Eosinophils of patients with localized and diffuse cutaneous leishmaniasis: Differential response to Leishmania mexicana, with insights into mechanisms of damage inflicted upon the parasites by eosinophils.

Eosinophils are mainly associated with parasitic infections and allergic manifestations. They produce many biologically active substances that contribute to the destruction of pathogens through the degranulation of microbicidal components and inflammatory tissue effects. In leishmaniasis, eosinophils have been found within inflammatory infiltrate with protective immunity against the parasite. We analyzed the responses of eosinophils from patients with localized (LCL) and diffuse (DCL) cutaneous leishmaniasis, as well as from healthy subjects, when exposed to Leishmania mexicana. All DCL patients exhibited blood eosinophilia, along with elevated eosinophil counts in non-ulcerated nodules. In contrast, only LCL patients with prolonged disease progression showed eosinophils in their blood and cutaneous ulcers. Eosinophils from DCL patients secreted significantly higher levels of IL-6, IL-8, and IL-13, compared to eosinophils from LCL patients. Additionally, DCL patients displayed higher serum levels of anti-Leishmania IgG antibodies. We also demonstrated that eosinophils from both LCL and DCL patients responded to L. mexicana promastigotes with a robust oxidative burst, which was equally intense in both patient groups and significantly higher than in healthy subjects. Coincubation of eosinophils (from donors with eosinophilia) with L. mexicana promastigotes in vitro revealed various mechanisms of parasite damage associated with different patterns of granule exocytosis: 1) localized degranulation on the parasite surface, 2) the release of cytoplasmic membrane-bound "degranulation sacs" containing granules, 3) release of eosinophil extracellular traps containing DNA and granules with major basic protein. In conclusion, eosinophils damage L. mexicana parasites through the release of granules via diverse mechanisms. However, despite DCL patients having abundant eosinophils in their blood and tissues, their apparent inability to provide protection may be linked to the release of cytokines and chemokines that promote a Th2 immune response and disease progression in these patients.

Impact of COVID-19 on the registration of tegumentary leishmaniasis cases in Maranhão, Brazil / Impacto da COVID-19 no registro de casos de leishmaniose tegumentar no Maranhão, Brasil / Impacto de la COVID-19 en el registro de casos de leishmaniasis tegumentaria en Maranhão, Brasil

Background and Objectives: Elucidating the potential impact of COVID-19 on surveillance interventions and programs, such as the tegumentary leishmaniasis one, during the first year of the pandemic can help understand its consequences for notification systems, which can inform immediate public policy and health education actions, as well as highlight the need to implement new strategies to strengthen epidemiological surveillance services. The objective of the present study was to analyze the possible impact of the COVID-19 pandemic on the number of cases of tegumentary leishmaniasis in Maranhão, Brazil. Methods: Ecological study of confirmed cases of tegumentary leishmaniasis in the period from January 2015 to December 2020. Data were obtained from the Brazilian Information System for Notifiable Diseases. The P-score metrics were used to evaluate the possible underreporting of tegumentary leishmaniasis. Results: In the period from 2015 to 2020, 7,886 new cases of the disease were registered. For the year 2020, 1,346 cases were expected, but 1,158 were notified, which represented a decrease of 13.94%. The regional health centers of São Luís, São João dos Patos, and Presidente Dutra showed the greatest drops in possible expected new cases. Conclusion: The challenges in diagnosing tegumentary leishmaniasis cases seem to have intensified in the context of COVID-19 in Maranhão, which signals an important alert for health services and managers.(AU)

