Sequential systemic platelet-activating factor and interleukin 8 primes neutrophils in patients with trauma at risk of multiple organ failure

Plasma from 33 patients at risk of multiple organ failure (MOF) after major trauma was tested for a priming effect on neutrophils, and for the presence of platelet-activating factor (PAF) activity and interleukin (IL) 8. Plasma sampled at 3, 6, 12 and 24 h after injury significantly primed normal neutrophils to release mean(s.e.m.) 1.26(0.19), 1.33(0.26), 1.04(0.14) and 0.86(0.13) nmol superoxide per min per 1.3 x 10(6) neutrophils respectively (P<0.05). Priming at 3 h after injury was inhibited by mean(s.e.m.) 63.8(7.0) per cent by the PAF antagonist, WEB 2170 (P<0.01). Mean(s.e.m.) plasma IL-8 was raised at 6 and 12 h after injury to 785(183) and 836(175) pg/ml (P<0.01). At 12 h after injury the plasma IL-8 level correlated directly with the number of units of red blood cells transfused (r=0.64, P<0.01), and was significantly higher in the group of six patients who developed MOF (P<0.05). These data suggest that after trauma the mediators PAF and IL-8 appear sequentially in the circulation, are potential mechanisms of circulating neutrophil priming, and that IL-8 may also be an early biochemical marker predicting the onset of MOF.