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.

Antigen-specific assessment of the immunological status of various groups in a leprosy endemic region.

BACKGROUND: Serological tests can be important tools to assist in the diagnosis of leprosy and can contribute to an earlier diagnosis. The aim of this study was to evaluate the antibody responses against phenolic glycolipid-1 (PGL-1), natural disaccharide linked to human serum albumin via an octyl (NDO-HSA), Leprosy IDRI Diagnostic-1 (LID-1) and natural disaccharide octyl--Leprosy IDRI Diagnostic-1 (NDO-LID) in leprosy patients, household contacts of patients and the general population. METHODS: Enzyme-linked immunosorbent assays were used to analyze the antigen-specific antibody responses of 94 leprosy cases, 104 household contacts of cases and 2.494 individuals from the general population. RESULTS: A positive correlation was observed for the antibody responses to all antigens studied. A higher proportion of seropositivity for all antigens, along with stronger magnitude of response, was observed in multibacillary (MB) leprosy patients and household contacts of MB leprosy patients compared with the levels observed in paucibacillary (PB) leprosy patients and household contacts of PB leprosy patients. A substantial and significant positive correlation was found between seropositivity and the bacterial index for the leprosy patients. Anti-PGL-1 tests were more frequently positive than anti-NDO-HSA tests among patients with all clinical forms of leprosy and among the group of household contacts. The LID-1 and NDO-LID antigens showed a greater capacity to identify household contacts and individuals from the general population infected with M. leprae. CONCLUSIONS: Tests that measure the antibody responses against LID-1, NDO-LID, NDO-HSA and PGL-1 were effective tools for the detection of patients with MB leprosy. Our data indicate that the anti-LID-1 and anti-NDO-LID responses were more effective than an anti-NDO-HSA response for the identification of individuals with subclinical infection.

Effects of aqueous extract of Echinodorus grandiflorus on the immune response in ovalbumin-induced pulmonary allergy.

BACKGROUND: Asthma is a disease characterized by intermittent obstruction of the airways and chronic inflammation that affects approximately 300 million people worldwide. The immune response in asthma is predominantly T(H)2, with high levels of total and allergen-specific IgE and bronchial eosinophilia. Asthma treatment is aimed at controlling the disease, and the drugs used currently have systemic adverse effects and generally are not effective in difficult-to-control cases. OBJECTIVE: To investigate the effect of aqueous extract of Echinodorus grandiflorus, a plant used in folk medicine for its diuretic and anti-inflammatory properties, in a model of pulmonary allergy. METHODS: BALB/c mice were intraperitoneally sensitized and nasally challenged with ovalbumin. Aqueous extract and dexamethasone treatments (0.1 mL/d per mouse) were initiated on day 32 and concluded on day 40. Eight hours after the last challenge evaluations, of serum, bronchoalveolar lavage, and lung tissue were performed. RESULTS: Oral treatment with the extract markedly reduced the number of total cells and eosinophils in bronchoalveolar lavage. The eosinophil peroxidase activity in lung tissue, the levels of ovalbumin-specific IgE in serum, the levels of CCL11, and the gene expression of interleukin 4 and interleukin 13 in lung tissue were also lower after treatment. CONCLUSIONS: These results suggest that the aqueous extract of E grandiflorus is able to modulate allergic pulmonary inflammation and may be useful as a potential therapeutic agent for asthma.

Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis.

The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB.

Serum IgA Antibodies Specific to M. leprae Antigens as Biomarkers for Leprosy Detection and Household Contact Tracking.

Leprosy remains endemic in several developing countries, such as India and Brazil, in part due to delayed diagnosis that facilitates ongoing transmission. Although immunoglobulins against several Mycobacterium leprae antigens have been indicated for the early diagnosis, and IgA participates in the early stages of leprosy and in subclinical infection, relatively little research has examined anti-M. leprae IgA responses. Here, we investigated serum IgA reactivity against NDO-HSA, LID-1 and NDO-LID, in paucibacillary (PB) and multibacillary (MB) patients and their household contacts, using enzyme-linked immunosorbent assay (ELISA). Diagnostic accuracy of each ELISA was evaluated by receiver operating characteristic (ROC) curve analysis. Our data reveal elevated IgA serum levels against the three M. leprae specific antigens in MB patients, whereas IgA reactivity in PB patients was increased only to NDO-HSA. Further, MB and PB household contacts displayed higher IgA reactivity to NDO-HSA than non-endemic controls. Our data suggest measurement of serum IgA against NDO-HSA as an additional tool in the diagnosis and classification of the disease, with potential utility for household contact follow-up.

