RT Journal Article SR Electronic T1 Limitations in the Classification of Childhood-onset Rheumatoid Arthritis JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 547 OP 553 DO 10.3899/jrheum.130563 VO 41 IS 3 A1 Emily G. Ferrell A1 Lori A. Ponder A1 Lauren S. Minor A1 Sheila T. Angeles-Han A1 Christine W. Kennedy A1 Kelly A. Rouster-Stevens A1 Mina Rohani-Pichavant A1 Larry B. Vogler A1 Sampath Prahalad YR 2014 UL http://www.jrheum.org/content/41/3/547.abstract AB Objective. Rheumatoid factor-positive polyarthritis (RF+ poly) is the juvenile idiopathic arthritis (JIA) category that resembles adult seropositive rheumatoid arthritis (RA). We studied children with RF+ and/or anticyclic citrullinated peptide antibody (anti-CCP)+ JIA to determine what proportion of those children meet International League of Associations for Rheumatology (ILAR) criteria for RF+ poly JIA and to assess for significant differences between children who meet RF+ poly criteria and those who are classified in other categories. Methods. Charts of children with JIA who were RF+ and/or anti-CCP+ were reviewed. Children with RF+ poly JIA were compared to children in other categories. Statistical analysis was performed using chi-square, Fisher’s exact test, and the Student’s t-test. Results. Of 56 children with RF+ and/or anti-CCP+ JIA, 34 (61%) met ILAR criteria for RF+ poly JIA. Twelve children had RF–/anti-CCP+ JIA with low anti-CCP titers. When these 12 children were excluded, there were few significant differences between children who met criteria for RF+ poly and those who were classified in other categories. The American College of Rheumatology/European League Against Rheumatism criteria for RA identified more RF+ children than did the ILAR RF+ poly classification (100% vs 77%). Conclusion. A number of children with RF+ arthritis were excluded from the RF+ poly JIA classification, though many demographic features and disease measures were similar to those of children who met criteria for RF+ poly JIA. We propose prioritization of RF/anti-CCP positivity over specific exclusions, along with inclusion of anti-CCP, in future revisions of the JIA classification criteria, to improve the sensitivity of diagnosing childhood-onset RA.