Is there a correlation between the release of interleukin-12 and the clinical outcome of polytrauma patients?

Introduction: Interleukin-12-p70 (IL-12-p70) is a potent immunoregulatory c ytokine composed of a heavy chain (p40) and a light chain (p35). Contradict ing results have been reported with regard to leukocyte release and systemi c concentration of IL-12 after polytrauma. Methods: We daily analyzed syste mic concentrations of IL-12 in polytrauma patients (n = 37, mean ISS 33.9) in comparison to healthy donor values during intensive carl course by ELISA . Patients were divided according to their mean IL-12 levels into those wit h elevated IL-12 (group 1, n = 7), those with decreased IL 12 (group 21 n = 4) and those with IL-12 in the normal range (group 3, n = 26). Results: Pa tients in group 1 revealed elevated levels of IL-12 up to p70 > 1000 pg/ml and p40 > 2500 pg/ml. The common clinical feature of group I was a thorax t rauma in combination with pneumonia (85 % survivors). Patients with single thorax trauma or pneumonia without thorax trauma (group 3) showed normal IL -12 values. Patients with decreased IL-12 levels revealed also a thorax tra uma and pneumonia but all patients succumbed. The groups significantly diff er in their stay in the intensive care unit, in TISS, in MODS score and in respiratory ratio, but not in ISS, mean CRP values and leukocyte counts. Co rrelation analysis revealed no significant relation between systemically al tered IL-12 values and clinical parameters, with the exception of a negativ e correlation of p70 and ISS (r = -0.785) or MODS score (r = -0.314) in gro up 1. Conclusions: After major injuries there is no overall suppression of IL-12 formation. Patients with normal or elevated IL-12 levels belong mainl y to the survivors, whereas patients with decreased IL-12 levels are at hig h risk of succumbing to multi-organ failure.