CRP and macrophage activation syndrome: In addition, children with MAS had significantly higher median concentrations of C-reactive protein (CRP) (189.08 vs. 129 mg/L), procalcitonin (8.35 vs. 1.855 ng/mL), ferritin (920.13 vs. 292.3 μg/L), D-dimers (3.78 vs. 2.4 mg/L), triglycerides (210 vs. 140 mg/dL), serum creatinine (0.65 vs. 0.48 mg/dL), urea (27 vs. 22 mg/dL), and activity of γ-glutamyl transpeptidase (40 vs. 20 U/L), and neutrophil count (9.4 vs. 7.04 103/μL).