-C1q antibodies appears to be a good marker for JSLE diagnosis.
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IPEX syndrome is a congenital disorder of immune regulation caused by mutations in the FOXP3 gene, which is required for the suppressive function of naturally arising CD4 + CD25 + regulatory T cells. In this case series we evaluated serum samples from 12 patients with IPEX syndrome for the presence of common autoantibodies associated with a broad range of autoimmune disorders. We note that 75% of patients (9/12) had 1 or more autoantibodies, an incidence far above the cumulative rate observed in the general population. The range of autoantibodies differed between patients and there was no predominant autoantibody or pattern of autoantibodies present in this cohort. Surprisingly, one patient had high-titer anti-mitochondrial antibodies (AMA) typically associated with primary biliary cirrhosis (PBC) although the patient had no signs of cholestasis. PBC is a well-characterized autoimmune disease that occurs primarily in women and includes the serological hallmarks of serum AMA and elevated IgM which were both present in this patient. PBC is virtually absent in children with the exception of one reported child with interleukin 2 receptor a (CD25) deficiency which is associated with an IPEX-like regulatory T cell dysfunction. Based on the present data and the available literature we suggest a direct role for CD4 + CD25 + regulatory T cells in restraining B cell autoantibody production and that defects in regulatory T cells may be crucial to the development of PBC. (C) 2010 Elsevier Ltd. All rights reserved.
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Neuromyelitis optica has not been thoroughly studied in Brazilian patients following the discovery of NMO-IgG and its specific antigen aquaporin-4. In this study we aimed to describe the clinical NMO-IgG immunological status and neuroimaging characteristics of recurrent neuromyelitis optica in a series Brazilian patients. We undertook a retrospective study of 28 patients with recurrent neuromyelitis optica, according to 1999 Wingerchuk`s diagnostic criteria. Data on NMO-IgG status, clinical features, and MRI findings were analyzed. Three men and 25 women were evaluated. Median age at onset of disease was 26 years (range 7-55); median time of follow-up was 7 years (range 2-14). The mean time elapsed between the first and the second attack was 17 months (median 8.5; range 2-88). NMO-IgG was detected in 18 patients (64.3%). Four patients died due to respiratory failure. Most patients presented with cervical (36%) and cervical-thoracic myelitis (46.4%). Holocord lesion was the most common pattern of involvement (50%) on the axial plane. We did not find a statistical association between myelitis extension and NMO-IgG result. Our series of Brazilian patients showed a younger age of onset than previously reported. In our series, in contrast to previous reports, there was no correlation between the extension of myelitis and NMO-IgG positivity.
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The aim of this study was to evaluate the frequency and clinical associations of HLA-DR alleles in Brazilian Caucasian patients with polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA). We evaluated 29 Caucasian patients with vasculitis classified as PAN or MPA according to the American College of Rheumatology (ACR) 1990 Criteria, Chapel Hill Consensus Conference (CHCC) nomenclature for vasculitis and EULAR recommendations for conducting clinical studies in systemic vasculitis. HLA-DR alleles were typed using polymerase chain reaction-amplified DNA, hybridized with sequence-specific low resolution primers. DNA obtained from 59 Caucasian healthy blood donors were used as control. In order to evaluate if a specific HLA may have influence on the clinical profile of those diseases, we also divided the patients according to Birmingham vasculitis score (BVAS) and Five-Factors Score (FFS) at the time of diagnosis. Increased frequency of HLA-DRB1*16 (p = 0.023) and DRB4*01 (p = 0.048) was found in patients with higher disease activity at the time of diagnosis (BVAS >= 22). Patients with less severe disease (FFS = 0) had a higher frequency of HLA-DRB1*03 (p = 0.011). Patients with gastrointestinal tract involvement had significantly increased frequency of HLA-DRB1*11 or B1*12 (p = 0.046), B1*13 (p = 0.021) and B3 (p = 0.008). In contrast, patients with renal disease, had higher frequency of DRB1*15 or DRB1*16 (p = 0.035) and B5 (p = 0.035). In the subgroup of patients with MPA, increased frequency of HLA-DRB1*15 was found in patients with BVAS >= 22 (p = 0.038) and FFS >= 1 (p = 0.039) suggesting that this allele is associated with more aggressive disease. Antineutrophil cytoplasmic antibodies (ANCA) negative MPA patients had significantly increased frequency of HLA-DRB1*11 or DRB1*12 when compared to ANCA positive patients (p = 0.023). Our results suggest that HLA-DR alleles may influence PAN and MPA clinical expression and outcome and that in MPA they participate in the mechanisms involved in the development to ANCA.
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Background Several primary immune deficiency disorders are associated with autoimmunity and malignancy, suggesting a state of immune dysregulation. The concept of immune dysregulation as a direct cause of autoimmunity in primary immune deficiency disorders (PIDDs) has been strengthened by the recent discovery of distinct clinical entities linked to single-gene defects resulting in multiple autoimmune phenomena including immune dysregulation, polyendocrinopathy, enteropathy and X-linked (IPEX) syndrome, and autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy (APECED) syndrome. Conclusion Reviewing recent advances in our understanding of the small subgroup of PIDD patients with defined causes for autoimmunity may lead to the development of more effective treatment strategies for idiopathic human autoimmune diseases.
