Lingampalli N, et al. - In view of the observation that rheumatoid factor (RF) and/or anti-citrullinated protein antibodies (ACPAs) develop years prior to clinical diagnosis of rheumatoid arthritis (RA), researchers investigated the interaction between these two autoantibodies and their combined effect on development of RA. RF, cytokines, and ACPA subtypes were measured in serial pre-clinical serum samples collected from 83 US veterans who all developed RA. Observations suggested that the combined presence of ACPAs and RF was associated with a more rapid progression to RA, indicating anti-cyclic citrullinated peptide+/rheumatoid factor (RF)+ individuals to have a more advanced preclinical disease state and that the onset of RA may be imminent.