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1.
PLoS Negl Trop Dis ; 14(5): e0008325, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32453754

RESUMEN

Leprosy urgently needs a precise and early diagnostic tool. The sensitivity of the direct (bacilli staining, Mycobacterium leprae DNA) and indirect (antibody levels, T cell assays) diagnostics methods vary based on the clinical form. Recently, PCR-based M. leprae DNA detection has been shown to differentially diagnose leprosy from other dermatological conditions. However, accuracy can still be improved, especially for use with less invasive clinical samples. We tested different commercial DNA extraction kits: DNeasy Blood & Tissue, QIAamp DNA Microbiome, Maxwell 16 DNA Purification, PowerSoil DNA Isolation; as well as in-house phenol-chloroform and Trizol/FastPrep methods. Extraction was performed on M. leprae-infected mouse footpads and different clinical samples of leprosy patients (skin biopsies and scrapings, lesion, oral and nasal swabs, body hair, blood on FTA cards, peripheral whole blood). We observed that the Microbiome kit was able to enrich for mycobacterial DNA, most likely due the enzymatic digestion cocktail along with mechanical disruption involved in this method. Consequently, we had a significant increase in sensitivity in skin biopsies from paucibacillary leprosy patients using a duplex qPCR targeting 16S rRNA (M. leprae) and 18S rRNA (mammal) in the StepOnePlus system. Our data showed that the presence of M. leprae DNA was best detected in skin biopsies and skin scrapings, independent of the extraction method or the clinical form. For multibacillary patients, detection of M. leprae DNA in nasal swabs indicates the possibility of having a much less invasive sample that can be used for the purposes of DNA sequencing for relapse analysis and drug resistance monitoring. Overall, DNA extracted with the Microbiome kit presented the best bacilli detection rate for paucibacillary cases, indicating that investments in extraction methods with mechanical and DNA digestion should be made.

2.
PLoS Negl Trop Dis ; 14(5): e0008247, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32433683

RESUMEN

Leprosy is a chronic infectious disease, caused by Mycobacterium leprae, which affects skin and peripheral nerves. Polymorphisms in genes associated with autophagy, metabolism, innate and adaptive immunity confer susceptibility to leprosy. However, these associations need to be confirmed through independent replication studies in different ethnicities. The population from Amazon state (northern Brazil) is admixed and it contains the highest proportion of Native American genetic ancestry in Brazil. We conducted a case-control study for leprosy in which we tested fourteen previously associated SNPs in key immune response regulating genes: TLR1 (rs4833095), NOD2 (rs751271, rs8057341), TNF (rs1800629), IL10 (rs1800871), CCDC122/LACC1 (rs4942254), PACRG/PRKN (rs9356058, rs1040079), IFNG (rs2430561), IL6 (rs2069845), LRRK2 (rs7298930, rs3761863), IL23R (rs76418789) and TYK2 (rs55882956). Genotyping was carried out by allelic discrimination in 967 controls and 412 leprosy patients. Association with susceptibility was assessed by logistic regression analyses adjusted for the following covariates: gender, age and ancestry. Genetic ancestry was similar in case and control groups. Statistically significant results were only found for IFNG and NOD2. The rs8057341 polymorphism within NOD2 was identified as significant for the AA genotype (OR = 0.56; 95% CI, 0.37-0.84; P = 0.005) and borderline for the A allele (OR = 0.76; 95% CI, 0.58-1.00; P = 0.053) and carrier (OR = 0.76; 95% CI, 0.58-1.00; P = 0.051). The rs2430561 SNP in IFNG was associated with disease susceptibility for the AT genotype (OR = 1.40; 95% CI, 1.06-1.85; P = 0.018) and carrier (OR = 1.44; 95% CI, 1.10-1.88; P = 0.008). We confirmed that NOD2 and IFNG are major players in immunity against M.leprae in the Amazon ethnic admixed population.

3.
Antimicrob Agents Chemother ; 64(7)2020 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-32340990

RESUMEN

A case of Mycobacterium leprae rifampin resistance after irregular antileprosy treatments since 1971 is reported. Whole-genome sequencing from four longitudinal samples indicated relapse due to acquired rifampin resistance and not to reinfection with another strain. A putative compensatory mutation in rpoC was also detected. Clinical improvement was achieved using an alternative therapy.

