title: Selective presence of IgG2b inducing factor in synovial fluid of patients with rheumatoid arthritis.
abstract: The factor, that we have defined and called IgG2b inducing factor, in synovial fluid of rheumatoid arthritis patients (RA-SF) has previously been well characterized both in vitro and in vivo revealing that RA-SF induces a significantly higher IgG2b antibody production in LPS activated murine spleen cells. This activity was separated from the hitherto identified cytokines or factors in RA-SF. In this study we have compared the IgG2b inducing activity in RA-SF with synovial fluid from patients with non-RA arthritides. Here we show that the IgG2b inducing activity is significantly enriched in patients with RA compared to patients with non-RA arthritides and it is not found in healthy, post-traumatic, control groups. We do not yet know the implications of this finding for the disease progress of rheumatoid arthritis, but we believe that the identification of this B cell differentiation factor might elucidate the mechanism leading to hyperactivation of B cells in rheumatoid arthritis.
authors.affiliation: Department of Immunology, Arrhénius laboratories for Natural Sciences, Stockholm University, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Ridderstad
authors.forename: M A
authors.initials: MA
authors.lastname: Abedi-Valugerdi
authors.forename: H
authors.initials: H
authors.lastname: Strom
authors.forename: L
authors.initials: L
authors.lastname: Dahlstedt
authors.forename: E
authors.initials: E
authors.lastname: Möller
mesh_terms: D000818:Animals; D001168:Arthritis / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D013154:Spleen / Q000276:immunology; D013582:Synovial Fluid / Q000276:immunology*
chemical_list: D016207:Cytokines; D007074:Immunoglobulin G; D015850:Interleukin-6; D008070:Lipopolysaccharides