MULTIPLE TRAUMA CAUSES A DRASTIC SHIFT IN PERIPHERAL DENDRITIC CELL SUBPOPULATIONS

Abstract

: Dendritic cells (DC) represent the integral part of the innate immune system and are potent initiators of inflammation. Two distinct subsets of DC could be identified: Myeloid DC (MDC) and plasmacytoid DC (PDC), which differ widely in many respects. Thus, this study was conducted to assess whether the different phases after multiple trauma showed significant differences in the frequency of circulating MDC and PDC. PATIENTS AND METHODS: 30 patients (41 +/− 14 years) with multiple trauma (ISS 25 +/− 8) and 9 healthy volunteers (30 +/− 5 years) were enrolled. Blood samples were taken on admission (D0) and on the following 5 days in a daily manner. The Miltenyi blood dendritic cell enumeration kit was used for determination of PDC and MDC. Results are presented as mean +/− SEM. Kruskal-Wallis-Test with alpha-correction was used for statistical evaluation, P < 0.05 was considered significant. The study was approved by the local ethics committee. RESULTS: Patients on admission had a significantly lower percentage of DC compared to the control group (0.6 +/− 0.1 vs. 1.0 +/− 0.1). The percentage of total DC increased with the time to values of the control group but the ratio of MDC to PDC declined significantly from 0.9 +/− 0.2 at D0 to 0.3 +/− 0.1 at D4 (control 1.3 +/− 0.3). DISCUSSION: In this work we described for the first time that multiple trauma is accompanied with drastic subpopulation changes of the DC-compartment. PDC own a different receptor configuration and offer other functional properties than MDC. Thus, the PDC overbalance may contribute to the immunological alterations that are observed in multiple trauma.