4.
Immunohorizons ; 4(2): 47-56, 2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32034084

RESUMEN

Erythema nodosum leprosum (ENL) is an inflammatory complication in leprosy. Yet, the involvement of ENL neutrophils in the inflammatory response against Mycobacterium leprae remains poorly explored. Our primary aim was to investigate the utility of the surface expression of neutrophil IL-10R1 as an ENL biomarker and, secondarily, to evaluate whether leprosy or healthy M. leprae-stimulated neutrophils produce cytokines and are able to respond to IL-10. We, in this study, describe a subpopulation of circulating neutrophils of ENL patients that exclusively expressed IL-10R1, providing evidence that IL-10R1+ neutrophils are present in ENL lesions. It was also found that ENL neutrophils, but not those of nonreactional leprosy controls, were able to secret detectable levels of TNF ex vivo and the addition of IL-10 blocked TNF release. It was likewise observed that M. leprae-stimulated, healthy neutrophils expressed IL-10R1 in vitro, and ENL-linked cytokines were released by M. leprae-cultured neutrophils in vitro. Moreover, consistent with the presence of a fully functional IL-10R, the addition of IL-10 prevented the release of M. leprae-induced cytokines. Most importantly, dead M. leprae revealed its superior capacity to induce CCL4 and IL-8 in primary neutrophils over live Mycobacterium, suggesting that M. leprae may hamper the inflammatory machinery as an immune escape mechanism.

5.
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
6.
Mem Inst Oswaldo Cruz ; 114: e190004, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31141020

RESUMEN

BACKGROUND: Dengue is an arthropod-borne viral disease with a majority of asymptomatic individuals and clinical manifestations varying from mild fever to severe and potentially lethal forms. An increasing number of genetic studies have outlined the association between host genetic variations and dengue severity. Genes associated to viral recognition and entry, as well as those encoding mediators of the immune response against infection are strong candidates for association studies. OBJECTIVES: The aim of this study was to investigate the association between MBL2, CLEC5A, ITGB3 and CCR5 genes and dengue severity in children. METHODS: A matched case-control study was conducted and 19 single nucleotide polymorphisms (SNPs) were investigated. FINDINGS: No associations were observed in single SNP analysis. However, when MBL2 SNPs were combined in haplotypes, the allele rs7095891G/rs1800450C/ rs1800451C/rs4935047A/rs930509G/rs2120131G/rs2099902C was significantly associated to risk of severe dengue under α = 0.05 (aOR = 4.02; p = 0.02). A second haplotype carrying rs4935047G and rs7095891G alleles was also associated to risk (aOR = 1.91; p = 0.04). MAIN CONCLUSIONS: This is the first study to demonstrate the association between MBL2 haplotypes and dengue severity in Brazilians including adjustment for genetic ancestry. These results reinforce the role of mannose binding lectin in immune response to DENV.


Asunto(s)
Dengue/genética , Integrina beta3/genética , Lectinas Tipo C/genética , Lectina de Unión a Manosa/genética , Receptores CCR5/genética , Receptores de Superficie Celular/genética , Estudios de Casos y Controles , Niño , Femenino , Genotipo , Haplotipos , Humanos , Masculino , Polimorfismo de Nucleótido Simple , Índice de Severidad de la Enfermedad
7.
BMC Infect Dis ; 19(1): 22, 2019 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-30616580

RESUMEN

BACKGROUND: Early detection of leprosy and multidrug therapy are crucial to achieve zero transmission and zero grade II incapacities goals of World Health Organization. Leprosy is difficult to diagnose because clinical forms vary and there are no gold standard methods to guide clinicians. The serological rapid tests aid the clinical diagnosis and are available for field use. They are easy to perform, do not require special equipment or refrigeration and are cheaper than the molecular tests. METHODS: We evaluated the performance of two rapid serological tests (PGL1 and NDO-LID) in the discrimination of leprosy cases from healthy individuals at the Alfredo da Matta Foundation, a reference center for the disease in Manaus, Amazonas, Brazil. PGL1 and NDO-LID rapid tests are capable of detecting specific antibodies of M. leprae, IgM and IgM/IgG, respectively. A total of 530 healthy subjects and 171 patients (50 with paucibacillary and 121 multibacillary leprosy) were included in the study. RESULTS: Among the paucibacillary leprosy patients, the sensitivity was 34.0 and 32.0% for the NDO-LID and PGL1, respectively. In multibacillary leprosy patients, the NDO-LID sensitivity was 73.6% and the PGL1 was 81.0%. Serological tests demonstrated specificities of 75.9% for PGL-1 and 81.7% for NDO-LID. The positive predictive value (PPV), negative predictive value (NPV) and accuracy in multibacillary patients were 47.9, 93.1, and 80.2% respectively for the NDO-LID, and 43.4, 94.6 76.8% for PGL1. CONCLUSIONS: The tests showed limited capacity in the diagnosis of the disease, however, the high negative predictive value of the tests indicates a greater chance of true negatives in this group favoring exclusion of leprosy. This characteristic of the ML flow test is important in aiding clinical Diagnosis, especially in a region endemic to the disease and with other confounding skin conditions.