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A new tuberculosis vaccine is urgently needed. Prime-boost strategies are considered very promising and the inclusion of BCG is highly desirable. In this investigation, we tested the protective efficacy of BCG delivered in the neonatal period followed by boosters in the adult phase with a DNA vaccine containing the hsp65 gene from Mycobacterium leprae (pVAXhsp65). Immune responses were characterized by serum anti-hsp65 antibody levels and IFN-gamma and IL-5 production by the spleen. Amounts of these cytokines were also determined in lung homogenates. Protective efficacy was established by the number of colony-forming units (CFU) and histopathological analysis of the lungs after challenge with Mycobacterium tuberculosis. Immunization with BCG alone triggered a significant reduction of CFU in the lungs and also clearly preserved the pulmonary parenchyma. BCG priming also increased the immunogenicity of pVAXhsp65. However, boosters with pVAXhsp65 or the empty vector abolished the protective efficacy of BCG. Also, higher IL-5 levels were produced by spleen and lungs after DNA boosters. These results demonstrated that neonatal BCG immunization followed by DNAhsp65 boosters is highly immunogenic but is not protective against tuberculosis.
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Background: A DNA vaccine (pVAXhsp65) containing the gene of a heat-shock protein (hsp65) from Mycobacterium leprae showed high immunogenicity and protective efficacy against tuberculosis in BALB/c mice. A possible deleterious effect related to autoimmunity needed to be tested because hsp65 is highly homologous to the correspondent mammalian protein. In this investigation we tested the effect of a previous immunization with DNAhsp65 in the development of experimental autoimmune encephalomyelitis (EAE), a rat model of multiple sclerosis. Methods: Female Lewis rats were immunized with 3 pVAXhsp65 doses by intramuscular route. Fifteen days after the last DNA dose the animals were evaluated for specific immunity or submitted to induction of EAE. Animals were evaluated daily for weight loss and clinical score, and euthanized during the recovery phase to assess the immune response and inflammatory infiltration at the central nervous system. Results: Immunization with pVAXhsp65 induced a specific immune response characterized by production of IgG(2b) anti-hsp65 antibodies and IFN-gamma secretion. Previous immunization with pVAXhsp65 did not change EAE clinical manifestations (weight and clinical score). However, the vaccine clearly decreased brain and lumbar spinal cord inflammation. In addition, it downmodulated IFN-gamma and IL-10 production by peripheral lymphoid organs. Conclusion: Our data demonstrated that this vaccine does not trigger a deleterious effect on EAE development and also points to a potential protective effect. Copyright (C) 2010 S. Karger AG, Basel
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The expression of peripheral tissue antigens (PTAs) in the thymus by medullary thymic epithelial cells (mTECs) is essential for the central self-tolerance in the generation of the T cell repertoire. Due to heterogeneity of autoantigen representation, this phenomenon has been termed promiscuous gene expression (PGE), in which the autoimmune regulator (Aire) gene plays a key role as a transcription factor in part of these genes. Here we used a microarray strategy to access PGE in cultured murine CD80(+) 3.10 mTEC line. Hierarchical clustering of the data allowed observation that PTA genes were differentially expressed being possible to found their respective induced or repressed mRNAs. To further investigate the control of PGE, we tested the hypothesis that genes involved in this phenomenon might also be modulated by transcriptional network. We then reconstructed such network based on the microarray expression data, featuring the guanylate cyclase 2d (Gucy2d) gene as a main node. In such condition, we established 167 positive and negative interactions with downstream PTA genes. Silencing Aire by RNA interference, Gucy2d while down regulated established a larger number (355) of interactions with PTA genes. T- and G-boxes corresponding to AIRE protein binding sites located upstream to ATG codon of Gucy2d supports this effect. These findings provide evidence that Aire plays a role in association with Gucy2d, which is connected to Several PTA genes and establishes a cascade-like transcriptional control of promiscuous gene expression in mTEC cells. (C) 2009 Elsevier Ltd. All rights reserved.
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Objective. To determine HLA-G expression in skin biopsies from patients with systemic sclerosis (SSc), and its association with epidemiological, clinical, and laboratory variables and survival. Methods. Paraffin-embedded skin biopsies obtained from 21 SSc patients (14 limited SSc, 7 diffuse SSc) and from 28 healthy controls were studied. HLA-G expression was evaluated by immunohistochemistry. Results. HLA-G molecules were detected in 57% of skin biopsies from patients with SSc (9 from limited SSc, 3 from diffuse SSc), whereas no control sample expressed HLA-G (p = 0.000004). In patients, HLA-G molecules were consistently observed within epidermal and some dermal cells. HLA-G expression was associated with a lower frequency of vascular cutaneous ulcers (p = 0.0004), telangiectasias (p = 0.008), and inflammatory polyarthralgia (p = 0.02). After a 15-year followup, SSc patients who exhibited HLA-G survived longer than patients who did not. Conclusion. HLA-G is expressed in skin biopsies from patients with SSc, and this is associated with a better disease prognosis. This Suggests a Modulatory role of HLA-G in SSc, as observed in other skin disorders. (First Release April 15 2009; J Rheumatol 2009;36:1230-4; doi:10.3899/jrheum.080552)