Justificativa e Objetivos: O potencial impacto da COVID-19 nas intervenções e nos programas de vigilância, como a leishmaniose tegumentar, durante o primeiro ano da pandemia, auxilia no entendimento das consequências da pandemia nos sistemas de notificação, com o intuito de subsidiar ações imediatas de políticas públicas e educação em saúde, além de evidenciar a necessidade de implementação de novas estratégias de fortalecimento dos serviços de vigilância epidemiológica. Este estudo teve como objetivo analisar o possível impacto da pandemia da COVID-19 no número de registros de casos de leishmaniose tegumentar no Maranhão, Brasil. Métodos: Trata-se de um estudo ecológico dos casos confirmados de leishmaniose tegumentar no período de janeiro de 2015 a dezembro de 2020. Os dados foram obtidos do Sistema de Informação de Agravos de Notificação. A métrica P-score foi utilizada para avaliar os possíveis subregistros de leishmaniose tegumentar. Resultados: No período de 2015 a 2020, foram registrados 7.886 casos novos da doença. Para o ano de 2020, eram esperados 1.346 casos, porém 1.158 foram notificados, o que representa uma diminuição de 13,94%. As regionais de saúde de São Luís, São João dos Patos e Presidente Dutra apresentam as maiores quedas de possíveis novos casos esperados. Conclusão: Os desafios no diagnóstico dos casos de leishmaniose tegumentar parecem ter se intensificado no contexto da COVID-19 no Maranhão, o que sinaliza um alerta importante para os serviços de saúde e gestores.(AU)

Justificación y Objetivos: El posible impacto de la COVID-19 en las intervenciones y programas de vigilancia, como el de la leishmaniasis tegumentaria, durante el primer año de la pandemia, ayuda a comprender las consecuencias de la pandemia en los sistemas de notificación, con el fin de subsidiar las acciones inmediatas de política pública y educación para la salud, además de resaltar la necesidad de implementar nuevas estrategias para fortalecer los servicios de vigilancia epidemiológica. Este estudio tuvo como objetivo analizar el posible impacto de la pandemia de COVID-19 en el número de registros de casos de leishmaniasis tegumentaria en Maranhão, Brasil. Métodos: Se trata de un estudio ecológico de los casos confirmados de leishmaniasis tegumentaria desde enero de 2015 hasta diciembre de 2020. Los datos se obtuvieron del Sistema de Información de Enfermedades de Declaración Obligatoria. Se utilizó la métrica P-score para evaluar los posibles subregistros de leishmaniasis tegumentaria. Resultados: Entre 2015 y 2020, se registraron 7.886 nuevos casos de la enfermedad. Para 2020 se esperaban 1.346 casos, pero se notificaron 1.158, lo que representa una disminución del 13,94%. Los centros regionales de salud de São Luís, São João dos Patos y Presidente Dutra presentaron las mayores caídas en los posibles nuevos casos esperados. Conclusión: Los desafíos en el diagnóstico de los casos de leishmaniasis tegumentaria parecen haberse intensificado en el contexto de la COVID-19 en Maranhão, lo que señala una alerta importante para los servicios y gestores de salud.(AU)

Case Report: Diffuse Cutaneous Leishmaniasis Successfully Treated with a Combination of Oral Rifampicin and Fluconazole.

Diffuse cutaneous leishmaniasis (DCL) is a rare parasitic infection caused by the Leishmania species. Diffuse cutaneous leishmaniasis commonly presents as non-ulcerating papules and nodules over the face, neck, and arms. A middle-aged female presented with multiple nodular lesions on her face, neck, and chest region. Histopathology of the lesions showed multiple amastigotes, confirming the diagnosis of DCL. She was successfully treated with a combination course of rifampicin and fluconazole. Here, we report the first case of DCL in north India, a non-endemic area for cutaneous leishmaniasis.

Uma história das leishmanioses no novo mundo: anos 1960 ao século XXI: Amazônia / A history of leishmaniasis in the new world: 1960s to the 21st century: Amazon

Analisam os fatores biológicos, sociais e ambientais responsáveis pela ocorrência da doença na Amazônia mostrando os cientistas e sanitaristas que tiveram papel fundamental nas pesquisas sobre essa e outras endemias

Successful treatment of diffuse cutaneous leishmaniasis caused by Leishmania amazonensis

Abstract Diffuse cutaneous leishmaniasis is a rare universal disease associated with an inadequate host cell immune response, caused by different species: infantum, aethiopica, major, mexicana, and others, which presents the challenge of a poor therapeutic response. In Brazil, it is caused by L. amazonensis. A case confirmed by histopathology with an abundance of vacuolated macrophages full of amastigotes and lymphocyte scarcity, identified by RFLP-ITS1PCR and in vitro decrease and exhaustion of the host cell immune response to L. amazonensis antigen, was treated early (3 months after the onset) with Glucantime (2 months) and allopurinol (29 months) with clinical cure, after a follow-up for 30 months after treatment.