Asunto(s)
Antígenos Bacterianos/inmunología , Glucolípidos/inmunología , Lepra/diagnóstico , Pruebas Serológicas/métodos , Adolescente , Adulto , Anciano , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Brasil , Estudios de Casos y Controles , Niño , Diagnóstico Precoz , Femenino , Humanos , Lepra/sangre , Lepra Multibacilar/diagnóstico , Lepra Paucibacilar/diagnóstico , Masculino , Persona de Mediana Edad , Mycobacterium leprae/inmunología , Sensibilidad y Especificidad
8.
Mem. Inst. Oswaldo Cruz ; 114: e190004, 2019. tab
Artículo en Inglés | LILACS | ID: biblio-1002688

RESUMEN

BACKGROUND Dengue is an arthropod-borne viral disease with a majority of asymptomatic individuals and clinical manifestations varying from mild fever to severe and potentially lethal forms. An increasing number of genetic studies have outlined the association between host genetic variations and dengue severity. Genes associated to viral recognition and entry, as well as those encoding mediators of the immune response against infection are strong candidates for association studies. OBJECTIVES The aim of this study was to investigate the association between MBL2, CLEC5A, ITGB3 and CCR5 genes and dengue severity in children. METHODS A matched case-control study was conducted and 19 single nucleotide polymorphisms (SNPs) were investigated. FINDINGS No associations were observed in single SNP analysis. However, when MBL2 SNPs were combined in haplotypes, the allele rs7095891G/rs1800450C/ rs1800451C/rs4935047A/rs930509G/rs2120131G/rs2099902C was significantly associated to risk of severe dengue under α = 0.05 (aOR = 4.02; p = 0.02). A second haplotype carrying rs4935047G and rs7095891G alleles was also associated to risk (aOR = 1.91; p = 0.04). MAIN CONCLUSIONS This is the first study to demonstrate the association between MBL2 haplotypes and dengue severity in Brazilians including adjustment for genetic ancestry. These results reinforce the role of mannose binding lectin in immune response to DENV.


Asunto(s)
Humanos , Receptores CCR5 , Cristalización , Dengue/epidemiología , Aedes
9.
PLoS Negl Trop Dis ; 12(12): e0007001, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30566440

RESUMEN

Leprosy is an infectious disease caused by Mycobacterium leprae and frequently resulting in irreversible deformities and disabilities. Ticks play an important role in infectious disease transmission due to their low host specificity, worldwide distribution, and the biological ability to support transovarial transmission of a wide spectrum of pathogens, including viruses, bacteria and protozoa. To investigate a possible role for ticks as vectors of leprosy, we assessed transovarial transmission of M. leprae in artificially-fed adult female Amblyomma sculptum ticks, and infection and growth of M. leprae in tick cell lines. Our results revealed M. leprae RNA and antigens persisting in the midgut and present in the ovaries of adult female A. sculptum at least 2 days after oral infection, and present in their progeny (eggs and larvae), which demonstrates the occurrence of transovarial transmission of this pathogen. Infected tick larvae were able to inoculate viable bacilli during blood-feeding on a rabbit. Moreover, following inoculation with M. leprae, the Ixodes scapularis embryo-derived tick cell line IDE8 supported a detectable increase in the number of bacilli for at least 20 days, presenting a doubling time of approximately 12 days. As far as we know, this is the first in vitro cellular system able to promote growth of M. leprae. Finally, we successfully transformed a clinical M. leprae isolate by inserting the reporter plasmid pCHERRY3; transformed bacteria infected and grew in IDE8 cells over a 2-month period. Taken together, our data not only support the hypothesis that ticks may have the potential to act as a reservoir and/or vector of leprosy, but also suggest the feasibility of technological development of tick cell lines as a tool for large-scale production of M. leprae bacteria, as well as describing for the first time a method for their transformation.


