[Changes in the cell-mediated immune system in post-traumatic sepsis].

Objective: We studied the alterations of cell-mediated immunity (CMI) in polytrauma patients and its relation with sepsis.

Design: a prospective study.

Setting: ICU, Ospedale Maggiore, Bologna (Italy).

Patients: We included in the study 42 patients with at least two of following criteria: 1) Trauma Score < or = 12; 2) Abbreviated Injury Score > or = 4; 3) Arterial Pressure on admission < or = 80 mmHg; 4) Injury Severity Score > or = 16. CMI examinations were carried out at three different post-traumatic times (T0-T2). Seventeen patients developed a sepsis within the first eight days from admission.

Results: Sepsis caused a temporary impairment in some lymphocyte subsets at T2. The patients who developed sepsis showed a significant subset percentage difference for CD3, CD3 activated (p < 0.05) and for interleukin-2 receptor (IL-2R) (p < 0.01) in comparison with the non septic group. At T2, the seven septic patients who died, showed a marked depression of IL-2 values (0.37 +/- 0.12 UI/ml) in comparison with the values of septic patients who survived (0.66 +/- 0.25 UI/ml; p < 0.01) and with the group of non septic patients (0.83 +/- 0.5 UI/ml; p < 0.001). Septic patients who had a IL-2 value of 0.45 or lower had a mortality of 75%. IL-2 values showed a specificity of 89% and a sensibility of 75% in predicting mortality in septic trauma patients.

Conclusion: We believe that in polytrauma patients IL-2 values monitoring could be a reliable index of the disfunction of CMI and that IL-2R sieric levels could be a diagnostic marker of impending sepsis.