The present invention relates to a kind of polypeptide or protein, and one kind is for diagnosing or treating autoimmune disease subject, which is characterized in that protein derived from the polypeptide or protein, including one or more epitope DPPX. In addition, the present invention relates to the methods of polypeptide as nucleic acid or vector encoded, it includes to such carrier, it is related to in-vitro diagnosis method and test kit is related to the pharmaceutical composition of such polypeptide, comprising this kind of polypeptide, with medical device or be coated with this polypeptide pharmaceutical composition and treat autoimmune disease method in use.