Anti-mycobacterial treatment reduces high plasma levels of CXC-chemokines detected in active tuberculosis by cytometric bead array.

Chemokines recruit and activate leukocytes, assisting granuloma formation. Herein, we evaluated plasma chemokines in patients with active tuberculosis (ATB) and after completing treatment (TTB) and compared them to BCG-vaccinated healthy controls (HC). Levels of chemokines were measured by cytometric bead array. Levels of CXCL8, CXCL9 and CXCL10 were higher in ATB patients compared to HC, but they decreased in TTB. Levels of CCL2 and CCL5 in ATB patients were similar to those observed in HC. Thus, the high levels of CXC-chemokines detected during ATB, which can modulate the trafficking of immune cells from the periphery to the site of infection, were reversed by anti-mycobacterial treatment.

Efficiency of rLb6H recombinant protein from Leishma-nia (Viannia) braziliensis for the detection of canine visceral leishmaniasis / Eficiência da proteína recombinante rLb6H de Leishmania (Viannia) brazi-liensis na detecção da leishmaniose visceral canina

Introduction: Visceral leishmaniasis (VL) is a serious endemic disease in many tropical and subtropical countries, with a strong incidence in Brazil. The disease is transmitted by the bite of infected female phlebotomine sandflies, with dogs being the main urban reservoirs of the parasite. The diverse clinical profile and the long incubation period are challenges for the diagnosis of canine visceral leishmaniasis (CVL). Recombinant proteins from Leishmania spp. have been studied as antigens that can increase the accuracy of serological tests. Objective: To evaluate the diagnostic performance of the recombinant protein rLb6H, from Leishmania braziliensis, in comparison to the reference antigens rK39 and rK28, from L. donovani, prioritizing the identification of subclinical infected dogs. Material and Methods: Serum IgG reactivity to rLb6H, rK28, and rK39 recombinant proteins was assessed in dogs with previously parasitological confirmation of CVL, subdivided according to their clinical status, using immunoenzymatic assay (ELISA). Diagnostic accuracy of each ELISA was evaluated by receiver operating characteristic (ROC) curve analysis. Results: While all antigens showed a better performance in detecting CVL in symptomatic dogs (SD), detection of CVL in the oligosymptomatic (OD) and asymptomatic (AD) groups was lower, but rLb6H achieved high sensitivity for asymptomatic CVL. Interestingly, the most reactive CVL samples to rK28 were barely detected by rLb6H, while the less reactive to rK28, mostly from the AD group, presented higher reactivity to rLb6H. Conclusion: The recombinant protein rLb6H showed utility in the detection of asymptomatic CVL, displaying a complementary reactivity to rK39 and rK28. Thus, these results suggest that rLb6H could be incorporated into multi-antigen strategies, to increase diagnostic accuracy of CVL.

Introdução: A leishmaniose visceral (LV) é uma doença endêmica grave em muitos países tropicais e subtropicais, tendo forte incidência no Brasil. A doença é transmitida pela picada de flebotomíneos fêmeas infectadas, sendo os cães os principais reservatórios urbanos do parasito. O perfil clínico diversificado e o longo período de incubação são desafios para o diagnóstico da leishmaniose visceral canina (LVC). Proteínas recombinantes de Leishmania spp. têm sido estudadas como antígenos que podem aumentar a precisão de testes sorológicos. Objetivo: Avaliar o desempenho diagnóstico da proteína recombinante rLb6H, de Leishmania braziliensis, em comparação com os antígenos de referência rK39 e rK28, de L. donovani, priorizando a identificação de cães com infecção subclínica. Material e Métodos: A reatividade de anticorpos IgG séricos às proteínas recombinantes rLb6H, rK28 e rK39 foi avaliada em cães com confirmação parasitológica prévia de LVC, subdivididos de acordo com seu quadro clínico, utilizando ensaio imunoenzimático (ELISA). A precisão diagnóstica de cada ELISA foi avaliada pela análise da curva ROC (receiver operating characteristic curve). Resultados: Enquanto todos os antígenos mostraram um melhor desempenho na detecção de CVL em cães sintomáticos (SD), a detecção de CVL nos grupos oligossintomáticos (OD) e assintomáticos (AD) foi menor, mas rLb6H alcançou alta sensibilidade para CVL assintomática. Curiosamente, as amostras de CVL mais reativas a rK28 foram pouco detectadas por rLb6H, enquanto as menos reativas a rK28, principalmente do grupo AD, apresentaram maior reatividade a rLb6H. Conclusão: A proteína recombinante rLb6H mostrou utilidade na detecção de CVL assintomática, apresentando uma reatividade complementar a rK39 e rK28. Assim, estes resultados sugerem que o rLb6H pode ser incorporado em estratégias multi-antígeno para aumentar a acurácia diagnóstica da leishmaniose visceral.

