Résumé
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.
Sujets)
Adolescent , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Mâle , Antigènes bactériens , Protéines bactériennes , Interféron gamma/biosynthèse , Mycobacterium tuberculosis/immunologie , Tuberculose pulmonaire/diagnostic , Antigènes bactériens/immunologie , Protéines bactériennes/immunologie , Études cas-témoins , Test ELISA , Sensibilité et spécificité , Tuberculose pulmonaire/immunologieRésumé
Patients with acute schistosomiasis were studied before and after oxamniquine treatment. They had been exposed to cercariae 5 to 9 weeks before, and presented compatible clinical manifestations, eosinophilia, and high levels of total IgE. Interferon-gamma (IFN-gamma) and interleukin-4 were measured by ELISA in whole blood samples under soluble egg antigen or soluble adult worm preparation stimulation. After treatment, the reduction of leukocytosis and eosinophilia were not significant, but total IgE levels decreased significantly, in contrast to IFN-gamma levels that were significantly increased. The oxamniquine treatment of acute schistosomiasis patients is followed by an improvement of a Th1 response in vitro. If this response has a protective aspect is unknown, and some investigations need to be realized.
Sujets)
Humains , Animaux , Mâle , Femelle , Enfant , Adolescent , Adulte , Antigènes d'helminthe/immunologie , Interféron gamma/biosynthèse , Oxamniquine/usage thérapeutique , Schistosoma mansoni/immunologie , Schistosomiase à Schistosoma mansoni/traitement médicamenteux , Schistosomicides/usage thérapeutique , Maladie aigüe , Anticorps antihelminthe/sang , Épidémies de maladies , Test ELISA , Fèces/parasitologie , Immunoglobuline E/sang , Interféron gamma/immunologie , Numération des oeufs de parasites , Schistosomiase à Schistosoma mansoni/sang , Schistosomiase à Schistosoma mansoni/immunologieRésumé
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.