Estudio comparativo entre las técnicas convencionales e inmunohistoquímicas para el diagnóstico de leishmaniosis canina

Abstract

In canine leishmaniosis, amastigotes can be revealed by Giemsa staining on samples of lesions from skin, spleen, liver, bone marrow and lymph nodes. A positive result must be considered with only one parasitized cell. The diagnosis can be unsuccessful because of the low sensitivity of traditional methods to detect the parasite. Immunohistochemical methods to detect Leishmania sp are simple, they do not need special equipment, and are highly sensitive and specific. The aim of this work was to evaluate techniques that are considered more sensitive and specific to diagnose visceral leishmaniosis. Samples were obtained from dogs from areas of argentine north-east. Forty two canines with positive serum diagnosis to Leishmania sp were selected for the extraction of bone marrow and skin samples in order to perform HE staining and immunohistochemistry. In bone marrow of 42 animals Leishmania amastigotes were observed using Giemsa stain. Immunohistochemistry revealed a 70% of positives to the parasite. In histological samples, Leishmania amastigotes were observed in 100% with immunohistochemistry, while only 65% were positive with HE stain. In paraffin embedded blocks, immunohistochemical technique is more sensitive for the detection of Leishmania amastigotes. Giemsa stain was more useful as it allowed the observation of not only Leishmania sp but also other types of microorganisms.