- Subjects must have a diagnosis of polyarticular juvenile idiopathic arthritis (JIA) age 4 to 17 by the American College of Rheumatology (ACR) criteria. Disease onset may have been systemic, polyarticular, or pauciarticular. If the disease was systemic onset, then the subjects must be free of any systemic JIA manifestations for at least 3 months before the time of qualification.