Immunochemotherapy in American cutaneous leishmaniasis: immunological aspects before and after treatment

In this study, we evaluated the immune response of patients suffering from cutaneous leishmaniasis treated with two distinct protocols. One group was treated with conventional chemotherapy using pentavalent antimonium salts and the other with immunochemotherapy where a vaccine against cutaneous leishmaniasis was combined with the antimonium salt. Our results show that, although no differences were observed in the necessary time for complete healing of the lesions between the two treatments, peripheral blood mononuclear cells from patients treated by chemotherapy showed smaller lymphoproliferative responses at the end of the treatment than those from patients in the immunochemotherapy group. Furthermore, IFN-gamma production was also different between the two groups. While cells from patients in the chemotherapy group produced more IFN-gamma at the end of treatment, a significant decrease in this cytokine production was associated with healing in the immunochemotherapy group. In addition, IL-10 production was also less intense in this latter group. Finally, an increase in CD8+ -IFN-gamma producing cells was detected in the chemotherapy group. Together these results point to an alternative treatment protocol where healing can be induced with a decreased production of a potentially toxic cytokine

Immunocytochemical identification of Leishmania and Trypanosoma cruzi amastigotes in situ with homologous and heterologous polyclonal antibodies

O método da peroxidase-antiperoxidase foi utilizado para estudar as propriedades imunocitoquímicas de Leishmanias e de amastigotas do Trypanosoma cruzi, in situ, após os tecidos terem sido submetidos a diferentes tipos de fixaçäo. Anti-soros foram obtidos de coelhos cronicamente infectados com três cepas de T. cruzi ou imunizados com L. mexicana amazonensis e L. braziliensis guyanensis e aplicados nos cortes histológicos de 5*m de espessura. Os antígenos de T. cruzi foram coroados muito bem pelos três soros anti-T. cruzi e pelos dois soros anti-Leishmania com diluiçöes entre 1:1.000 e 1:2. Diferentemente, os antígenos de Leishmania foram revelados pelos soros anti-Leishmania somente em baixas diluiçöes, ou seja, entre 1:60 e 1:160 enquanto que os soros anti-T. cruzi, mesmo nestas diluiçöes baixas quando usados para revelar Leishmania. Embora näo haja explicaçäo clara para esta reaçäo imunocitoquímicacruzada "reversa-monodirecional" entre Leishmania e amastigotas de T. cruzi os resultados do presente trabalho mostram que anticorpos policlonais contra diferentes espécies de Leishmania, quando usados para detecçäo imunocitoquímica de Leishmania e T. cruzi in situ, reagem mais fortemente com amastigotas de T. cruzi do que com espécies homólogas