CXCL8 and respiratory failure: As shown in Fig 1, high plasma IL-8/CXCL8 [median(IQR), 17.6(5.9–27.3) vs 4.3(3.6–9.0) pg/mL, P<0.001) and IL-6 [16.2(7.4–37.7) vs 8.7(5.5–15.0) pg/mL, P = 0.026] concentrations were significantly associated with development of respiratory failure; the same cytokines were also associated with ICU admission/death.