ABSTRACT
Macrophage or reticuloendothelial system (RES) phagocytic defense mechanisms are important to organ function and host survival in critically ill surgical, trauma, or bum patients. The association of pulmonary leukostasis with acute lung vascular injury during bacteria or thrombin-induced lung microembolization may be mediated by this mechanism. The "adhesive" property of fibronectin may be ideal for this opsonic function. Ingestion of foreign objects by phagocytic cells is a highly selective process which is linked to the "recognition capability" of the macrophages and/or leukocytes. Fibronectin is a high molecular weight adhesive glycoprotein found in the blood, lymph, and tissue fluid as well as in the extracellular matrix of many cells. In tissue culture, fibronectin can be produced by fibroblasts, vascular endothelial cells, macrophages, and hepatocytes, as well as other cell types. Thus, a relationship may exist between reticuloendothelial system phagocytic failure and the development of lung failure in septic surgical or injured patients.
