Anti-cyclic citrullinated peptide (anti-CCP) antibodies in children with juvenile idiopathic arthritis

Area of Science:

• Rheumatology
• Immunology
• Pediatric Rheumatology

Background:

• Juvenile idiopathic arthritis (JIA) is a heterogeneous autoimmune disease.
• Identifying biomarkers for disease course and severity in JIA is crucial for effective management.
• Anti-cyclic citrullinated peptide antibodies (anti-CCP) are established markers in adult rheumatoid arthritis.

Purpose of the Study:

• To investigate the presence of anti-CCP antibodies in patients with JIA.
• To determine if anti-CCP antibodies can predict a more destructive disease course in JIA.
• To explore the association between anti-CCP antibodies and disease characteristics in JIA.

Main Methods:

• Serum samples from 71 JIA patients across various subtypes were analyzed using anti-CCP ELISA.
• Follow-up samples were tested to assess longitudinal antibody presence.
• Correlations between anti-CCP status and disease characteristics, medication, and radiological damage were evaluated.

Main Results:

• Anti-CCP antibodies were detected in 73% of polyarticular IgM-rheumatoid factor (RF) positive JIA patients, versus 3% in other JIA patients (p < 0.0001).
• While anti-CCP positive patients showed a higher prevalence of radiological damage (80%), this association was not significant when corrected for IgM-RF positivity.
• No significant differences in disease duration, medication, or anti-nuclear antibody status were observed between anti-CCP positive and negative groups.

Conclusions:

• Anti-CCP antibodies are detectable in JIA sera, but are almost exclusively found in the polyarticular IgM-RF positive subset.
• The presence of anti-CCP antibodies in JIA is strongly linked to IgM-RF positivity.
• Anti-CCP antibodies may not be an independent predictor of radiological damage in JIA when IgM-RF is considered.