The invention concerns an artificial antigen specifically identified by the anti-filaggrin
autoantibodies present in the serum of patients suffering from rheumatoid polyarthritis,
and consisting of one polypeptide comprising all or part of the sequence of one
filaggrin unit or of a related molecule, in which an arginine radical has been
substituted by a citrulline radical. The invention also concerns the use of this
antigen for diagnosing rheumatoid polyarthritis.
