The leprosy reaction is associated with salivary anti-Porphyromonas gingivalis IgA antibodies.

The aim of the study was to evaluate the association between salivary anti-Porphyromonas gingivalis IgA antibodies and the leprosy reaction. The levels of salivary anti - P. gingivalis IgA antibodies, together with salivary flow and pH were measured in individuals diagnosed with leprosy and associated with the development of the leprosy reaction. Saliva was collected from 202 individuals diagnosed with leprosy at a reference leprosy treatment center, 106 cases with the leprosy reaction and 96 controls without the leprosy reaction. Anti - P. gingivalis IgA was evaluated by indirect immunoenzyme assay. Non-conditional logistic regression analysis was employed to estimate the association between antibody levels and the leprosy reaction. There was a positive statistically significant association between the levels of anti - P. gingivalis IgA and the presence of the leprosy reaction, controlling for confounders: age, sex, level of education and alcoholic beverage consumption: ORajusted: 2.55; IC 95%: 1.34-4.87. Individuals with leprosy who had high levels of salivary anti - P. gingivalis IgA had approximately twice as many chances of developing the leprosy reaction. The findings suggest a possible relationship between salivary anti - P. gingivalis IgA antibodies and the leprosy reaction.

Cross-Reactivity Using Chimeric Trypanosoma cruzi Antigens: Diagnostic Performance in Settings Where Chagas Disease and American Cutaneous or Visceral Leishmaniasis Are Coendemic.

Chimeric T. cruzi antigens have been proposed as a diagnostic tool for chronic Chagas disease (CD) in both settings where Chagas disease is endemic and those where it is not endemic. Antibody response varies in accordance to each T. cruzi strain, presenting challenges to the use of antigens lacking demonstrated cross-reactivity with Leishmania spp. Our group expressed four chimeric proteins (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) and previously assessed their diagnostic performance to determine cross-reactivity with Leishmania spp. Here, we validated our findings using serum samples from different Brazilian geographic areas reporting endemic Chagas disease, endemic visceral or American cutaneous leishmaniasis (ACL), or both. Overall, 829 serum samples were evaluated using commercial and IBMP enzyme-linked immunosorbent assays. Due to the absence of a reference assay to diagnosis CD, latent class analysis (LCA) was performed through the use of a statistical model. The incidence of cross-reactivity for ACL-positive samples varied from 0.35% (IBMP-8.3) to 0.70% (IBMP-8.1 and IBMP-8.2). Regarding visceral leishmaniasis (VL)-positive samples, the IBMP-8.2 and IBMP-8.3 antigens cross-reacted with six (3.49%) and with only one sample (0.58%), respectively. No cross-reactivity with either ACL or VL was observed for the IBMP-8.4 antigen. Similarly, no cross-reactions were found when VL-positive samples were assayed with IBMP-8.1. The agreement among the results obtained using IBMP antigens ranged from 97.3% for IBMP-8.2 and 99% for IBMP-8.1 and IBMP-8.3 to 100% for IBMP-8.4, demonstrating almost perfect agreement with LCA. Accordingly, in light of the negligible cross-reactivity with both ACL and VL, we suggest the use of IBMP antigens in regions where T. cruzi and Leishmania spp. are coendemic.

Monocyte subpopulations study in patients with plaque psoriasis.

Psoriasis is a chronic and systemic, immune-mediated, inflammatory disease, mainly manifested by skin and / or joints lesions, presenting with a wide degree of clinical severity, but generally with great impact on patients' quality of life. Despite advances in the understanding of its pathogenesis, especially regarding the participation of T-lymphocytes and the key role of TNF, the triggering factor of the disease at the molecular level remains unknown, as well as the function of other cell populations. By presenting antigens to T-lymphocytes, monocytes assume an important role in both innate and adaptive immune response. In the last two decades, by using flow cytometry with antibodies against CD14 (receptor for lipopolysaccharide) and CD16 (low affinity receptor for IgG), human blood monocytes were classified into three subpopulations: classical (CD14++CD16-), intermediate (CD14++CD16+), and non-classical (CD14+CD16++). Under normal conditions the population of classical monocytes corresponds to about 85%, while intermediate to 5.4%, and nonclassical to 9.2%. However, intermediate and nonclassical subsets are increased in various inflammatory situations, such as moderate to severe asthma, colorectal cancer, and rheumatoid arthritis. Despite psoriasis being considered a disease of inflammatory nature, scarce studies evaluating the frequency of subpopulations of monocytes in psoriatic patients are found on current medical literature, and they are restricted to peripheral blood analysis. This study aims to identify the frequency of monocyte subpopulations in blood levels as well as lesional skin of plaque psoriasis patients, and to evaluate their association to cytokines, and clinical disease severity.

Imunoregulação e resposta imune sistêmica e tecidual na Leishmaniose mucosa / Imunoregulation and sistemic and tissue immune response of mucosal leishmaniasis

Na infecção humana por Leishmania há uma complexa interação parasito-hospedeiro, levando a uma variedade de formas clínicas. Em áreas de transmissão de L. braziliensis, cerca de 3 por cento dos pacientes com leishmaniose cutânea desenvolvem a forma mucosa da doença concomitantemente ou após cicatrização da ulcera. Células mononucleares do sangue periférico (CMSP) de pacientes com LM secretam maiores níveis de IFN-y do que as de pacientes com LC quando estimuladas com antígeno solúvel de leishmania (SLA). A presente tese é composta de 4 trabalhos e teve objetivo principal caracterizar a resposta imune de pacientes com LM e LC em células de sangue periférico e no tecido, e determinar fatores que possam estar envolvidos na resposta inflamatória exacerbada de pacientes com LM. Análise por citometria de fluxo demonstrou que a célula CD4+ é a principal célula produtora de IFN-y em pacientes com LC ou LM. (...) O presente estudo mostrou que pacientes com LM apresentam uma maior freqüencia de células CD4+ ativadas maior do que pacientes com LC. Essas células não são propriamente moduladas por antagonistas de citocinas envolvidas em diferenciação e proliferação linfocitária ou por antígenos que induzem IL-10, contribuindo também para este aspecto uma menor expressão de IL-10.

Characterization of the immune response to Leishmania infantum recombinant antigens.

Leishmaniases have a high prevalence in tropical countries. In order to improve existing diagnostic systems based on total Leishmania proteins, and to identify antigen candidates for vaccine development, an intensive search for the identification of antigens was performed using molecular biology techniques. In this study, the immune response to three L. infantum recombinant antigens was evaluated. Upon stimulation with KMP11, mononuclear cells from leishmaniasis patients produced high levels of IL-10, while a predominant IFN-gamma production could be observed in cultures stimulated with H2A and soluble Leishmania antigen. All the recombinant antigens induced very little IL-5. KMP11 decreased IFN-gamma production by 48% in cultures of peripheral blood mononuclear cells from cutaneous leishmaniasis patients who had been stimulated with soluble Leishmania antigen. Furthermore, antibodies to KMP11 were detected in the sera from all patients with visceral leishmaniasis and in the majority of the sera from patients with cutaneous leishmaniasis or individuals with asymptomatic L. chagasi infection. Thus, KMP11 is recognized by cells and sera of patients with different clinical forms of leishmaniasis, and KMP11, through IL-10 production, proved to be a potent antigen in modulating type 1 immune response.