Résumé
Background: Cellular immune mechanisms of the resistance to infection by T cruzi as well as the pathogenesis of Chagas disease are still controversial. Aim: To quantify and analyse the peripheral blood immune cells from chagasic and non chagasic patients by flow cytometry. Patients and methods: Peripheral blood samples were taken from 21 individuals seropositive for Chagas disease, under no specific treatment. Control samples from 21 healthy blood donors were also obtained. To quantify immune cells populations by flow cytometry, antibodies against CD3, CD4, CD8, CD16/56, CD45/14, CD19 and HLA-DR markers were used. Results: The percentage of CD8+ cells was low and the CD4+/CD8+ ratio was high in chagasic patients, compared to their non infected counterparts. No statistically significant differences in the number of CD4+, NK, B, CD4+HLADR+ and CD8+HLADR+ cells, were observed within the two groups. Conclusions: These results show that Chilean chronic chagasic patients have lower percentage of CD8+ cells and higher CD4+/CD8+ ratio than non infected individuals
Sujets)
Humains , Mâle , Adulte , Femelle , Adulte d'âge moyen , Maladie de Chagas , Immunophénotypage/méthodes , Trypanosoma cruzi , Lymphocytes T CD4+ , Études cas-témoins , Numération des lymphocytes , Lymphocytes T CD8+ , Cytométrie en flux/méthodesRésumé
Amplification by the polymerase chain reaction (PCR) of Trypanosoma cruzi kinetoplastic DNA was used to enhance sentitivity in the detection of the parasite in blood, with the ultimate goal of improving the parasitological diagnosis of Chagas' disease in 0-10 year-old infected children. Twenty eight children were evaluated by using xenodiagnosis (XD) and PCR. Whereas XD detected 75,0 percent of the cases PCR was positive in 96,8 percent. The usefulness of the PCR was further investigated in the 28 children who have received specific treatment with nifurtimox. Negativetion of XD after three and six months post treatment respectively. These observations suggest that PCR is the most sensitive and quick technique available for direct detection of T. cruzi in chagasic children and that it can be a very useful tool for the follow-up of infected subjects after specific chemotherapeutical treatment