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1.
Rev Soc Bras Med Trop ; 53: e20200197, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33263683

RESUMEN

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.

2.
Infect Dis Poverty ; 9(1): 167, 2020 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-33341111

RESUMEN

BACKGROUND: Leprosy is a chronic infectious disease classified into two subgroups for therapeutic purposes: paucibacillary (PB) and multibacillary (MB), closely related to the host immune responses. In this context it is noteworthy looking for immunological biomarkers applicable as complementary diagnostic tools as well as a laboratorial strategy to follow-up leprosy household contacts. METHODS: The cross-sectional study enrolled 49 participants, including 19 patients and 30 healthy controls. Peripheral blood mononuclear cells (PBMC) were isolated and incubated in the presence of Mycobacterium leprae bacilli. The cells were prepared for surface (CD4+ and CD8+) and intracytoplasmic cytokine staining (IFN-γ, IL-4 and IL-10). Multiple comparisons amongst groups were carried out by ANOVA, Kruskal-Wallis, Student T or Mann-Whitney test. Comparative analysis of categorical variables was performed by Chi-square. Functional biomarker signature analysis was conducted using the global median values for each biomarker index as the cut-off edge to identify the proportion of subjects with high biomarker levels. RESULTS: The cytokine signature analysis demonstrated that leprosy patients presented a polyfunctional profile of T-cells subsets, with increased frequency of IFN-γ+ T-cell subsets along with IL-10+ and IL-4+ from CD4+ T-cells, as compared to health Controls (Venn diagram report). Moreover, statistical analysis was carried out using parametric or non-parametric variance analysis followed by pairwise multiple comparisons, according to the data normality distribution. L(PB) displayed a polyfunctional profile characterized by enhanced percentage of IFN-γ+, IL-10+ and IL-4+ produced by most T-cell subsets, as compared to L(MB) that presented a more restricted cytokine functional profile mediated by IL-10+ and IL-4+ T-cells with minor contribution of IFN-γ produced by CD4+ T-cells. Noteworthy was that HHC(MB) exhibited enhanced frequency of IFN-γ+ T-cells, contrasting with HHC(PB) that presented a cytokine profile limited to IL-10 and IL-4. CONCLUSIONS: Our data demonstrated that L(PB) displayed enhanced percentage of IFN-γ+, IL-10+ and IL-4+ as compared to L(MB) that presented functional profile mediated by IL-10+ and IL-4+ T-cells and HHC(MB) exhibited enhanced frequency of IFN-γ+ T-cells, contrasting with HHC(PB). Together, our findings provide additional immunological features associated with leprosy and household contacts. These data provide evidence that biomarkers of immune response can be useful complementary diagnostic/prognostic tools as well as insights that household contacts should be monitored to access putative subclinical infection.


Asunto(s)
Biomarcadores/sangre , Lepra/inmunología , Linfocitos T/inmunología , Adolescente , Adulto , Anciano , Células Cultivadas , Niño , Trazado de Contacto , Estudios Transversales , Citocinas/inmunología , Salud de la Familia , Femenino , Humanos , Lepra/clasificación , Leucocitos Mononucleares/inmunología , Masculino , Persona de Mediana Edad , Mycobacterium lepraemurium/inmunología , Adulto Joven
3.
Rev. Soc. Bras. Med. Trop ; 53: e20200197, 2020.
Artículo en Inglés | LILACS, Coleciona SUS, Sec. Est. Saúde SP | ID: biblio-1143857

RESUMEN

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.


Asunto(s)
Humanos , Lepra/diagnóstico , Mycobacterium leprae/genética , Ensayo de Inmunoadsorción Enzimática , Pruebas Serológicas , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad
4.
PLoS Negl Trop Dis ; 13(6): e0007400, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31181059

