Diagnostic accuracy of anti-cyclic citrullinated peptide antibodies in juvenile idiopathic arthritis.

OBJECTIVE: To correlate serum anti-cyclic citrullinated peptide antibodies (anti-CCP) levels with juvenile idiopathic arthritis (JIA) subtypes and with an erosive disease course. METHODS: The study group comprised 122 children with JIA; 16 were evaluated during both active disease and remission. Nineteen children with systemic lupus erythematosus (SLE), 27 with rheumatoid arthritis (RA), and 15 healthy children were also included in the study. Twelve children with JIA were rheumatoid factor (RF) positive, and 34 patients had persistent erosive joint disease. Anti-CCP antibody levels were determined by ELISA; values above 5 relative units were regarded as positive. RESULTS: Three girls with seropositive polyarticular JIA and erosive joint disease had positive anti-CCP values. Children evaluated during active disease and remission, patients with SLE, and healthy children all had negative anti-CCP antibody levels. However, 19/27 (70%) adult patients with RA had positive anti-CCP antibody values. CONCLUSIONS: In contrast with RA, anti-CCP positivity is only rarely found in patients with JIA. In patients with RF positivity and/or in patients with erosive joint disease, anti-CCP can be detected.

Hepatitis B vaccination in children with juvenile idiopathic arthritis.

OBJECTIVES: To evaluate the responsiveness of children with juvenile idiopathic arthritis (JIA) to hepatitis B vaccination and to determine the most useful vaccination schedule. METHODS: 39 children with JIA were enrolled in the study; all were in remission and negative to serological testing for hepatitis B surface antigen (HbsAg). The control group consisted of 41 healthy children. There were two different vaccination schedules: group I was vaccinated at 0, 1, and 3 months; group II was vaccinated at 0, 1, and 6 months. Positive responsiveness to the vaccine was defined as an anti-hepatitis B antibody titre above 10 mIU/ml. RESULTS: All the children except one with systemic JIA developed an antibody response. None of the JIA patients experienced a flare up or clinical deterioration related to the vaccination. The antibody levels in children with JIA were significantly lower than in the healthy controls. Comparison of the antibody levels between the two vaccination schedules showed no statistical difference in the controls; in the JIA subjects the group II schedule resulted in a trend to a greater response than the group I schedule (p<0.07). Vaccine responsiveness was not influenced by either methotrexate or prednisolone treatment. CONCLUSIONS: Children with JIA had an adequate response to hepatitis B vaccination and the response was not affected by immunosuppressive treatment. A vaccination schedule at 0, 1, and 6 months seems to be preferable to 0, 1, and 3 months.