IL5 and leprosy: Peripheral blood analysis of leprosy patients also showed that, after stimulation with recombinant M. leprae antigens, there is a predominant induction of Th1 cytokine secretion (IFN-γ, IL-2 and IL-12) in paucibacillary presentations and Th2 cytokines (IL-4, IL-5 and IL-6) in multibacillary presentations.6, 20