Canine visceral leishmaniasis as a systemic fibrotic disease

Abstract

We propose that canine visceral leishmaniasis (CVL) is a systemic fibrotic disease, as evidenced by the wide distribution of fibrosis that we have found in the dogs suffering from chronic condition. The inflammatory cells apparently direct fibrosis formation. Twenty-four cases (symptomatic dogs) were identified from a total of one hundred and five cases that had been naturally infected with Leishmania chagasi and had been documented during an epidemiological survey of CVL carried out by the metropolitan area of the municipality of Belo Horizonte, MG, Brazil. The histological criterion was intralobular liver fibrosis, as has been described previously in dogs with visceral leishmaniasis. In addition to the findings in the liver, here we describe and quantify conspicuous and systemic deposition of collagen in other organs, including spleen, cervical lymph nodes, lung and kidney of all the infected symptomatic dogs. Thus we report that there is a systematic fibrotic picture in these animals, where inflammatory cells appear to direct fibrosis in all organs that have been studied. Therefore we propose that CVL is a systemic fibrotic disease.

Comportamento dos marcadores bioquímicos de injúria hepática nos cães com leishmaniose visceral

“…Ao comparar os dados deste analito entre os diferentes grupos constatou-se diferença estatística significativa entre os animais classificados como sintomáticos e assintomáticos (Tabela 1). A hipoalbuminemia pode estar relacionada ao hipercatabolismo proteico, a lesão renal, a desnutrição e/ou ao defeito na síntese hepática decorrente da inflamação do fígado mediada pela resposta imune em pacientes com leishmaniose e já foi correlacionada a maior frequência de óbitos em pacientes humanos (Solano-Gallego et al, 2009, Silva et al, 2013.…”

“…Os tecidos cutâneo, renal e cardíaco são os mais frequentemente acometidos (Silva et al, 2013, Godoy et al, 2016. Contudo, o envolvimento do fígado, manifestado por hepatomegalia é considerado comum nos casos de leishmaniose visceral com manifestações como icterícia, hipoalbuminemia, fibrose, colestase (Valladares et al, 1997, Melo et al, 2009, Medeiros et al, 2010.…”

Immunohistochemical study of renal fibropoiesis associated with dogs naturally and experimentally infected with two different strains ofLeishmania(L.)infantum

“…Visceral leishmaniasis in human beings and dogs is a systemic chronic inflammatory disease that promotes extracellular interstitial matrix (ECM) alterations. These alterations are mainly formed by collagen deposition (fibrosis) as a consequence of this visceral inflammation.…”

“…These alterations are mainly formed by collagen deposition (fibrosis) as a consequence of this visceral inflammation. In fact, some studies have shown a direct association between fibrosis and Leishmania infection .…”

“…Melo et alreported an intense collagen deposition in livers of dogs naturally infected with L.infantum independent of the clinical status, but directly related to the parasite hepatic tissue load. Silva et al, working with 24 symptomatic dogs, described the remarkable systematic collagen deposition in organs such as liver, lungs, kidneys, lymph nodes and spleens, especially in the first three ones. In a more recent work, Madeira et al discussed some mechanisms for liver fibrosis associated with canine visceral leishmaniasis (CVL).…”