Juvenile idiopathic arthritis (JIA) is the most common form of arthritis in children. The etiology is unknown. Several types of arthritis fall under the JIA heading. Oligoarticular JIA with antinuclear antibodies affects about half of all children. There 's no specific markers. Our purpose is to identify new markers in this pathology. The ProtoArray®Human Protein Microarray allows rapid and efficient detection of protein interaction using a suitable protein or small molecule probe. The investigators hope so detect novel potential autoantigen biomarkers specific in JIA.