Zytokin-Expressionsprofile in infizierten Verbrennungswunden

Inspite of dramatic improvements in the management of burns, infection still remains a serious risk for the burn patient. Bacterial infection and thermal injury have been shown to trigger the inflammatory response. The aim of this study was to shed light on the impact of acute and subacute burn injury with or without infection on cytokine profiles. Sprague-Dawley rats (n =20) were randomized into three groups: 1) burn only 2) burn and bacteria (106 colony forming units of multi-drug resistant pseudomonas aeruginosa) and 3) sham burn. Animals in the first two groups received a 30% TBSA partial thickness burn. Weight changes were monitored daily. Blood was collected after 12,24,48,72 h and 6 and 12 days, and was used for cytokine ELISAs, LPS quantification, and peripheral blood analysis. Animals were sacrificed either after 6 or 12 days. Skin was harvested for bacterial counts, histological analysis and RNA isolation for microarray analysis. Infected animals showed substantial weight loss until day 6 postburn. We also found higher plasma levels (p <0.05) of IL-1β, TNF-α and IL-10 in the infected group compared to the uninfected burn group throughout the observation periods. The m-RNA expression levels showed no difference in cytokine expression, except for IL-1. Endotoxin levels were elevated significantly in the infected burn group during the first 2 days postinjury. Our results suggest that burn wound infection elicits a systemic and local release of cytokines with corresponding upregulation of m-RNA levels. High TNF-α levels were seen in the infected group during the initial period of weight loss, with a later significant upregulation of the anti-inflammatory cytokine IL-10 seen when weight gain resumed.