Asunto(s)
Vectores Arácnidos/fisiología , Ixodes/microbiología , Ixodidae/microbiología , Lepra/transmisión , Mycobacterium leprae/fisiología , Animales , Vectores Arácnidos/microbiología , Línea Celular , Femenino , Humanos , Ixodes/fisiología , Ixodidae/fisiología , Lepra/microbiología , Masculino , Mycobacterium leprae/genética , Conejos
10.
PLoS One ; 13(10): e0204232, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30339664

RESUMEN

Public policy planning associated with the management of the Science, Technology, and Innovation is decisive to improve public health. It is important to develop novel strategies to plan, supervise, manage, use and evaluate research using indicators that extrapolates metrics in current use. In 2011, the Brazilian government introduced the Brazil Without Extreme Poverty plan (BWEP) that aimed to integrate several conditional cash transfer programs (CCT). The original that aimed to integrate of the CCTs were expanded in order to integrate social justice and dignity that induced several actions towards the promotion of social development of the beneficiaries. An induced action involved a partnership between BWEP (From the Ministry of Social Development), CAPES (Brazilian Higher Education Agency) and The Oswaldo Cruz Foundation (FIOCRUZ, a Public Health Institution), that dedicated scholarships for PhD and postdoc students committed to the BWEP to promote health research in its multiple approaches and the vulnerable associated population. Using the Social Studies of Science and Technology (SSST) framework, this paper analyzes the dynamics of knowledge production in the context of program implementation. Herein, we report on the follow-up activities performed in BWEP Health Action, directing research projects to align with the goals of the program, evaluating the progress of these research, and defining strategies for improved their management. We analyze the advances and difficulties encountered in the implementation, monitoring and evaluation of this innovative program in the academic training level, and we emphasize the critical need to expand and improve similar initiatives aimed at guiding the scientific and technological production in health to meet the social demands.


Asunto(s)
Investigación Biomédica/economía , Ciencias Sociales/legislación & jurisprudencia , Brasil , Humanos , Conocimiento , Pobreza , Salud Pública , Política Pública , Poblaciones Vulnerables
11.
BMC Infect Dis ; 18(1): 422, 2018 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-30143000

RESUMEN

BACKGROUND: The major factors contributing for nerve damage and permanent disabilities in leprosy are type 1 or reversal reactions (RR) and type 2 or erythema nodosum leprosum (ENL). Gene profiling of leprosy reactions have shown that different pathways are activated during the course of reactions, which is consistent with the exacerbated immune response exhibited by these patients. METHODS: We used qPCR to screen a panel of 90 genes related to the immune response in leprosy in RNA-derived peripheral leukocytes of patients with (N = 94) and without leprosy reactions (N = 57) in order to define expression signatures correlated to RR or ENL. RESULTS: Our results show that there is a marked signature for RR in the blood, comprising genes mostly related to the innate immune responses, including type I IFN components, autophagy, parkins and Toll like receptors. On the other hand, only Parkin was differentially expressed in the ENL group. CONCLUSIONS: The data put together corroborates previous work that brings evidence that an acute uncontrolled exacerbated immune response designed to contain the spread of M. leprae antigens might be cause of RR pathogenesis. Identifying a blood profile useful to predict leprosy reactions prior to its development might help to reduce the morbidity associated to this disabling disease.


Asunto(s)
Inmunidad Innata/genética , Lepra/genética , Mycobacterium leprae/inmunología , Adulto , Análisis Químico de la Sangre/métodos , Estudios de Casos y Controles , Femenino , Perfilación de la Expresión Génica , Humanos , Lepra/sangre , Lepra/inmunología , Leucocitos/metabolismo , Leucocitos/patología , Masculino , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa
12.
Mem Inst Oswaldo Cruz ; 113(6): e170489, 2018 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-29768622

