In the recent years, the role of IL-18 in the pathogenesis of secondary haemophagocytic lymphohistiocytosis (sHLH), also referred to as macrophage activation syndrome (MAS), in the context of autoinflammatory diseases, including sJIA, is emerging.
This suggests constitutive activation of the IL-1beta/IL-18-producing inflammasome, and supports the hypothesis that Schnitzler's syndrome is a new autoinflammatory disease.