Histopathological and immunohistochemical aspects of American cutaneous leishmaniasis before and after different treatments.

Background: The histopathology and immune responses of the healing process of leishmaniasis are still poorly studied.

Objectives: This study aimed to examine the histopathological and immunological aspects of lesions of patients with cutaneous leishmaniasis before and after different therapeutic methods.

Methods: We studied 23 individuals grouped according to the treatments: Glucantime, Glucantime + Leishvacin and Glucantime + Leishvacin associated with Bacillus Calmette-Guerin.

Cluster randomised trial to evaluate the effectiveness of a vaccine against cutaneous leishmaniasis in the Caratinga microregion, south-east Brazil.

Background: The eco-epidemiological complexity of American cutaneous leishmaniasis (ACL) has made it difficult to devise an efficient strategy for management of the disease, and development of an effective vaccine remains the most promising approach. The objective of the study was to determine the reduction in incidence of ACL following intramuscular administration of two doses of a killed Leishmania (Leishmania) amazonensis vaccine.

Methods: A cluster randomised trial was conducted from 2002 to 2011 in 108 localities in an endemic area of southeast Brazil.

Comparison among three polymerase chain reaction assays on detection of DNA from Leishmania in biological samples from patients with American cutaneous leishmaniasis.

Introduction: The study analyzed positivity of polymerase chain reaction (PCR) on detection of DNA from Leishmania in patients' samples.

Methods: Extracted DNA was submitted to L150/L152, 13Y/13Z, and seminested PCR (snPCR).

Results: Results were evidenced by bands of approximately 120, 720, and 670 bp for L150/L152, 13Y/13Z, and snPCR, respectively.

Immunological changes in canine peripheral blood leukocytes triggered by immunization with first or second generation vaccines against canine visceral leishmaniasis.

In this study, we summarized the major phenotypic/functional aspects of circulating leukocytes following canine immunization with Leishvaccine and Leishmune®. Our findings showed that Leishvaccine triggered early changes in the innate immunity (neutrophils and eosinophils) with late alterations on monocytes. Conversely, Leishmune(®) induced early phenotypic changes in both, neutrophils and monocytes.

Comparative evaluation of phenol and thimerosal as preservatives for a candidate vaccine against American cutaneous leishmaniasis.

For decades thimerosal has been used as a preservative in the candidate vaccine for cutaneous leishmaniasis, which was developed by Mayrink et al. The use of thimerosal in humans has been banned due to its mercury content. This study addresses the standardization of phenol as a new candidate vaccine preservative.

Increase of NK cells and proinflammatory monocytes are associated with the clinical improvement of diffuse cutaneous leishmaniasis after immunochemotherapy with BCG/Leishmania antigens.

Diffuse cutaneous leishmaniasis (DCL) is characterized by disseminated lesions and the absence of a specific cellular immune response. Here, the immunochemotherapy outcome of a patient with DCL from Amazonian Brazil infected with Leishmania (Leishmania) amazonensis is presented. After several unsuccessful chemotherapy treatment regimens and many relapses, a monthly immunotherapy scheme of L.

Alterations in phenotypic profiles of peripheral blood cells from patients with human American cutaneous leishmaniasis following treatment with an antimonial drug and a vaccine.

The susceptibility or resistance of a vertebrate host to leishmaniasis is related to the species of Leishmania and to the host immune response of the host. In the present study, the phenotypic profiles of the peripheral blood cells of patients with American cutaneous leishmaniasis (ACL) were evaluated before and after receiving three different therapeutic regimens. The study population comprised 24 patients, living in an ACL-endemic area of Caratinga (MG, Brazil), who had been diagnosed as ACL-positive on the basis of characteristic lesions, the Montenegro skin reactivity test, and/or positive parasitology.

T-cell-derived cytokines, nitric oxide production by peripheral blood monocytes and seric anti-Leishmania (Leishmania) chagasi IgG subclass patterns following immunization against canine visceral leishmaniasis using Leishvaccine and Leishmune.

It is generally accepted that distinct cytokine expression by the cellular immune response plays a critical role during the outcome of experimental as well as natural canine visceral Leishmaniasis (CVL). Despite the fact that immunoprophylaxis of CVL has become an important control strategy and protective immunity has been reported upon immunization with whole as well as purified Leishmania antigens, the cytokine profile of T-cells triggered by anti-CVL vaccines still remain to be determined. Herein, we have developed a cross-sectional analysis of German Shepherd dogs submitted to vaccination protocols with Leishvaccine (n=6) and Leishmune (n=6).

Systemic and compartmentalized immune response in canine visceral leishmaniasis.

Human visceral leishmaniasis (VL) and canine visceral leishmaniasis (CVL) are the most important emerging diseases with high prevalence in Latin American countries and are mainly caused by Leishmania (L.) chagasi (Syn=L. infantum).

