The extent of traumatic damage determines a graded depression of the endotoxin responsiveness of peripheral blood mononuclear cells from patients with blunt injuries

Objective: To study whether the endotoxin responsiveness of peripheral bloo d mononuclear cells correlates with the severity of injury in trauma patien ts. Design: Prospective, observational study, Setting: University trauma center. Patients: Fifty-nine patients with blunt trauma (Injury Severity Score [ISS ] 4 to 57 points). Interventions: Standard emergency department care, surgical care, and posto perative intensive care unit treatment, Measurements and Main Results: Whole blood and serum were obtained 94 +/- 8 9 (SD) mins post trauma (day 0) and during a 14-day period postinjury, Endo toxin-induced tumor necrosis factor-alpha (TNF-alpha) synthesis of peripher al blood mononuclear cells ex vivo was tested using a whole blood assay, Se rum samples were assayed for TNF-alpha concentrations, A reduced capacity o f whole blood to produce TNF-alpha ex vivo with endotoxin treatment was fou nd to be closely correlated with the ISS, The capacity to produce TNF-alpha on endotoxin stimulation of whole blood from patients with an ISS greater than or equal to 16 points was depressed immediately after trauma and did n ot reach normal values during the observation period, In patients with an I SS >22 points, maximum depression of the capacity of whole blood to produce TNF-alpha occurs within 100 mins post injury, In contrast, in patients wit h an ISS <22 points, maximal depression of whole blood TNF-alpha production occurs with a delay of 24 to 48 hrs after trauma, Based on pre- and postop erative values, primary surgical intervention caused a decrease of the endo toxin stimulated TNF-alpha production of whole blood in the latter patient subgroup, as well as in the entire patient population (ISS 4 to 57) when se condary surgical treatment was neccesary 5 to 13 days after trauma. Conclusions: The extent of traumatic tissue damage leads to a graded depres sion of immunocyte function and appears to be amplified by surgical treatme nt. The endotoxin responsiveness of peripheral blood mononuclear cells disp lays a functional marker of the anatomically defined severity of injury and gives insights into the regulation of immunocyte function after severe blu nt trauma.