Homocysteinylated alpha 1 antitrypsin as an antigenic target of autoantibodies in seronegative rheumatoid arthritis patients
Rheumatoid arthritis (RA) is a chronic autoimmune disease and rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) are the most frequently detected autoantibodies (autoAbs). To date, more than 20% of RA cases are still defined as seronegative forms (seronegative RA, SN-RA). The aim of this study was to identify new antigenic targets of autoAbs in RA patients, which can also be recognized in SN-RA. Using a proteomic approach, we tested sera from SN-RA patients by analyzing synovial fluid (SF) proteins from these patients.