Resumo Introdução/Objetivo: Evidências recentes sugerem que anormalidades que envolvem os linfócitos Th17 estão associadas à fisiopatologia do lúpus eritematoso sistêmico (LES). Além disso, os linfócitos T multifuncionais (LTM), ou seja, aqueles que produzem múltiplas citocinas simultaneamente, estão presentes no meio inflamatório e podem estar implicados no processo autoimune observado no LES. No presente estudo, objetiva-se caracterizar o estado funcional dos linfócitos T CD4+ no LES e determinar simultaneamente a concentração de IL-2, IFN-γ e IL-17 em culturas de linfócitos sob estímulos exógenos e autoantigênicos. Pacientes e métodos: Dezoito pacientes com doença ativa, 18 com doença inativa e 14 controles saudáveis foram submetidos à análise do estado funcional dos linfócitos T CD4+. Resultados: Encontrou-se que os pacientes com LES apresentaram uma diminuição na quantidade total de células CD4+, um aumento na quantidade de linfócitos T ativados e um aumento na frequência de linfócitos Th17 em comparação com controles saudáveis (HC). As células LTM tinha frequência aumentada em pacientes com LES e houve um aumento na frequência de LTM trifuncionais em pacientes com LES ativo em comparação com aqueles com LES inativo. Curiosamente, as células MTF produziram quantidades maiores de IFN-γ do que os linfócitos T monofuncionais em pacientes e controles. Conclusão: Analisados em conjunto, esses dados indicam a participação dos linfócitos Th17 recentemente ativados e células MTF na fisiopatologia do LES.

Abstract Introduction/Objective: Recent evidence suggests that abnormalities involving Th17 lymphocytes are associated with the pathophysiology of systemic lupus erythematosus (SLE). In addition, multifunctional T cells (MFT), i. e., those producing multiple cytokines simultaneously, are present in the inflammatory milieu and may be implicated in the autoimmune process observed in SLE. In the present study, we aimed to characterize the functional status of CD4+ T cells in SLE by simultaneously determining the concentration of IL-2, IFN-γ and IL-17 in lymphocyte cultures under exogenous and self-antigenic stimuli. Patients and methods: Eighteen patients with active disease, 18 with inactive disease, and 14 healthy controls had functional status of CD4+ T cells analyzed. Results: We found that SLE patients presented a decreased number of total CD4+ cells, an increased number of activated T cells, and an increased frequency of Th17 cells compared to healthy controls (HC). MFT cells had increased frequency in SLE patients and there was an increased frequency of tri-functional MFT in patients with active SLE compared with those with inactive SLE. Interestingly, MTF cells produced larger amounts of IFNγ than mono-functional T cells in patients and controls. Conclusion: Taken together these data indicate the participation of recently activated Th17 cells and MTF cells in the SLE pathophysiology.

A vacinação é a principal forma de prevenção contra a Febre Amarela (FA), doença de importância em saúde pública no Brasil. Entretanto, pessoas que vivem com HIV possivelmente possuem conhecimentos insuficientes a respeito da FA, suas formas de prevenção e também sobre vacinas de modo geral. Métodos: Neste estudo baseado em questionários de autopreenchimento, avaliamos dados de 158 pacientes infectados por HIV atendidos em três diferentes serviços ambulatoriais do Município de São Paulo. Foram coletados dados demográficos, clínicos, e dados relacionados ao grau de conhecimento a respeito de vacinas, da FA e de suas formas de prevenção. Além disso, avaliamos individualmente a indicação e antecedente de vacinação contra FA. Resultados: Embora a maioria dos participantes tenha identificado corretamente que a vacina é a principal forma de prevenção da FA, poucos tinham conhecimento a respeito da gravidade clínica e ausência de tratamento específico da doença. Discrepância na vacinação (caracterizada quando o participante deveria ter recebido a vacina, mas não a recebeu) foi observada em 18,8% dos casos. Conclusão: A FA é importante agravo em saúde pública, passível de prevenção, e nossos resultados demonstram que são necessárias mais ações de educação voltadas à população de pessoas que vivem com HIV.

Introduction: Vaccination is the main preventive strategy against Yellow Fever (YF), which is a public health concern in Brazil. However, HIV-infected patients might have insufficient knowledge regarding YF, YF prevention, and vaccines in general. Methods: In this questionnaire-based study, data from 158 HIV-infected individuals were addressed in three distinct outpatient clinics in São Paulo. Information was collected on demographic and clinical characteristics, as well as patients' knowledge of vaccines, YF and YF preventive strategies. In addition, individual YF vaccine recommendations and vaccine status were investigated. Results: Although most participants adequately ascertain the vaccine as the main prevention strategy against YF, few participants were aware of the severity and lack of specific treatment for YF. Discrepancy in YF vaccine (patients who should have taken the vaccine, but did not) was observed in 18.8% of participants. Conclusion: YF is an important and preventable public health concern, and these results demonstrate that more information is necessary for the HIV-infected population.

