A deiminated viral peptide to detect antibodies in rheumatoid arthritis.

The data presented suggest that a deiminated viral peptide is specifically recognized by antibodies contained in rheumatoid arthritis (RA) sera. Antipeptide antibodies are not associated with the presence or severity of specific manifestations of RA, but are more frequent in subjects with erosive arthritis. Taking into account the association with rheumatoid factor and with erosive arthritis, we can conclude that antipeptide antibodies are markers of severe forms of RA. Our data also show familial aggregation of anticitrullinated peptide antibodies.