Association between mast cells, tissue remodelation and parasite burden in the skin of dogs with visceral leishmaniasis

• Published in: Veterinary parasitology Vol. 243; pp. 260 - 266
• Main Authors: Cardoso, Jamille Mirelle de Oliveira, Ker, Henrique Gama, Aguiar-Soares, Rodrigo Dian de Oliveira, Moreira, Nádia das Dores, Mathias, Fernando Augusto Siqueira, Reis, Levi Eduardo Soares, Roatt, Bruno Mendes, Vieira, Paula Melo de Abreu, Coura-Vital, Wendel, Carneiro, Cláudia Martins, Reis, Alexandre Barbosa
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30-08-2017
• Subjects: Animals; Canine visceral leishmaniasis; Dog Diseases - parasitology; Dog Diseases - pathology; Dogs; Female; Histopathology; Leishmania infantum; Leishmaniasis, Visceral - parasitology; Leishmaniasis, Visceral - pathology; Leishmaniasis, Visceral - veterinary; Male; Mast cells; Mast Cells - physiology; Parasite load; Skin; Skin - parasitology; Skin - pathology; Skin; Mast cells; Histopathology; Canine visceral leishmaniasis; Parasite load
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2017.05.028

•The OD and SD dogs presented higher parasite burden in the ear skin than the AD dogs.•The histological evaluation of the skin of infected dogs showed an inflammatory reaction and the intensity varied according the clinical status.•It was observed a predominance of type III collagen fibers in the evaluated groups in relation to the normal pattern represented in the CD group.
Canine visceral leishmaniosis (CVL) is a zoonosis of major public health impact caused by organisms of the genus Leishmania which is transmitted to human and animals by phlebotomine sand flies. The skin is the first point of contact with Leishmania parasites for sandy fly vectors and it is considered an important reservoir compartment in infected dogs. The aim of this study was to determine the main histophatologic alterations in ear skin of dogs naturally infected by Leishmania infantum with different clinical status and different degrees of parasitism. Therefore, thirty-four dogs naturally infected with L. infantum were grouped according to their clinical status in asymptomatic (AD, n=11), oligosymptomatic (OD, n=11) and symptomatic dogs (SD, n=12) as well as their degrees of parasite load in the skin as low (LP, n=11), median (MP, n=11) and high (HP, n=12) parasitism. Additionally, ten dogs were used as control (CD, n=10). At necropsy, skin samples were collected for further histological and parasitological analysis. The OD and SD groups presented higher parasite burden than AD group. The inflammation was higher in SD group when compared to OD and AD. The LP, MP and HP groups showed an increasing inflammatory process, indicating that a great parasite load is accompanied by a major inflammatory process in the skin. The number of mast cells was higher in the OD and LP groups than CD group, suggesting that these cells may be involved in tissue remodeling, since that an increase of type III collagen fibers and decrease type I collagen fibers were observed in these groups. Taken together, our results enable a better understanding of the alterations in skin of CVL dogs and consequently new insights about the pathogenesis of CVL.