100 resultados para HLA Antigens

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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O objetivo deste estudo foi avaliar a presença de aloanticorpos anti-HLA classe I em pacientes infectados pelo HIV-1 e relacioná-la aos diferentes cursos clínicos da doença. Amostras de sangue de 145 indivíduos HIV positivo foram coletadas em tubos com EDTA. A infecção pelo HIV-1 foi confirmada por teste ELISA e a presença de aloanticorpos anti-HLA classe I determinada em seguida. A evolução clínica foi definida como rápida (<1 ano entre diagnóstico e morte), moderada (1-3 anos) ou lenta (>3 anos). A presença de aloanticorpos anti-HLA classe I foi menor em indivíduos saudáveis em relação aos infectados pelo HIV-1 (4,2% contra 32,4%). Porém, a distribuição destes aloanticorpos entre os indivíduos infectados foi igual, independente da evolução clínica. Deste modo, a presença de aloanticorpos anti-HLA classe I não é um fator determinante na piora clínica do paciente.

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Em agosto de 1983 foram observados 85 habitantes do Município de Humaitá, Estado do Amazonas, Brasil, com a finalidade de estudar a prevalência dos antígenos de HLA -A, -B, -C e DR, dentre os quais 38 eram doentes com malária causada pelo Plasmodium falciparum Todos eles foram examinados para avaliação de esplenomegalia, exame parasitológico de sangue e pesquisa de anticorpos de malária. Foram constituídos três grupos: (I) 25 indivíduos nascidos na região Amazônica que nunca tiveram malária; (II) 38 indivíduos naturais da Amazônia que tinham sido tratados de malária no passado, ou que estavam tendo malária atual, e (III) 22 doentes com malária que contraíram na Amazônia e eram procedentes de outras regiões do Brasil. Foram colhidas amostras de sangue de cada um deles, separados os linfôcitos e os antígenos de HLA foram tipados pelo teste de microlinfocitotoxidade. Houve elevada freqüência de antígenos não identificados, nos grupos estudados, o que sugere ou a existência de homozigoze, oufenôtipo não identificado nessa população. Houve alta freqüência fenotípica de antígeno deAg(W24) (44,7%) no Grupo II, quando comparado ao Grupo 1(32%) ou Grupo III (9%). Os indivíduos do Grupo II mostraram também elevada freqüência do antígeno DR4 (80%) quando comparado ao Grupo 1(36,3%) ou Grupo III(16,6%). Essas observações sugerem a possibilidade de suscetibilidadegenética ã malária entre os nativos da Amazônia e indicam a necessidade da realização de inquéritos mais extensos sobre a freqüência de antígenos de HLA em habitantes de zona endêmica de malária.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This study was undertaken to investigate human leucocyte antigen (HLA) associations with benign migratory glossitis and psoriasis in Brazilian patients and particularly to determine whether benign migratory glossitis is also associated with HLA-Cw6, the classical association observed in psoriasis. The results showed a highly significant association of Cw6 with both psoriasis and benign migratory glossitis, with this antigen being present in 59.% of the patients with psoriasis, in 43.8% of the patients with benign migratory glossitis, and in only 12.6% of the controls. Other significant positive associations, although at a lower significance level, were with B13, both in psoriasis and in benign migratory glossitis, and with B17, only in psoriasis. To our knowledge, this is the first report on the association of Cw6 with benign migratory glossitis. We believe that this finding reinforces the concept of a pathogenetic relationship between benign migratory glossitis and psoriasis.

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The genetics of psoriasis and benign migratory glossitis has relationship with the major HLA. The authors reviewed the literature about the association between HLA with psoriasis and benign migratory glossitis. HLA-Cw6 presents a particularly strong association, irrespective of different racial or ethnic groups, suggesting that Cw6 itself, or a closely linked gene in strong linkage disequilibrium, is the major HLA-linked susceptibility gene for psoriasis. The white Brazilian population shows the established associations between psoriasis and the HLA antigens Cw6, B13 and B17 reported in several Caucasian populations, and shows association between benign migratory glossitis and HLA-Cw6.

