Snapshot assessment of RNA-expression in severely burned patients using the PAXgene™ Blood RNA System: A pilot study

Severe burn induces destabilization of the immune system and the likelihood of multiple organ dysfunction syndrome. Current studies focus on RNA-expression analyses of immune system cells, however, the present methods of analysis are complex, potentially altered by artefacts and therefore not feasible for routine analyses. The new PAXgene™ Blood RNA System provides “snapshot” analysis of RNA by immediate cell lysis and prevention of RNA-degradation. Using this system the aim of this study was to analyse intracellular cytokine RNA-expression under clinical conditions. Whole blood samples (PAXgene™ tubes) of nine severely burned patients were drawn at admission and 6, 12, 24, 48 and 72 h after trauma during routine treatment. Four healthy individuals served as control. Analysis of RNA-expression of TNF-alpha as pro-inflammatory and IL-10 as anti-inflammatory mediator was performed by RT-PCR. The RNA-expression of TNF-alpha was increased at 72 h after burn. The increase occurred mainly in surviving patients. In contrast, RNA-expression of IL-10 was elevated already at 24 h and the difference between surviving and deceased patients occurred earlier. We demonstrate for the first time a “snapshot” analysis of cytokine RNA-expression in severely burned patients under routine conditions. The results correspond well to current hypothesis of posttraumatic MODS development.