Phenotypic features of circulating leucocytes as immunological markers for clinical status and bone marrow parasite density in dogs naturally infected by Leishmania chagasi.

Canine visceral leishmaniasis (CVL) manifests itself as a broad clinical spectrum ranging from asymptomatic infection to patent severe disease. Despite relevant findings suggesting changes on lymphocytes subsets regarding the CVL clinical forms, it still remains to be elucidated whether a distinct phenotypic profile would be correlated with degree of tissue parasite density. Herein, we have assessed the correlation between the clinical status as well as the impact of bone marrow parasite density on the phenotypic profile of peripheral blood leucocytes in 40 Brazilian dogs naturally infected by Leishmania chagasi. Our major findings describe the lower frequency of B cells and monocytes as the most important markers of severe CVL. Our main statistically significant findings reveal that the CD8(+) T cell subset reflects most accurately both the clinical status and the overall bone marrow parasite density, as increased levels of CD8(+) lymphocytes appeared as the major phenotypic feature of asymptomatic disease and dogs bearing a low parasite load. Moreover, enhanced major histocompatibility complex (MHC)-II density as well as a higher CD45RB/CD45RA expression index seems to represent a key element to control disease morbidity. The association between clinical status, bone marrow parasitism and CD8(+) T cells re-emphasizes the role of the T cell-mediated immune response in the resistance mechanisms during ongoing CVL. Higher levels of circulating T lymphocytes (both CD4(+) and CD8(+) T cells) and lower MHC-II expression by peripheral blood lymphocytes seem to be the key for the effective immunological response, a hallmark of asymptomatic CVL.

Immunochemotherapy in American cutaneous leishmaniasis: immunological aspects before and after treatment.

In this study, we evaluated the immune response of patients suffering from cutaneous leishmaniasis treated with two distinct protocols. One group was treated with conventional chemotherapy using pentavalent antimonium salts and the other with immunochemotherapy where a vaccine against cutaneous leishmaniasis was combined with the antimonium salt. Our results show that, although no differences were observed in the necessary time for complete healing of the lesions between the two treatments, peripheral blood mononuclear cells from patients treated by chemotherapy showed smaller lymphoproliferative responses at the end of the treatment than those from patients in the immunochemotherapy group. Furthermore, IFN-gamma production was also different between the two groups. While cells from patients in the chemotherapy group produced more IFN-gamma at the end of treatment, a significant decrease in this cytokine production was associated with healing in the immunochemotherapy group. In addition, IL-10 production was also less intense in this latter group. Finally, an increase in CD8+ -IFN-gamma producing cells was detected in the chemotherapy group. Together these results point to an alternative treatment protocol where healing can be induced with a decreased production of a potentially toxic cytokine.

Immunochemotherapy in American cutaneous leishmaniasis: immunological aspects before and after treatment

In this study, we evaluated the immune response of patients suffering from cutaneous leishmaniasis treated with two distinct protocols. One group was treated with conventional chemotherapy using pentavalent antimonium salts and the other with immunochemotherapy where a vaccine against cutaneous leishmaniasis was combined with the antimonium salt. Our results show that, although no differences were observed in the necessary time for complete healing of the lesions between the two treatments, peripheral blood mononuclear cells from patients treated by chemotherapy showed smaller lymphoproliferative responses at the end of the treatment than those from patients in the immunochemotherapy group. Furthermore, IFN-gamma production was also different between the two groups. While cells from patients in the chemotherapy group produced more IFN-gamma at the end of treatment, a significant decrease in this cytokine production was associated with healing in the immunochemotherapy group. In addition, IL-10 production was also less intense in this latter group. Finally, an increase in CD8+ -IFN-gamma producing cells was detected in the chemotherapy group. Together these results point to an alternative treatment protocol where healing can be induced with a decreased production of a potentially toxic cytokine

Histopathology of human American cutaneous leishmaniasis before and after treatment.

