title: Metabolite-specific (IgG) and drug-specific antibodies (IgG, IgM) in two cases of trimethoprim-sulfamethoxazole-induced immune thrombocytopenia.
abstract: Two cases of trimethoprim-sulfamethoxazole (TMP-SMX)-induced immune thrombocytopenia are reported in which unusual drug-dependent platelet antibodies were demonstrated by immunofluorescence and enzyme-linked immunosorbent assay. Whereas two distinct sulfamethoxazole-dependent antibodies of the IgG and IgM class were detectable in the serum of one patient, the serum of the other patient contained a platelet antibody exclusively reactive with N-4-acetyl-sulfamethoxazole, a metabolite of sulfamethoxazole. Urine from a healthy volunteer collected after administration of therapeutic doses of TMP-SMX proved to be an appropriate source of ex vivo metabolites for antibody testing. The results of this study stress the role of metabolite-specific antibodies in drug-dependent immune thrombocytopenia and underscore the necessity of including metabolite preparations of drugs in serologic analyses.
authors.forename: V
authors.initials: V
authors.lastname: Kiefel
authors.forename: S
authors.initials: S
authors.lastname: Santoso
authors.forename: S
authors.initials: S
authors.lastname: Schmidt
authors.forename: A
authors.initials: A
authors.lastname: Salama
authors.forename: C
authors.initials: C
authors.lastname: Mueller-Eckhardt
mesh_terms: D000368:Aged; D000906:Antibodies / Q000276:immunology*; D000917:Antibody Formation; D000918:Antibody Specificity; D001792:Blood Platelets / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations / Q000009:adverse effects / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D013420:Sulfamethoxazole / Q000009:adverse effects* / Q000276:immunology; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000276:immunology; D014295:Trimethoprim / Q000009:adverse effects* / Q000276:immunology; D015662:Trimethoprim, Sulfamethoxazole Drug Combination
chemical_list: D000906:Antibodies; D004338:Drug Combinations; D007074:Immunoglobulin G; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D014295:Trimethoprim; D013420:Sulfamethoxazole