RESUMEN

BACKGROUND: The severity of chronic chagasic cardiomyopathy (CCC), the most frequent clinical outcome of Chagas disease (CD), has been associated with cytokine-enriched heart tissue inflammation, and high serum levels of transforming growth factor (TGFß), interferon-gamma (IFNγ), and tumour necrosis factor (TNF). Conversely, increased interleukin (IL)-10 serum concentrations have been associated with asymptomatic CD. Cytokines and cytokine-related gene polymorphisms may control cytokine expression and have been proposed to contribute to CCC outcomes. OBJECTIVES: We evaluated the association of 13 cytokine-related genes (TGFB: rs8179181, rs8105161, rs1800469; IL10: rs1800890, rs1800871, rs1800896; IFNG: rs2430561; TNF: rs1800629; BAT1: rs3853601; LTA: rs909253, rs2239704; TNFR1: rs767455; TNFR2: rs1061624) with risk and progression of CCC. FINDINGS: Four hundred and six seropositive patients from CD endemic areas in the state of Pernambuco, north-eastern Brazil, were classified as non-cardiopathic (A, 110) or cardiopathic (mild, B1, 163; severe, C, 133). We found no evidence of TGFB, IL10, TNF, or TNFR1/2 gene polymorphisms associated with CCC risk or progression. Only BAT1 rs3853601 -22G carriers (B1 vs. C: OR = 0.5; p-value = 0.03) and IFNG rs2430561 +874AT (A vs. C: OR = 0.7; p-value = 0.03; A vs. B1+C: OR = 0.8; p-value = 0.02) showed a significant association with protection from cardiopathy in a logistic regression analysis with adjustment for gender and ethnicity; however, the association disappeared after performing adjustment for multiple testing. A systematic review of TNF rs1800629 -308G>A publications included five studies for meta-analysis (534 CCC and 472 asymptomatic patients) and showed no consensus in pooled odds ratio (OR) estimates for A allele or A carriers (OR = 1.4 and 1.5; p-values = 0.14 and 0.15, respectively). In CD patients, TNF serum levels were increased, but not affected by the TNF rs1800629 -308A allele. MAIN CONCLUSIONS: Our data suggest no significant contribution of the analysed gene variants of cytokine-related molecules to development/severity of Chagas' heart disease, reinforcing the idea that parasite/host interplay is critical to CD outcomes.


Asunto(s)
Cardiomiopatía Chagásica/genética , Citocinas/genética , Polimorfismo de Nucleótido Simple/genética , Brasil , Estudios de Casos y Controles , Cardiomiopatía Chagásica/complicaciones , Cardiomiopatía Chagásica/inmunología , Femenino , Predisposición Genética a la Enfermedad , Humanos , Interferón gamma/genética , Masculino , Persona de Mediana Edad , Pronóstico , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Receptores Tipo II del Factor de Necrosis Tumoral/genética , Índice de Severidad de la Enfermedad , Factores Socioeconómicos , Factor de Crecimiento Transformador beta/genética , Factor de Necrosis Tumoral alfa/genética
13.
Front Immunol ; 9: 806, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29755459

RESUMEN

For those with leprosy, the extent of host infection by Mycobacterium leprae and the progression of the disease depend on the ability of mycobacteria to shape a safe environment for its replication during early interaction with host cells. Thus, variations in key genes such as those in pattern recognition receptors (NOD2 and TLR1), autophagic flux (PARK2, LRRK2, and RIPK2), effector immune cytokines (TNF and IL12), and environmental factors, such as nutrition, have been described as critical determinants for infection and disease progression. While parkin-mediated autophagy is observed as being essential for mycobacterial clearance, leprosy patients present a prominent activation of the type I IFN pathway and its downstream genes, including OASL, CCL2, and IL10. Activation of this host response is related to a permissive phenotype through the suppression of IFN-γ response and negative regulation of autophagy. Finally, modulation of host metabolism was observed during mycobacterial infection. Both changes in lipid and glucose homeostasis contribute to the persistence of mycobacteria in the host. M. leprae-infected cells have an increased glucose uptake, nicotinamide adenine dinucleotide phosphate generation by pentose phosphate pathways, and downregulation of mitochondrial activity. In this review, we discussed new pathways involved in the early mycobacteria-host interaction that regulate innate immune pathways or metabolism and could be new targets to host therapy strategies.


Asunto(s)
Autofagia , Interacciones Huésped-Patógeno/inmunología , Inmunidad Innata , Interferón Tipo I/inmunología , Lepra/inmunología , Citocinas/inmunología , Progresión de la Enfermedad , Glucosa/metabolismo , Humanos , Interferón Tipo I/genética , Lepra/metabolismo , Infecciones por Mycobacterium/inmunología , Infecciones por Mycobacterium/terapia , Mycobacterium leprae/inmunología , Receptores de Reconocimiento de Patrones/inmunología , Transducción de Señal
14.
Front Immunol ; 9: 615, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29696014

