Navegando por Palavras-chave "immunologic tolerance"

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    Células T regulatórias naturais (T REGS) em doenças reumáticas
    (Sociedade Brasileira de Reumatologia, 2008-12-01) Cruvinel, Wilson de Melo [UNIFESP]; Mesquita Júnior, Danilo [UNIFESP]; Araújo, Júlio Antônio Pereira [UNIFESP]; Carvalho, Karina Inacio [UNIFESP]; Kállas, Esper Georges [UNIFESP]; Andrade, Luiz Eduardo Coelho [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Católica de Goiás; Universidade de São Paulo (USP); Fleury Medicina Diagnóstica Setor de Imunologia
    The healthy immune system must keep the delicate balance between the capacity to respond to exogenous antigens and to keep the tolerance to endogenous antigens. In the absence of an adequate response to exogenous agents the individual is subjected to the deleterious effect of the invasion for pathogens. On the other hand, if the immune system responds in an unwary exacerbated way harmful inflammatory consequences may result. Well-established mechanisms of maintaining self-tolerance include clonal deletion and anergy. Despite the functional evidence in favor of the existence of suppressor T cells, for many years immunologists failed to identify the phenotypic characteristics and to confirm the existence of these lymphocytes. The recent demonstration of different phenotypes of cells, now designated regulatory T cells, reintroduced the paradigm of active regulation of auto-reactivity by particular subtypes of lymphocytes. This subject is of great interest in the contemporary literature. It has been shown that excess regulatory function may be associated with increased susceptibility to infectious and neoplastic diseases. On the other hand decreased regulatory function may cause autoimmunity. In fact, several experimental models of diverse autoimmune conditions have been developed by decreasing or abolishing regulatory T cells. Counterpart of this phenomenon has been sought for in several human autoimmune diseases. At this moment it seems that the most important subtype of regulatory cells are the natural regulatory T cells (TREGS), which represent about 5% of peripheral blood CD4 T lymphocytes. These cells are characterized by the constitutive expression of FOXP3, GITR, CTLA-4 and high levels of CD25. The present article reviews the basic knowledge on the TREGS and the several studies describing the status and function of these cells in autoimmune rheumatic diseased.
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    Teste de desencadeamento aberto no diagnóstico de alergia à proteína do leite de vaca
    (Sociedade Brasileira de Pediatria, 2010-04-01) Correa, Fernanda Ferreira [UNIFESP]; Vieira, Mário César; Yamamoto, Danielle Reis; Speridião, Patrícia da Graça Leite [UNIFESP]; Morais, Mauro Batista de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital Pequeno Príncipe Centro de Gastroenterologia Pediátrica
    OBJECTIVES: To report the results of open challenge tests performed in children fed with cow's milk-free diet. DESCRIPTIONS: Cross-sectional study evaluating cow's milk open challenge performed under supervision in a hospital setting during 2.5 hours and ambulatory follow-up for 30 days when no immediate reaction occurred. One hundred and twenty-one patients were included, with ages between 4 and 95 months. Cow's milk open challenge tests were positive in 28 patients (23.1%). A clinical manifestation of cow's milk allergy different from the one presented at diagnosis occurred in 12 (24.9%) patients with positive challenge. Positive challenge was more frequent (p = 0.042) in patients fed with extensively hydrolyzed formulae or amino acid-based formulae (30.3%) when compared to those fed with other exclusion diets (14.5%). CONCLUSION: Open challenge allowed the interruption of exclusion diet in a significant proportion of the patients.