3-Bromopyruvate: A new strategy for inhibition of glycolytic enzymes in Leishmania amazonensis.

The compound 3-bromopyruvate (3-BrPA) is well-known and studies from several researchers have demonstrated its involvement in tumorigenesis. It is an analogue of pyruvic acid that inhibits ATP synthesis by inhibiting enzymes from the glycolytic pathway and oxidative phosphorylation. In this work, we investigated the effect of 3-BrPA on energy metabolism of L. amazonensis. In order to verify the effect of 3-BrPA on L. amazonensis glycolysis, we measured the activity level of three glycolytic enzymes located at different points of the pathway: (i) glucose kinases, step 1, (ii) glyceraldehyde 3-phosphate dehydrogenase (GAPDH), step 6, and (iii) enolase, step 9. 3-BrPA, in a dose-dependent manner, significantly reduced the activity levels of all the enzymes. In addition, 3-BrPA treatment led to a reduction in the levels of phosphofruto-1-kinase (PFK) protein, suggesting that the mode of action of 3-BrPA involves the downregulation of some glycolytic enzymes. Measurement of ATP levels in promastigotes of L. amazonensis showed a significant reduction in ATP generation. The O2 consumption was also significantly inhibited in promastigotes, confirming the energy depletion effect of 3-BrPA. When 3-BrPA was added to the cells at the beginning of growth cycle, it significantly inhibited L. amazonensis proliferation in a dose-dependent manner. Furthermore, the ability to infect macrophages was reduced by approximately 50% when promastigotes were treated with 3-BrPA. Taken together, these studies corroborate with previous reports which suggest 3-BrPA as a potential drug against pathogenic microorganisms that are reliant on glucose catabolism for ATP supply.

Successful treatment of diffuse cutaneous leishmaniasis caused by Leishmania amazonensis.

Diffuse cutaneous leishmaniasis is a rare universal disease associated with an inadequate host cell immune response, caused by different species: infantum, aethiopica, major, mexicana, and others, which presents the challenge of a poor therapeutic response. In Brazil, it is caused by L. amazonensis. A case confirmed by histopathology with an abundance of vacuolated macrophages full of amastigotes and lymphocyte scarcity, identified by RFLP-ITS1PCR and in vitro decrease and exhaustion of the host cell immune response to L. amazonensis antigen, was treated early (3 months after the onset) with Glucantime (2 months) and allopurinol (29 months) with clinical cure, after a follow-up for 30 months after treatment.

Differential regulation of E-NTPdases during Leishmania amazonensis lifecycle and effect of their overexpression on parasite infectivity and virulence.

Infections caused by Leishmania amazonensis are characterized by a persistent parasitemia due to the ability of the parasite to modulate the immune response of macrophages. It has been proposed that ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDases) could be able to suppress the host immune defense by reducing the ATP and ADP levels. The AMP generated from E-NTPDase activity can be subsequently hydrolyzed by ecto-nucleotidases, increasing the levels of adenosine, which can reduce the inflammatory response. In the present work, we provide new information about the role of E-NTPDases on infectivity and virulence of L. amazonensis. Our data demonstrate that not only the E-NTPDase activity is differentially regulated during the parasite development but also the expression of the genes ntpd1 and ntpd2. E-NTPDase activity increases significantly in axenic amastigotes and metacyclic promastigotes, both infective forms in mammalian host. A similar profile was found for mRNA levels of the ntpd1 and ntpd2 genes. Using parasites overexpressing the genes ntpd1 and ntpd2, we could demonstrate that L. amazonensis promastigotes overexpressing ntpd2 gene show a remarkable increase in their ability to interact with macrophages compared to controls. In addition, both ntpd1 and ntpd2-overexpressing parasites were more infective to macrophages than controls. The kinetics of lesion formation by transfected parasites were similar to controls until the second week. However, twenty days post-infection, mice infected with ntpd1 and ntpd2-overexpressing parasites presented significantly reduced lesions compared to controls. Interestingly, parasite load reached similar levels among the different experimental groups. Thus, our data show a non-linear relationship between higher E-NTPDase activity and lesion formation. Previous studies have correlated increased ecto-NTPDase activity with virulence and infectivity of Leishmania parasites. Based in our results, we are suggesting that the induced overexpression of E-NTPDases in L. amazonensis could increase extracellular adenosine levels, interfering with the balance of the immune response to promote the pathogen clearance and maintain the host protection.

