Carbamylation Modification of Novel Synovial Fluid and Serum Proteins and Its Role of Anti-Carbanylated Protein Autoantibodies in the Clinic Association of Rheumatoid Arthritis Was Investigated

Rheumatoid arthritis is a chronic inflammatory disease associated with joint destruction. Inflammation of the joints are associated with autoimmune phenomena and erosion of cartilage and bone in rheumatoid synovitis. The myeloperoxidase (MPO) converts thiocyanate to cyanate that react with side chains of protein including lysine, cysteine, methionine, serine, threonine, tyrosine and arginine to form carbamylated protein adducts in inflammation process. Protein carbamylation links inflammation, smoking, rheumatoid arthritis (RA), Sjogren's syndrome (SS), systemic lupus erythematosus (SLE), diabetes mellitus, cataract, chronic kidney diseases, uremia and atherosclerosis. Anti-carbamylated proteins autoantibodies show high immunogenicity in diseases and contribute to the pathogenesis of several diseases including RA, SLE, atherosclerosis, primary SS, bronchiectasis, chronic kidney diseases and atherosclerosis. In preliminary research, we found four different novel wheat germ agglutinin (WGA)-bound carbamylated proteins in synovial fluid (SF) of RA patients compared to osteoarthritis (OA) patients, level of carbamylated protein adducts and anti-carbamylated BSA IgM in SF from RA patients are higher significant than OA patients, and level of carbamylated protein adducts and anti-carbamylated BSA IgM in serum from patients with RA are higher significant than OA patients and healthy controls. The goal of this study will validate carbamylation modification of novel synovial fluid and serum proteins and investigate the role of anti-carbanylated protein autoantibodies in the clinic association of rheumatoid arthritis.