Diffuse Intralobular Liver Fibrosis in Dogs Naturally Infected with Leishmania (Leishmania) chagasi

Melo, Ferdinan Almeida; Amaral, Marina; Oliveira, Patrícia da Silva; Lima, Wanderson Geraldo de; Andrade, M.C Melcon; Michalick, Marilene Suzan Marques; Raso, Pedro; Tafuri, Washington Luiz; Tafuri, Wagner Luiz

doi:10.4269/ajtmh.2008.79.198

Cited by 21 publications

(34 citation statements)

References 28 publications

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“…For semi-quantitative analysis, inflammatory mononuclear cells were counted using ocular analysis and rated: (1) Slight: 1–9 cells per field/20 fields; (2) moderate: 10–30 cells per field/20 fields; (3) intense: > 30 cells per field/20 fields. For quantitative analysis, images were analyzed using software, viewed on a computer video screen, and transferred to a computer-assisted image analysis system (Kontron Elektronic/Carl Zeiss, Germany) [49]. Under microscopic analysis, a minimum of 20 fields for each slide mounted with paraffinized GIT segment fragments was counted.…”

Section: Methodsmentioning

confidence: 99%

Expression of Toll-like receptors 2 and 9 in cells of dog jejunum and colon naturally infected with Leishmania infantum

et al. 2013

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BackgroundInfection with parasite protozoa is a long-term health issue in tropical and subtropical regions throughout the world. The Toll-like receptor (TLR) signaling pathway is one of the first-responding defense systems against Leishmania. The aim of this study was to investigate the expression of TLR2 and TLR9 in jejunum and colon and its correlation with CD11c, CD11b, and CD14 receptors used as markers for dendritic cells and macrophages.MethodsTwenty four dogs infected with Leishmania infantum were used in this study. Cytometry was carried out in lamina propria cells from jejunum and colon using markers for TLR2, TLR9, CD11b, CD11c and CD14.ResultsCellular inflammatory exudate was diffuse in the mucosa and submucosa, predominately comprising mononuclear cells: plasma cells, macrophages, and lymphocytes. Despite the parasite load, microscopy showed no erosion was evident in the epithelial mucosa layers. The colon harbored more parasites than the jejunum. Flow cytometry revealed higher frequency of TLR2+ and CD11c+ dendritic cells in the colon than in the jejunum. Conversely, TLR9-expressing cells were more frequent in jejunum. Moreover, frequency of macrophages (CD11b+ and CD14+) expressing simultaneity TLR9 were lower in the colon than in jejunum, while CD11c+ cells predominated in the colon. Despite of the negative ELISA serum results, IL-10 and TNF-α were higher in jejunum than colon of infected animals. However, IL-4 was higher in colon than jejunum of infected animals. A higher expression these cytokines were demonstrated in infected dogs compared to uninfected dogs.ConclusionsThere was no correlation between clinical signs and pathological changes and immunological and parasitological findings in the gastrointestinal tract in canine visceral leishmaniasis. However, jejunum showed a lower parasite load with increased frequency and expression of CD11b, TLR9, CD14/CD11b/TLR9 receptors and IL-10 and TNF-α cytokines. Conversely, the colon showed a higher parasite load along with increased frequency and expression of TLR2, CD11c receptors, and IL-4 cytokine. Thus, Leishmania infantum is able to interfere in jejunum increased expression of TLR2, TLR9, CD11b, CD14, CD14/CD11b/TLR9 receptors, IL-10, and TNF-α; and in colon increased expression of CD11c, TLR2, TLR9, CD11b, CD14 e, CD14/CD11b/TLR9 receptors, IL-10, and TNF-α.

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Section: Methodsmentioning

confidence: 99%

Expression of Toll-like receptors 2 and 9 in cells of dog jejunum and colon naturally infected with Leishmania infantum

et al. 2013

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“…In contrast, in cold and dry conditions, even when inflammation at the inoculation site was seen, a dry exfoliative squamous dermatitis with hair loss until alopecia was noted, starting at the inguen and spreading mainly to the back of the mice until it reached the face. This type of dermatitis has been reported for dogs (Binhazim et al 1992;Brachelente et al 2005;Melo et al 2008;Travi et al 2009), and felines (Solano-Gallego et al 2007) infected with L. infantum. In humans, this may be similar to the post-kala-azar dermal leishmaniasis caused by L. infantum (Zijlstra et al 1995) or L. donovani after treatment (Das et al 2009).…”

mentioning

confidence: 89%

“…In fact, the only exception was the brain. The distribution of Leishmania in several organs has been documented for visceral Leishmania acquired naturally by dogs, giving rise to the following pathogenic conditions: colitis (Adamama-Moraitou et al 2007), nephropathy (Costa et al 2003), liver fibrosis (Melo et al 2008), genital lesions (Diniz et al 2005), and transplacental transmission of parasites (Pangrazio et al 2009). This indicates a broad spectrum for this disease, which may be true for dermal species as well.…”

mentioning

confidence: 98%

Effect of Ambient Temperature on the Clinical Manifestations of Experimental Diffuse Cutaneous Leishmaniasis in a Rodent Model

