Inflammatory biomarkers showed increased cytokine levels in CLS patients: TNF-α (day 1: 1.8[0–3] vs. 0.5[0–1] ng/L, P = 0.038), IL-1ß (day 1: 0.4[0–1.2] vs. 0.2[0–0.5] ng/L, P = 0.019), IL-6 (day 1: 164[66–385] vs. 90[40–212] ng/L, P = 0.001), IL-8 (day 1: 115[68–272] vs. 54[30–106] ng/L, P < 0.001), and IL-10 (day 1: 7[3–16] vs. 4[2–7] ng/L, P < 0.001) showed higher serum concentrations in CLS patients. This evidence concerns the gene CXCL8 and capillary leak syndrome.