Limitations in the classification of childhood-onset rheumatoid arthritis.
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%).


CONCLUSIONS
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.
From the Department of Pediatrics, and the Department of Human Genetics, Emory University School of Medicine; Children's Healthcare of Atlanta, Atlanta, Georgia, USA.
Emily G
EG
Ferrell
Lori A
LA
Ponder
Lauren S
LS
Minor
Sheila T
ST
Angeles-Han
Christine W
CW
Kennedy
Kelly A
KA
Rouster-Stevens
Mina
M
Rohani-Pichavant
Larry B
LB
Vogler
Sampath
S
Prahalad
D000293:Adolescent; D001171:Arthritis, Juvenile / Q000145:classification* / Q000175:diagnosis / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D010456:Peptides, Cyclic / Q000276:immunology; D012217:Rheumatoid Factor / Q000097:blood
D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor
CYCLIC CITRULLINATED PEPTIDE; JUVENILE IDIOPATHIC ARTHRITIS; RHEUMATOID ARTHRITIS; RHEUMATOID FACTOR; SEROLOGIC MARKERS