title: Beta2-microglobulin-containing IgG complexes in sera and synovial fluids of rheumatoid arthritis and systemic lupus erythematosus patients.
abstract: The occurrence and composition of complexed beta2-microglobulin (beta2m) in sera and synovial fluids of rheumatoid arthritis and systemic lupus erythematosus patients and control persons was investigated. Beta2m-containing complexes were detected in immune complex (IC)-enriched fractions isolated by precipitation with 3% polyethylene glycol 6000, in the macromolecular peaks after Sephadex G-200 gel filtration, and in IC desorbed from solid-phase Clq. Beta2m complexes were demonstrated also after precipitation of redissolved PEG-insoluble material by anti-human beta2m serum or isolation of the complexes by use of Sephadex-anti-beta2m. IgG was co-isolated with beta2m on Sephadex-anti-beta2m and free beta2m inhibited the binding of IgG to Sephadex anti-beta2m, indicating that IgG was present in the complexed beta2m. Analysis by SDS-polyacrylamide gradient electrophoresis under reducing conditions indicated that the purified beta2m complexes contained IgG and beta2m.
mesh_terms: D000936:Antigen-Antibody Complex / Q000032:analysis*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001609:Beta-Globulins / Q000276:immunology*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D013582:Synovial Fluid / Q000032:analysis / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000032:analysis / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D001609:Beta-Globulins; D007074:Immunoglobulin G; D001613:beta 2-Microglobulin