Seroreactivity to new Mycobacterium leprae protein antigens in different leprosy-endemic regions in Brazil

New Mycobacterium leprae protein antigens can contribute to improved serologic tests for leprosy diagnosis/classification and multidrug therapy (MDT) monitoring. This study describes seroreactivity to M. leprae proteins among participants from three highly endemic leprosy areas in Brazil: central-western Goiânia/Goiás (GO) (n = 225), Rondonópolis/Mato Grosso (MT) (n = 764) and northern Prata Village/Pará (PA) (n = 93). ELISA was performed to detect IgG to proteins (92f, 46f, leprosy IDRI diagnostic-1, ML0405, ML1213) and IgM to phenolic glycolipid-I (PGL-I). Multibacillary (MB) leprosy had positive rates for PGL-I that were similar to those for proteins; however, some anti-PGL-I-negative subjects were positive for proteins, suggesting that adding protein antigen to PGL-I can enhance the sensitivity of MB leprosy detection. In MT, different degrees of seroreactivity were observed and ranked for MB, former patients after MDT, paucibacillary (PB) leprosy, household contact (HHC) and endemic control (EC) groups. The seroreactivity of PB patients was low in GO and MT. HHCs from different endemic sites had similar IgG antibody responses to proteins. 46f and 92f were not recognised by most tuberculosis patients, ECs or HHCs within GO, an area with high BCG vaccination coverage. Low positivity in EC and HHC was observed in PA and MT. Our results provide evidence for the development of an improved serologic test that could be widely applicable for MB leprosy testing in Brazil.

Leprosy patients: neurotrophic factors and axonal markers in skin lesions / Pacientes com hanseníase: fatores neurotróficos e marcadores axonais em lesões de pele

Neurotrophins are growth factors with crucial roles in neural pathophysiology. These mediators functionally modulate nociceptive fibers, and changes in neurotrophins expression have been correlated with early loss of nociception in leprosy. This study investigated the expression of NGF, BDNF, and NT3 in dermal nerves of leprosy patients. Characterization of Remak bundles was achieved by p75NTR, and axonal markers NF-L and PGP 9.5 immunostaining. Clinical parameters of neural impairment have been evaluated by Semmes-Wenstein monofilaments. Our findings demonstrated decrease of NGF in borderline leprosy, when compared to control specimens. Similar results were observed in PGP 9.5 expression (borderline: p<0.001 and lepromatous: p<0.05) and NF-L (lepromatous: p<0.05), suggesting advanced Remak bundles degeneration in multibacillary leprosy. It has also been observed positive correlation between p75NTR and PGP 9.5, indicating association between Schwann cells and axons in Remak bundles. Present data indicate that neurotrophins imbalance may participate in the establishment of peripheral nerve damage.

Neurotrofinas são fatores de crescimento com papel fundamental na fisiopatologia neural. Esses mediadores modulam funcionalmente fibras nociceptivas. Mudanças em sua expressão têm sido relacionadas à perda precoce da nocicepção na hanseníase. Este estudo investigou a expressão de NGF, BDNF e NT3 em nervos dérmicos de pacientes hansenianos. A caracterização de fibras nervosas não mielinizadas foi feita por p75NTR e marcadores axonais NF-L e PGP 9.5. Os parâmetros clínicos de dano neural foram avaliados por monofilamentos Semmes-Wenstein. Nossos achados demonstram diminuição de NGF nos pacientes dimorfos em comparação aos controles. Resultados similares foram observados para PGP 9.5 (dimorfos: p<0,001; virchowianos: p<0,05) e NF-L (virchowianos: p<0.05), sugerindo degeneração avançada das terminações nervosas na hanseníase multibacilar. Foi observada correlação positiva entre p75NTR e PGP 9.5, indicando associação entre células de Schwann e axônios em fibras nervosas não mielinizadas. Os resultados indicam que o desequilíbrio na expressão das neurotrofinas pode participar do dano neural periférico.

