SERUM LEVELS OF ADHESION MOLECULES AND CYTOKINES IN PATIENTS WITH ACUTE-LEUKEMIA

The cytokine network and the adhesion molecule system are intercellula r signal pathways. The cytokine effects are modulated in vivo by solub le cytokine antagonists, whereas the cell to cell contact mediated by adhesion molecules and their ligands may be blocked by the soluble for ms of the adhesion molecules. The cytokine network is important for pr oliferation and cytokine secretion by acute leukaemia blasts, and memb rane-bound adhesion molecules are important for blast interactions wit h neighbouring cells of the in vivo microenvironment. Both these signa l systems are operative during the period of cytopenia following inten sive chemotherapy for acute leukaemia. In the present review, we discu ss the influence of disease status, chemotherapy and complicating infe ctions on serum levels of cytokines and soluble adhesion molecules in acute leukaemia patients. We have demonstrated increased serum levels of both cytokines and cytokine antagonists in acute leukaemia patients with complicating bacterial infections during chemotherapy-induced cy topenia. Serum levels of the selectin adhesion molecules were decrease d during bacterial infections in leukopenic patients compared to healt hy individuals. In contrast, the intercellular adhesion molecule-1 res ponse and the cytokine/cytokine antagonist responses were qualitativel y similar to responses seen in previously healthy individuals with ser ious bacterial infections.