RESUMEN

Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD), a disease caused by Trypanosoma cruzi infection. A hallmark of chronic chagasic cardiomyopathy (CCC) is a fibrogenic inflammation mainly composed of CD8+ and CD4+ T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs) in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines CCL2 (rs1024611) and CCL5 (rs2107538, rs2280788) and the CCL5/RANTES receptors CCR1 (rs3181077, rs1491961, rs3136672) and CCR5 (rs1799987) with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A, n = 110) or cardiopathic (mild, B1, n = 163; severe, C, n = 133). Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity, CCL5 -403 (rs2107538) CT heterozygotes (OR = 0.5, P-value = 0.04) and T carriers (OR = 0.5, P-value = 0.01) were associated with protection against CCC. To gain insight into the participation of the CCL5-CCR5/CCR1 axis in CCC, mice were infected with the Colombian T. cruzi strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1+ CD8+ T cells and CD14+ macrophages were decreased, while frequencies of CCR5+ cells were increased. Importantly, CCR1+CD14+ macrophages were mainly IL-10+, while CCR5+ cells were mostly TNF+. CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met-RANTES therapy) in infected Ccr5-/- mice supported a protective role for CCR1 in CCC. Furthermore, parasite antigen stimulation of CD patient blood cells increased the frequency of CCR1+CD8+ T cells and CCL5 production. Collectively, our data support that a genetic variant of CCL5 and CCR1+ cells confer protection against Chagas heart disease, identifying the CCL5-CCR1 axis as a target for immunostimulation.


Asunto(s)
Cardiomiopatía Chagásica/genética , Quimiocina CCL5/genética , Genotipo , Miocardio/metabolismo , Trypanosoma cruzi/fisiología , Adulto , Animales , Brasil , Células Cultivadas , Cardiomiopatía Chagásica/inmunología , Quimiocina CCL2/sangre , Quimiocina CCL2/genética , Quimiocina CCL5/metabolismo , Enfermedad Crónica , Progresión de la Enfermedad , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Miocardio/patología , Polimorfismo de Nucleótido Simple , Receptores CCR1/genética , Receptores CCR1/metabolismo , Receptores CCR5/genética , Receptores CCR5/metabolismo , Riesgo
15.
Trials ; 19(1): 244, 2018 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-29685164

RESUMEN

BACKGROUND: The annual new-case detection rate for leprosy, while generally stable over the last decade, shows that transmission rates have remained stagnant despite the successful worldwide administration of multidrug therapy since the 1980s. As such, novel control strategies are urgently needed. Focusing on managing leprosy patient contacts, the most susceptible to contracting the disease, has been seen as a potential strategy in limiting the spread of leprosy as shown by a number of recent epidemiological studies. Immunoprophylaxis with Bacillus Calmette-Guérin (BCG) has been seen as an effective preventive measure due to its ability to stimulate the development of cellular immunity which is essential in controlling the disease, especially in its multibacillary (MB) forms. The association of immunoprophylaxis with chemoprophylaxis in a single dose of rifampicin has been shown to be a promising preventive strategy, although a variety of studies have found instances of early case detection just a few months after BCG vaccination. METHODS/DESIGN: The present study is a phase IV chemoprophylactic clinical trial consisting of administration of a single dose of rifampicin in MB leprosy patient contacts under care at the Souza Araújo Outpatient Clinic/FIOCRUZ as part of a randomized (2:1), double-blind, placebo-controlled study. It is comprised of two groups: 1) rifampicin + BCG; and 2) placebo + BCG. DISCUSSION: The aim is to evaluate whether the use of chemoprophylaxis with a single dose of rifampicin in MB leprosy patient contacts prior to the BCG vaccine would be able to prevent the onset of leprosy in those cases that may occur just a few months after vaccination. Contact subclinical infections (polymerase chain reaction) and the immunological parameters (anti-PGL-1, anti-LID-1, and IFN-γ) will be evaluated and the results will be compared after 12 months of follow-up. TRIAL REGISTRATION: The Brazilian Registry of Clinical Trials (ReBEC), RBR-69QK5P . Retrospectively registered on 1 June 2017.


Asunto(s)
Vacuna BCG/administración & dosificación , Trazado de Contacto , Leprostáticos/administración & dosificación , Lepra Multibacilar/prevención & control , Rifampin/administración & dosificación , Adolescente , Adulto , Anciano , Vacuna BCG/efectos adversos , Brasil , Niño , Preescolar , Ensayos Clínicos Fase IV como Asunto , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Lactante , Leprostáticos/efectos adversos , Lepra Multibacilar/inmunología , Lepra Multibacilar/microbiología , Lepra Multibacilar/transmisión , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Rifampin/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Vacunación , Adulto Joven
16.
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
17.
PLoS Negl Trop Dis ; 12(2): e0006261, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29481570

