Decreased antioxidant capacity and increased oxidative stress in patients with juvenile idiopathic arthritis

Purpose: Juvenile idiopathic arthritis (JIA) is a common rheumatic disease in children which has three types. Systemic type goes with fever oligoarticular type involving joints are less than five and the polyarticular type more than five joints involved. Reactive oxygen species (ROS) have been implicated in its pathogenesis. The ROS generated damage proteins, lipids and serve to amplify the signaling pathways sustaining the synovitis. Enzymes such as superoxide dismutase (SOD) and catalase protect cellular systems from ROS. Our hypothesis is; patients with JIA could have defective defense mechanisms against ROS, which can vary from one type to other. Patients and Methods: We investigated antioxidant status including plasma SOD, catalase and serum ceruloplasmin levels in 25 JIA patients. Also, malondialdehyde (MDA), a product generated by the oxygenation of arachidonic acid, levels were measured. Results: Three patients had systemic; 10 with oligoarticular and 12 with polyarticular J A and control subject number is 20. Plasma SOD and catalase levels were lower, ceruloplasmin and MDA levels were higher were higher in the study group than in controls. There were a negative correlation between catalase, MDA and SOD levels in patients. In between JIA types; the lowest catalase and ceruloplasmin levels were found in oligoarticular type. Conclusively, present study suggested that patients with JIA have decreased antioxidant capacity and defective defense mechanism against ROS and this could be more evident in patients with oligoarticular JIA. In addition, elevated ceruloplasmin levels do not seem to protect against ROS in JIA.