Associations of erosive arthritis with anti-cyclic citrullinated peptide antibodies and MHC Class II alleles in systemic lupus erythematosus.

The frequency of EA in SLE is likely to be higher than previously reported. Anti-CCP+ patients with SLE are more likely to have EA. Anti-CCP may be a useful serological marker for EA for patients presenting with synovitis. Anti-citrulline antibodies may have a pathogenic role in the development of major erosions, resulting in clinical features that overlap SLE with RA (rhupus).