title: Rheumatoid factor isotypes in patients with rheumatoid arthritis and in subjects with "false-positive" reactions.
abstract: The appearance of RFs, as detected by standard serological techniques, often precedes the onset of clinical RA by years. This pre-rheumatoid immunological reactivity is not associated with C-reactive protein response or occurrence of antibodies against native type II collagen. The profile of RF isotypes appeared to be similar between pre-rheumatoid and rheumatoid sera. RA sera contained somewhat more frequently IgG and IgA class RFs than "false-positive" sera from a community-based population sample. 7S IgM could be detected at about the same frequency in rheumatoid sera, in RF-positive pre-rheumatoid sera and in sera with "false-positive" RF reactions. The significance of the findings in terms of the pathogenesis of RA will be discussed.
authors.affiliation: National Public Health Institute, Helsinki, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Aho
authors.forename: T
authors.initials: T
authors.lastname: Tuomi
authors.forename: A
authors.initials: A
authors.lastname: Heinonen
authors.forename: M
authors.initials: M
authors.lastname: Heliövaara
authors.forename: T
authors.initials: T
authors.lastname: Palosuo
mesh_terms: D000328:Adult; D000372:Agglutination Tests; D001172:Arthritis, Rheumatoid / Q000097:blood*; D005189:False Positive Reactions; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000032:analysis* / Q000276:immunology; D012217:Rheumatoid Factor / Q000032:analysis / Q000276:immunology*
chemical_list: D007132:Immunoglobulin Isotypes; D012217:Rheumatoid Factor