title: Differing antibody IgG isotypes in the polar forms of leprosy and cutaneous leishmaniasis characterized by antigen-specific T cell anergy.
abstract: Leprosy and American cutaneous leishmaniasis are tropical diseases which present a spectrum of clinical and immunological manifestations. Lepromatous leprosy and diffuse cutaneous leishmaniasis are the severe, progressive polar forms of disease characterized by persistent T cell anergy. Relative concentrations of antibodies belonging to the four IgG isotypes have been determined in these forms of disease as well as active visceral leishmaniasis, which presents transitory T cell anergy. Leishmania-specific IgG4 antibodies predominated in 19/20 sera from patients with diffuse cutaneous leishmaniasis, and IgG1 antibodies predominated in 9/10 cases of untreated visceral leishmaniasis. The predominant IgG isotype of Mycobacterium leprae-specific antibodies in untreated lepromatous leprosy was remarkably variable (IgG1, IgG2, IgG3 and IgG4 in 8, 6, 2 and 1 sera, respectively). Differing IgG antibody isotypes have been associated with distinct CD4+ T cell helper subpopulations and their characteristic lymphokine profiles in several pathologies. These results suggest that T cell anergy in chronic intracellular infections may be associated with as yet undefined mechanisms which modulate reported T helper cell-lymphokine isotype relationships.
authors.affiliation: Instituto de Biomedicina, Universidad Central de Venezuela, Caracas.
authors.forename: M
authors.initials: M
authors.lastname: Ulrich
authors.forename: V
authors.initials: V
authors.lastname: Rodriguez
authors.forename: M
authors.initials: M
authors.lastname: Centeno
authors.forename: J
authors.initials: J
authors.lastname: Convit
mesh_terms: D000328:Adult; D002908:Chronic Disease; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007132:Immunoglobulin Isotypes / Q000276:immunology*; D016774:Leishmaniasis, Diffuse Cutaneous / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology; D015440:Leprosy, Lepromatous / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes