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.

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Résumé.Poursuivant l'analyse systémique du foyer leishmanien des Cévennes méridionales, les auteurs exposent le résultat d'une étude des diverses formes, spontanées et provoquées, de la maladie canine ; cette étude basée sur une expérimentation au long cours et sur les données d'enquêtes, prend en compte simultanément, l'évolution clinique, parasitologique et immuno logique. Les deux types nosologiques classiques, patent et latent, sont confirmés. Le type latent est lui-même composé de formes précliniques, les plus fréquentes (environ 90 %), et de formes résolutives (environ 10 %). L'importance épidémiologique d'une telle distinction est soulignée. Ainsi, les états prépatents, souvent fort longs, peuvent permettre au parasite de se maintenir, plusieurs années durant, sans faire appel à la transmission vectorielle. En fait, l'établissement des fréquences et des durées de ces diverses formes constituent autant d'indices indispensa bles à l'amélioration des modèles théoriques, actuellement proposés. Summary.Ecology of leishmaniasis in the south of France. 10. Developmental stages and clinical characterization of canine leishmaniasis in relation to epidemiology.In an analytical study of a focus of leishmaniasis in Southern France (Cévennes), a clini cal, parasitological and immunological comparison was made of dogs with natural and expeAccepté le 30 mars 1979.Article available at http://www.parasite-journal.org or https://doi.org/10.1051/parasite/1979543277 278 G. LANOTTE ET COLLABORATEURS rimental infections of leishmaniasis. Observations were made in longterm laboratory expe riments and on dogs found infected in field surveys. Two main clinical forms, patent and latent, were apparent. The latent form could be further subdivided into two types namely preclinical (the commonor: about 90 %) and resolving (about 10 %). The epidemiological significance of these distinctions is emphasized. Prepatent states, often lasting for very long periods, can result on the maintenance of the parasites for several years without the need for transmission by the vector. The prevalence and duration of the different forms of disease in dogs are thought to be of great importance in the epidemiology of leishmaniasis in foci in which canids are reservoir hosts.