title: Cell populations in the lesion of human cutaneous leishmaniasis: a light microscopical, immunohistochemical and ultrastructural study.
abstract: To characterize the in situ cellular immune response in localized cutaneous leishmaniasis (LCL), the authors studied frozen skin biopsies from 50 patients with LCL due to Leishmania braziliensis guyanensis. A panel of 31 monoclonal antibodies was used, which defined the number and distribution of inflammatory cell subsets. Skin inflammatory infiltrates were composed of T cells (with a local CD4/CD8 ratio of 1.05 +/- 0.7 vs 1.48 +/- 0.3 in peripheral blood), macrophages and a smaller number of B cells, natural killer cells and granulocytes. Most of the T cells expressed activation markers (interleukin-2 and transferrin receptors, HLA-DR+) and an increase in T-cell-receptor gamma delta expression was noted. Analysis of the CD4+ subpopulations with newly available reagents showed that helper T cells (CD4+CD45RO+) exceeded the suppressor/inducer subset (CD4+CD45RA+) by 1.4:1. There were no differences between local immune variables from patients with primary infection (45 patients) and those with recurrence (5). In 7 patients, biopsies were analysed before and 1 month after specific treatment, and did not show significant differences except for a small increase of dermal CD1a+ (Langerhans) cells/mm2. The observed pattern of cellular skin infiltration suggests an immune-mediated tissue injury including T-cell-mediated cytotoxicity and delayed hypersensitivity reactions in addition to direct parasitic action.
authors.affiliation: Laboratoire de Parasitologie, Institut Pasteur de Guyane, Cayenne, French Guiana.
authors.forename: P
authors.initials: P
authors.lastname: Esterre
authors.forename: J P
authors.initials: JP
authors.lastname: Dedet
authors.forename: C
authors.initials: C
authors.lastname: Frenay
authors.forename: M
authors.initials: M
authors.lastname: Chevallier
authors.forename: J A
authors.initials: JA
authors.lastname: Grimaud
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D016516:CD4-CD8 Ratio; D006098:Granulocytes / Q000276:immunology; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007694:Killer Cells, Natural / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000628:therapy; D008264:Macrophages / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000032:analysis; D011990:Receptors, Transferrin / Q000032:analysis; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D006684:HLA-DR Antigens; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin