EXPRESSION AND FUNCTION OF L-SELECTIN MOLECULES (LECAM-1) IN B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA

Background. The notion that adhesion molecules play a crucial role in lymphoma/leukemia dissemination is widely accepted. Individual cases o f B-cell chronic lymphocytic leukemia (B-CLL) show well-defined variab les in the extent and pattern of peripheral blood and nodal involvemen t. The L-selectin adhesion molecule (TQ1/Leu-8, LAM series and LECAM-1 ) initiates the attachment of lymphocytes to the high endothelial venu les (HEVs), and as a consequence the entrance of lymphocytes from the blood into the peripheral lymph node (recirculation which may be opera tive in lymphoma/leukemia dissemination as well). Materials and Method s. The constitutional expression of L-selectin molecules (LECAM-1) on peripheral blood mononuclear cells (PBMCs) from B-CLL (16 cases) was e xamined and correlated with receptor function in an HEV-binding assay and in a ligand immobilization test. Results and Conclusions. A correl ation was found between constitutional expression and function of the L-selectins, namely the higher the number of cells expressing L-select in molecules at a measurable level on the cell surface, the greater th e number of cells showing attachment in the tests. It is suggested tha t many aspects of the biological and clinical heterogeneity of B-CLL w ill be explained by revealing the exact adhesion profile and function in different subtypes of the disease.