Extensive citrullination of human serum albumin is physiological and not inherently immunogenic in rheumatoid arthritis.

ABSTRACT: Autoantibodies against citrullinated proteins are diagnostic of rheumatoid arthritis (RA), a chronic and systemic autoimmune condition that affects synovial joints. Proteomic studies have revealed that human serum albumin is among the proteins that are citrullinated in RA. Anti-citrullinated protein antibodies reacting with albumin have also been reported. Here, we show that albumin is citrullinated at 11 arginine residues in the blood of both RA patients and, surprisingly, in healthy donors and to a very similar stoichiometry, albeit with some subtle differences. Albumin citrullination exhibited slightly different patterns in synovial fluid from RA patients compared to RA serum-derived albumin, although overall stoichiometry was similar. Incubation of albumin with live neutrophils or reco

SUBMITTER: Mustelin C 

PROVIDER: S-EPMC12314391 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature