Initial posttraumatic translocation of NF-kappaB and TNF-alpha mRNA expression in peripheral blood monocytes of trauma patients with multiple injuries: a pilot study

Abstract

Post-traumatic inflammation is connected to monocyte dysfunction characterized by reduced NF-kappaB translocation during the first post-traumatic days. Because the exact dynamic of monocytic NF-kappaB translocation in patients directly after trauma remains unclear, the aim of this pilot study was to measure the intranuclear presence of NF-kappaB in monocytes from patients with multiple injuries initially after the trauma and during the early post-traumatic period and to compare these results with downstream-placed mRNA expression alteration of TNF-alpha, as well as with clinical data. Eleven patients were enrolled with an Injury Severity Score of 16 to 66 points, and blood samples were drawn on admission within 90 min and at 6, 12, 24, 48, and 72 h after trauma. NF-kappaB translocation of monocytic nuclear protein was analyzed by electrophoretic mobility shift assay and was quantified by densitometry as arbitrary units. In addition, monocytes of healthy volunteers were analyzed either native (-, control) or after LPS stimulation (+, control). For determination of downstream mRNA encoding for TNF-alpha, quantitative reverse transcriptase-PCR was performed. For both parameters, the negative control values were set as baseline (=1) and results from positive controls and patients were given as a relative alteration ratio without unit. Initial post-traumatic NF-kappaB translocation was significantly increased in trauma patients on admission (88 +/- 37) and 6 h after trauma (59 +/- 28) compared with the baseline level. In contrast, TNF-alpha mRNA was not increased on admission (1.7 +/- 0.9) and decreased even below baseline after 12 h. The substantial information of our study arises from the analysis of the dynamic of NF-kappaB translocation of monocytes. Enabled by closely matched sequential blood sampling strictly standardized to the traumatic event, an essential increase of monocytic signal transduction and transcription could be elucidated in the very early post-traumatic period, which precedes the down-regulation of the innate immune system.