Previously reported by our group, we show that chronic chagasic patients display higher percentages of CD4+/CD8+ (double-positive) peripheral T cells co-expressing CD38 and HLA-DR when compared with uninfected controls; in addition, the patients with severe cardiomyopathy produced less IFN-γ than those with non-cardiac involvement [12]. This evidence concerns the gene CD8A and cardiomyopathy.