[Detection of Leishmania (Viannia) braziliensis in vascular endothelium lesions of patients with localized cutaneous leishmaniasis]

Abstract

In the present study, we examined the cutaneous lesions of 8 patients with cutaneous leishmaniasis, from regions situated near the rivers Chama-Mocoties, in Merida state, Venezuela. The lesions of the patients were diagnosed on the basis of clinical, parasitological and immmunological examinations. The Polymerase Chain Reaction (PCR) assay showed infection by Leishmania (Viannia) braziliensis in cutaneous lesions samples. Histopathology of skin biopsy specimens showed inflammatory infiltrates of mononuclear and polymorphonuclear leukocytes. Granulomatous reactions and amastigotes were observed in the dermis. The histological sections of the cutaneous lesions in one patient (No. 5), showed alterations in the integrity of dermal blood vessels, leishmanial antigens on the superficial endothelium and free parasites in the capillary lumen and inside mononuclear cells. The Leishmania amastigotes also were detected in the cytoplasm of neutrophils in Giemsa-stained imprints. The skin biopsies examined using immunofluorescence (IFI) and immunoperoxidase assay (PAP), show amastigotes and antigenic material adsorbed on the vecinity of the walls of dermal microvessels. Based on these results, we concluded that in the cutaneous lesions it is possible to show the presence of intra and extracellular parasites, attached to wall of the dermal blood vessels and free, in the capillary lumen. The circulating parasites in peripheral blood may allow the possibility of developing secondary infections as well as the propagation of the infection in endemic areas of leishmaniasis, where the parasite circulates between domestic and wild reservoirs, vector insects and humans living in those areas.