RESUMEN

BACKGROUND: The high rate of leprosy cases among children under 15 years of age in Brazil indicates ongoing transmission within the community. The identification of the new leprosy cases among contacts can help identify the source of infection and interrupt the transmission chain. This study aims to determine the detection rate of previously undiagnosed cases of leprosy among schoolchildren who are under 15 years of age living in Manaus, Amazonas, Brazil, and their possible source of infection by contact tracing. METHODOLOGY/PRINCIPAL FINDINGS: This was a school-based, cross-sectional study in which the identification of active leprosy cases was conducted in 277 out of 622 randomly selected public schools in Manaus, Amazonas, Brazil. Suspected cases of leprosy were referred to the Alfredo da Matta Foundation, a reference center for leprosy in Manaus. A total of 34,547 schoolchildren were examined, and 40 new leprosy cases were diagnosed. Among new cases, 57.5% were males, and 80.0% demonstrated paucibacillary leprosy. A total of 196 of 206 registered contacts were screened, and 52.5% of the newly diagnosed children's cases had at least one positive household contact. In these contacts, grandparents (52.4%) were the most common co-prevalent cases, while 14.3% were uncles, 9.5% were parents and 9.5% were granduncles. Seven contacts (5.0%), including four siblings of child patients were newly diagnosed. Our data indicate that the prevalence is 11.58 per 10,000, which is 17 times higher than the registered rate. CONCLUSIONS/SIGNIFICANCE: This study suggests that the detection rate of leprosy among schoolchildren may have remained unchanged over the past thirty years. It also indicates that that active case finding is necessary for reaching the World Health Organization's goals of zero detection among children, especially in endemic areas where the prevalence of leprosy is obscure. Moreover, we assert that all children must have their household contacts examined in order to identify the possible source of infection and interrupt the disease's transmission. Novel strategies to reinforce contact tracing associated with large-scale strategies of chemo- and immune-prophylaxis should be expanded to prevent the perpetuation of the disease cycle.


Asunto(s)
Trazado de Contacto , Lepra Paucibacilar/epidemiología , Lepra Paucibacilar/transmisión , Lepra/epidemiología , Lepra/transmisión , Adolescente , Brasil/epidemiología , Niño , Preescolar , Estudios Transversales , Familia , Femenino , Humanos , Lepra/diagnóstico , Lepra/microbiología , Lepra Paucibacilar/diagnóstico , Lepra Paucibacilar/microbiología , Masculino , Mycobacterium leprae , Prevalencia , Instituciones Académicas
18.
s.l; s.n; 2018. 25 p. ilu, tab, graf.
No convencional en Inglés | Sec. Est. Saúde SP, HANSEN, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1025298

RESUMEN

Leprosy is an infectious disease caused by Mycobacterium leprae and frequently resulting in irreversible deformities and disabilities. Ticks play an important role in infectious disease transmission due to their low host specificity, worldwide distribution, and the biological ability to support transovarial transmission of a wide spectrum of pathogens, including viruses, bacteria and protozoa. To investigate a possible role for ticks as vectors of leprosy, we assessed transovarial transmission of M. leprae in artificially-fed adult female Amblyomma sculptum ticks, and infection and growth of M. leprae in tick cell lines. Our results revealed M. leprae RNA and antigens persisting in the midgut and present in the ovaries of adult female A. sculptum at least 2 days after oral infection, and present in their progeny (eggs and larvae), which demonstrates the occurrence of transovarial transmission of this pathogen. Infected tick larvae were able to inoculate viable bacilli during blood-feeding on a rabbit. Moreover, following inoculation with M. leprae, the Ixodes scapularis embryo-derived tick cell line IDE8 supported a detectable increase in the number of bacilli for at least 20 days, presenting a doubling time of approximately 12 days. As far as we know, this is the first in vitro cellular system able to promote growth of M. leprae. Finally, we successfully transformed a clinical M. leprae isolate by inserting the reporter plasmid pCHERRY3; transformed bacteria infected and grew in IDE8 cells over a 2-month period. Taken together, our data not only support the hypothesis that ticks may have the potential to act as a reservoir and/or vector of leprosy, but also suggest the feasibility of technological development of tick cell lines as a tool for large-scale production of M. leprae bacteria, as well as describing for the first time a method for their transformation.


