CXCL8 and septic shock: In comparison with the concentrations of CRP, those of the acute-phase proteins PCT and PSP/reg and the pro-inflammatory cytokines IL-6 and IL-8 were significantly higher in patients with septic shock than in patients with severe sepsis, and the median PSP/reg concentration was about five times higher in patients with septic shock (343.5 ng/L) than in patients with severe sepsis (73.5 ng/L).