title: American tegumentary leishmaniasis: a quantitative analysis of Langerhans cells presents important differences between L. (L.) amazonensis and Viannia subgenus.
abstract: A quantitative study was conducted on the density of Langerhans cells (LCs) CD1a+ in specimens obtained from patients with American tegumentary leishmaniasis (ATL) lesions without previous treatment, as well as from control healthy individuals. LC density was significantly higher among infected patients when compared to controls and also higher in longer term ones. Regarding parasite quantities, these were proportionally inverse and diminished in chronic patients. Localized cutaneous leishmaniasis (LCL) showed an increase in cell population when compared to diffuse cutaneous leishmaniasis (DCL). A tendency towards density increase was observed in LC Leishmania (Leishmania) amazonensis patients when compared to Leishmania (Viannia) sp. Regarding the delayed hypersensitivity test (DTH, Montenegro skin test), L. (L.) amazonensis demonstrated a peculiar behavior because it is a poor cell immune inducer, presenting--among LCL patients--higher density in negative Montenegro patients than in positive ones. Negative DTH responses are usually poor in LC, although this was not evidenced in this study, possibly due to cell reposition, in order to stimulate immune response. Such results confirm the important role of LC in ATL, while suggesting that L. (L.) amazonensis may be a good model for LC studies as APC in ATL, due to its spectral immunological and clinical behavior.
authors.affiliation: Departamento de Medicina Comunitária, Universidade do Estado do Pará, Perebebuí 2623, 66087-670 Belém, Pará, Brazil.
authors.forename: Marília Brasil
authors.initials: MB
authors.lastname: Xavier
authors.forename: Fernando Tobias
authors.initials: FT
authors.lastname: Silveira
authors.forename: Sâmia
authors.initials: S
authors.lastname: Demachki
authors.forename: Márcia Milene Rodrigues
authors.initials: MM
authors.lastname: Ferreira
authors.forename: José Luiz Martins
authors.initials: JL
authors.lastname: do Nascimento
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D018949:Antigens, CD1 / Q000378:metabolism; D005260:Female; D006790:Host-Parasite Interactions; D006801:Humans; D007801:Langerhans Cells / Q000276:immunology*; D007891:Leishmania / Q000145:classification / Q000276:immunology* / Q000472:pathogenicity*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology / Q000469:parasitology* / Q000503:physiopathology*; D016774:Leishmaniasis, Diffuse Cutaneous / Q000276:immunology / Q000469:parasitology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012882:Skin Tests
chemical_list: D018949:Antigens, CD1; C419393:CD1a antigen