In this work to discern whether parasite factors influence outcome of infection towards one of these two forms of ATL, we assessed the production of IFN-γ, TNF-α, IL-5 and IL-10 through the stimulation in vitro of peripheral blood mononuclear cells (PBMC) from DL and CL patients with L. braziliensis antigens isolated from DL and CL patients. This evidence concerns the gene IFNG and infection.