title: Seropositive versus seronegative rheumatoid arthritis--time for a new definition.
authors.forename: K
authors.initials: K
authors.lastname: Aho
authors.forename: P
authors.initials: P
authors.lastname: Kurki
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood / Q000145:classification* / Q000453:epidemiology / Q000276:immunology; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D015415:Biomarkers; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007633:Keratins / Q000276:immunology; D009031:Moscow / Q000453:epidemiology; D011379:Prognosis; D012217:Rheumatoid Factor / Q000097:blood*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D007633:Keratins; D012217:Rheumatoid Factor