Potential antigenic targets used in immunological tests for diagnosis of tegumentary leishmaniasis: A systematic review.

Immunological tests may represent valuable tools for the diagnosis of human tegumentary leishmaniasis (TL) due to their simple execution, less invasive nature and potential use as a point-of-care test. Indeed, several antigenic targets have been used with the aim of improving the restricted scenario for TL-diagnosis. We performed a worldwide systematic review to identify antigenic targets that have been evaluated for the main clinical forms of TL, such as cutaneous (CL) and mucosal (ML) leishmaniasis. Included were original studies evaluating the sensitivity and specificity of immunological tests for human-TL, CL and/or ML diagnosis using purified or recombinant proteins, synthetic peptides or polyclonal or monoclonal antibodies to detect Leishmania-specific antibodies or antigens. The review methodology followed PRISMA guidelines and all selected studies were evaluated in accordance with QUADAS-2. Thirty-eight original studies from four databases fulfilled the selection criteria. A total of 79 antigens were evaluated for the detection of antibodies as a diagnostic for TL, CL and/or ML by ELISA. Furthermore, three antibodies were evaluated for the detection of antigen by immunochromatographic test (ICT) and immunohistochemistry (IHC) for CL-diagnosis. Several antigenic targets showed 100% of sensitivity and specificity, suggesting potential use for TL-diagnosis in its different clinical manifestations. However, a high number of proof-of-concept studies reinforce the need for further analysis aimed at verifying true diagnostic accuracy in clinical practice.

Distribuição espacial da concentração de casos de Leishmaniose Tegumentar em municípios da Região de Campinas e as considerações sobre os limites espaciais das Sub-bacias Hidrográficas para construção do cenário da Vigilância Entomológica nesta Região / Spatial distribution of the concentration of tegumentary Leishmaniasis cases in municipalities in the Region of Campinas and the considerations on the spatial limits of the Hydrographic Sub-basins for the construction of the scenario of the Entomological Surveillance in this Region

Durante vários anos de transmissão de Leishmaniose tegumentar na região de Campinas-SP, alguns municípios apresentaram elevado número de casos em relação a esta região. Os principais municípios foram estudados, considerando os limites espaciais das Sub-bacias Hidrográficas dos Rios Principais e a concentração de casos avaliada pelo estimador de Kernel no contexto das relações ecológicas do modelo mancha-corredormatriz como relevantes para estabelecer o cenário para Vigilância Entomológica da doença nesta região. Os resultados demonstraram que 86% (6/7) dos principais "pontos quentes" de casos e 77,6% (38/49) das Sub-bacias Hidrográficas com ocorrência de casos, os Rios Principais estavam presentes. Os resultados observados neste estudo sugeriram maior permeabilidade da matriz para ocorrência da doença em mosaicos com a presença dos Rios Principais e reforça a necessidade de considerar os limites espaciais das Sub-bacias Hidrográficas dos Rios Principais para elaboração dos cenários da Vigilância Entomológica da doença nesta Região.

Isolation of intact Leishmania amazonensis large parasitophorous vacuoles from infected macrophages by density gradient fractionation.

As the causative agent of hard-to-treat diffuse cutaneous leishmaniasis, Leishmania (L.) amazonensis persists in the host organism sheltered within large Parasitophorous Vacuoles (PVs) formed mainly in macrophages. In the present study, I present a simple and efficient method for L. amazonensis PV isolation. Isolated PVs are intact as demonstrated by the conservation of lysosomal probes loaded into PVs before the procedure. The method is useful for studies aiming at a complete and accurate molecular profile of these structures, to better understand the biogenesis of this pathogen-containing vacuole and its implication in parasite persistence and in leishmaniasis pathogenesis.

