Association between skin parasitism and a granulomatous inflammatory pattern in canine visceral leishmaniosis

Abstract

In this work we examined 76 stray dogs from an area of endemic visceral leishmaniosis, in order to determine whether the presence of skin inflammation or a specific inflammatory pattern could be taken as indicative of infection with Leishmania chagasi, and whether the parasite burden in the skin could be associated with the intensity or the nature of the inflammatory process. Inflammatory infiltrates were observed in the skin of 51 out of 55 animals with diagnosis of leishmaniosis, and in 17 out of 21 animals without signs of infection. Amastigotes were identified in the skin of 29 out of the 55 animals with diagnosis of leishmaniosis. Granuloma and a monomorphic macrophage inflammatory infiltrate, and not a mixed focal or mixed diffuse inflammation, were significantly associated with skin parasitism, both in terms of frequency ( P=0.015 in the Chi-square test) and intensity ( P=0.005 in the Kruskal-Wallis test). A low parasite burden was associated with a multifocal inflammatory pattern.

Expression of Regulatory T Cells in Jejunum, Colon, and Cervical and Mesenteric Lymph Nodes of Dogs Naturally Infected with Leishmania infantum

“…Epithelioid macrophages were present, with multinuclear cells, although they lacked a typical granulomatous formation in the majority of the cases. The significance of granuloma, according to some authors, is that it is directly related to the lowest parasite tissue burden (27,30). We observed parasites associated with the inflammatory response throughout the mucosa, but without inducing severe pathologies, such as ulcers or necrosis.…”

Histological and parasitological distinctive findings in clinically-lesioned and normal-looking skin of dogs with different clinical stages of leishmaniosis

“…Conversely, previous studies included either dogs with more severe disease, i.e. exfoliative dermatitis [14] or even stray dogs, which could present co-factors, such as co-infections or malnutrition, affecting the severity of disease [12, 13]. …”

Pathology of dogs in Campo Grande, MS, Brazil naturally co-infected with Leishmania infantum and Ehrlichia canis

“…In fact, Leishmania dissemination to the skin in dogs and human beings appears to be a late event in the course of infection (HERWALDT, 1999;TRAVI et al, 2001;DOS SANTOS et al, 2004). Moreover, the presence of parasites in ear skin may be favored by injuries and auto-traumatism, which induce inflammatory reactions (TAFURI et al, 2001;XAVIER et al, 2006).…”