The T cell phenotypes in the lesion of patients with cutaneous leishmaniasis

Leishmaniasis recidivans recurrence after 43 years: a clinical and immunologic report after successful treatment

We describe a patient with very late recurring leishmaniasis recidivans from whom lesional biopsy samples were obtained during and after topical steroid treatment that demonstrated the ability of the host to contain the parasite in the absence of therapy. Combination therapy with intralesional sodium stibogluconate and oral itraconazole was successful and immunologic data suggest that both CD4(+) and CD8(+) T cell subsets had roles in this disease process.

Cell populations in the lesion of human cutaneous leishmaniasis: a light microscopical, immunohistochemical and ultrastructural study

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.

Parasite antigens recognized by patients with cutaneous leishmaniasis

Humoral and cell-mediated responses to crude and purified parasite antigens were examined in patients with active cutaneous leishmaniasis caused by Leishmania major. The patients had serum antibody titres against parasite lysates ranging from 1/500 to 1/10,000 and recognized multiple components by Western blotting with molecular weights between 5000 and greater than 200,000. Several components, particularly at 5 and 50 kD, were recognized by most of the patients. The lymphoproliferative responses to two pure antigens, promastigote surface protease and lipophosphoglycan, both considered potential candidates for the development of a human vaccine were measured. No response to promastigote surface protease was observed even at 10 micrograms/ml; however, weak proliferation to lipophosphoglycan was consistently present. T cell blots examining peripheral blood lymphocyte proliferation, showed antigen-specific responses to a 72-82 kD component in promastigote lysates.