Polyarticular JIA is a form of arthritis that begins in children under the age of 16 and involves the inflammation of several joints. Because neutrophils (a type of white blood cell that is involved in immunity) are the most abundant cells within the synovial fluid of children with JIA, a multicenter team of scientists worked together to understand the role of neutrophils in polyarticular JIA (Arthritis Research & Therapy, September 2006).

They found that in children with polyarticular JIA, the genes that initiate neutrophil activation are seen in much higher levels than in children without JIA. They also discovered that even when their disease is well controlled, abnormalities in neutrophil gene expression persist. Their findings suggest that developing medications to inhibit neutrophil activity may limit the development and progression of polyarticular JIA.