KFD-MAS patients had lower absolute peripheral white blood cell (WBC, p = 0.02), platelet (p = 0.002), serum albumin levels (p = 0.01), and lymphocyte count (p < 0.0001), and higher lactate dehydrogenase (LDH) levels (p < 0.0001). Here, ALB is linked to macrophage activation syndrome.