Testes sorológicos anti-NDO-HSA, anti-LID-1 e anti-NDO-LID em contatos domiciliares de área não endêmica de hanseníase / Anti-NDO-HSA, anti-LID-1 and anti-NDO-LID serological tests in household contacts of a non-endemic leprosy area

Introdução: Diversos fatores podem interferir no desenvolvimento da hanseníase, entre eles fatores genéticos, convívio com o caso de hanseníase e classificação operacional do caso. Testes sorológicos que avaliam a reatividade de anticorpos IgM e IgG frente a antígenos específicos para o Mycobacterium leprae (M. leprae) podem atuar como auxiliares na vigilância dos contatos e/ou população de risco. Objetivo: Analisar o comportamento dos testes sorológicos anti-PGL-1 sintético (NDO-HSA), anti-LID-1 e anti-NDO-LID em área não endêmica de hanseníase e sua relação com características do caso de hanseníase. Material e métodos: Trata-se de um estudo transversal, do tipo analítico, realizado com 35 contatos domiciliares (CD) dos casos de hanseníase. A coleta de dados ocorreu no período de agosto/2016 a fevereiro/2017 por meio de visitas domiciliares. A reatividade de anticorpos IgM e IgG frente aos antígenos Natural disaccharide linked to human serum albumin via octyl (NDO-HSA), Leprosy IDRI diagnostic 1 (LID-1) e Natural disaccharideoctyl - Leprosy IDRI Diagnostic 1(NDO-LID) foi avaliada por ensaio imunoenzimático (ELISA). Os dados foram exportados e analisados no software StatisticalPackage for the Social Sciences (SPSS®) 24 for Windows. Resultados: Foi observada maior proporção de positividade aos testes em CD de casos multibacilares (MB), que residiam com o caso de hanseníase na época do diagnóstico e que tinham parentesco consanguíneo com o caso. Esses casos de hanseníase MB também apresentaram soropositividade frente aos antígenos testados. O valor do índice ELISA foi maior no grupo de CD de casos MB. Houve concordância moderada e significativa (K= 0,53; p< 0,0001) entre os testes anti-NDO-HSA e anti-NDO-LID, mas não foi detectada diferença entre os testes anti-NDO-HSA e anti-LID-1 (K= -0,05; p= 0,678). A correlação foi positiva entre os três antígenos, porém, entre LID-1 e NDO-HSA, não houve significância estatística (p<0,186). Conclusão: Os resultados sugerem que testes sorológicos em conjunto com as características avaliadas nos contatos domiciliares em área não endêmica de hanseníase,podem atuar como auxiliares na detecção de indivíduos infectados pelo M. leprae, contribuindo para vigilância dos contatos domiciliares

Introduction: Several factors may interfere in the development of leprosy, including genetic factors, conviviality with leprosy patients and operational classification of the case. Serological tests performed to evaluate the reactivity of IgM and IgG antibodies response against Mycobacterium leprae (M. leprae) specific antigens may be used as auxiliary tools for transmission surveillance and/or population at risk. Objective: To analyze the performance of anti-PGL-1 (NDO-HSA), anti-LID-1 and anti-NDO-LID serological tests in non-endemic area of leprosy and the relationship with characteristics of the leprosy case. Material and methods: This is a cross-sectional analytical study of 35 household contacts (HC) of leprosy cases. Data collection was carried out from August 2016 to February 2017 with home visits. The reactivity of IgM and IgG antibodies to Natural disaccharide linked to human serum albumin via octyl (NDO-HSA), Leprosy IDRI diagnostic 1 (LID-1) and Natural disaccharide octyl - Leprosy IDRI Diagnostic 1 (NDO-LID) was evaluated through enzyme-linked immunosorbent assay (ELISA). Data were exported and analyzed using Statistical Package for Social Sciences (SPSS®) 24 for Windows. Results: A higher proportion of positivity was observed in the HC tests of multibacillary (MB) leprosy cases who lived in the same dwelling with a leprosy case at the time of diagnosis and had a degree of kinship with the case. These multibacillary leprosy cases also showed seropositivity to the antigens tests. ELISA test index value was higher in the HC group of MB leprosy cases. There was moderate agreement (K = 0.53, p <0.0001) between anti-NDO-HSA and anti-NDO-LID tests, but no difference was found between anti-NDO-HSA and anti-LID -1 (K = -0.05, p = 0.678). Three antigens were positively correlated, but there was no statistical significance (p <0.186) between LID-1 and NDO-HSA. Conclusion: The results suggest that serological tests in combination with the characteristics assessed during household contacts in a non-endemic area may represent efficient auxiliary tools for the detection of M. leprae-infected individuals, providing a contribution to the surveillance of household contacts

