The effect of severe burn injury on proinflammatory cytokines and leukocyte behavior: its modulation with granulocyte colony-stimulating factor

Severe injury causes immunosuppression, The main contributors are impaired leukocyte function and a cytokine dysbalance. GCSF increases PMN count, fun ction and modulates the inflammatory response. However GCSF may overactivat e leukocytes. The purpose of this study is to investigate whether GCSF is a ble to restore immune competence after severe injury. Lewis rats were divid ed into three groups: 30% TBSA burn + vehicle; 30% TBSA burn + GCSF (150 mu g rhGCSF); Control. Blood samples were taken for total white cell count, P MNs, TNF alpha and IFN gamma. Leukocyte rolling and sticking were measured in the cremaster muscle microcirculation. Leukocyte diapedesis was investig ated by lavage of the abdominal cavity and the lungs. Total white cell and PMN counts in the burn + GCSF group were significantly higher (P < 0.001) t han in burn + vehicle animals. Leukocyte adherence and diapedesis were not elevated in the burn + GCSF group as compared to the burn + vehicle group. TNF alpha (P < 0.05) and IFN gamma (P < 0.001) levels were significantly in creased in the burn + vehicle animals compared to the burn + GCSF animals. GCSF modifies the immune system, as shown by an increase in white cell and PMN counts and by balancing the overall immune response from proinflammator y to normal, as shown by decreased TNFa and IFN gamma levels. GCSF does not overactivate PMNs (C) 1999 Elsevier Science Ltd and ISBI. All rights reser ved.