Excerpt
To the Editor:
Anti-citrullinated protein antibodies (ACPA) are highly specific for rheumatoid arthritis (RA) and precede the onset of clinical symptoms by several years, with increasing titers as patients approach disease onset1,2. The synovium is the primary site of pathology in RA, and ACPA are readily detectable in the synovial fluid and tissue of patients with RA3. The transition from asymptomatic autoimmunity to clinically detectable synovitis is not well understood. We describe the serological and synovial features of a young woman from a multi-case RA family who initially had asymptomatic autoimmunity, then subsequently developed clinical features suggestive of early RA...