by American College of Rheumatology According to new research findings presented at the 2019 ACR/ARP Annual Meeting, adenosine deaminase 2 (ADA2) in the peripheral blood is a sensitive, specific biomarker for macrophage activation syndrome, a potentially life-threatening complication of systemic juvenile idiopathic arthritis (systemic JIA) (Abstract #920). About one child in every 1,000 develops some...