Advances in flow cytometric serology for canine visceral leishmaniasis: diagnostic applications when distinct clinical forms, vaccination and other canine pathogens become a challenge.

We have previously reported the applicability of flow cytometry anti-fixed Leishmania infantum chagasi promastigotes IgG (FC-AFPA-IgG) as a novel serological device for laboratorial diagnosis of CVL. Herein, we validate throughout a blind study applied into a broader range of coded sera samples that FC-AFPA-IgG at serum dilution 1:8192 have an outstanding performance to discriminate the serological reactivity of canine visceral leishmaniasis (CVL, n=64) and Leishmune vaccines (VAC, n=62) and non-infected controls (NI, n=25). Moreover, we have evaluated the performance of indirect immunofluorescence antibody test (IFAT) and the crude-antigen enzyme-linked immunosorbent assay (ELISA) in parallel with FC-AFPA-IgG, to discriminate the seroreactivity of NI, CVL and VAC.

Despite Leishvaccine and Leishmune trigger distinct immune profiles, their ability to activate phagocytes and CD8+ T-cells support their high-quality immunogenic potential against canine visceral leishmaniasis.

Phenotypic features of peripheral blood leukocytes have been investigated as a pre-requisite to characterize the protective immunity attributed to both Leishvaccine and Leishmune. Our results showed that either those vaccine were accompanied by distinct profiles on innate immune compartment. While Leishvaccine promoted early changes in phenotypic features of neutrophils and eosinophils with late involvement of monocytes, Leishmune induced early and persistent activation of neutrophils and monocytes, without changes on eosinophil activation status.

Evaluation of an immunochemotherapeutic protocol constituted of N-methyl meglumine antimoniate (Glucantime) and the recombinant Leish-110f + MPL-SE vaccine to treat canine visceral leishmaniasis.

The evaluation of the efficacy of an immunochemotherapy protocol to treat symptomatic dogs naturally infected with Leishmania chagasi was studied. This clinical trial had the purpose to test the combination of N-methyl meglumine antimoniate (Glucantime and the second generation recombinant vaccine Leish-110f plus the adjuvant MPL-SE to treat the canine leishmaniasis (CanL). Thirty symptomatic naturally infected mongrel dogs were divided into five groups.

The influence of copper, selenium and zinc on the response to the Montenegro skin test in subjects vaccinated against American cutaneous leishmaniasis.

We evaluated the relationship between the trace elements copper, zinc and selenium and the response to the Montenegro skin test (MST) in 172 volunteers vaccinated against American cutaneous leishmaniasis. The MST diameter was categorized as negative and in quartiles of positive response, constituting five groups. Trace element serum levels were analyzed by coupled plasma atomic emission spectrometry and hydride generation atomic absorption spectrometry, with study subjects classified into two groups depending on low or high levels of trace elements observed.

Antigenicity of a whole parasite vaccine as promising candidate against canine leishmaniasis.

Human visceral leishmaniasis, one of the most important zoonoses, is caused by the protozoa Leishmania chagasi (syn. L. infantum) and is present as a fatal disease common in South America and Europe where dogs and wild canids are the main reservoirs.

Histopathology, parasite density and cell phenotypes of the popliteal lymph node in canine visceral leishmaniasis.

While enlargement of popliteal lymph nodes (LN) is frequently described in canine visceral leishmaniasis (CVL), there are few histopathologic studies of lymph nodes during this chronic immunopathological condition. Besides a detailed histopathologic analysis, we have characterized the parasite load and major immunophenotypic features of the LN in Leishmania (Leishmania) chagasi-infected dogs. Our major histopathological findings highlight that hypertrophy/hyperplasia of LN cortical and medullary zones was the principal characteristic observed in asymptomatic dogs (AD), whereas atrophy of LN cortical zone was predominant in symptomatic animals (SD).

Histopathological and immunohistochemical investigations of the hepatic compartment associated with parasitism and serum biochemical changes in canine visceral leishmaniasis.

The immunopathological evaluation of the hepatic compartment associated with parasitism and biochemical findings are essential for understanding the genesis of hepatomegaly in canine visceral leishmaniasis (CVL). Three clinical groups of dogs naturally infected with Leishmania chagasi [i.e.

Mixed cytokine profile during active cutaneous leishmaniasis and in natural resistance.

Most studies on immune response in human cutaneous leishmaniasis evaluate patients with active disease in comparison with healthy uninfected controls or patients that have had the lesions healed, however, little is known about the immune response associated with natural resistance. In this paper we evaluate the cytokine expression patterns of T-cells and the plasmatic levels of nitrite and nitrate in patients with localized cutaneous leishmaniasis (LCL) as well as endemic non-infected individuals with positive (MST) and negative (NI) Montenegro skin test, without previous history of leishmanial lesions. Our results demonstrated an increased number of IFN-gamma+ and TNF-alpha+ T-cells and high level of plasma nitrite and nitrate in LCL patients.

