It is provided polypeptides reacting with rheumatism-associatedautoantibodies, polypeptidescomprising the sequence of native vimentin of SEQ ID NO:1, wherein itcomprise, comparedto the native sequence SEQ ID NO:1, in at least one of positions 16, 17, 19,41, 58, 59, 60,68, 76, 140, 142, 147, 363 or 452 one additional arginine residue and exhibitsa reactivity torheumatism-associated autoantibodies. It is further provided a diagnosticagent comprisingany of the polypeptides, a diagnostic kit comprising the diagnostic agent anda process for invitro detection of rheumatic diseases.
