title: Autoantibody-mediated bone loss.
abstract: In rheumatoid arthritis (RA), the presence of autoantibodies such as the rheumatoid factor and antibodies against citrullinated proteins is highly correlated with the severity of disease and bone loss. For many years, the involvement of autoantibodies in bone resorption has merely been attributed to enhanced tissue infiltration and the production of inflammatory cytokines that promote osteoclastogenesis. However, recent research provides evidence for a direct activation of osteoclasts and their precursors by autoantibodies, which is independent of inflammation. The depletion of B-cells with rituximab that substantially reduces autoantibody levels seems to be as effective as the well-established treatment with tumor necrosis factor-antagonists in RA patients that do not respond to methotrexate, highlighting the significance of autoantibodies for RA and bone loss.
authors.affiliation: Department of Internal Medicine 3, University of Erlangen-Nuremberg, Erlangen, Germany, Ulrike.Harre@uk-erlangen.de.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Harre
authors.forename: Nicolai A
authors.initials: NA
authors.lastname: Kittan
authors.forename: Georg
authors.initials: G
authors.lastname: Schett
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D001862:Bone Resorption / Q000276:immunology*; D006801:Humans; D010010:Osteoclasts / Q000502:physiology*; D010456:Peptides, Cyclic / Q000276:immunology; D012217:Rheumatoid Factor / Q000276:immunology; D000069283:Rituximab; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D018501:Antirheumatic Agents; D001323:Autoantibodies; D010456:Peptides, Cyclic; D014409:Tumor Necrosis Factor-alpha; C487763:cyclic citrullinated peptide; D000069283:Rituximab; D012217:Rheumatoid Factor