Immunology markers that can be predictive for the diagnosis of juvenile idiopathic arthritis

Background: This study aimed to investigate the implications of antinuclear antibodies (ANAs) in juvenile idiopathic arthritis (JIA), the association with uveitis and the favorable evolution of the disease. Methods: We followed 45 pediatric patients suffering from JIA, according to the International League of Associations for Rheumatology (ILAR), for a period of 2 years. ANAs were followed through immunofluorescence methods using a high-performance immunofluorescence automatic Helios device. Results: A total of 15 of the ANA-positive patients presented an oligoarticular form of the disease, eight of them presented a polyarticular form of the disease and two of them presented a systemic form. The most severe forms have associated iridocyclitis. ANA-positive patients presented an earlier onset of disease in comparison with ANA-negative ones. ANA-positive patients from different ILAR categories had similar characteristics of the disease such as onset age (earlier), higher prevalence in females and the presence of asymmetric arthritis or iridocyclitis. Conclusions: ANA may be an important marker for JIA and association with iridocyclitis. Following ANA titer in evolution might be a criterion for assessing the evolution of the disease. The association between positive ANA, oligoarticular JIA, iridocyclitis and a 2- to 4-year-old onset is common.