High levels of serum matrix metalloproteinases in dogs with natural visceral leishmaniosis: A preliminary report

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fungal pyogranulomatous encephalitis in a dog with leishmaniosis

É relatado um caso de encefalite piogranulomatosa em um cão fêmea de um ano de idade, da raça Fila Brasileiro. Ao exame macroscópico do cérebro, evidenciou-se área amolecida e hemorrágica no córtex frontal direito e na superfície de corte do hemisfério esquerdo, afetando a substância branca e áreas corticais profundas. O diagnóstico de encefalite piogranulomatosa micótica multifocal foi realizado através de exame histopatológico, que mostrou a presença de macrófagos, células gigantes, focos de hemorragia e hifas septadas de coloração marrom, com distribuição difusa e invadindo a luz de vasos. A identificação de formas amastigotas no imprint de linfonodo poplíteo confirmou o diagnóstico de leishmaniose. A infecção micótica no cérebro deste cão foi relacionada com a ocorrência concomitante de leishmaniose, uma doença imunossupressora.

Leishmania chagasi infection in cats with dermatologic lesions from an endemic area of visceral leishmaniosis in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leishmania chagasi infection in cats with dermatologic lesions from an endemic area of visceral leishmaniosis in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Neutrophil dysfunction varies with the stage of canine visceral leishmaniosis

Canine visceral leishmaniosis (CVL) causes a dependent-stage alteration in neutrophil oxidative metabolism. When production of reactive oxygen species (ROS) exceeds the antioxidant capacity of neutrophils, apoptosis is triggered, impairing the viability and function of these cells, which can predispose dogs to infection. However, the uremic condition observed in late-stage CVL can also alter the viability and function of human neutrophils. To more clearly understand this relationship, the apoptosis rate and oxidative metabolism of neutrophils from control dogs (n= 20) were compared to dogs in moderate (n= 15) and very severe (n= 15) stage CVL, classified according to LeishVet Consensus. To assess neutrophil oxidative metabolism, superoxide production was measured using the nitroblue tetrazolium reduction test (NBT) in isolated neutrophils. The apoptosis rate of neutrophils was estimated using the morphological method. Moderate-stage dogs presented increased superoxide production, while dogs with very severe stage CVL presented decreased superoxide production and an increase neutrophil apoptosis rate. Leishmaniosis causes differential neutrophil dysfunction according to disease stage. In moderate stage CVL, increased superoxide production is observed with no change in neutrophil viability. However, in very severe stage CVL, decreased superoxide production and increased apoptosis occur associated with uremia. © 2013 Elsevier B.V.

Alteration of sFAS and sFAS ligand expression during canine visceral leishmaniosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hypertension and its correlation with renal lesions in dogs with leishmaniosis

To evaluate the prevalence of hypertension and its correlation with the severity of renal injury and proteinuria in dogs with leishmaniosis, sixty-six dogs were divided into two groups. Group 1 (G1) was composed of 54 dogs included in stage 1 of chronic kidney disease (CKD), and group 2 (G2) of twelve dogs in stages 2 and 3 of CKD. Prevalence of hypertension was 28.8%, comprising 22.2% of the dogs from G1 and 58.3% from G2 (P=0.011). The mean arterial blood pressure (BP) of dogs from G1 (135.7 +/- 20.5) was lower than from G2 (170.0 +/- 26.3) (P <0.001). Urine proteincreatinine ratio (UP/C) revealed values above 0.5 in 75.7% of the dogs, with 34% presenting hypertension. All dogs with hypertension had histopathological and laboratory evidence of glomerular disease. Although there was no statistically significant correlation between elevated BP and the severity of glomerular lesions (P=0.408), there was a statistically significant correlation between elevated BP and increased UP/C in the studied population (P=0.002). Thus, dogs with leishmaniosis and renal disease must be screened for the presence of hypertension so that treatment may be instituted as early as possible, in countries where treatment is allowed, to prevent the progression of renal damage.

IL-6 and TNF-alpha production during active canine visceral leishmaniasis

We investigated the production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) during canine visceral leishmaniasis (VL) to gain a better understanding of the role of such multi-functional cytokines in parasite resistance. IL-6 and TNF-alpha levels were measured by capture ELISA in sera from 8 healthy dogs from a non-endemic area (control group) and in sera from 16 dogs from Aracatuba, SP, Brazil, an area endemic for leishmaniosis. The dogs from the endemic area were selected by positive ELISA serology against total Leishmania chagasi antigen, positive spleen imprints for Leishmania, and the presence of at least three clinical signs associated with active visceral leishmaniasis (fever, dermatitis, lymphoadenopathy, onychogryphosis, weight loss, cachexia, locomotory difficulty, conjunctivitis, epistaxis, hepatosplenomegaly, edema, and apathy).Enhanced systemic IL-6 production was found in sera from dogs with the active disease compared to healthy dogs (t-test, P < 0.05). In contrast, TNF-alpha did not differ between the two groups studied. There was no correlation between IL-6 production and anti-leishmanial antibody titers in the sera. Our findings suggest that IL-6 is a good marker of active disease during leishmaniasis, and that other cytokines may be involved in the hypergammaglobulinemia characteristic of canine visceral leishmaniasis. (c) 2006 Published by Elsevier B.V.

