Best of 2021: Very high levels of IL-18 IL-18 (> 10 000 pg/ml) is associated with Macrophage Activation syndrome (with systemic JIA) as well as primary and secondary Hemophagocytic lymphohistiocytosis (HLH) https://t.co/FQPAHZTi4M https://t.co/UkNh2no123