Aspects of the granulomatous reaction in the liver of mice infected and reinfected with two different geographical strains of Schistosoma mansoni.

In this study, which was undertaken in relation to the histopathologic behavior of two different strains (LE-Belo Horizonte, MG and SJ-São José dos Campos, SP) in infections and reinfections (homologous or heterologous) with Schistosoma mansoni, the authors confirmed a more accentuated pathogenicity of the SJ strain. All the reinfections showed the presence of typical granulomas of the acute phase, when performed either with the same strain (homologous) or with a different strain (heterologous) of the parasite of the primo infection. The possible mechanisms responsible for reactivation of the immunopathologic response in reinfections are discussed.