An atypical case of
acquired immunodeficiency syndrome-associated mucocutaneous lesions due to Leishmania braziliensis is described. Many vacuolated macrophages laden with amastigote forms of the parasite were found in the lesions.
Leishmanin skin test and serology for
leishmaniasis were both negative. The patient was resistant to
therapy with conventional drugs (antimonial and
amphotericin B). Interestingly, remission of lesions was achieved after an alternative combined
therapy of antimonial associated with
immunotherapy (whole promastigote
antigens). Peripheral blood mononuclear cells were separated and stimulated in vitro with Leishmania
antigens to test the lymphoproliferative responses (LPR). Before the combined immunochemotherapy, the LPR to leishmanial
antigens was negligible (stimulation index - SI=1.4). After the first course of combined
therapy it became positive (SI=4.17). The
antigen responding cells were predominantly T-cells (47.5%) most of them with CD8+ phenotype (33%). Very low CD4+ cells (2.2%) percentages were detected. The increased T-cell responsiveness to leishmanial
antigens after combined
therapy was accompanied by
interferon-g (IFN-g) production as observed in the cell culture supernatants. In this patient, healing of the
leishmaniasis lesions was associated with the induction of a specific T-cell immune response, characterized by the production of IFN-g and the predominance of the CD8+ phenotype among the Leishmania-reactive T-cells.