CCL2, CXCL8, CXCL9 and CXCL10 serum levels increase with age but are not altered by treatment with hydroxychloroquine in patients with osteoarthritis of the knees.

AIM: Osteoarthritis (OA) is a major cause of morbidity and incapacity in the elderly. This study evaluates serum levels of the chemokines CCL2, CXCL8, CXCL9, and CXCL10 in 16 patients with primary OA of the knees, and investigates how treatment with hydroxychloroquine (HCQ) for 4 months affects these chemokine levels. METHOD: Thirteen elderly patients received a placebo. Healthy control groups consisted of 10 elderly individuals (age > 60 years) with no clinical or radiological evidence of OA (CT-O), and 10 young adult individuals, (CT-Y group, age < 40 years). RESULTS: The CT-Y group presented lower levels of all chemokines studied, in comparison to the other groups. HCQ treatment did not alter the serum levels of CCL2 (P = 0.80), CXCL8 (P = 0.76), CXCL9 (P = 0.95) and CXCL10 (P = 0.74) in OA patients. CONCLUSION: Hydroxychloroquine treatment did not alter the serum levels of CCL2, CXCL8, CXCL9 or CXCL10 in patients with OA of the knees, although increased serum levels correlated with aging for all subjects, including controls.

Autotransplantation of Spleen Mitigates Drug-Induced Liver Damage in Splenectomized Mice.

PURPOSE: The spleen presents numerous functions, including the production of immunoglobulins and blood filtration, removing microorganisms and cellular debris. The spleen also has anatomical and functional relationship with the liver, but there are few studies on this topic. The aim of this study was to assess the effect of splenectomy and autologous spleen transplantation on both filtering functions of spleen and acetaminophen-induced hepatotoxicity. MATERIALS AND METHODS: Fifty-two BALB/c mice were randomized into four groups: splenectomized; splenectomy and splenic autotransplantation in the greater omentum; sham operated control; and non-operated control. At day 7th, 14th, and 28th after surgery, splenic filtration was assessed by counting Howell-Jolly bodies (HJB) and pitted red cells (PIT). The animals received 400 mg/kg acetaminophen by gavage at day 28th and after 12 or 24 hours were euthanized for evaluation of splenic and hepatic morphology. RESULTS: The splenectomized group demonstrated reduced filtration of HJB and PIT in all analyzes, while the autotransplanted group developed progressive recovery of function after the 14th day. At day 28 after surgery the implants showed similar histology in comparison to normal spleen. Liver histology showed more intense centrilobular necrosis in splenectomized group in comparison to the others, suggesting a protective role of spleen in acetaminophen-induced liver injury. CONCLUSIONS: Splenic implants showed structural and functional recovery, demonstrating the ability of autologous implant to rescue filtering function of intact spleen. Furthermore, the integrity of splenic function appears to influence liver morphology, since the presence of the splenic implants mitigated the effects of chemically-induced liver damage.

Detection of IgG1 antibodies against Mycobacterium tuberculosis DosR and Rpf antigens in tuberculosis patients before and after chemotherapy.

