Myocarditis in different experimental models infected by Trypanosoma cruzi is correlated with the production of IgG1 isotype.

Abstract

This study was designed to verify the relationship between IgG antibodies isotypes and myocarditis inTrypanosoma cruzi infection using mice and dogs infected with different T. cruzi strains. The animals wereinfected with benznidazole-susceptible Berenice-78 and benznidazole-resistant AAS and VL-10 strains.The IgG subtypes were measured in serum samples from dogs (IgG, IgG1, and IgG2) and mice (IgG, IgG1,IgG2a, and IgG2b). The infection of dogs with VL-10 strain induced the highest levels of heart inflammationwhile intermediate and lower levels were detected with Berenice-78 and AAS strains, respectively. Similarresults were found in mice infected with VL-10, but not in those infected with AAS or Berenice-78 strains.The AAS strain induced higher levels of heart inflammation in mice, while Berenice-78 strain was notable to induce it. Correlation analysis between myocarditis and antibody reactivity index revealed veryinteresting results, mainly for IgG and IgG1, the latter being the most exciting. High IgG1 showed asignificant correlation with myocarditis in both experimental models, being more significant in dogs(r = 0.94, p < 0.0001) than in mice (r = 0.58, p = 0.047). Overall, our data suggest that IgG1 could be a goodmarker to demonstrate myocarditis intensity in Chagas disease.©