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CONTEXTO E OBJETIVO:Para a realização de transplantes de medula óssea com material alogênico, é necessária a verificação de histocompatibilidade das moléculas do sistema HLA (human leukocyte antigen), fundamental para o sucesso desses transplantes. O objetivo desta pesquisa foi caracterizar os doadores de medula óssea segundo gênero, idade, etnia e grupos HLA de um centro regional de hemoterapia brasileiro.TIPO DE ESTUDO E LOCAL:Estudo descritivo dos doadores cadastrados em um centro regional de hemoterapia de um hospital público universitário da região Sudeste do Brasil.MÉTODOS:Foram consultadas as fichas dos 66.780 doadores cadastrados entre 2005 e junho de 2011 e tabuladas as variáveis estudadas.RESULTADOS:Encontrou-se distribuição equilibrada entre os gêneros, e 82,8% dos doadores tinham até 45 anos de idade. Quanto à etnia auto-referida, 77,3% se apresentaram como brancos, 15,0% como pardos, 5,7% como negros, os 2% restantes dividindo-se em outras etnias. Quanto à caracterização imunogenética, no grupo alélico HLA-A, o mais frequente foi o HLA-A*02, com 39,20%; no grupo alélico HLA-B, o mais comum foi o HLA-B*35, com 14,18%; no grupo alélico HLA-DRB1, o mais frequente foi o HLA-DRB1*03, com 17,03% do total de doadores. Quando esses resultados são comparados com os dados do cadastro nacional de doadores (REDOME), observam-se diferenças demográficas e imunogenéticas, que se explicam pelo histórico de imigração da região de Ribeirão Preto, no Sudeste brasileiro.CONCLUSÕES:Os resultados encontrados reforçam a importância de conhecer o perfil demográfico e imunogenético das regiões do Brasil, para reduzir o tempo de espera por um doador histocompatível.

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The immunogenetic study of senile cataract showed that the association with the HLA antigens and Ia antigens suggests an influence of the antigenicity for cataractogenesis, but not a peculiar specificity. However, the investigation of the immunoglobulins in lens suggest that the lens pathology may be produced by antibodies reacting with the lens capsule and consequently interfering with the lens epithelial metabolism, and contributes to the complex mechanism of cataract formation.

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The aim of this paper is to analyze 87 cases of kidney transplants obtained from nonrelated donors; in 20 of these, a donor-specific transfusion procedure4 was added to the pretreatment protocol of each recipient.

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West syndrome is a severe epilepsy, occurring in infancy, that comprises epileptic seizures known as spasms, in clusters, and a unique EEG pattern, hypsarrhythmia, with psychomotor regression. Maturation of the brain is a crucial component. The onset is within the first year of life, before 12 months of age. Patients are classified as cryptogenic (10 to 20%), when there are no known or diagnosed previous cerebral insults, and symptomatic (80 to 90%), when associated with pre-existing cerebral damages. The time interval from a brain insult to infantile spasms onset ranged from 6 weeks to 11 months. West syndrome has a time-limited natural evolutive course, usually disappearing by 3 or 4 years of age. In 62% of patients, there are transitions to another age-related epileptic encephalopathies, the Lennox-Gastaut Syndrome and severe epilepsy with multiple independent foci. Spontaneous remission and remission after viral infections may occur. Therapy with ACTH and corticosteroids are the most effective. Reports about intravenous immunoglobulins action deserve attention. There is also immune dysfunction, characterized mainly by anergy, impaired cell-mediated immunity, presence of immature thymocytes in peripheral blood, functional impairment of T lymphocytes induced by plasma inhibitory factors, and altered levels of immunoglobulins. Changes in B lymphocytes frequencies and increased levels of activated B cells have been reported. Sensitized lymphocytes to brain extract were also described. Infectious diseases are frequent and may, sometimes, cause fatal outcomes. Increase of pro-inflamatory cytokines in serum and cerebrospinal fluid of epileptic patients were reported. Association with specific HLA antigens was described by several authors (HLA-DR7, HLA-A7, HLA-DRw52, and HLA-DR5). Auto-antibodies to brain antigens, of several natures (N-methyl-d-aspartate glutamate receptor, gangliosides, brain tissue extract, synaptic membrane, and others), were described in epileptic patients and in epileptic syndromes. Experimental epilepsy studies with anti-brain antibodies demonstrated that epileptiform discharges can be obtained, producing hyperexcitability leading to epilepsy. We speculate that in genetically prone individuals, previous cerebral lesions may sensitize immune system and trigger an autoimmune disease. Antibody to brain antigens may be responsible for impairment of T cell function, due to plasma inhibitory effect and also cause epilepsy in immature brains. © 2008 Bentham Science Publishers Ltd.