Chemical therapy for the treatment of leishmaniasis is still inadequate, and a number of drugs and therapeutic programs are being tested. Besides treatment, the ultimate goal is an effective cure, and histopathological analyses of the lesion cicatrices constitute an important measure of treatment success, or otherwise, in this respect. In this paper, we describe histopathological patterns in cases of American cutaneous leishmaniasis in 32 patients from the municipality of Caratinga, Minas Gerais, Brazil, before and after treatment with the following therapeutic methods: 1) leishvacin + glucantime; 2) leishvacin + BCG associated with glucantime; 3) glucantime; 4) leishvacin + BCG. Lesion fragments were collected from all patients by biopsy prior to, and approximately 30 days after, each treatment which resulted in a clinical diagnosis of cure. Following the analysis of slides, the preparations were described from a histopathological point of view and grouped taking into account the prevalence or significance of the characteristic elements. This process resulted in the following classification: 1. exudative reaction (ER); 2. exudative giant cell reaction (EGCR); 3. exudative productive reaction (EPR); 4. exudative productive giant cell reaction (EPGCR); 5. exudative productive necrotic reaction (EPNR); 6. necrotic exudative reaction (NER); 7. productive exudative reaction (PER), 8. productive giant cell reaction (PGCR); 9. productive exudative giant cell reaction (PEGCR); 10. productive exudative giant cell granulomatous reaction (PEGCGR); 11. productive reaction (PR) and 12. productive cicatricial (cure) reaction (PCR). After this analysis, it was noted that clinical cure did not always coincide with histopathological cure.

Histopathology of human American cutaneous leishmaniasis before and after treatment

Chemical therapy for the treatment of leishmaniasis is still inadequate, and a number of drugs and therapeutic programs are being tested. Besides treatment, the ultimate goal is an effective cure, and histopathological analyses of the lesion cicatrices constitute an important measure of treatment success, or otherwise, in this respect. In this paper, we describe histopathological patterns in cases of American cutaneous leishmaniasis in 32 patients from the municipality of Caratinga, Minas Gerais, Brazil, before and after treatment with the following therapeutic methods: 1) leishvacin + glucantime; 2) leishvacin + BCG associated with glucantime; 3) glucantime; 4) leishvacin + BCG. Lesion fragments were collected from all patients by biopsy prior to, and approximately 30 days after, each treatment which resulted in a clinical diagnosis of cure. Following the analysis of slides, the preparations were described from a histopathological point of view and grouped taking into account the prevalence or significance of the characteristic elements. This process resulted in the following classification: 1. exudative reaction (ER); 2. exudative giant cell reaction (EGCR); 3. exudative productive reaction (EPR); 4. exudative productive giant cell reaction (EPGCR); 5. exudative productive necrotic reaction (EPNR); 6. necrotic exudative reaction (NER); 7. productive exudative reaction (PER), 8. productive giant cell reaction (PGCR); 9. productive exudative giant cell reaction (PEGCR); 10. productive exudative giant cell granulomatous reaction (PEGCGR); 11. productive reaction (PR) and 12. productive cicatricial (cure) reaction (PCR). After this analysis, it was noted that clinical cure did not always coincide with histopathological cure.

A quimioterapia para a leishmaniose não é satisfatória e existem hoje, várias drogas e esquemas terapêuticos em teste. Além do tratamento ideal, busca-se um critério de cura efetivo, onde a análise da histopatologia da cicatriz poderá ser de grande valia. Este trabalho propõe caracterizar o padrão histopatológico de casos humanos de leishmaniose tegumentar americana, em 32 pacientes do município de Caratinga-MG, antes e após o tratamento com os seguintes métodos terapêuticos: 1) leishvacin + glucantime; 2) leishvacin + BCG associado ao glucantime; 3) glucantime; 4) leishvacin + BCG. Foram colhidos fragmentos das lesões de todos os pacientes, através de biópsias, antes e após o tratamento, com diagnóstico de cura. Após análise das lâminas, as preparações foram descritas, do ponto de vista histopatológico, e agrupadas levando em conta a prevalência e a significância do elemento característico. Tal processo resultou na classificação: 1. reação exsudativa; 2. reação exsudativa giganto-celular; 3. reação exsudativa produtiva; 4. reação exsudativa produtiva giganto-celular; 5. reação exsudativa produtiva necrótica; 6. reação necrótica exsudativa; 7. reação produtiva exsudativa; 8. reação produtiva giganto-celular; 9. reação produtiva exsudativa giganto-celular; 10. reação produtiva exsudativa giganto-celular granulomatosa; 11. reação produtiva e 12. reação produtiva cicatricial (cura histopatológica). Observamos após tal análise, que nem sempre a cura clínica coincide com a cura histopatológica.

