[The prevalence of anti-cyclic citrullinated peptide antibodies in juvenile idiopathic arthritis].

OBJECTIVES To assess the presence of anti-cyclic citrullinated peptide antibodies in a cohort of patients with juvenile idiopathic arthritis. METHODS Anti-cyclic citrullinated peptide antibodies was tested for with an enzyme linked immunoabsorbent assay (ELISA) in serum samples of patients from the Hospital de Clínicas de Porto Alegre, all less than 18 years old and with previous diagnosis for at least 6 months. IgMRF (rheumatoid factor) and antinuclear antibodies in Hep-2 cells were also assayed. RESULTS Serum samples were analyzed from 45 patients. The presence of high levels of anti-cyclic citrullinated peptide antibodies was found in the serum of just one child (2%), who presented sero-positive polyarthritis. CONCLUSIONS Anti-cyclic citrullinated peptide antibodies can be detected in children with juvenile idiopathic arthritis, but much less frequently than in adults with rheumatoid arthritis. It still remains to be determined whether anti-cyclic citrullinated peptide antibodies can identify a subset of juvenile idiopathic arthritis patients with the potential to progress to adult rheumatoid arthritis.