title: Autoantibodies and their target antigens in Sjögren's syndrome.
abstract: The subject of this review is the humoral autoimmune response in Sjögren's syndrome. Autoantibodies in this disease are primarily directed against the Ro/SS-A and La/SS-B autoantigens and against IgG (rheumatoid factor). The Ro/SS-A and La/SS-B autoantigens consist of a number of antigenic proteins coupled to small RNA molecules. These RNA-protein particles are present in all human cells and are strongly conserved throughout various species. Anti-Ro/SS-A and anti-La/SS-B autoantibodies can be detected using counter-immunoelectrophoresis, immunoblotting technique, ELISA or RNA precipitation assays. The preferred method of screening for anti-Ro/SS-A antibodies in human sera is counter-immunoelectrophoresis; anti-La/SS-B antibodies are best detected with the immunoblotting technique. Anti-Ro/SS-A antibodies are found in 60% of patients with Sjögren's syndrome, but are not specific markers for this disease. Anti-La/SS-B antibodies are present in approximately 40% of patients with Sjögren's syndrome; the only other disease where the antibody has been detected is systemic lupus erythematosus (15% positive). The origin and possible pathogenetic role of autoantibodies in Sjögren's syndrome is still unclear. Our view is that the current evidence supports a mechanism whereby autoantibodies are the product of an oligoclonal B-cell proliferation. The only instance where autoantibodies probably play a direct pathogenetic role is the occurrence of congenital heart block in the offspring of anti-Ro/SS-A and anti-La/SS-B positive mothers.
authors.affiliation: Department of Autoimmune Diseases, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam.
authors.forename: J F
authors.initials: JF
authors.lastname: Meilof
authors.forename: R J
authors.initials: RJ
authors.lastname: Smeenk
mesh_terms: D001323:Autoantibodies / Q000032:analysis / Q000737:chemistry; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology*; D006801:Humans; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D012859:Sjogren's Syndrome / Q000276:immunology*; D000097585:SS-B Antigen; D000099207:SS-A Antigen
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000097585:SS-B Antigen; D000099207:SS-A Antigen; C116006:RO60 protein, human