Fig. 1

Elevated extracellular histones in the plasma of ARDS patients. aMedian plasma histones were significantly increased in ARDS patients than in healthy controls (both p < 0.0001). b Plasma histone levels correlated with disease severity. Severe ARDS patients had higher extracellular histone levels than moderate or mild patients (all p < 0.05). c Median plasma histones were higher in nonsurvivor ARDS patients than those in survivors (p = 0.017). d Sequential plasma histone levels in ARDS patients at admission and days 3–5 and days 7–9. According to 28-day mortality, patients surviving the episode of ARDS (good prognosis) had a significant reduction in histone levels whereas nonsurvivors (poor prognosis) did not. Variables were expressed as median (interquartile range)