Seroreactivity to new Mycobacterium leprae protein antigens in different leprosy-endemic regions in Brazil

New Mycobacterium leprae protein antigens can contribute to improved serologic tests for leprosy diagnosis/classification and multidrug therapy (MDT) monitoring. This study describes seroreactivity to M. leprae proteins among participants from three highly endemic leprosy areas in Brazil: central-western Goiânia/Goiás (GO) (n = 225), Rondonópolis/Mato Grosso (MT) (n = 764) and northern Prata Village/Pará (PA) (n = 93). ELISA was performed to detect IgG to proteins (92f, 46f, leprosy IDRI diagnostic-1, ML0405, ML1213) and IgM to phenolic glycolipid-I (PGL-I). Multibacillary (MB) leprosy had positive rates for PGL-I that were similar to those for proteins; however, some anti-PGL-I-negative subjects were positive for proteins, suggesting that adding protein antigen to PGL-I can enhance the sensitivity of MB leprosy detection. In MT, different degrees of seroreactivity were observed and ranked for MB, former patients after MDT, paucibacillary (PB) leprosy, household contact (HHC) and endemic control (EC) groups. The seroreactivity of PB patients was low in GO and MT. HHCs from different endemic sites had similar IgG antibody responses to proteins. 46f and 92f were not recognised by most tuberculosis patients, ECs or HHCs within GO, an area with high BCG vaccination coverage. Low positivity in EC and HHC was observed in PA and MT. Our results provide evidence for the development of an improved serologic test that could be widely applicable for MB leprosy testing in Brazil

The effect of phosphoethanolamine intake on mortality and macrophage activity in mice with solid ehrlich tumors

The aim of the present study was to examine the effect of a diet rich in synthetic PEtn on the metabolism macrophages of tumor-bearing mice. The results demonstrated that PEtn increased the animals' survival time. In addition, the treated animals released smaller amounts of hydrogen peroxide (H2O2) and nitric oxide (NO) than the non-treated animals, particularly after day 14. From the results it could be concluded that H2O2 and NO were important in the modulation of neoplastic growth, and pointed to a promising role of PEtn in the control of human neoplasms.

Mycobacterium leprae downregulates the expression of PHEX in Schwann cells and osteoblasts

Neuropathy and bone deformities, lifelong sequelae of leprosy that persist after treatment, result in significant impairment to patients and compromise their social rehabilitation. Phosphate-regulating gene with homologies to endopeptidase on the X chromosome (PHEX) is a Zn-metalloendopeptidase, which is abundantly expressed in osteoblasts and many other cell types, such as Schwann cells, and has been implicated in phosphate metabolism and X-linked rickets. Here, we demonstrate that Mycobacterium leprae stimulation downregulates PHEX transcription and protein expression in a human schwannoma cell line (ST88-14) and human osteoblast lineage. Modulation of PHEX expression was observed to a lesser extent in cells stimulated with other species of mycobacteria, but was not observed in cultures treated with latex beads or with the facultative intracellular bacterium Salmonella typhimurium. Direct downregulation of PHEX by M. leprae could be involved in the bone resorption observed in leprosy patients. This is the first report to describe PHEX modulation by an infectious agent.

Considerações sobre o envolvimento da cavidade bucal na hanseníase / Considerations on oral cavity involvement in leprosy

As lesões causadas pela proliferação do Mycobacterium leprae (M. leprae) foram significantemente reduzidas nos últimos anos com a detecção precoce de casos novos.Consequentemente, as lesões maxilofaciais e da mucosa bucal passaram ser cada vez menos relatadas. A despeito de ser menos evidente, a infecção da cavidade bucal pelo M. leprae pode revelar detalhes importantes a respeito da transmissibilidade e imunopatogenia da hanseníase.A associação entre a infecção da mucosa bucal e a perda óssea alveolar, bem como a participação da resposta imune local na proteção contra a doença, ainda são tópicos de pesquisa não explorados totalmente. Infelizmente, o tratamento da hanseníase não possibilitou a prevenção total de suas seqüelas, nem impediu transmissão dessa doença. As razões acima justificam rever algumas perguntas não respondidas do passado.

