Patent ID: 8207299

Claim:
An isolated peptide recognized by anti-citrullinated protein autoantibodies (ACPAs) present in the serum of patients suffering from rheumatoid arthritis (RA), wherein said peptide comprises at least one citrullyl residue, and is chosen from the group consisting of: a peptide consisting of the sequence X 1 PAPPPISGGGYX 2 AX 3 (SEQ ID NO: 1) in which X 1 , X 2 and X 3 each represent a citrullyl residue or an arginyl residue, and at least X 3 is a citrullyl residue; and a peptide of 5 to 25 amino acids, comprising a fragment of at least 5 consecutive amino acids of the peptide consisting of SEQ ID NO:1, including at least X 3 as a citrullyl residue.