title: Immune response to sulfamethoxazole in patients with AIDS.
abstract: Antibody- and cell-mediated responses to sulfamethoxazole (SMX) were analyzed in AIDS patients with or without a history of hypersensitivity and in negative controls. In 20 of 20 (P < 0.01) human immunodeficiency virus (HIV)-seropositive patients with skin reactions to cotrimoxazole, we found SMX-specific antibodies, while only 9 of 20 and 17 of 20 HIV-seropositive patients without a history of hypersensitivity to cotrimoxazole had SMX-specific immunoglobulin M (IgM) and IgG, respectively. The levels of specific IgM and IgG were higher in patients with skin reactions than in patients without reactions (IgM, 1.0 +/- 0.19 versus 0.47 +/- 0.23 [P < 0.001]; IgG, 0.68 +/- 0.15 versus 0.47 +/- 0.14 [P < 0.001] [mean optical density values +/- standard deviations]). Seronegative controls with no history of exposure to sulfa compounds did not have SMX-specific IgG or IgM antibodies, and controls with a history of intake of SMX with or without reactions had low levels of IgG and IgM. The SMX-specific IgG subclasses were exclusively IgG1 and IgG3. None of the patients had detectable SMX-specific IgE or IgA antibodies nor did they exhibit a cell-mediated response as measured by a lymphocyte proliferation assay. Antibodies to SMX recognized N-acetyl-sulfonamide, N-(2-thiazolyl)-sulfanilamide, sulfadiazine, and sulfisoxazole but did not recognize sulfanilamide or 3-amino-5-methyl isoxazole in an inhibition assay. It is not known whether the SMX-specific antibodies associated with hypersensitivity reactions to SMX in HIV-seropositive patients have a pathogenic role in these reactions. Sulfanilamide or 3-amino-5-methyl isoxazole, on the other hand, could be potential alternative therapies in HIV-seropositive patients with a history of skin reactions to SMX.
authors.affiliation: Department of Microbiology and Immunology, University of Ottawa, Ontario, Canada.
authors.forename: M P
authors.initials: MP
authors.lastname: Daftarian
authors.forename: L G
authors.initials: LG
authors.lastname: Filion
authors.forename: W
authors.initials: W
authors.lastname: Cameron
authors.forename: B
authors.initials: B
authors.lastname: Conway
authors.forename: R
authors.initials: R
authors.lastname: Roy
authors.forename: F
authors.initials: F
authors.lastname: Tropper
authors.forename: F
authors.initials: F
authors.lastname: Diaz-Mitoma
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000328:Adult; D000917:Antibody Formation / Q000187:drug effects; D000918:Antibody Specificity; D004342:Drug Hypersensitivity / Q000209:etiology / Q000276:immunology; D006241:Haptens / Q000032:analysis; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007223:Infant; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D013420:Sulfamethoxazole / Q000009:adverse effects* / Q000097:blood; D013449:Sulfonamides / Q000276:immunology / Q000494:pharmacology; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use
chemical_list: D006241:Haptens; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D013449:Sulfonamides; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D013420:Sulfamethoxazole