title: Immunofixation improves the detection of monoclonal gammopathy of undetermined significance (M.G.U.S.) in patients with rheumatoid arthritis.
abstract: Monoclonal gammopathy of undetermined significance (MGUS) was detected by immunofixation (IFX) in 6% of patients with rheumatoid arthritis (RA), whereas it was detected by immunoelectrophoresis in only 1% of these patients. Most of the patients with both RA and MGUS had polyclonal B cell activation, together with their monoclonal band, extra-articular features and long-lasting disease, which suggests a direct relationship between MGUS and RA status.
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications*; D003430:Cross-Sectional Studies; D005602:France; D006801:Humans; D006942:Hypergammaglobulinemia / Q000150:complications*; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007158:Immunologic Techniques; D009101:Multiple Myeloma / Q000209:etiology; D008258:Waldenstrom Macroglobulinemia / Q000209:etiology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M