RESUMEN

BACKGROUND: Early detection of Mycobacterium leprae is a key strategy for disrupting the transmission chain of leprosy and preventing the potential onset of physical disabilities. Clinical diagnosis is essential, but some of the presented symptoms may go unnoticed, even by specialists. In areas of greater endemicity, serological and molecular tests have been performed and analyzed separately for the follow-up of household contacts, who are at high risk of developing the disease. The accuracy of these tests is still debated, and it is necessary to make them more reliable, especially for the identification of cases of leprosy between contacts. We proposed an integrated analysis of molecular and serological methods using artificial intelligence by the random forest (RF) algorithm to better diagnose and predict new cases of leprosy. METHODS: The study was developed in Governador Valadares, Brazil, a hyperendemic region for leprosy. A longitudinal study was performed, including new cases diagnosed in 2011 and their respective household contacts, who were followed in 2011, 2012, and 2016. All contacts were diligently evaluated by clinicians from Reference Center for Endemic Diseases (CREDEN-PES) before being classified as asymptomatic. Samples of slit skin smears (SSS) from the earlobe of the patients and household contacts were collected for quantitative polymerase chain reaction (qPCR) of 16S rRNA, and peripheral blood samples were collected for ELISA assays to detect LID-1 and ND-O-LID. RESULTS: The statistical analysis of the tests revealed sensitivity for anti-LID-1 (63.2%), anti-ND-O-LID (57.9%), qPCR SSS (36.8%), and smear microscopy (30.2%). However, the use of RF allowed for an expressive increase in sensitivity in the diagnosis of multibacillary leprosy (90.5%) and especially paucibacillary leprosy (70.6%). It is important to report that the specificity was 92.5%. CONCLUSION: The proposed model using RF allows for the diagnosis of leprosy with high sensitivity and specificity and the early identification of new cases among household contacts.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Composición Familiar , Salud de la Familia , Lepra/diagnóstico , Mycobacterium leprae/genética , Mycobacterium leprae/inmunología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antibacterianos/sangre , Inteligencia Artificial , Brasil , Niño , Preescolar , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Técnicas de Diagnóstico Molecular/métodos , ARN Ribosómico 16S/genética , Sensibilidad y Especificidad , Pruebas Serológicas/métodos , Adulto Joven
5.
BMC Infect Dis ; 18(1): 153, 2018 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-29609530

RESUMEN

BACKGROUND: Characterization of the Mycobacterium leprae genome has made possible the development of Polymerase Chain Reaction (PCR) systems that can amplify different genomic regions. Increased reliability and technical efficiency of quantitative PCR (qPCR) makes it a promising tool for early diagnosis of leprosy. Index cases that are multibacillary spread the bacillus silently, even before they are clinically diagnosed. Early detection and treatment could prevent transmission in endemic areas. METHODS: In this study, the qPCR technique is used to detect DNA of M. leprae in samples of slit skin smears (SSS) of the ear lobe and blood of leprosy patients and their asymptomatic household contacts residing in Governador Valadares, MG, Brazil, a hyperendemic area for leprosy. A total of 164 subjects participated in the study: 43 index cases, 113 household contacts, and, as negative controls, 8 individuals who reported no contact with patients nor history of leprosy in the family. The qPCR was performed to amplify 16S rRNA fragments and was specifically designed for M. leprae. RESULTS: Of asymptomatic household contacts, 23.89% showed bacillary DNA by qPCR in samples of SSS and blood. Also, 48.84% of patients diagnosed with leprosy were positive for qPCR while the bacillary load was positive in only 30.23% of patients. It is important to note that most patients were already receiving treatment when the collection of biological material for qPCR was performed. The level of bacillary DNA from household contacts was similar to the DNA levels detected in the group of paucibacillary patients. CONCLUSION: Considering that household contacts comprise a recognizable group of individuals with a high risk of disease, as they live in close proximity to a source of infection, qPCR can be used to estimate the risk of progress towards leprosy among household contacts and as a routine screening method for a chemoprophylactic protocol.


Asunto(s)
Infecciones Asintomáticas/epidemiología , ADN Bacteriano/aislamiento & purificación , Composición Familiar , Lepra/epidemiología , Mycobacterium leprae/genética , Adulto , Brasil/epidemiología , Trazado de Contacto/métodos , Femenino , Humanos , Lepra/diagnóstico , Lepra/transmisión , Masculino , Mycobacterium leprae/aislamiento & purificación , Prevalencia , ARN Ribosómico 16S/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados
6.
Hansen. int ; 41(1/2): 55-63, 2016. map, ilus
Artículo en Portugués | LILACS, Sec. Est. Saúde SP, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-972896

RESUMEN

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.


Asunto(s)
Masculino , Femenino , Humanos , Trazado de Contacto/estadística & datos numéricos , Trazado de Contacto , Lepra/diagnóstico , Lepra/epidemiología , Lepra/prevención & control , Brasil/epidemiología , Enfermedades Endémicas/prevención & control , Educación en Salud
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