OCCURRENCE OF ANTIPERINUCLEAR, ANTIKERATIN, AND ANTI-RA-33 ANTIBODIESIN JUVENILE CHRONIC ARTHRITIS

Objectives-Antiperinuclear factor (APF), antikeratin antibodies (AKA), and anti-RA 33 antibodies are currently considered to be good markers for the diagnosis of adult rheumatoid arthritis with or without rheum atoid factor (RF). The prevalence of these markers was retrospectively reviewed in children with juvenile chronic arthritis (JCA) to determi ne whether they were associated with specific features. Methods-One hu ndred and twenty-four patients with JCA participated in this study. Co ntrols included 28 patients with juvenile systemic lupus erythematosus and 21 healthy children. Antiperinuclear factor and AKA were determin ed by indirect immunofluorescence on buccal mucosal cells and oesophag us sections respectively. Anti-RA 33 antibodies were detected using a Western blot technique on HeLa cell nuclear extract. Results-Antiperin uclear factor was virtually absent in all the tested subgroups and ant i-RA 33 antibodies were detected only in a subset of patients with RF positive polyarticular onset. Antikeratin antibodies were found in 27% of all children with JCA and in 42% of those with RF negative polyart icular onset. These results were statistically significant compared wi th healthy controls, but the presence of AKA was not specific to any p atient subgroup. Moreover, in contrast with previous studies in adult RA, no relation was found between the presence of AKA and disease seve rity or activity. Conclusion-These data suggest that APF, AKA, and ant i-RA 33 antibodies are not useful for the diagnosis or classification of JCA.