Surface phenotype and adhesion activity of B-cell chronic lymphoid leukemias

Surface phenotypes and adhesion activity to human umbilical vein endothelial cells (HUVECs) were studied using leukemic cells from 12 Japanese patients with B-cell chronic lymphoid leukemias including 7 with chronic lymphocytic leukemia (CLL), 1 with prolymphocytic leukemia (PLL), 2 with hairy cell leukemia (HCL) and 2 with HCL variant (HCL-V). CD13 and CD23 were found to be characteristically positive in CLL, whereas they were not expressed in non-CLL cases except for positivity of CD23 in two such cases. Except for CD11b, all other leukocyte integrins examined (CD11a, CD11c and CD18) and their ligand (CD54) were highly expressed in non-CLL cases. Adhesion activity of leukemic cells to HUVECs after co-culture with HUVECs was well correlated with the expression of CD11b, CD18 and CD54, but showed no predilection for any leukemia subtype. Positivity for CD5, CD21, CD23 and CD13 changed after the co-culture with HUVEC. These results suggest that adhesion activity after co-culture. does not correlate with the leukemia subtype and that endothelial cells activate or differentiate leukemic cells.