ANTI-CITRULLINE ANTIBODY ASSAY IN CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS

M.A.J. Van Rossum , R.M. Van Soesbergen , R. Ten Cate , S.W.K. De Kort , B.A.W. De Jong , A.H. Zwinderman , B.A.C. Dijkmans , W.J. Van Venrooij Pediatrics, Leiden University Medical Center, Leiden, Rheumatology, VU Medical Center, Jan van Breemen Instituut, Slotervaart Ziekenhuis, Amsterdam, Biochemistry, UMC St Radboud, Nijmegen, Epidemiology and Biostatistics, Amsterdam Medical Center, Amsterdam, NetherlandsObjectives: To determine if anti-citrulline antibodies (anti-CCP) can be detected in sera of patients with juvenile idiopathic arthritis (JIA) and if they can be used to identify patients with a more destructive disease course.Methods: 100 Serum samples of 71 JIA patients were tested by two different ELISA tests for anti-CCP. Of 27 JIA patients follow-up serum samples were tested. Relations were analysed between anti-CCP and disease characteristics, medication, and radiological damage (presence of joint space narrowing and/or erosions).Results: The tested serum samples came from patients of all 8 different subtypes of JIA patients (age mean 9.6, median 10.5 years) including 11 polyarticular rheumatoid factor positive (IgM-RF) patients. Anti-CCP was positive in 82% of the IgM-RF positive JIA patients and in 3% of the other JIA subtype patients (p<0.001). Disease duration, presence of clinical arthritis, medication use, and anti-nuclear antigen positivity did not differ significantly between anti-CCP positive and negative patients. Testing of follow-up samples showed almost identical anti-CCP results. All polyarticular IgM-RF positive JIA patients had radiological damage resulting in a significant difference between anti-CCP positive and negative patients (p=0.006).Conclusion: Anti-citrulline antibodies can be detected in sera of patients with juvenile idiopathic arthritis but almost exclusively in patients with polyarticular rheumatoid factor positive JIA. A possible relation with disease course within this group has to be studied further.1. - Schellekens GA, De Jong BAW, Van den Hoogen FHJ, Van de Putte LBA, Van Venrooij WJ: Citrulline is an essential constituent of antigenic determinants recognized by rheumatoid arthritis-specific antigens. J Clin Invest 1998;101:273-81.2. - Schellekens GA, Visser H, De Jong BAW, Van den Hoogen FHJ, Hazes JMW, Breedveld FC, Van Venrooij WJ: The diagnostic properties of rheumatoid arthritis antibodies recognizing a cyclic citrullinated peptide. Arthritis Rheum 2000;43:155-63.1. - Schellekens GA, De Jong BAW, Van den Hoogen FHJ, Van de Putte LBA, Van Venrooij WJ: Citrulline is an essential constituent of antigenic determinants recognized by rheumatoid arthritis-specific antigens. J Clin Invest 1998;101:273-81.2. - Schellekens GA, Visser H, De Jong BAW, Van den Hoogen FHJ, Hazes JMW, Breedveld FC, Van Venrooij WJ: The diagnostic properties of rheumatoid arthritis antibodies recognizing a cyclic citrullinated peptide. Arthritis Rheum 2000;43:155-63.Citation: , volume , supplement , year 2002, page Session: Paediatric rheumatology