title: Prevalence of anti-beta-2 microglobulin autoantibodies in sera of rheumatoid arthritis patients with extra-articular manifestations.
abstract: The frequency and concentration of specific factors binding beta 2 microglobulin were investigated in sera and synovial fluids of patients and in sera of normal controls. High anti-beta 2 m activity was detected in the sera of adult RA patients, particularly in those of with extra-articular disease. Similarly, anti-beta 2 m was present in the synovial fluids of RA but not of osteoarthrosis patients. Both the binding of anti-beta 2 m activity to the Sepharose staphylococcal protein A and its elution position in the second 'IgG' peak after Sephadex G-200 gel filtration suggest the antibody nature of the activity. The possibility of differences not only in titre but also in the specificity of heterologous and homologous anti-beta 2 m antibodies are discussed.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex / Q000032:analysis; D001171:Arthritis, Juvenile / Q000150:complications / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D001609:Beta-Globulins / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000032:analysis; D013205:Staphylococcal Protein A / Q000276:immunology; D013582:Synovial Fluid / Q000276:immunology; D001613:beta 2-Microglobulin / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D001609:Beta-Globulins; D013205:Staphylococcal Protein A; D001613:beta 2-Microglobulin; D012217:Rheumatoid Factor