RESUMO
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.
Assuntos
Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Antígenos de Bactérias , Proteínas de Bactérias , Interferon gama/biossíntese , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/diagnóstico , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Sensibilidade e Especificidade , Tuberculose Pulmonar/imunologiaRESUMO
Specific IgG and IgM responses to soluble egg antigen (SEA) and keyhole limpet haemocyanin (KLH) were measured by ELISA in patients with acute and chronic schistosomiasis. The tests based upon IgM and IgG antibodies responses to KLH presented the best diagnostic discrimination, and can be used in conjunction with clinical and epidemiological data to the differential diagnosis of acute schistosomiasis.