Quiñonez-Díaz

Mancilla-Ramı́rez

Avila-García

et al. 2012

Vector-Borne and Zoonotic Diseases

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Dermal species of Leishmania have a relatively broad temperature range for optimal growth in vitro, with temperature differences accompanied by a form change. This suggests that when the host is living in moderate temperatures (22°C), infection may proceed at temperatures lower than those that occur in tropical regions (32°C), and a different clinical expression of the disease due to a different parasitic form may result. The aim of this study was to investigate the effect of environmental temperature on the clinical expression of the disease. BALB/C mice infected with Leishmania mexicana were housed at 32°±2°C or 22°±1°C, and assessed for the development of inflammation and the presence of parasites in organs using PCR and immunohistology. The clinical expression of leishmaniasis at 32°C included inflammation at the site of inoculation with swelling of the nose and tail, whereas at 22°C, up to 50% of the infected mice developed dry exfoliative dermatitis with alopecia on the dorsum. In both cases, parasite colonization was confirmed in the skin, with parasites at more external locations at 22°C. Parasite visceralization was confirmed in all internal organs and glands in both cases based on PCR and immunohistology. In conclusion, the clinical expression of diffuse leishmaniasis by Leishmania mexicana in laboratory mice is modified by temperature, from nodular inflammation at 32°C, to dry exfoliative dermatitis and alopecia at 22°C, with parasite visceralization in both cases.

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“…CVL infection is considerably more prevalent than clinical illness in endemic areas; this has been reported both in Brazil and Europe (Mediterranean basin countries) [7-13]. Furthermore, clinical signs of the disease are highly variable and can include lymphadenopathy [14,15], skin lesions [16-18], progressive weight loss [19], hepatosplenomegaly [20,21], ocular and musculoskeletal abnormalities, renal disease and epistaxis [22-24]. …”

Section: Introductionmentioning

confidence: 99%

Histopathological and parasitological study of the gastrointestinal tract of dogs naturally infected with Leishmania infantum

et al. 2011

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BackgroundThe aim of this study was to provide a systematic pathological and parasitological overview of the gastrointestinal tract (GIT), including the stomach, duodenum, jejunum, ileum, caecum and colon, of dogs naturally infected with Leishmania.MethodsTwenty mongrel dogs naturally infected with Leishmania (Leishmania) infantum and obtained from the Control Zoonosis Center of the Municipality of Ribeirão das Neves, Belo Horizonte Metropolitan area, Minas Gerais (MG) state, Brazil, were analyzed. The dogs were divided into two groups: Group 1 comprised nine clinically normal dogs and group 2 comprised 11 clinically affected dogs. After necropsy, one sample was collected from each GIT segment, namely the stomach, duodenum, jejunum, ileum, caecum and colon. Furthermore, paraffin-embedded samples were used for histological and parasitological (immunohistochemistry) evaluation and a morphometrical study were carried out to determine the parasite load (immunolabeled amastigote forms of Leishmania). The Friedman and the Mann Whitney tests were used for statistical analysis. The Friedman test was used to analyze each segment of the GIT within each group of dogs and the Mann Whitney test was used to compare the GIT segments between clinically unaffected and affected dogs.ResultsThe infected dogs had an increased number of macrophages, plasma cells and lymphocytes, but lesions were generally mild. Parasite distribution in the GIT was evident in all intestinal segments and layers of the intestinal wall (mucosal, muscular and submucosal) irrespective of the clinical status of the dogs. However, the parasite load was statistically higher in the caecum and colon than in other segments of the GIT.ConclusionThe high parasite burden evident throughout the GIT mucosa with only mild pathological alterations led us to consider whether Leishmania gains an advantage from the intestinal immunoregulatory response (immunological tolerance).

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Diffuse Intralobular Liver Fibrosis in Dogs Naturally Infected with Leishmania (Leishmania) chagasi

Cited by 21 publications

References 28 publications

Expression of Toll-like receptors 2 and 9 in cells of dog jejunum and colon naturally infected with Leishmania infantum

Expression of Toll-like receptors 2 and 9 in cells of dog jejunum and colon naturally infected with Leishmania infantum

Effect of Ambient Temperature on the Clinical Manifestations of Experimental Diffuse Cutaneous Leishmaniasis in a Rodent Model

Histopathological and parasitological study of the gastrointestinal tract of dogs naturally infected with Leishmania infantum

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