Leishmaniose visceral canina: estudo imunocitoquímico dos antígenos do MHC classe II no fígado e órgäos linfóides / Canine visceral leishmaniasis: immunocytochemical study of the MHC class II antigens in liver and lymphoid organs

O objetivo deste trabalho foi o de estudar a expressäo imunocitoquímica dos antígenos do MHC classe II no fígado e órgäos linfóides (baço, linfonodos e placas de Peyer) de cäes, sem raça definida, experimentalmente e naturalmente infectados com Leishmania chagasi. Cortes em criostato de fígado, baço, linfonodos e placas de Peyer foram corados pela técnica imunocitoquímica peroxidase anti-peroxidase (PAP). A marcaçäo imunocitoquímica para os antígenos do MHC classe II revelou a mesma topografia em todos os órgäos examinados de todos os animais infectados. Entretanto, a expressäo dos antígenos do MHC classe II foi menos intensa nos linfonodos cervicais e abdominais dos cäes naturalmente infectados, indicando que L. chagasi é capaz de inibir a expressäo dos antígenos do MHC classe II

Histopathology and immunocytochemical study of type 3 and type 4 complement receptors in the liver and spleen of dogs naturally and experimentally infected with Leishmania (Leishmania) chagasi.

The objective of this study was to compare the histopathological changes and expression of CR3 and CR4 in the liver and spleen of dogs naturally and experimentally infected with L. chagasi. The basic histopathological lesions observed mainly in naturally infected dogs were: epithelioid hepatic granulomas, hyperplasia and hypertrophy of Kupffer cells, Malpigui follicles and mononucleated cells of the red pulp of the spleen. Sections from the liver and spleen by immunocytochemistry technique showed the presence of CD11b, c/CD 18 antigens in the control and infected animals and no qualitative or quantitative differences in the liver. Nevertheless, CD18 was always increased in the spleen of naturally and experimentally infected dogs. These results indicate that there is a difference in the activation of CD18 in both experimental and natural cases of canine visceral leishmaniasis that should play an important role in the immunological response to Leishmania chagasi infection.

The kinetics of Montenegro skin tests in dogs inoculated with an antileishmaniasis vaccine: A histopathologic study

A intradermorreaçäo de Montenegro (IRM) é um método de diagnóstico muito utilizado para a Leishmaniose Tegumentar Americana (LTA). Entretanto, säo relativamente poucos os trabalhos a respeito das alteraçöes texturais provocadas pelo antígeno, sobretudo em cäes. Estudou-se a histopatologia da cinética do teste cutâneo de Montenegro em cäes vacinados experimentalmente com vacina antileishmaniose tegumentar americana (vacina anti-LTA) 6, 12, 24, 48 e 72 horas, 7 e 14 dias após a administraçäo do antígeno. O quadro histopatológico geral segue o padräo observado nas inflamaçöes inespecíficas. Nas primeiras 24 horas, observou-se, geralmente, o exsudato menos intenso e predominantemente composto de granulócitos neutrófilos; após 48 e 72 horas, mais acentuado e constituído principalmente de células mononucleares. Aos 7 e 14 dias a reaçäo tendia a ser menos intensa

Isolation Leishmania sp from aqueous humor of a patient with cutaneous disseminated leishmaniasis and bilateral iridocyclitis (preliminary report)

Os autores descrevem um caso raro de leishmaniose con lesoes cutaneas disseminadas, manifestacoes sistemicas e comprometimento ocular, sendo este caracterizado por iridociclite bilateral nao granulomatosa. A gravidade do quadro oftalmologico e a ausencia de resposta ao tratamento, a despeito da melhora das manifestacoes cutaneas e sistemicas, levaram a realizacao de puncao propedeutica da camada anterior ocular. A partir do humor aquoso isolou-se Leishmania sp. Os autores desconhecem na literatura qualquer outro caso onde tal achado tenha sido demonstrado

Isolation of Leishmania sp. from aqueous humor of a patient with cutaneous disseminated leishmaniasis and bilateral iridocyclitis (preliminary report).

The authors report an uncommon case of leishmaniasis with disseminated cutaneous lesions, systemic manifestations and ocular involvement, the latter being characterized by bilateral nongranulomatous iridocyclitis. The severity of the ophthalmologic lesions and its unresponsiveness to therapy (in spite of satisfactory regression of both systemic and cutaneous manifestations) lead to a needle aspiration of the anterior eye chamber content. From this material Leishmania sp was isolated. To our knowledge this is the first time that Leishmania has been shown into the ocular globe.

Schistosoma mansoni: immunodepresion of hepatic schistosome granuloma formation in mice infected by Trypanosoma cruzi

A infecçäo de camundongos pelo Trypanosoma cruzi inibe a formaçäo do granuloma hepático esquistossomótico. Este efeito imunodepressor ocorreu em camundongos com a fase aguda ou crônica da doença de Chagas, sendo os granulomas significativamente menores que nos animais controles. Os dados sugerem que a doença de Chagas deprime diretamente a imunidade celular