Isotype patterns of immunoglobulins: hallmarks for clinical status and tissue parasite density in Brazilian dogs naturally infected by Leishmania (Leishmania) chagasi.

The role of anti-leishmanial immune response underlying the susceptibility/resistance during canine visceral leishmaniasis (CVL) has been recognized throughout ex vivo and in vitro investigations. Recently, we demonstrated that immunoglobulin levels (Igs), as well as the parasite load are relevant hallmarks of distinct clinical status of CVL. To further characterize and upgrade the background on this issue, herein, we have evaluated, in Leishmania (Leishmania) chagasi naturally infected dogs, the relationship between tissue parasitism (skin, bone marrow, spleen, liver and lymph node), the CVL clinical status (asymptomatic (AD), with no suggestive signs of the disease; oligosymptomatic (OD), with maximum three clinical signs-opaque bristles; localized alopecia and moderate loss of weight; symptomatic (SD), serologically positive with severe clinical signs of visceral leishmaniasis), and the humoral immunological profile of anti-Leishmania immunoglobulins (IgG, IgG1, IgG2, IgM, IgA and IgE).

Immuno-biochemical evaluations of phenol and thimerosal as antigen preservatives in Montenegro skin test.

Montenegro skin test (MST) represents the main complementary diagnostic test for tegumentary leishmaniases (TL) in endemic regions. Most antigen formulations used for the MST contain thimerosal as preservative. The Food and Drug Administration (FDA), however, recommended reducing or eliminating thimerosal from vaccines and other biological reagents and the Agência Nacional de Vigilância Sanitária (ANVISA) in Brazil, prohibited the use of mercurial compounds in immunobiologicals.

Immunotherapy, immunochemotherapy and chemotherapy for American cutaneous leishmaniasis treatment.

The first choice of treatment for American cutaneous leishmaniasis is the pentavalent antimonial drug. Although it has been shown that this treatment is mostly effective and indicated, some disadvantages should be taken into account such as side effects, long term treatment inconveniences and counter-indication for patients suffering from cardiopathy, nephropathy; yet, aging, pregnancy and other conditions. With the advent of the vaccine anti-American cutaneous leishmaniasis as a prophylactic measure, studies on therapy using the vaccine associated or not with other drugs have been performed by many investigators and it is currently among the alternative treatments and prevention measures for American cutaneous leishmaniasis.

Comparison of polymerase chain reaction with other laboratory methods for the diagnosis of American cutaneous leishmaniasis: diagnosis of cutaneous leishmaniasis by polymerase chain reaction.

An evaluation of 5 laboratory methods for diagnosing American cutaneous leishmaniasis (ACL) was carried out on patients from an endemic area of Brazil. From 164 patients presenting cutaneous lesions, and suspected to have ACL, 133 (81.1%) were confirmed for the disease by Montenegro skin test (MST) and/or parasitologic examination (PE).

Parasite density and impaired biochemical/hematological status are associated with severe clinical aspects of canine visceral leishmaniasis.

We have performed a detailed investigation in 40 dogs naturally infected with Leishmania infantum (syn. chagasi), subdivided into three groups: asymptomatic (AD = 12), oligosymptomatic (OD = 12) and symptomatic (SD = 16), based on their clinical features. Twenty non-infected dogs (CD) were included as control group.

Identification and antimicrobial susceptibility of micro-organisms recovered from cutaneous lesions of human American tegumentary leishmaniasis in Minas Gerais, Brazil.

An evaluation of the microbiota present in cutaneous ulcers from 31 patients with a clinical and parasitological diagnosis of American tegumentary leishmaniasis (ATL) was carried out by the standard filter paper disc technique, including antimicrobial susceptibility of the bacterial isolates. Microbial examination indicated that 21 patients (67.7%) were contaminated with one to four bacteria and some of them also with yeast.

[Aspects of the ecology and behaviour of phlebotomines in endemic area for visceral leishmaniasis in State of Minas Gerais].

Studies on the behavioral and feeding habits of some species of phlebotominae sand flies have contributed to the comprehension of the epidemiology of leishmaniasis. In the present work, systematic captures were performed monthly in the municipality of Porteirinha (MG) using 28 light traps (CDC) from January to December 2002. Fourteen different species of phlebotomine were captured in a total of 1,408 specimens.

Immunogenicity in dogs of three recombinant antigens (TSA, LeIF and LmSTI1) potential vaccine candidates for canine visceral leishmaniasis.

Control of canine visceral leishmaniasis (VL) remains a difficult and serious problem mostly because there is no reliable and effective vaccine available to prevent this disease. A mixture of three recombinant leishmanial antigens (TSA, LeIF and LmSTI1) encoded by three genes highly conserved in the Leishmania genus have been shown to induce excellent protection against infection in both murine and simian models of cutaneous leishmaniasis. A human clinical trial with these antigens is currently underway.