Leishmaniasis Cutánea Difusa por Leishmania (Viannia) brasiliensis. A propósito de un caso / Diffuse Cutaneous Leishmaniasis by Leishmania (Viannia) brasiliensis. About a case

La leishmaniasis cutánea o mucocutánea presenta variedad de formas clínicas, siendo la más frecuente la úlcera moldurada. Una forma poco frecuente es la llamada leishmaniasis cutánea difusa caracterizada por presentar pápulas, tubérculos, nódulos, placas e infiltración. Inicialmente localizadas, pero con tendencia a la progresión, pudiendo llegar a ser diseminadas. Es una forma aún no comunicada en Paraguay. Presentamos el caso de una mujer adulta mayor, con placas y nódulos en ambos miembros inferiores, y cuyo frotis y anatomía patológica confirmaron el diagnóstico de leishmaniasis. Clínicamente clasificada como leishmaniasis cutánea difusa, la PCR y HRM demostraron ser producida por Leishmania (Viannia) brasiliensis.

Cutaneous or mucocutaneous leishmaniasis presents a variety of clinical forms, the most common being a molded ulcer. A rare form is the so-called diffuse cutaneous leishmaniasis characterized by presenting papules, tubers, nodules, plaques and infiltration; initially located but with a tendency to progression, and may become widespread. It is a form not reported in Paraguay. We present the case of an older adult woman, with plaques and nodules on both lower limbs, and whose smear and pathological anatomy confirmed the diagnosis of leishmaniasis. Clinically classified as diffuse cutaneous leishmaniasis, PCR and HRM were shown to be produced by Leishmania (Viannia) brasiliensis.

Differential expression of polyamine biosynthetic pathways in skin lesions and in plasma reveals distinct profiles in diffuse cutaneous leishmaniasis.

Tegumentary leishmaniasis (TL) is a parasitic disease that can result in wide spectrum clinical manifestations. It is necessary to understand host and parasite determinants of clinical outcomes to identify novel therapeutic targets. Previous studies have indicated that the polyamine biosynthetic pathway is critical for Leishmania growth and survival. Despite its importance, expression of the such pathway has not been previously investigated in TL patients. We performed an exploratory analysis employing Systems Biology tools to compare circulating polyamines and amino acid concentration as well as polyamine pathway gene expression in cutaneous lesions patients presenting with distinct TL disease presentations. Diffuse cutaneous leishmaniasis (DCL) was associated with higher concentrations of amino acids, polyamines and its substrate transporters than mucosal cutaneous leishmaniasis or localized cutaneous leishmaniasis. In addition, the RNA expression of polyamine-related genes of patients lesions from two separate cohorts demonstrated that differential activation of this pathway is associated with parasite loads and able to discriminate the clinical spectrum of TL. Taken together, our findings highlight a new aspect of DCL immunopathogenesis indicating that the polyamine pathway may be explored as a novel therapeutic target to control disease burden.

First epidemiological description of tegumentar and visceral Leishmaniasis in Patrocínio municipality, Minas Gerais (2000-2017) / Primeira descrição epidemiológica de leishmaniose tegumentar e visceral no município de Patrocínio, Minas Gerais (2000-2017)