Asunto(s)
Humanos , Animales , Masculino , Femenino , Conejos , Vectores Arácnidos/fisiología , Vectores Arácnidos/microbiología , Línea Celular , Ixodes/fisiología , Ixodes/microbiología , Ixodidae/fisiología , Ixodidae/microbiología , Lepra/microbiología , Lepra/transmisión , Mycobacterium leprae/fisiología , Mycobacterium leprae/genética
19.
Mem. Inst. Oswaldo Cruz ; 113(6): e170489, 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-894934

RESUMEN

BACKGROUND The severity of chronic chagasic cardiomyopathy (CCC), the most frequent clinical outcome of Chagas disease (CD), has been associated with cytokine-enriched heart tissue inflammation, and high serum levels of transforming growth factor (TGFβ), interferon-gamma (IFNγ), and tumour necrosis factor (TNF). Conversely, increased interleukin (IL)-10 serum concentrations have been associated with asymptomatic CD. Cytokines and cytokine-related gene polymorphisms may control cytokine expression and have been proposed to contribute to CCC outcomes. OBJECTIVES We evaluated the association of 13 cytokine-related genes (TGFB: rs8179181, rs8105161, rs1800469; IL10: rs1800890, rs1800871, rs1800896; IFNG: rs2430561; TNF: rs1800629; BAT1: rs3853601; LTA: rs909253, rs2239704; TNFR1: rs767455; TNFR2: rs1061624) with risk and progression of CCC. FINDINGS Four hundred and six seropositive patients from CD endemic areas in the state of Pernambuco, north-eastern Brazil, were classified as non-cardiopathic (A, 110) or cardiopathic (mild, B1, 163; severe, C, 133). We found no evidence of TGFB, IL10, TNF, or TNFR1/2 gene polymorphisms associated with CCC risk or progression. Only BAT1 rs3853601 −22G carriers (B1 vs. C: OR = 0.5; p-value = 0.03) and IFNG rs2430561 +874AT (A vs. C: OR = 0.7; p-value = 0.03; A vs. B1+C: OR = 0.8; p-value = 0.02) showed a significant association with protection from cardiopathy in a logistic regression analysis with adjustment for gender and ethnicity; however, the association disappeared after performing adjustment for multiple testing. A systematic review of TNF rs1800629 −308G>A publications included five studies for meta-analysis (534 CCC and 472 asymptomatic patients) and showed no consensus in pooled odds ratio (OR) estimates for A allele or A carriers (OR = 1.4 and 1.5; p-values = 0.14 and 0.15, respectively). In CD patients, TNF serum levels were increased, but not affected by the TNF rs1800629 −308A allele. MAIN CONCLUSIONS Our data suggest no significant contribution of the analysed gene variants of cytokine-related molecules to development/severity of Chagas' heart disease, reinforcing the idea that parasite/host interplay is critical to CD outcomes.


Asunto(s)
Humanos , Estudios de Casos y Controles , Cardiomiopatía Chagásica/complicaciones , Citocinas/genética , Predisposición Genética a la Enfermedad , Interferón gamma/genética , Polimorfismo de Nucleótido Simple , Receptores Tipo I de Factores de Necrosis Tumoral
20.
Infect Genet Evol ; 56: 99-110, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29133029

RESUMEN

Dengue is a major worldwide problem in tropical and subtropical areas; it is caused by four different viral serotypes, and it can manifest as asymptomatic, mild, or severe. Many factors interact to determine the severity of the disease, including the genetic profile of the infected patient. However, the mechanisms that lead to severe disease and eventually death have not been determined, and a great challenge is the early identification of patients who are more likely to progress to a worse health condition. Studies performed in regions with cyclic outbreaks such as Cuba, Brazil, and Colombia have demonstrated that African ancestry confers protection against severe dengue. Highlighting the host genetics as an important factor in infectious diseases, a large number of association studies between genetic polymorphisms and dengue outcomes have been published in the last two decades. The most widely used approach involves case-control studies with candidate genes, such as the HLA locus and genes for receptors, cytokines, and other immune mediators. Additionally, a Genome-Wide Association Study (GWAS) identified SNPs associated with African ethnicity that had not previously been identified in case-control studies. Despite the increasing number of publications in America, Africa, and Asia, the results are quite controversial, and a meta-analysis is needed to assess the consensus among the studies. SNPs in the MICB, TNF, CD209, FcγRIIA, TPSAB1, CLEC5A, IL10 and PLCE1 genes are associated with the risk or protection of severe dengue, and the findings have been replicated in different populations. A thorough understanding of the viral, human genetic, and immunological mechanisms of dengue and how they interact is essential for effectively preventing dengue, but also managing and treating patients.


Asunto(s)
Virus del Dengue/fisiología , Dengue/genética , Dengue/virología , Predisposición Genética a la Enfermedad , Interacciones Huésped-Patógeno , Alelos , Dengue/inmunología , Estudio de Asociación del Genoma Completo , Antígenos HLA/genética , Humanos , Inmunidad Innata , Inmunomodulación/genética , Evaluación del Resultado de la Atención al Paciente , Polimorfismo Genético , Pronóstico , Proyectos de Investigación
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