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The morphologic appearance and clinical behavior of the human urinary bladder papillary transitional cell carcinoma (TCC) probably result from a complex interaction between carcinogenic insults and host resistance during the patient's life. While the main recognized risk factors are of environmental origin (e.g. smoking), relatively little information exists about the susceptibility to TCC development. The human leukocyte antigen G (HLA-G) molecule plays an important role in immune response regulation and has been implicated in the inhibition of the cytolytic function of natural killer and cytotoxic T cells. Several lines of evidence indicate that HLA-G polymorphisms influence the expression level and production of different HLA-G isoforms. The aim of this study was to explore a possible influence of the HLA-G polymorphism on the susceptibility to urinary bladder TCC development and progression in smokers and nonsmokers Brazilian subjects. The HLA-G locus was found to be associated with susceptibility to TCC development and progression. The G*0104 allelic group (specially the G*010404 allele) and the G*0103 allele were associated with a tobacco-dependent influence on TCC development. The G*0104 group was associated with progression to high-grade tumors, irrespective of smoking habit, while the G*0103 allele was associated to high-grade tumor only in smoking patients. Our results are an evidence that the HLA-G locus itself, or as part of an extended haplotype encompassing this chromosome region (particularly the HLA-A given the high linkage disequilibrium observed between them in this data series), may be associated with TCC susceptibility and tumor progression, suggesting a tobacco-dependent influence of these polymorphisms.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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PURPOSE: Subclinical inflammation may be observed in patients using topical antiglaucomatous drugs. The objective of this study was to investigate inflammation in conjunctiva of glaucoma patients using prostaglandin analogs, by the detection of an immunogenetic marker (HLA-DR) and compare the effect of 3 different drugs: latanoprost, bimatoprost, and travoprost in the induction of this inflammation. SUBJECTS AND METHODS: Thirty-three patients with primary open-angle glaucoma were evaluated without and with prostaglandin analogs topical therapy. Imprints of conjunctival cells were obtained, fixed on glass slides, and prepared for immunohistochemical analysis. RESULTS: Before the use of prostaglandin analogs, 4 of the 33 patients evaluated presented expression of HLA-DR in the conjunctiva (mild). After 1 month on prostaglandin analog treatment, all but 1 patient presented HLA-DR staining. HLA-DR expression of these 32 patients was scored as mild (19 patients), medium (11 patients), or intense (2 patients). The differences were statistically significant both when the presence and the increased expression of HLA-DR were considered (P<0.001). When the 3 different groups were analyzed (latanoprost, bimatoprost, and travoprost) no statistically significant difference was found (P=0.27). CONCLUSIONS: The use of prostaglandin analogs eye drops provokes a subclinical inflammatory reaction, observed by HLA-DR expression, even after a short period of treatment, independently of the class of the prostaglandin analogs used. © 2009 Lippincott Williams & Wilkins, Inc.

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Introduction: HLA-G and HLA-E are two nonclassical class I molecules, which have been well recognized as modulators of innate and adaptive immune responses, and the expression of these molecules in virus infected cells has been associated with subversion of the immune response. Objective: In this study we performed a cross-sectional study, systematically comparing the expression of HLA-G and HLA-E in benign, premalignant and malignant laryngeal lesions, correlating with demographic and clinical variables and with the presence of high-risk and low-risk HPV types. Materials and methods: Laryngeal lesions were collected from 109 patients and stratified into 27 laryngeal papillomas, 17 dysplasias, 10 in situ laryngeal carcinomas, 27 laryngeal carcinomas without metastases, 28 laryngeal carcinomas with metastasis along with their respective draining cervical lymph nodes, and 10 normal larynx specimens. The expression of HLA-G and HLA-E molecules was determined by immunohistochemistry. HPV DNA detection and typing was performed using generic and specific primers. Results: HLA nonclassical molecules showed a distinct distribution pattern, according to the larynx lesion grade. HLA-G expression increased in benign and premalignant lesions, and gradually decreased in invasive carcinomas and in respective draining cervical lymph nodes. Conversely, HLA-E expression increased as far as lesion grade increased, including increased molecule expression in the draining lymph nodes of malignant lesions. Only 17 (15.6%) patients were HPV DNA positive. Conclusions: Overexpression of HLA-E and underexpression of HLAG appear to be good markers for malignant larynx lesion.