Diagnosis of tuberculosis (TB) remains challenging. Serum IgG1 antibodies against Mycobacterium tuberculosis active growth phase antigens (ESAT-6/CFP-10, Rv0717 and Rv3353), DosR regulon-encoded proteins (Rv1733, Rv1737, Rv2628 and Rv2029), and resuscitation-promoting factors (Rv0867 and Rv2389) were evaluated in TB patients using ELISA. Active TB patients showed elevated levels of IgG1 antibodies against ESAT-6/CFP-10, Rv0717, Rv3353, Rv1733, Rv2628, Rv2029 and Rv0867 in comparison to healthy controls (p < 0.001). These levels remained high after the initiation of treatment, while responses to Rv0717 and Rv1733 peaked early during treatment. IgG1 responses to ESAT-6/CFP-10, Rv3353, Rv2628, Rv2029 and Rv0867 declined to control levels after the completion of 6 months chemotherapy. ROC analysis confirmed the good diagnostic performance of Rv0717, Rv1733, Rv3353, Rv2628, Rv2029 and Rv0867antigens. These data suggest that detecting IgG1 antibodies against M. tuberculosis antigens, including DosR and Rpf proteins, may represent an additional tool in the diagnosis of tuberculosis.

Challenging Mycobacterium tuberculosis dormancy mechanisms and their immunodiagnostic potential.

Mycobacterium tuberculosis is the etiologic agent of tuberculosis, one of the world's greatest cause of morbidity and mortality due to infectious disease. Many evolutionary mechanisms have contributed to its high level of adaptation as a host pathogen. Prior to become dormant, a group of about 50 genes related to metabolic changes are transcribed by the DosR regulon, one of the most complex and important systems of host-pathogen interaction. This genetic mechanism allows the mycobacteria to persist during long time periods, establishing the so-called latent infection. Even in the presence of a competent immune response, the host cannot eliminate the pathogen, only managing to keep it surrounded by an unfavorable microenvironment for its growth. However, conditions such as immunosuppression may reestablish optimal conditions for bacterial growth, culminating in the onset of active disease. The interactions between the pathogen and its host are still not completely elucidated. Nonetheless, many studies are being carried out in order to clarify this complex relationship, thus creating new possibilities for patient approach and laboratory screening.

Proteínas de checkpoint imunológico como novo alvo da imunoterapia contra o câncer: revisão da literatura / Immune checkpoint proteins as new target for cancer immunotherapy: literature review

Uma nova era no tratamento do câncer está surgindo com o uso de anticorpos capazes de inibir pontos de bloqueio do sistema imunológico, chamados de "inibidores de checkpoint". Um novo conceito de "balas mágicas", que no início do século passado foram imaginadas por Paul Ehrlich como capazes de atuar diretamente na destruição de alvos tumorais, é representado agora por anticorpos direcionadas contra moléculas que bloqueiam a atividade antitumoral do sistema imunológico, como o antígeno-4 de linfócito T citotóxico (CTLA-4) e a proteína-1 de morte celular programada (PD-1). Essas novas imunoterapias vêm revolucionando a forma de tratar diferentes tipos de câncer. Nesta revisão selecionamos estudos sobre CTLA-4 e PD-1, seus ligantes em células apresentadoras de antígenos, assim como destacamos a importância da descoberta de antígenos tumorais e o papel do sistema imunológico na imunovigilância tumoral. Nesse estudo são discutidos aspectos relacionados aos efeitos de imunoterapias baseadas no uso de anticorpos monoclonais anti-CTLA-4 e anti-PD-1/ PD-L1, como o risco de serem estimuladas respostas direcionadas a tecidos saudáveis e outros efeitos adversos, bem como o uso de terapias combinadas que podem contribuir para melhorar a eficiência do tratamento do câncer.

A new era in cancer treatment is emerging with the use of antibodies directed against immune checkpoint proteins, known as "checkpoint inhibitors". A novel concept of "magic bullets", concepted by Paul Ehrlich at the beginning of the last century, as being capable of acting directly on the destruction of tumor targets, is now represented by antibodies directed against molecules which block the antitumor activity of the immune system, such as Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) and Programmed Cell Death Protein-1 (PD-1). These new immunotherapies have revolutionized the treatment of different cancer types. Studies on CTLA-4, PD-1, and their ligands in antigen presenting cells are discussed in this review. The importance of tumor antigen discovery and the role of the immune system in immune surveillance of tumors were highlighted. Also in the present study, aspects related to the effects of immunotherapies based on the use of anti-CTLA-4 and anti-PD-1/ PD-L1 monoclonal antibodies are described, such as the risk of stimulating responses to normal tissues and other adverse effects, as well as the use of combination therapies which can improve the efficacy of cancer treatment.

