Open AccessAntibodies to synovial antigens in recent‐onset rheumatoid arthritis
Author(s) -
Mccol Geoffrey J.,
Cram David S.,
Harrison Leonard C.
Publication year - 1995
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780381009
Subject(s) - antigen , antibody , synovitis , rheumatoid arthritis , immunology , rheumatoid factor , synovial membrane , medicine , autoimmune disease , arthritis , immunoglobulin g , microbiology and biotechnology , biology
Objective . To identify synovial antigens that bind to serum antibodies from subjects with recent‐onset rheumatoid arthritis (RA) (<6 months of synovitis). Methods . Soluble and insoluble fractions of Triton X‐100 extracts of RA and normal synovial tissue, and normal spleen and placenta, were immunoblotted with sera from 27 patients with recent‐onset RA, 13 autoimmune disease control subjects, and 13 blood bank control donors. Bound immunoglobulin was probed with 125 I‐labeled protein A. Results . Antibodies in the sera of 20 (74%) patients with recent‐onset RA recognized at least 1 of 5 antigens in both a disease‐ and tissue‐specific and nonspecific manner. Anti‐La antibodies, usually associated with primary Sjögren's syndrome, were detected in 2 sera. Eight sera had increased reactivity to an IgG heavy and light chain dimer. There was strong binding of 8 sera with a 35‐kd doublet and of 3 sera with a 55‐kd species in RA and normal synovial lysates (insoluble fractions). Two sera uniquely recognized a 45‐kd protein only in the RA synovial lysate (soluble fraction). Conclusion . IgG antibodies in the sera of patients with recent‐onset RA show positive immunoblots for 3 novel synovial antigens of 35‐kd, 55‐kd, and 45‐kd, as well as for 2 previously characterized antigens (La and IgG). Thus, a variety of synovial antigens appear to be recognized by B cells even early in the clinical course of RA.