Biomarkers of Chronic Uveitis in Juvenile Idiopathic Arthritis: Predictive Value of Antihistone Antibodies and Antinuclear Antibodies

Abstract

Objective.To study the predictive value of antinuclear autoantibody (ANA) tests and antihistone antibodies (AHA) as risk factors for development of chronic asymptomatic uveitis of insidious onset in juvenile idiopathic arthritis (JIA).Methods.ANA by indirect immunofluorescence using HEp-2 cells (IF-ANA), ELISA for ANA (E-ANA), and AHA were analyzed in sera of 100 children with recent-onset JIA and in 58 control sera. Clinical features, including age at onset, JIA subgroup, and presence of uveitis, were recorded in this prospective population-based cohort study.Results.E-ANA was positive in 4 of the 100 sera, and was not associated with uveitis. Chronic uveitis developed in 16 children with JIA: in 14 of 68 positive for IF-ANA ≥ 80, and in 13 of 44 positive for AHA ≥ 8 U/ml. IgM/IgG AHA were found in higher proportions in children with uveitis (mean 12.4 U/ml) than in those with JIA and no uveitis (mean 6.9 U/ml) or in healthy controls (mean 4.3 U/ml).Conclusion.No association was found between E-ANA and uveitis, and most IF-ANA-positive sera were E-ANA-negative. E-ANA is not clinically relevant in this setting and should never be used to determine frequencies of eye examinations to detect new uveitis in JIA. AHA ≥ 8 U/ml, IF-ANA titer ≥ 320, and young age at onset of arthritis were significant predictors for development of chronic uveitis. The diagnostic value of AHA ≥ 8 U/ml as a biomarker of chronic uveitis in JIA is very similar to IF-ANA ≥ 80.