Tolerogenic citrullinated peptide for arthritis

Disease-specific autoantibodies directed against post-translation citrullinated proteins/peptides (ACPAs) are specific serological markers for rheumatoid arthritis (RA) and have been accepted as one of the classification criteria for the disease. Beyond diagnosis these autoantibodies have also been shown also to predict disease severity. These autoantibodies can be detected several years prior to the clinical onset of RA, with increasing titers overtime, as disease onset is established. Citrullination is a post-translational modification of proteins in which arginine is converted into citrulline, an unnatural amino acid which is not encoded by DNA. The reaction is catalyzed by calcium-dependent peptidyl arginine deiminase (PAD). Citrullinated proteins have been detected in the synovial membranes and synovial