TY - JOUR T1 - Clinical Utility of Antipeptidyl Arginine Deiminase Type 4 Antibodies JF - The Journal of Rheumatology JO - J Rheumatol DO - 10.3899/jrheum.180905 SP - jrheum.180905 AU - Erika Darrah AU - Laura Martinez-Prat AU - Michael Mahler Y1 - 2019/01/15 UR - http://www.jrheum.org/content/early/2019/01/11/jrheum.180905.abstract N2 - Rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA) are important biomarkers in the diagnosis of rheumatoid arthritis (RA) but leave a gap of > 50% seronegative in early RA1. In addition, there is marked clinical heterogeneity in the seropositive group, precluding the use of RF and ACPA alone as prognostic biomarkers. These characteristics drive the demand for novel diagnostic and prognostic markers in RA1. ER -