In situ cellular immune response in non-ulcerated skin lesions due to Leishmania (L) infantum chagasi infection

Skin lesions of patients affected by non-ulcerated cutaneous leishmaniasis (NUCL) caused by L. (L.) infantum chagasi are characterized by lymphohistiocytic inflammatory infiltrate associated with epithelioid granuloma and scarce parasitism. However, the in situ cellular immune response of these patients is unclear. Therefore, the aim of the present study was to characterize the cellular immune response in the skin lesions of patients affected by NUCL. Methods Twenty biopsies were processed by immunohistochemistry using primary antibodies to T lymphocytes (CD4, CD8), NK cells, B lymphocytes, macrophages, nitric oxide synthase and interferon-gamma. Results Immunohistochemistry revealed higher expression of all cellular types and molecules (IFN-γ, iNOS) in the dermis of diseased skin compared to the skin of healthy individuals (p < 0.05). Morphometric analysis performed in the skin lesions sections showed the predominance of CD8+ T lymphocytes in the mononuclear infiltrate, followed by macrophages, mostly iNOS+, a response that could be mediated by IFN-γ. Conclusion Our study improves knowledge of the cellular immune response in non-ulcerated or atypical cutaneous leishmaniasis caused by L. (L.) infantum chagasi in Central America and pointed to the pivotal participation of CD8+ T lymphocytes in the host defense mechanisms against the parasite in patients with NUCL.(AU)

Lipophosphoglycans from dermotropic Leishmania infantum are more pro-inflammatory than those from viscerotropic strains

Although Leishmania infantum is well-known as the aethiological agent of visceral leishmaniasis (VL), in some Central American countries it may cause atypical non-ulcerated cutaneous leishmaniasis (NUCL). However, the mechanisms favoring its establishment in the skin are still unknown. Lipophosphoglycan (LPG) is the major Leishmania multivirulence factor involved in parasite-host interaction. In the case of viscerotropic L. infantum, it causes an immunosuppression during the interaction with macrophages. Here, we investigated the biochemical and functional roles of LPGs from four dermotropic L. infantum strains from Honduras during in vitro interaction with murine macrophages. LPGs were extracted, purified and their repeat units analysed. They did not have side chains consisting of Gal(β1,4)Man(α1)-PO4 common to all LPGs. Peritoneal macrophages from BALB/c and C57BL/6 were exposed to LPG for nitric oxide (NO) and cytokine (TNF-α and, IL-6) production. LPGs from dermotropic strains from Honduras triggered higher NO and cytokine levels compared to those from viscerotropic strains. In conclusion, LPGs from dermotropic strains are devoid of side-chains and exhibit high pro-inflammatory activity.

Situación epidemiológica de la toxoplasmosis en Honduras / Epidemiology of toxoplasmosis in Honduras

La Toxoplasmosis es una infección producida por el protozoario coccidio Toxoplasma gondii,transmitida al hombre a través de ooquistes en las deposiciones de los gatos, quistes en carne crudao semicocida, trasplantes de órganos, transfusiones de sangre y transplacentaria. Es una de lasinfecciones más diseminadas en todo el mundo y creemos que Honduras no escapa a esa realidad, al reunir las condiciones epidemiológicas, climáticas y de saneamiento ambiental apropiadas al ciclo biológico del parásito. Se estudiaron 4.588 muestras de sangre tomadas en papel filtro, en los18 departamentos de Honduras. Se emplearon las técnicas ELISA e inmunofluorescencia indirecta(RIFI) IgG. Se encontró una seroprevalencia general de 48por cento por ELISA y 43por cento por RIFI. Entreambas hubo discordancia de 7,4por cento, a favor de la RIFI, que corresponden en el 90por cento de los casos a títulos bajos y probablemente a razones técnicas al procesar el papel filtro ya que no se puedenrealizar diluciones menores en el caso de la RIFI. No se observó diferencia por sexo. Todas las edades se ven afectadas, desde 32por cento en los menores de 4 años a 58por cento en los mayores de 65 años. Lasmayores prevalencias por Departamentos, se observaron en Colón (74por cento) e Islas de la Bahía (71por cento). Las de menor prevalencia en Santa Bárbara (7por cento) y Olancho (15por cento). Las de mayor prevalencia corresponden a poblaciones cerradas, mientras que las otras son poblaciones dispersas...

Treatment and seroconversion in a cohort of children suffering from recent chronic Chagas infection in Yoro, Honduras

Between 1999-2002, Médécins Sans Frontières-Spain implemented a project seeking to determine the efficacy and safety of benznidazole in the treatment of recent chronic Chagas disease in a cohort of seropositive children in the Yoro Department, Honduras. A total of 24,471 children were screened for Trypanosoma cruzi IgG antibodies through conventional enzyme-linked immunosorbent assays (ELISA) on filter paper. Recombinant ELISA (0.93 percent seroprevalence) showed 256 initially reactive cases, including 232 confirmed positive cases. Of these, 231 individuals were treated with benznidazole (7.5 mg/kg/day) for 60 days and were followed with a strict weekly medical control and follow-up protocol. At the end of the project, 229 patients were examined by the Honduras Secretariat of Health for post-treatment serological assessments; 88.2 percent seroconverted after 18 months and 93.9 percent seroconverted after three years. No differences were found in the seroconversion rates according to age or sex. Most of the side effects of the treatment were minor. These results support the argument that in areas where T. cruzi I is predominant and in areas affected by T. cruzi II, when vector transmission has been interrupted, Chagas disease diagnosis and treatment are feasible, necessary and ethically indisputable.

Caracterización Clínico epidemiológica de pacientes con leishmaniasis atendidos en el Hospital Escuela / Clinical and Epidemiologic Characterization of patients with Leishmaniasis at Hospital Escuela

Objetivo: Determinar las características clínicas y epidemiológicas, incluyendo la respuesta terapéutica, de los pacientes con leishmaniasis atendidos en el Hospital Escuela en el período 2000 – 2008. Materiales y métodos: Estudio descriptivo, transversal y longitudinal. Incluyó evaluaciones retrospectiva de pacientes hospitalizados (2000 – 2006) y prospectiva de pacientes ambulatorios en la Consulta Externa de Dermatología (2007 – 2008). Resultados: Se caracterizaron 57 pacientes hospitalizados y 69 pacientes ambulatorios. Del total de casos, 57 (45.2%) correspondieron a leishmaniasis cutánea no ulcerada (LCNU), 16 (12.7%) a leishmaniasis cutánea ulcerada (LCU), 10 (7.9%) a leishmaniasis mucocutánea (LMC) y 43 (34.1%) a leishmaniasis visceral (LV). En 105 casos (83.3%), el diagnóstico se sospechó clínicamente y se confirmó por laboratorio. En general, las características sociodemográficas y clínicas de los pacientes fueron similares a las ya descritas en Honduras. La evaluación de la respuesta terapéutica en los casos ambulatorios demostró curación clínica en 83.3% de los casos LCU y 94.4% de los casos LCNU. Se evidenció administración subóptima del tratamiento en los casos hospitalizados de LMC (30.0%) y LV (65.2%). Conclusiones: Se debe estandarizar y fortalecer el abordaje diagnóstico y terapéutico de los casos de leishmaniasis atendidos en el Hospital Escuela. Se recomienda realizar el diagnóstico parasitológico, incluyendo cultivo, para poder caracterizar las especies parasitarias circulantes en...