Identification of lipopolysaccharide‐binding protein as a novel citrullinated autoantigen in rheumatoid arthritis

Background A specific feature of the autoimmune response in rheumatoid arthritis (RA) is presence anti-citrullinated protein antibodies (ACPAs) patient sera. These can appear several years before disease onset and are involved development RA. Objective We performed proteomic analysis by mass spectroscopy to identify novel citrullinated antigens autoantibodies RA patients. Methods Polypeptides isolated from sera patients were identified Orbitrap high-precision spectrometry then citrulline-containing proteins selected. The levels ACPAs against these newly autoantigens 100 50 healthy controls determined enzyme-linked immunosorbent assays. Results total 135 profile included 11 antigens. Three had been reported previous studies. epitopes increased compared with those controls. Autoantibodies one antigens, lipopolysaccharide-binding (LBP), was significantly associated activities. titer LBP (anti-cLBP) closely related infection incidence Conclusion Serum technology a feasible method Anti-cLBP severity