HYSTOPATHOLOGY AND Leishmania sp. IMMUNOSTAINING IN THIRD EYELID OF Leishmania (Leishmania) chagasi NATURALLY INFECTED DOGS

Abstract Canine visceral leishmaniasis (CVL) is a disease with multisystemic injuries, and among the various tissues affected, the third eyelid (TE) is often involved. This ocular adnexa has been studied for the leishmaniasis pathogenesis elucidation and for diagnosis advance. This study aimed to carry out the parasite immunodetection and evaluate histologic lesions in TE of Leishmania (leishmania) chagasi naturally infected dogs. Twenty-six TE samples from infected dogs were submitted to histologic evaluation and to immunohistochemistry for Leishmania sp. The main lesion observed in the third eyelid conjunctiva (TEC) was lymphoplasmacytic inflammation, with Mott cells and parasitized histiocytes. Additionally, loss of epithelial stratification, ulceration, goblet cells thinning or hyperplasia were often found. The same inflammatory pattern was observed in the third eyelid lacrimal gland (TELG), often accompanied by acinar atrophy and secretory ducts dilatation. Immunohistochemistry revealed parasitism in all samples, in different intensities.