Utility of immunoglobulin isotypes against LID-1 and NDO-LID for, particularly IgG1, confirming the diagnosis of multibacillary leprosy

BACKGROUND Leprosy remains a health problem in many countries, with difficulties in diagnosis resulting in delayed treatment and more severe disabilities. Antibodies against several Mycobacterium leprae antigens have, however, shown value as diagnostic and/or prognostic markers. OBJECTIVES The objective of this study was to evaluate serum immunoglobulin (Ig) IgM and IgG subclass reactivity against three M. leprae specific antigens: NDO-HSA, a conjugate formed by natural octyl disaccharide bound to human serum albumin; LID-1, the fusion protein product of the ml0405 and ml2331 genes; and NDO-LID, a combination of LID-1 and NDO. METHODS Sera from healthy controls, paucibacillary (PB) and multibacillary (MB) leprosy patients, and their respective household contacts, were evaluated for the presence of antigen-specific IgM, IgG, and IgG subclass antibodies by enzyme-linked immunosorbent assay (ELISA). The sensitivity and specificity of each ELISA were evaluated by receiver operating characteristic (ROC) curve analysis. FINDINGS Our data confirm that serum IgM antibodies against NDO-HSA and IgG antibodies against LID-1, as well as IgG/M antibodies against NDO-LID, are markedly increased in MB patients. For the first time, our data reveal a selective increase in IgG1 and IgG3 antibodies against LID-1 and NDO-LID in MB patients, demonstrating that these antibody isotypes are suitable for differentiation between MB and PB patients. ROC curve analysis indicates an improved capacity for diagnosing MB leprosy patients using the detection of IgG antibodies, particularly the IgG1 isotype, specific to LID-1 and NDO-LID over the performance levels attained with NDO-HSA. CONCLUSIONS Our findings indicate that serological tests based on the detection of antigen-specific IgG1 antibodies are a useful tool to differentiate MB from PB patients, and indicate the enhanced performance of the LID-1 and NDO-LID antigens in the serodiagnosis of leprosy.

Biomphalaria spp. (Preston, 1910) snails in the municipality of Juiz de Fora, Zona da Mata Mineira mesoregion, ate of Minas Gerais, Brazil

This study focuses on the geographic distribution of the snail of the genus Biomphalaria and evaluates its infectivity by Schistosoma mansoni in 5264 specimens collected in the municipality of Juiz de Fora, Minas Gerais, Brazil. Of the 31 locations studied, 6 were reservoirs, 11 rudimentary holding ponds, 7 irrigation ditches, 5 lakes, 1 ornamental pond, and 1 waterfall. Intermediate hosts were found only in the rudimentary ponds and ditches, which were 100 percent positive. Using morphological and molecular analysis techniques, B. tenagophila, B. peregrina, and B. straminea were identified. This is the first report of B. stramínea in the municipality, and evaluation of its infective potential revealed susceptibility of 25.4 percent. Although we did not find specimens of Biomphalaria infected by S. mansoni, the data obtained indicate the presence of intermediate hosts, especially in the irrigation ditches in Juiz de Fora, and their proximity to contaminated areas.