Prospects for new leprosy diagnostic tools, a narrative review considering ELISA and PCR assays

Abstract Slit skin smear and histopathological examinations are currently the main laboratory tools used to aid the diagnosis of leprosy. However, their sensitivity is low, and many cases are not detected. New methodologies have been studied to develop more accurate tests. This narrative review aims to raise attention to the results of molecular (polymerase chain reaction) and serological (Enzyme-Linked Immunosorbent Assay) tests applied to the diagnosis of leprosy, and to summarize the available information about the former. Original scientific articles published in indexed international journals, whose study involved aspects of the diagnosis and classification of leprosy cases or home contacts, were selected. The data were extracted independently using a standardized method that dictated the inclusion of the following information: diagnosis in Paucibacillary and Multibacillary cases and in household contacts; sample number; sample type; study design; studied variables; statistical analysis employed; main results; and limitations identified. In clinical practice, the results from molecular and serological tests are assessed separately, with moderate sensitivity and specificity. However, an integrated study of these methodologies has been suggested for greater accuracy in diagnosis.

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.

A importância da busca ativa como estratégia de controle da hanseníase em territórios endêmicos / The importance of active surveillance as a strategy to control leprosy in endemic areas

De acordo com a literatura, contatos de casos de hanseníase apresentam maior risco de adoecimento e, nesse sentido, é primordial fortalecer e ampliar as ações de busca ativa de casos no âmbito da atenção primária de saúde, potencializando a ampliação do diagnóstico precoce, tratamento oportuno e demais medidas de vigilância, controle e reabilitação necessárias. Neste cenário, objetivou-se realizar a busca ativa de novos casos de hanseníase em um distrito rural do município de Mantena, MG, e caracterizar a situação socioeconômica e epidemiológica da doença na região. Foram realizadas visitas aos residentes do distrito e palestras informativas sobre a doença, sendo os moradores convidados a participar da pesquisa. Um total de 292 indivíduos foi examinado no período de julho de 2016 a fevereiro de 2017. Foram diagnosticados 27 casos novos, 22 dos quais eram multibacilares. Os graus de incapacidade 1 e 2 foram identificados em 74% da amostra. Sobre as variáveis socioeconômicas, a maioria dos casos possui baixa escolaridade e baixa renda familiar, além de todos os casos terem tido contato com a doença em algum momento. A busca ativa foi eficiente para a detecção de casos novos de hanseníase na população estudada e contribuiu para o controle da doença que é endêmica na região. Ademais, a busca ativa foi relevante, especialmente considerando a baixa instrução dos indivíduos e, portanto, menor acesso à informação.

Contacts of leprosy cases present a higher risk of illness and, therefore it is essential to strengthen and expand actions to actively search for cases in primary health care, thus intensifying early diagnosis, timely treatment and other surveillance measures, and improve control and rehabilitation. In this setting, we aimed to perform the active search of new cases of leprosy in the rural area of Mantena, MG, and to characterize the socioeconomic and epidemiological situation related to the disease in the region. For this purpose, visits were made to the residents of the region with informative talks about the disease, and subsequently inhabitants were invited to participate in the research. A total of 292 individuals were examined from July 2016 to February 2017. Twenty-seven new cases were diagnosed, 22 of which were multibacillary. Grade 1 and 2 physical disabilities were identified in 74% of the new cases. Regarding socioeconomic variables, the majority of the cases had little schooling and low family income. In addition, all cases had had contact with the illness, at some point. We conclude that the active search was efficient to detect new leprosy cases in the population, and it contributed to the control of the disease, which is endemic in the region. In addition, active search is an important methodology, especially when the population involved has little schooling and thus less access to information.

