As a result, infection in humans and in animal models leads to a macrophage activation syndrome (MAS) [52] where a key role in severity of tissue damage is related to high serum levels of IL-10, IL-12, ferritin and especially IFN-γ [20,31,49,50], secreted by NK and NKT cells, but also by a component of adaptive immunity, CD8 T lymphocytes. This evidence concerns the gene IL10 and macrophage activation syndrome.