B lymphocytes deficiency results in altered immune response and increased susceptibility to Mycobacterium leprae in a murine leprosy model.

Leprosy is a chronic and infectious disease that primarily affects the skin and peripheral nervous system, presenting a wide spectrum of clinical forms with different degrees of severity. The distinct host immune response patters developed in the response to the bacillus Mycobacterium leprae, the leprosy etiologic agent, are associated with the spectral clinical forms and outcome of the disease. In this context, B cells are allegedly involved in the disease immunopathogenesis, usually as antibody-producing cells, but also as potential effector or regulatory elements. In order to determine the regulatory B cells role in experimental leprosy, this study evaluated the outcome of M. leprae infection in B cell deficient mice (BKO) and WT C57Bl/6 control, by means of microbiological/bacilloscopic, immunohistochemical and molecular analysis, performed 8 months after M. leprae inoculation. The results demonstrated that infected BKO showed a higher bacilli number when compared with WT animals, demonstrating the importance of these cells in experimental leprosy. The molecular analysis demonstrates that the expression of IL-4, IL-10 and TGF-ß was significantly higher in the BKO footpads when compared to WT group. Conversely, there was no difference in IFN-γ, TNF-α and IL-17 expression levels in BKO and WT groups. IL-17 expression was significantly higher in the lymph nodes of WT group. The immunohistochemical analysis revealed that M1 (CD80+) cells counts were significantly lower in the BKO group, while no significant difference was observed to M2 (CD206+) counts, resulting a skewed M1/M2 balance. These results demonstrated that the absence of B lymphocytes contribute to the persistence and multiplication of M. leprae, probably due to the increased expression of the IL-4, IL-10 and TGF-ß cytokines, as well as a decrease in the number of M1 macrophages in the inflammatory site.

Simultaneous analysis of multiple T helper subsets in leprosy reveals distinct patterns of Th1, Th2, Th17 and Tregs markers expression in clinical forms and reactional events.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Previous studies have demonstrated that the difference among clinical forms of leprosy can be associated with the immune response of patients, mainly by T helper (Th) and regulatory T cells (Tregs). Then, aiming at clarifying the immune response, the expression of cytokines related to Th1, Th2, Th17 and Tregs profiles were evaluated by qPCR in 87 skin biopsies from leprosy patients. Additionally, cytokines and anti-PGL-1 antibodies were determined in serum by ELISA. The results showed that the expression of various targets (mRNA) related to Th1, Th2, Th17 and Tregs were significantly modulated in leprosy when compared with healthy individuals, suggesting the presence of a mixed profile. In addition, the targets related to Th1 predominated in the tuberculoid pole and side and Th2 and Tregs predominated in the lepromatous pole and side; however, Th17 targets showed a mixed profile. Concerning reactional events, Tregs markers were decreased and IL-15 was increased in reversal reaction and IL-17F, CCL20 and IL-8 in erythema nodosum leprosum, when compared with the respective non-reactional leprosy patients. Additionally, ELISA analysis demonstrated that IL-22, IL-6, IL-10 and anti-PGL-1 antibody levels were significantly higher in the serum of patients when compared with healthy individuals, and IL-10 and anti-PGL-1 antibodies were also increased in the lepromatous pole and side. Together, these results indicate that Th1, Th2 and Th17 are involved in the determination of clinical forms of leprosy and suggest that decreased Tregs activity may be involved in the pathogenesis of reactional events.

Simultaneous analysis of multiple T helper subsets in leprosy reveals distinct patterns of Th1, Th2, Th7 and tregs markers expression in clinical forms and reactional events

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Previous studies have demonstrated that the difference among clinical forms of leprosy can be associated with the immune response of patients, mainly by T helper (Th) and regulatory T cells (Tregs). Then, aiming at clarifying the immune response, the expression of cytokines related to Th1, Th2, Th17 and Tregs profiles were evaluated by qPCR in 87 skin biopsies from leprosy patients. Additionally, cytokines and anti-PGL-1 antibodies were determined in serum by ELISA. The results showed that the expression of various targets (mRNA) related to Th1, Th2, Th17 and Tregs were significantly modulated in leprosy when compared with healthy individuals, suggesting the presence of a mixed profile. In addition, the targets related to Th1 predominated in the tuberculoid pole and side and Th2 and Tregs predominated in the lepromatous pole and side; however, Th17 targets showed a mixed profile. Concerning reactional events, Tregs markers were decreased and IL-15 was increased in reversal reaction and IL-17F, CCL20 and IL-8 in erythema nodosum leprosum, when compared with the respective non-reactional leprosy patients. Additionally, ELISA analysis demonstrated that IL-22, IL-6, IL-10 and anti-PGL-1 antibody levels were significantly higher in the serum of patients when compared with healthy individuals, and IL-10 and anti-PGL-1 antibodies were also increased in the lepromatous pole and side. Together, these results indicate that Th1, Th2 and Th17 are involved in the determination of clinical forms of leprosy and suggest that decreased Tregs activity may be involved in the pathogenesis of reactional events.

Hanseníase em crianças e adolescentes: revisão bibliográfica e situação atual no Brasil / Leprosy in children and adolescents: bibliographical review and current situation in Brasil

Introdução: A hanseníase é uma doença endêmica no Brasil, com prevalência acima do esperado pela Organização Mundial da Saúde para todas as faixas etárias, inclusive a pediátrica. Objetivo: Esse trabalho tem o objetivo de revisar os aspectos epidemiológicos, históricos, imuno-patológicos e clínicos da hanseníase e suas peculiaridades na população infantil. Fontes pesquisadas: Foi realizada uma ampla revisão bibliográfica no PubMed e em sites oficiais do Ministério da Saúde do Brasil e da Organização Mundial da Saúde, com as palavras hanseníase em crianças e adolescentes. Síntese dos dados: Com a suspeita clínica, diagnóstico precoce, tratamento adequado com a poliquimioterapia, controle dos contactantes íntimos com exame clínico e aplicação da BCG, é possível o controle da doença, interrompendo o ciclo de transmissão e diminuindo os casos em crianças, adolescentes e adultos, para níveis inferiores a 1 /10.000 habitantes, como recomendado.

Introduction: Leprosy is endemic in Brazil, with prevalence higher than expected by the World Health Organization for all ages, including children. Objective: This paper aims to review the epidemiology, history, immunology, pathology and clinical aspect of leprosy and its peculiarities in childhood. Data Source: Wasperformed an extensive literature review on PubMed and on official websites of Health’ Ministry in Brazil and World Health Organization with the words leprosy in children and adolescents. Data Synthesis: With clinical suspicion, early diagnosis, adequate treatment with multidrug therapy and prevention contacts withBCG administration, Brazil can control the disease by interrupting the transmission cycle and reducing the cases in children, adolescents and adults for levels less than 1 / 10,000 individuals, as recommended...