PYCARD and macrophage activation syndrome: Notably, in some severe cases among children, KD has been associated with macrophage activation syndrome, marked by significantly elevated levels of pyroptosis-related proteins, including apoptosis-associated speck-like protein containing CARD (ASC), caspase-1, IL-1β, IL-18, GSDMD, and LDH in their serum (Table 2) (23).