Differential immunostimulating effect of granulocytemacrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF) and interferon γ (IFNγ) after severe trauma

Objective: Severe trauma leads to an increased vulnerability to bacterial sepsis. In the present study, we compared the immunostimulating potential of granulocytecolony stimulating-factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma). Design: Prospective clinical experimental study. Setting: University hospital intensive care unit and research facility. Patients: 6 Patients with an Injury Severity Score (ISS) of more than 25 points. Interventions: Heparinized blood samples of severely injured patients and 12 healthy volunteers were incubated in vitro with 10ng/ml GM-CSF, 10ng/ml G-CSF or 10ng/ml IFN-gamma for 6 h. Measurements: Flow cytometry: HLA-DR expression on monocytes, B- and T-lymphocytes. ELISA: LPS-induced TNF alpha and IL-10 production. Results: In all patients reduced cytokine production and HLA-DR expression on monocytes was established. After administration of GM-CSF and IFN-y in vitro, the level of HLA-DR expression on monocytes and the ex vivo TNF alpha-synthesis increased while only GM-CSF increased significantly IL-10-liberation after LPS-stimulation. However, only IFN-y had the capacity to enhance HLA-DR on B- and T-Lymphocytes. G-CSF in vitro had no significant effect on the measured parameter. Conclusions: These data suggest that GM-CSF and IFN-y may serve to support immune functions in severely injured patients.