Leishmaniasis is a disease that can affect visceral organs (visceral leishmaniasis; VL) or mucous membranes and skin, causing lesions of different forms and levels of severities (tegumentary leishmaniasis; TL). Like several others, leishmaniasis is a neglected disease, as the pharmaceutical industry seems to show little to no interest in developing new drugs targeting the disease. This study aims to trace the epidemiological profile of leishmaniasis in the Municipality of Patrocínio, State of Minas Gerais, over a period of time. Secondary data of reported cases from 2000 to 2017 were analyzed as provided by the Patrocinio Health Department. As no literature was found on the status of such a disease in Patrocinio, it is important to trace the epidemiological profile of leishmaniasis in the area. The findings pointed out that the disease affected predominantly male in the economically active population, mainly from the urban area, and that it had no relationship with professional activity. Twenty-two cases of leishmaniasis (15 of TL and 7 of VL) were reported, all of which were treated and cured. Five cases of TL and 1 case of VL were autochthonous, and confirmed cases of canine infection took place in 2011, 2016 and 2017.KEYWORDS: Alto Paranaíba. Autochthonous. Human leishmaniasis. Triângulo Mineiro. INTRODUCTION Leishmaniasis is a parasitic disease caused by protozoa of the Leishmania genus, which are transmitted from one host to another by phlebotomine sandflies (NAGLE et al., 2014). It may affect both visceral organs and skin surfaces (HANDLER et al., 2015) and lead to four major clinical syndromes: cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), visceral leishmaniasis or kala-azar (VL) and post-kala-azar dermal leishmaniasis (PKDL) (ANVERSA et al., 2018). Leishmaniasis is treated as a public health problem due to its high incidence and the disorders it can cause to the affected individuals. TL is characterized by ulcers on the face and/or extremities and nasal/oral/pharyngeal mucous (HANDLER et al, 2015), which can cause deformities such as disfiguring and permanent scars with partial or total mutilation of the nasopharyngeal mucosa, with further social, economic and psychological implications (ANVERSA et al., 2018, SUNYOTO; BOELAERT; MEHEUS, 2019). The mortality rate for VL, a more severe form, is 10%, making it the second most deadly tropical parasitic infection in the world after malaria (HANDLER et al., 2015). Updated regional information on the disease is important for epidemiological surveillance. However, the actual number of leishmaniasis cases is unknown due to underreporting, lack of epidemiological surveillance system or adequate diagnostic methods. Most data on incidence rates are based on estimates (PACE, 2014). Around 1.5 to 2 million new cases of leishmaniasis are estimated to occur annually worldwide: 500,000 are VL; 1 to 1.5 million cases are related to cutaneous or mucocutaneous leishmaniasis. Both forms commonly occur in Brazil (ANVERSA et al., 2018; WHO, 2020). Silva (2017) reported that the highest incidence rates of VL in the State of Minas Gerais, Brazil, from 2002 to 2013 were concentrated in the mesoregions in the North (Noroeste de Minas, Norte de Minas, and Jequitinhonha), in the East (Vale do Rio Doce) and in the center of the state (Central Mineira and Metropolitana de Belo Horizonte). The other mesoregions (Campo das Verentes, Oeste de Minas, Sul/Sudoeste de Minas, Triângulo Received: 08/04/19 Accepted: 20/12/19

A leishmaniose é uma doença que pode afetar órgãos viscerais (leishmaniose visceral; LV) ou as mucosas e a pele, provocando lesões de diferentes formas e gravidades (leishmaniose tegumentar; LT). Como várias outras moléstias, a leishmaniose é uma doença negligenciada, já que a indústria farmacêutica parece mostrar pouco ou nenhum interesse em desenvolver novos medicamentos direcionados à enfermidade. O estudo teve como objetivo traçar o perfil epidemiológico da leishmaniose no município de Patrocínio, estado de Minas Gerais, ao longo de um período de tempo. Dados secundários de casos registrados no período de 2000 a 2017 foram analisados, conforme fornecido pelo Departamento de Saúde de Patrocínio. Como não foi encontrada literatura sobre a situação dessa doença em Patrocínio, é importante traçar o perfil epidemiológico da leishmaniose na região. Os achados apontaram que a doença afetou predominantemente o sexo masculino da população economicamente ativa, principalmente da área urbana, e que não tinha relação com a atividade profissional. Foram notificados 22 casos de leishmaniose (15 de LT e 7 de LV), todos tratados e curados. Cinco casos de LT e 1 de LV foram considerados autóctones, e houve casos confirmados de infecção canina nos anos de 2011, 2016 e 2017.

Case Report: Coinfection by Leishmania amazonensis and HIV in a Brazilian Diffuse Cutaneous Leishmaniasis Patient.

Diffuse cutaneous leishmaniasis (DCL) is a rare type of leishmaniasis characterized by diffuse skin lesions. In Brazil, Leishmania (L.) amazonensis is the main etiological agent of this clinical form. The state of Maranhão has the highest prevalence of this disease in the country, as well as a high rate of HIV infection. Here, we report the first case of DCL/HIV of Brazil. A 46-year-old man from the Amazonian area of Maranhão state presented atypical lesion in the left upper limb and dissemination of diffuse erythematous nodules over his entire body. Histopathological examination confirmed the presence of intracellular amastigotes of Leishmania, and a polymerase chain reaction and molecular identification by restriction fragment profile identified L. (L.) amazonensis as the causative agent of the disease. The patient was also diagnosed with HIV virus after the leishmaniasis diagnosis. The initial treatments for leishmaniasis were liposomal amphotericin B (AmB-L) (4 mg/kg) for 10 days and prophylactic use of Glucantime® (10 mg/Sb+5/kg) for 2 months. After unsuccessful initial treatments, he was treated with a combination of AmB-L (4 mg/kg) alternated with pentamidine (4 mg/kg) for 10 days but failed in the first therapeutic cycle. Subsequently, he had a good response to treatment with pentamidine (4 mg/kg).