Efeitos contrastantes da vitamina D sobre a resposta imune inata e adquirida e seu impacto na recuperação da tuberculose / Contrasting effects of Vitamin D on innate and acquired immune responses and its impact on tuberculosis recover

A vitamina D é um hormônio essencial para o organismo, podendo ser obtida da dieta ou, principalmente, gerada pela pele após exposição à luz solar ultravioleta B. Na sua forma ativa (1,25(oH)2D) ela controla a absorção de cálcio e fósforo do intestino para a corrente sanguínea e participa de diversos processos celulares e fisiológicos. A ligação da 1,25(oH)2D ao receptor da vitamina D (VDr) presente em diversas células, como as células do sistema imunológico, induz a transcrição de genes que podem, por exemplo, modular a resposta imune inata e adquirida. A deficiência de vitamina D ou do VDR é associada a problemas de saúde como desordens esqueléticas, hipertensão, doenças cardiovasculares, diabetes mellitus, dislipidemias, doenças autoimunes e doenças infecciosas. Neste sentido, a suplementação com vitamina D tem sido proposta como uma possível medida preventiva, podendo ser aplicada em muitas patologias, em especial na tuberculose. Principal causa de morte por um único agente infeccioso, a tuberculose é responsável por cerca de 1,3 milhões de óbitos por ano no mundo. Publicações recentes apontam efeitos diversos da vitamina D na resposta imune inata e adquirida. A 1,25(oH)2D3 na presença do interferon (IFN)-γ é capaz de aumentar a atividade bactericida do macrófago contra o M. tuberculosis, aumentando a produção de peptídios antimicrobianos e estimulando a autofagia, favorecendo assim a lise de bacilos localizados em fagossomos. Por outro lado, a vitamina D em linfócitos T mostra efeito tolerogênico que favorece o controle de respostas inflamatórias excessivas. Neste trabalho de revisão são apresentados estudos recentes envolvendo efeitos da vitamina D na resposta imune inata e adquirida. Além disso, considerações sobre deficiência de vitamina D e maior risco de contrair tuberculose, e efeitos contrastantes da suplementação com vitamina D na prevenção e tratamento da TB, são discutidos.

Vitamin D is an essential hormone for the body, and can be obtained from diet or, mainly, generated by the skin after exposure to ultraviolet B sunlight. In its active form (1.25(oH)2D) it controls the absorption of calcium and phosphorus from the intestine into the bloodstream and participates in several cellular and physiological processes. Binding of 1,25(oH)2D to the Vitamin D receptor (VDr) present in several cells, such as cells of the immune system, induces transcription of genes that can, for example, modulate the innate and adaptive immune response. Deficiency of Vitamin D or VDr is associated with health problems such as skeletal disorders, hypertension, cardiovascular disease, diabetes mellitus, dyslipidemias, autoimmune diseases and infectious diseases. In this sense, Vitamin D supplementation has been proposed as a possible preventive measure and can be applied in several pathologies, especially in tuberculosis. main cause of death by a single infectious agent, tuberculosis accounts for about 1.3 million deaths per year worldwide. recent publications point to contrasting functions of Vitamin D in the innate and acquired immune response. 1.25(oH)2D3 in the presence of interferon (IFN)-γ is capable of increasing the bactericidal activity of the macrophage against M. tuberculosis, increasing the production of antimicrobial peptides and stimulating autophagy, thus favoring the lysis of bacilli located in phagosomes. on the other hand, Vitamin D in T lymphocytes shows a tolerogenic effect that favors the control of excessive inflammatory responses. In this review, recent studies involving Vitamin D effects on the innate and acquired immune responses are presented. In addition, considerations about Vitamin D deficiency and increased risk of contracting tuberculosis, and contrasting effects of Vitamin D supplementation on the prevention and treatment of TB, are discussed.

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.

