ABSTRACT
BACKGROUND: Tegumentary leishmaniasis and leprosy display similar spectra of disease phenotypes, which are dependent on cell-mediated immunity to specific antigens. Diffuse cutaneous leishmaniasis and lepromatous leprosy represent the anergic end of the spectrum, whereas mucocutaneous leishmaniasis and tuberculoid leprosy are associated with marked antigen-specific cellular immune response. METHODS: We characterized and compared the cell-mediated response to Leishmania and Mycobacterium leprae antigens in a patient with an intriguing association of mucocutaneous leishmaniasis with lepromatous leprosy, which are at opposite ends of the immunopathological spectra of these diseases. This was done by performance of skin tests and by assessment of the cell proliferation and cytokine production of peripheral blood mononuclear cells (PBMCs). RESULTS: Strong skin-test reactions and PBMC proliferation were observed in response to Leishmania antigens but not to M. leprae antigens. The stimulation of PBMCs with Leishmania and M. leprae antigens induced comparable levels of tumor necrosis factor- alpha , interleukin-5, and interleukin-10. However, the interferon- gamma response to Leishmania antigens was remarkably high, and that to M. leprae antigens was almost nil. CONCLUSIONS: We found that concomitant leprosy and tegumentary leishmaniasis can produce opposite polar forms associated, respectively, with absent or exaggerated cell-mediated immune responses to each pathogen. This suggests that independent mechanisms influence the clinical outcome of each infection. Moreover, interferon- gamma appears to play a major role in the clinical expression of these intracellular infections.
Subject(s)
Antigens, Bacterial/immunology , Antigens, Protozoan/immunology , Interferon-gamma/metabolism , Leishmaniasis, Mucocutaneous/immunology , Leprosy, Lepromatous/immunology , Animals , Antiprotozoal Agents/therapeutic use , Cell Proliferation , Humans , Leishmania/immunology , Leishmaniasis, Mucocutaneous/drug therapy , Leishmaniasis, Mucocutaneous/metabolism , Leprostatic Agents/therapeutic use , Leprosy, Lepromatous/drug therapy , Leprosy, Lepromatous/metabolism , Male , Middle Aged , Mycobacterium leprae/immunology , Neutrophils/immunology , Neutrophils/metabolism , Skin TestsABSTRACT
Flow cytometry has been used as a powerful technique for studying cell surface antigen expression as well as intracellular molecules. Its capability of analyzing multiple parameters simultaneously on a single cell has allowed identification and studies of functional cell subsets within heterogeneous populations. In this respect, several techniques have been developed during the past few years to study cytokine-producing cells by flow cytometry in humans and several animal models.