Lesions secondary to Mycobacterium leprae (M. leprae) proliferation have been significantly abbreviated in recent years due to early detection of new cases of leprosy. Consequently, oral and maxillofacial lesions have been each time less reported. In spite of been less evident, the infection of oral cavity by M. leprae may reveal important details regarding the transmission and immunopathology of leprosy. The association between oral mucosal infection and alveolar bone loss, as well as the role of local immune response in protection against this pathogen, are still not fully explored. Unfortunately, the treatment of leprosy did not allow the full prevention of sequels neither hindered the transmission of this disease. The reasons above justify reviewing some unanswered questions of the past.

Distúrbios angioproliferativos bucais e cutâneos: correlações histopatológicas e expressão de mediadores angiogênicos / Oral and cutaneous angioproliferative diseases: histopathologic correlations and expression of angiogenic mediators

A mucosa bucal e a pele podem apresentar distúrbios vasculares proliferativos com comportamento biológico variado. Para classificar tais lesões foram adotados critérios etiopatogênicos e a avaliação desses critérios em grupos específicos de lesões angioproliferativas pode contribuir para o diagnóstico e tratamento das mesmas. O objetivo desse estudo retrospectivo foi caracterizar as principais lesões angioproliferativas da mucosa bucal, comparando-as com os mesmos tipos de lesões cutâneas, em relação aos achados histopatológicos e à expressão endotelial do fator de crescimento fibroblástico básico (FGFb) e do receptor p75 para neurotrofinas (p75NTR). Foram utilizados espécimes arquivados em blocos parafinados, divididos conforme o diagnóstico microscópico em seis grupos: (I) malformações venosas; (II) malformações linfáticas; (III) granulomas piogênicos; (IV) hemangiomas capilares; (V) hemangiomas arteriovenosos; (VI) sarcomas de Kaposi. Cada grupo foi subdividido em dois grupos quanto a sua localização bucal e cutânea. Os padrões microscópicos das lesões angioproliferativas bucais e cutâneas de nossa amostra são similares e podem ser classificadas sob os mesmos parâmetros. No entanto, alguns grupos apresentaram diferenças quanto ao estádio de maturação das lesões, em relação à incidência e principalmente em relação à expressão dos mediadores estudados. A diferença na expressão de FGFb e p75NTR, observada entre os grupos bucais e cutâneos dos mesmos tipos de lesões, permitiunos concluir que a evolução da angiogênese na mucosa bucal e na pele não é necessariamente mediado pelos mesmos fatores. Tais diferenças abrem perspectivas para pesquisas futuras e abordagens terapêuticas baseadas em tecnologias moleculares.

The oral mucosa and the skin may present proliferative vascular diseases with varied biological behavior. To classify such lesions, pathogenic criteria were adopted in specific groups of vascular lesions. The objective of this retrospective study was to characterize the main oral vascular lesions, comparing them with the same types of cutaneous lesions. The histopathologic findings were compared, as well as the endothelial expression of basic fibroblastic growth factor (FGFb) and p75 neurotrophin receptor (p75NTR). Paraffin embedded specimens were purchased and divided, according to microscopic diagnostic, into six groups: (I) venous malformations; (II) lymphatic malformations; (III) pyogenic granulomas; (IV) capillary hemangiomas; (V) arteriovenous hemangiomas; (VI) Kaposi sarcomas. Each group was divided in two subgroups of oral and cutaneous location. The microscopic data demonstrated that oral and cutaneous vascular lesions, in our sample, are similar and they can be classified under the same parameters. However, some groups presented differences related to maturation stage, incidence, and expression FGFb and p75NTR. These differences allowed us to conclude that the evolution of angiogenic process inside oral mucosa and in the skin, not necessarily is mediated by the same biological factors. Such differences open perspectives for future researches and therapeutic approaches, based on molecular technologies.