Preliminary results in the immunodiagnosis of tuberculosis in children based on T cell responses to ESAT-6 and PPD antigens.

The aim of this work was to study the difference in interferon gamma (IFN-gamma) production by T lymphocytes after early secretory antigen target 6 (ESAT-6) or purified protein derivate (PPD) stimulation in whole blood culture supernatants from children with suspected tuberculosis (TB) disease (n = 21), latent TB infection (n = 16) and negative controls (NC) (n = 22) from an endemic area in Brazil. The concentration of IFN-gamma (pg/ml) was measured by enzyme linked immunosorbent assay and the differences in the IFN-gamma levels for each group were compared and evaluated using an unpaired Student's t-test; p values < 0.05 were considered significant. Measurement of IFN-gamma levels after ESAT-6 stimulation raised the possibility of early diagnosis in the latent TB group (p = 0.0030). Nevertheless, the same group showed similar responses to the NC group (p > 0.05) after PPD stimulation. The IFN-gamma assay using ESAT-6 as an antigenic stimulus has the potential to be used as a tool for the immunodiagnosis of early TB in children.

Preliminary results in the immunodiagnosis of tuberculosis in children based on T cell responses to ESAT-6 and PPD antigens

The aim of this work was to study the difference in interferon gamma (IFN-gamma) production by T lymphocytes after early secretory antigen target 6 (ESAT-6) or purified protein derivate (PPD) stimulation in whole blood culture supernatants from children with suspected tuberculosis (TB) disease (n = 21), latent TB infection (n = 16) and negative controls (NC) (n = 22) from an endemic area in Brazil. The concentration of IFN-gamma (pg/ml) was measured by enzyme linked immunosorbent assay and the differences in the IFN-gamma levels for each group were compared and evaluated using an unpaired Student's t-test; p values < 0.05 were considered significant. Measurement of IFN-gamma levels after ESAT-6 stimulation raised the possibility of early diagnosis in the latent TB group (p = 0.0030). Nevertheless, the same group showed similar responses to the NC group (p > 0.05) after PPD stimulation. The IFN-gamma assay using ESAT-6 as an antigenic stimulus has the potential to be used as a tool for the immunodiagnosis of early TB in children.

[Asthma in schoolchildren from Recife, Brazil. Prevalence comparison: 1994-95 and 2002]. / Asma em escolares do Recife -- comparação de prevalências: 1994-95 e 2002.

OBJECTIVES: To describe the prevalence of asthma and asthma variants in schoolchildren from Recife in 2002, and to compare these data with data from 1994-95; to analyze the relationship between maternal schooling and the presence of asthma or worsening asthma; and to evaluate the diagnostic accuracy of the yearly prevalence of wheezing as an asthma indicator. METHODS: Cross-sectional study. A probabilistic sample of 3,086 and 2,774 13- and 14-year-old students answered a written questionnaire in 1994-95 and 2002, as part of the International Study of Asthma and Allergies in Childhood. RESULTS: The following prevalence rates were observed in 1994-95 and 2002, respectively: cumulative prevalence of referred asthma: 21 vs 18.2%; cumulative prevalence of wheezing: 39 vs 38%; yearly prevalence of wheezing: 19.7 vs 19.4%; yearly prevalence of night cough: 31 vs 38%; yearly prevalence of exercise-induced wheezing: 20.6 vs 23.8%. The yearly prevalence of asthma attacks was 16.3 vs 15.2% for 1 to 3 attacks; 2.7% vs 1.2% for 4 to 12 attacks; and 1% vs 0.4% for more than 12 attacks. The yearly prevalence of attacks that disturbed sleep was 13 and 10.3%. The yearly prevalence of attacks with compromised speech was 4.8 and 4.1%. Higher levels of maternal schooling were related to higher cumulative prevalence of referred asthma and to cumulative and yearly prevalence of wheezing. CONCLUSIONS: The prevalence of asthma and its severe forms is high in teenager students in Recife. It is also related to higher levels of maternal schooling.

Asma em escolares do Recife - comparação de prevalências: 1994-95 e 2002 / Asthma in schoolchildren from Recife, Brazil. Prevalence comparison: 1994-95 and 2002

OBJETIVOS: Descrever a prevalência atual (2002) de asma e suas variantes em escolares da cidade do Recife, comparando os dados com o período de 1994-95; analisar a relação entre instrução materna e o surgimento ou o agravamento da asma; e avaliar a acurácia diagnóstica da prevalência anual de sibilância como indicador de asma. MÉTODO: Em um corte transversal, estudou-se, por questionário escrito, uma amostra probabilística de escolares de 13 e 14 anos em Recife, em 1994-95 (n = 3.086) e 2002 (n = 2.774), como parte do projeto ISAAC (International Study of Asthma and Allergies in Childhood). RESULTADOS: Em 1994-95 e 2002, as prevalências foram, respectivamente: cumulativa de asma referida, 21 e 18,2 por cento; cumulativa de sibilância, 39 e 38 por cento; anual de sibilância, 19,7 e 19,4 por cento; anual de tosse equivalente de asma, 31 e 38 por cento; anual de sibilância desencadeada por exercício, 20,6 e 23,8 por cento. A prevalência anual de crises, estratificada em 1 a 3, 4 a 12 e mais de 12 foi: 16,3, 2,7 e 1 por cento em 1994-95 e 15,2, 1,2 e 0,4 por cento em 2002. A prevalência anual de crises que comprometeram o sono foi, respectivamente, de 13 e 10,3 por cento; a prevalência de crises com prejuízo da fala foi de 4,8 e 4,1 por cento. Nível mais elevado de instrução materna associou-se a maior prevalência cumulativa de asma referida, prevalência cumulativa e anual de sibilância. CONCLUSÕES: A prevalência de asma e suas formas graves é elevada em escolares adolescentes do Recife e está associada a maior instrução materna.