OBJECTIVES: The purpose of this study was to investigate the association between T cell receptor excision circle levels in peripheral blood mononuclear cells and regulatory T cells that co-express CD25 and Foxp3 in healthy children and adolescents of different ages. MATERIALS AND METHODS: The quantification of signal-joint T-cell receptor excision circle levels in the genomic DNA of peripheral blood mononuclear cells was performed using real-time quantitative PCR. The analysis of CD4, CD8, CD25, and Foxp3 expression was performed using flow cytometry. RESULTS: Ninety-five healthy controls (46 females and 49 males) ranging in age from 1 to 18 years were analyzed. The mean T-cell receptor excision circle count in all individuals was 89.095¡36.790 T-cell receptor excision circles per microgram of DNA. There was an inverse correlation between T-cell receptor excision circles counts and age (r = -0.846; p<0.001) as well as between the proportion of CD4+CD25+Foxp3+ T cells and age (r = -0.467; p = 0.04). In addition, we observed a positive correlation between the amount of CD4+CD25+Foxp3+ T cells and the amount of Tcell receptor excision circles per microgram of DNA in individuals of all ages (r = -0.529; p = 0.02). CONCLUSIONS: In this study, we observed a decrease in the thymic function with age based on the fact that the level of T-cell receptor excision circles in the peripheral blood positively correlated with the proportion of regulatory T cells in healthy children and adolescents. These findings indicate that although T-cell receptor excision circles and regulatory T cells levels decrease with age, homeostasis of the immune system and relative regulatory T cells population levels are maintained in the peripheral blood.

Com a ameaça internacional do bioterrorismo, a varíola voltou a ganhar destaque mundial. Os autores revisam aspectos da varíola e trazem considerações atuais da utilização do agente como arma biológica. Também apresentam dados dos esforços atuais na produção e desenvolvimento de vacinas contra a doença.

With the international threat of bioterrorism, smallpox is again a matter of intense debate. The authors review this disease and raise considerations on the exploitation of the etiologic agent as a biological weapon. Also bring to discussion the available efforts to produce and develop vaccines against the disease.

Hepatitis C virus (HCV) causes infectious hepatitis worldwide. It is transmitted mainly by blood products and sharing of intravenous paraphernalia during illicit drug use. High prevalence rates have been described among specific groups considered to be at higher risk for HCV infection, including prison inmates. The objectives of this study were: to determine the HCV seroprevalence among inmates of Casa de Detenção de São Paulo; to identify risk factors for HCV infection; and to compare the seroprevalence of HCV to other blood borne or sexually transmitted diseases. From December, 1993, to January, 1994, a total of 779 inmates were interviewed to collect information on sociodemographic status, sexual behavior, and past experience with illicit drugs. Blood samples were obtained from 756 inmates for serological tests. 310 (41%) blood samples were positive for anti-HCV, 425 (56.2%) were negative, and 21 (2.8%) showed indeterminate results. In this population, we found a seroprevalence of 13.7% for HIV, 3.3% for syphilis (VDRL), and 68.1% for hepatitis B virus previous infection. Four variables were each identified as associated with a positive anti-HCV serologic test: a positive VDRL (OR = 2.63 IC 95% 1.08 to 6.36); a time of current imprisonment longer than 130 months (OR = 2.44 IC 95% 1.04 to 5.71); previous incarceration at Casa de Detenção de São Paulo (OR = 1.73 IC 95% 1.19 to 2.52) and; illicit drug use before admission to the Casa de Detenção de São Paulo (OR = 1.64 IC 95% 1.15 to 2.33). The seroprevalence of HCV antibodies among the study population was high (41%), indeed, one of the highest clusters of HCV infection recorded until now. Four variables were each shown to be associated with HCV infection. The simultaneous presence of these 4 variables is associated with an 82% probability of being anti-HCV positive. Although risk factor analysis indicates most HCV infections occur prior to inprisonment, initiation of control measures to prevent continued transmission after incarceration should be done.

Por meio do benznidazol e do nifurtimox foram tratados 49 pacientes acometidos de doença de Chagas. Xenodiagnóstico prévio tinha sempre resultado positivo, evidenciando parasitemia pelo Trypanosoma cruzi e sendo as seguintes as formas clínicas: indeterminada-19; cardíaca-28; digestiva-4 (dois pacientes apresentavam formas mistas). Quanto ao benznidazol, houve administração de 5 a 8 mg/kg/dia, durante dois meses, e a propósito do nifurtimox o esquema terapêutico começou com a dose de 5 a 7 mg/kg/dia, sucedendo aumento progressivo até 15 a 17 mg/kg/dia, no decurso de quatro meses. O benznidazol, usado por 41 doentes, propiciou negativação em 26 (63.4%) à avaliação realizada por meio do xenodiagnóstico, em etapas de um a 20 anos e, em média, de 6 a 7 anos. Por seu turno, com o nifurtimox verificou-se uma negativação relativamente a somente um indivíduo, tendo o seguimento sido efetuado em etapas de um a 18 anos. Pôde-se constatar que o benznidazol mostrou-se melhor tolerado e também mais eficiente no sentido de negativar a parasitemia. Todavia, é desejável a disponibilidade de fármacos dotados de maior eficácia e melhor tolerabilidade para coibir a infecção devida ao Trypanosoma cruzi.

Forty-nine American Trypanosomiasis (Chagas' disease) patients, with xenodiagnosis proven parasitemia were treated by the authors. Forty-one of these patients were given benznidazole, at dosages ranging from 5mg/kg/day to 8mg/kg/day, during a pre-established period of 60 days. In this group, 17 patients had an undetermined form of the disease, whereas 22 had cardiologic disease and 4 had digestive disease (two patients had a mixed form of the disease). Side effects were frequent, and led to the discontinuation of treatment in 17 patients. The follow-up period ranged from 1 to 20 years (mean follow-up period of 6 yrs. 7 mo). 26 (63.4%) of the patients became parasitemia-negative. The other eight patients were treated with nifurtimox, during 120 days, following a variable dose regime of 5mg/kg/day (initial dose) to 17 mg/kg/day (final dose). Six of them had severe side effects, and only one patient remained parasitemia-negative throughout the observation period (ranging from 1 to 18 years). Benznidazole proved to be better tolerated and more effective in the management of parasitemia when compared to nifurtimox, although more effective and less toxic drugs are still desirable.