Differential Regulation of l-Arginine Metabolism through Arginase 1 during Infection with Leishmania mexicana Isolates Obtained from Patients with Localized and Diffuse Cutaneous Leishmaniasis.

l-Arginine metabolism through arginase 1 (Arg-1) and inducible nitric oxide synthase (NOS2) constitutes a fundamental axis for the resolution or progression of leishmaniasis. Infection with Leishmania mexicana can cause two distinct clinical manifestations: localized cutaneous leishmaniasis (LCL) and diffuse cutaneous leishmaniasis (DCL). In this work, we analyzed in an in vivo model the capacity of two L. mexicana isolates, one obtained from a patient with LCL and the other from a patient with DCL, to regulate the metabolism of l-arginine through Arg-1 and NOS2. Susceptible BALB/c mice were infected with L. mexicana isolates from both clinical manifestations, and the evolution of the infection as well as protein presence and activity of Arg-1 and NOS2 were evaluated. The lesions of mice infected with the DCL isolate were bigger, had higher parasite loads, and showed greater protein presence and enzymatic activity of Arg-1 than the lesions of mice infected with the LCL isolate. In contrast, NOS2 protein synthesis was poorly or not induced in the lesions of mice infected with the LCL or DCL isolate. The immunochemistry analysis of the lesions allowed the identification of highly parasitized macrophages positive for Arg-1, while no staining for NOS2 was found. In addition, we observed in lesions of patients with DCL macrophages with higher parasite loads and stronger Arg-1 staining than those in lesions of patients with LCL. Our results suggest that L. mexicana isolates obtained from patients with LCL or DCL exhibit different virulence or pathogenicity degrees and differentially regulate l-arginine metabolism through Arg-1.

GK1 Improves the Immune Response Induced by Dendritic Cells of BALB/c Mice Infected with Leishmania mexicana Promastigotes.

PURPOSE: Dendritic cells (DCs) are the most potent antigen-presenting cells (APCs), and their capacity to activate the immune response has been widely used in immunotherapies against different diseases, predominantly cancer. However, they have not been so widely used in immunotherapies against infectious diseases. Leishmania mexicana is the causative agent of cutaneous leishmaniasis in Mexico, which can result in localized cutaneous leishmaniasis (LCL) and diffuse cutaneous leishmaniasis (DCL). DCL is characterized by the incapability of the immune response to control the parasite, which thus disseminates to all teguments. Treatments against DCL have shown low efficacy, which is a reason why alternative therapies such as immunotherapies are promising. One adjuvant that has proven its effectiveness in immunotherapies against some cancers and infections is GK1, a component of the SPVac vaccine against porcine cysticercosis. GK1 has the capacity to elicit proinflammatory cytokines and chemokines from DCs and macrophages. METHODS: We pulsed bone marrow-derived dendritic cells (BMDCs) with GK1 and a lysate obtained from L. mexicana promastigotes and tested the efficacy of this combination against the infection of susceptible mice with L. mexicana. RESULTS: We found that BMDCs stimulated with GK1 and a lysate of L. mexicana promastigotes secreted IFN-γ and IL-12, and when they were adoptively transferred to BALB/c mice which were then infected with L. mexicana promastigotes, there was a reduction in the size of the lesion and in the parasite load. CONCLUSIONS: The adjuvant properties of GK1 along with parasite antigens may have a protective effect against the infection of BALB/c mice with L. mexicana.

Uma história das leishmanioses no Novo Mundo: fins do século XIX aos anos 1960

Apanhado dos estudos sobre as leishmanioses no Brasil englobando a descoberta dos seus agentes etiológicos, diversas espécies associadas às diferentes formas clínicas da doença, seus hospedeiros reservatórios e os flebotomíneos vetores, bem como aspectos da epidemiologia e ações de controle implementadas em contextos sociopolíticos e momentos diversos