Immunological aspects of leprosy

Abstract

The clinical spectrum of leprosy has been associated with immunological alterations induced by the parasite M.leprae on the host. It was observed that lepromatous leprosy present a depressed cellular immune response associated with elevated production of suppressor cytokines (IL-4 and TGF

b) and reduced levels of cytokines related with the induction of the immune response (IL-1,TNFa and IFNg). Furthemore, all these alterations are associated with depressed production of intracellular oxidative elements responsible for the parasite destruction, the reactives of oxigen and nitrogen, the latter evaluated by the enzyme induced NO synthase (iNOS). On the other hand, in tuberculoid leprosy, high levels of inflammatory cytokines and absence of suppressor cytokines have been described.