Fig 4 graphically represents the sensitivity and 1-specificity of each study. nevertheless, animal models had shown that IgM antibody might last and participate in long-lasting protection against obligate intracellular bacterium [28]. The hypothesis that not all infected individuals produce anti PGL1 IgM antibodies and that presence can result from both recent and old infection with M leprae is plausible and consistent with the lack of ability of anti PGL1 to predict accurately who will and who will not develop leprosy. The gene discussed is CD40LG; the disease is leprosy.