Trauma patients with positive cultures have higher levels of circulating macrophage migration inhibitory factor (MIF)

Macrophage migration inhibitory factor (MIF) is a pituitary "stress" hormon e that plays a critical role in the host immune response. The aims of the s tudy were to determine whether MIF was detectable in the circulation of tra uma patients, to assess whether MIF levels were associated with injury seve rity, days post injury, infection, and to examine concentrations of other p ro-inflammatory cytokines in circulation. We collected plasma samples from 35 trauma (multiple injury) patients and 18 healthy controls. Concentration s of MIF, TNF-alpha, IL-1 beta, and IL-6 were measured by ELISA. Average MI F concentration in plasma of trauma patients was 14 fold higher than that o f healthy controls (19,439 +/-2,615 pg/ml in trauma Vs 1,337 +/- 286 pg/ml in control; p=0.0002). There was no correlation between MIF values and inju ry severity score or days post injury. Average level of IL-6 in trauma pati ents was 587 +/- 85 pg/ml but was not correlated with MIF concentration. TN F-alpha and IL-1 beta were not detectable in trauma patients or healthy con trols. Higher MIF levels were associated with positive cultures (blood, uri ne, sputum, wound). These data suggest that MIF may be a possible indicator of infection in trauma patients.