Evaluation of transformation growth factor beta(1), interleukin-10, and interferon-gamma in male symptomatic and asymptomatic dogs naturally infected by Leishmania (Leishmania) chagasi

The aims of this study were to evaluate the immunomodulatory role of TGF-beta(1), 1L-10, and INF-gamma in spleen and liver extracts and supernatant cultures of white spleen cells from male symptomatic and asymptomatic dogs, naturally infected by Leishmania (Leishmania) chagasi. Thirty dogs from Aracatuba, São Paulo, Brazil, an endemic leishmaniosis area, were selected by positive ELISA serological reaction for Leishmania sp. and divided into two groups: asymptomatic (n=15) and symptomatic (n=15) consisting of animals with at least three characteristic signs (fever, dermatitis, lymphoadenopathy, onychogryphosis, weight loss, cachex a, locomotion problems, conjunctivitis, epistaxis, hepatosplenomegaly, edema, and apathy). After euthanasia, spleen and liver fragments were collected for ex vivo quantification of TGF-beta(1), IL-10, and INF-gamma. Naturally active in vitro produced TGF-beta(1) was also evaluated in spleen cell culture supernatant. Spleen and liver extract of asymptomatic dogs had higher mean TGF-beta(1) levels than symptomatic dogs. High concentrations of IL-10 were found in spleen, and mainly in liver extract of both groups. Higher INF-gamma concentrations were found in spleen extracts of symptomatic dogs, and in liver extracts of asymptomatic dogs. Extract of this cytokire was lower in spleen extract. Although INF-gamma is being produced in canine infection, mean levels of TGF-beta(1) and IL-10 from spleen and liver extracts were quantitatively much higher; suggesting that immune response in both asymptomatic and symptomatic dogs A as predominantly type Th2. (c) 2006 Elsevier B.V. All rights reserved.

Potential role for dog fleas in the cycle of Leishmania spp.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

IgG subclass profile of serum antibodies to Leishmania chagasi in naturally infected and vaccinated dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Presença de anticorpos anti-Neospora caninum e Toxoplasma gondii em cães com leishmaniose visceral da região de Araçatuba, São Paulo, Brasil

Dogs that had positive and negative sera to Leishmania chagasi from the region of Araçatuba, São Paulo, Brazil, were evaluated for the presence of anti-Neospora caninum and anti-Toxoplasma gondii antibodies as potential co-infecting agents. Blood samples were collected from 204 dogs and out of them 98 were carriers of leishmaniosis. Sera were tested for the presence of anti-L. chagasi antibodies by ELISA, and anti-T. gondii and anti-N. caninum by an indirect fluorescent antibody test (IFAT). Age, gender, and association between the presences of anti-L. chagasi antibodies and seroprevalence to N. caninum and T. gondii were analyzed by chi-square test. Out of the 204 sera investigated, 36 (17.6%) were positive for N. caninum (IFAT=50) and 75 (36.8%) to T. gondii (IFAT=16) with titers that varied from 50 to 6400 for N. caninum, and from 16 to 16384 for T. gondii. The copresence of anti-L. chagasi, N. caninum and T. gondii antibodies was observed in 17 (8.3%) dogs. Antibodies to N. caninum were observed in four (3.8%) out of 106 dogs that were negative for L. chagasi, and in 32 (32.6%) out of the 98 dogs that were positive for L. chagasi. Anti-T. gondii antibodies were found in 40 (41.0%) and in 35 (33.0%) of the 98 positive dogs and in 106 negative dogs for L. chagasi, respectively. An association between the presence of antibodies against L. chagasi and a positive response to N. caninum (p<0.001) was observed. The gender and age of the dogs did not show an association between the presence of antibodies and any of the agents studied (p>0.05), with the exception of age and presence of anti-L. chagasi antibodies, in which only a slight association was observed (p=0.038). Within this interaction, a higher number of dogs, older than four years, were positive for this agent when compared to other age groups.

Estudo da reatividade cruzada em amostras de soro de cães positivos para Leishmania sp., Babesia canis e Ehrlichia canis, pelo ensaio imunoenzimático indireto e pela reação de imunofluorescência indireta

To verify the presence of cross-reaction among leishmaniosis, ehrlichiosis and babesiosis in serological diagnostics used in human visceral leishmaniasis control programs, serum samples from leishmaniasis endemic and non-endemic areas were collected and tested by Indirect Fluorescent Antibody (IFAT) and Enzyme-linked immunosorbent assay (ELISA). All serum samples from endemic areas were positive for Leishmania sp., by ELISA and IFAT, 51% positive for Babesia canis and 43% for Ehrlichia canis by IFAT. None of the serum samples from non-endemic areas were positive for Leishmania sp., by IFAT, but 67% were positive for B. canis and 78% for E. canis using the same test. When tested by ELISA for Leishmania sp., four samples from non-endemic area were positive. These dogs were then located and no clinical signs, parasites or antibody was detected in new tests for a six month period. Only one of these 4 samples was positive for B. canis by IFAT and ELISA and three for E. canis by IFAT. The results of the work suggest a co-infection in the endemic area and no serological cross-reaction among these parasites by IFAT and ELISA.

Fatores predisponentes à ocorrência de leptospirose e leishmaniose em cães no Distrito de Córrego Rico, Jaboticabal-SP

Pós-graduação em Medicina Veterinária - FCAV