Distinct cytokine profiles of circulating mononuclear cells stimulated with Staphylococcus aureus enterotoxin A in vitro during early and late episodes of chronic osteomyelitis

We investigated the cytokine profile of peripheral mononuclear cells from chronic osteomyelitis (OST) patients following in vitro stimulation with staphylococcal enterotoxin A (SEA). We demonstrate that stimulation with SEA induced prominent lymphocyte proliferation and high levels of tumour necrosis factor (TNF)-α, interleukin (IL)-4 and IL-10 secretion in both OST and non-infected individuals (NI). Even though stimulation with SEA had no impact on IL-6 production in either patient group, the baseline level of IL-6 production by cells from OST patients was always significantly less than that produced by cells from NI. After classifying the osteomyelitic episodes based on the time after the last reactivation event as "early" (1-4 months) or "late" osteomyelitis (5-12 months), we found that increased levels of TNF-α and IL-4 in combination with decreased levels of IL-6 were observed in the early episodes. By contrast, increased levels of IL-10, IL-2 and IL-6 were hallmarks of late episodes. Our data demonstrate that early osteomyelitic episodes are accompanied by an increased frequency of "high producers" of TNF-α and IL-4, whereas late events are characterised by increased frequencies of "high producers" of IL-10, IL-6 and IL-2. These findings demonstrate the distinct cytokine profiles in chronic osteomyelitis, with a distinct regulation of IL-6 production during early and late episodes.

Perfil epidemiológico da hanseníase num município superendêmico do interior do sudeste brasileiro / Epidemiological profile of leprosy in the hyperendemic municipality in the inner of brazilian southeastern

A hanseníase é uma doença infecto-contagiosa de evolução crônica que se manifesta principalmente através de sinais e sintomas dermatoneurológicos. O objetivo deste trabalho foi avaliar a situação epidemiológica da hanseníase no município de Teófilo Otoni (TO)-MG, no período de 2001 a 2010 de forma descritiva e retrospectiva.Os altos coeficientes de detecção geral e em menores de 15 anos encontrados, mantêm o município como hiperendêmico para hanseníase, sinalizando a necessidade de intensificar as ações de vigilância epidemiológica.O percentual médio de grau 2 de incapacidade,entre os casos novos estudados no momento do diagnóstico foi considerado alto (10,1%) segundo Ministério da Saúde (MS). O percentual médio de casos novos avaliados, no momento da alta por cura, apresentando grau 2 de incapacidade física foi de 4,3%. O coeficiente de prevalência no município de TO foi considerado médio (1- 4,9/10.000hab) no período de 2001 a 2010 com exceção dos anos de 2003, 2004 e 2005 quando foi considerado muito alto (12,7; 14,1 e 12,6/10.000 habitantes)respectivamente. Com relação a variável prevalência oculta, verificou-se que 526 casos de hanseníase não foram diagnosticados no município, significando que 40,3% dos doentes permaneceram sem diagnóstico naquele período, podendo atuar como fontes de contágio contribuindo para a cadeia de transmissão da doença.É necessário que o município promova e intensifique a descentralização das ações de controle da doença,desenvolva programas de capacitação para as equipes multiprofissionais da Estratégia de Saúde da Família(ESF) e estimule a busca ativa de novos casos.

Leprosy is an infectious disease manifested primarily bysigns and symptoms dermato-neurological. The objectiveof this study was to evaluate the epidemiological situation of leprosy in the city of Teofilo Otoni (TO), MGstate in the period 2001-2010 as a descriptive and retrospective study. The high detection rates in general and in children under 15 years found in TO, keep this municipality as hyper-endemic for leprosy, signaling the need to strengthen the epidemiological surveillance. The average percentage of grade 2 disability among new cases studied at diagnosis was considered high (10.1 %) according to the Ministry of Health in Brazil. The average percentage of new cases assessed at the time of discharge after cure, with grade 2 disability was 4.3 %. The prevalence rate in the city of TO was considered medium (1 to 4.9 /10.000 hab ) in the period from 2001 to 2010 except for the years 2003 , 2004 and 2005 when it was considered very high ( 12.7 , 14.1 and 12.6 / 10.000 hab) respectively. Regarding the prevalence hidden variable, it was found that 526 cases of leprosy were not diagnosed in the city,meaning that 40.3 % of patients remained undiagnosed at that time and may act as sources of infection contributing to the chain of disease transmission. It is necessary for the municipality to promote and intensify the decentralization of control of the disease, and also develop training programs for the multidisciplinary teams at family health strategy (ESF) and encourage active search for new cases.