Increased Frequency of CD4 and CD8 Regulatory T Cells in Individuals under 15 Years with Multibacillary Leprosy

Abstract

Background: Leprosy is a chronic disease, caused by Mycobacterium leprae, which poses a serious public health problem worldwide. Its high incidence in people under 15 years old in Ceara state, Brazil, reflects the difficulty of its control. The spectrum of clinical manifestations is associated with the immune response developed, with the Th1 and Th2 responses being related to the paucibacillary and multibacillary forms, respectively. Regulatory T cells (Treg), which can suppress Th1 and Th2 response, have received special attention in the literature and have been associated with development of chronic infections. However, their role in leprosy in individuals under 15 years old has not yet been elucidated. We evaluated the frequency of CD4 + /CD8 + CD25 high FOXP3 + and CD4 + /CD8 + CD25 high FOXP3 high cells in leprosy patients and household contacts, in both cases under 15 years old.