Challenging Mycobacterium tuberculosi s dormancy mechanisms and their immunodiagnostic potential

ABSTRACT Mycobacterium tuberculosis is the etiologic agent of tuberculosis, one of the world's greatest cause of morbidity and mortality due to infectious disease. Many evolutionary mechanisms have contributed to its high level of adaptation as a host pathogen. Prior to become dormant, a group of about 50 genes related to metabolic changes are transcribed by the DosR regulon, one of the most complex and important systems of host-pathogen interaction. This genetic mechanism allows the mycobacteria to persist during long time periods, establishing the so-called latent infection. Even in the presence of a competent immune response, the host cannot eliminate the pathogen, only managing to keep it surrounded by an unfavorable microenvironment for its growth. However, conditions such as immunosuppression may reestablish optimal conditions for bacterial growth, culminating in the onset of active disease. The interactions between the pathogen and its host are still not completely elucidated. Nonetheless, many studies are being carried out in order to clarify this complex relationship, thus creating new possibilities for patient approach and laboratory screening.

Human serum antibody reactivity towards Paracoccidioides brasiliensis antigens treated with sodium metaperiodate.

In this study, we evaluated the profile of anti-Paracoccidioides brasiliensis immunoglobulin isotypes in serum from patients with the acute and chronic forms of paracoccidioidomycosis, using the whole Paracoccidioides brasiliensis antigen and the antigen treated with sodium metaperiodate. All the immunoglobulin isotypes present in the serum from patients with the acute and chronic forms of paracoccidioidomycosis presented higher reactivity towards the whole antigen than to the antigen treated with metaperiodate (P < 0.05). The reactivity of IgG and IgM to the antigen treated with metaperiodate was greater in serum from patients with the acute form of the disease (P < 0.05), while IgA was more reactive in serum from patients with the chronic form (P < 0.05). There was greater reactivity of IgG1 and IgG2 to the whole antigen and the antigen treated with metaperiodate in the serum from patients with paracoccidioidomycosis than there was in serum from patients with other parasitic infections (P < 0.05). Furthermore, IgG1 from patients with the acute form recognized the 19kDa, 27kDa and 31kDa antigens in the western blot test. Thus, the results suggest that modifications to the epitopes of Paracoccidioides brasiliensis antigens may help to improve the immunodiagnosis of paracoccidioidomycosis.

Immunological diagnosis of tuberculosis: problems and strategies for success.

Tuberculosis remains a serious social and public health problem, affecting millions of people annually. The bacille Calmette-Guerin (BCG) vaccine, used prophylactically, does not impede the progression of the disease, which usually manifests as decreased cellular immunity. Early diagnosis, together with polychemotherapy, can control the dissemination of the tuberculosis infection. The current diagnostic methods present certain problems. Such problems include the low sensitivity of sputum smear microscopy, the fact that performing microbiological cultures is quite time-consuming, and the low specificity of the skin test with the purified protein derivative of M. tuberculosis. New diagnostic methods, which use specific antigens such as the early secreted antigenic target 6-kDa and culture filtrate protein 10kDa, are being evaluated. The genes that encode these antigens are located in the DNA region of difference 1 of M. tuberculosis, M. africanum and M. bovis. However, they are absent from the M. bovis (BCG) and from most environmental mycobacteria. Diagnostic methods such as QuantiFERON-TB(R) and T SPOT.TB(R), which are based on the production of interferon-gamma by T lymphocytes, in response to those antigens, are being tested and have been found to outstrip the purified protein derivative skin test in the following characteristics: greater sensitivity; lower cross-reactivity due to BCG vaccination or infection with environmental mycobacteria; and execution time. The introduction of diagnostic methods that are more specific and sensitive, together with gaining a better understanding of the molecular and cellular mechanisms that regulate the parasite-host interaction, can increase the efficiency of strategies devised to combat tuberculosis.

Thalidomide analogs from diamines: Synthesis and evaluation as inhibitors of TNF-alpha production.

Fourteen thalidomide analogs bearing two phthalimido units were prepared in high yields (83-94%) by condensation of different diamines with phthalic or 3-nitrophthalic anhydride. An in vitro investigation of the compounds as inhibitors of the TNF-alpha production was performed. The inhibition was higher for compounds bearing amino and nitro groups and was modulated by increasing the size of the spacers between the phthalimide groups.

Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis

The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB.