Objective: Autoantibodies observed in patients with rheumatoid arthritis (RA) during clinical trials of immunomodulating agents may cause concern about possible induction of autoimmunity by the therapeutic intervention. We determined the frequency and variability of selected autoantibodies in patients with early rheumatoid factor (RF) positive RA during a prospective observational study.
Method: The study cohort consisted of 276 patients with active RA and with RF > or = 40 IU, who were enrolled between January 1, 1993, and April 1, 2000, before starting disease modifying antirheumatic drug (DMARD) therapy (average duration of symptoms, 7 mo).