To the Editor:
Serum 14-3-3η is a novel joint-derived proinflammatory mediator implicated in the pathogenesis of rheumatoid arthritis (RA)1. Unlike rheumatoid factor (RF) or anticitrullinated protein antibody (ACPA), which can arise as a consequence of disease in sites distinct from inflamed joints, 14-3-3η hyperexpression in RA is restricted to synovial joints with a significantly higher expression in synovial fluid than matched serum2. In our recent report by Maksymowych, et al …
Address correspondence to Dr. S.J. Naides, Immunology 101A, Quest Diagnostics Nichols Institute, 33608 Ortega Highway, San Juan Capistrano, California 92629, USA. E-mail: stanley.j.naides{at}questdiagnostics.com