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

Objective: To determine the associations of erosive arthritis (EA) with anti-cyclic citrullinated peptide (anti-CCP) antibodies and major histocompatibility class (MHC) II alleles in systemic lupus erythematosus (SLE).

Methods: One hundred four patients with SLE were evaluated for arthritis and classified as EA, nonerosive arthritis, or no arthritis. EA was further classified as major or minor erosions.