EXPRESSION OF AN ADHESION MOLECULE AND HOMING IN B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA .2. L-SELECTIN EXPRESSION MEDIATED CELL-ADHESION REVEALED BY IMMOBILIZED ANALOG CARBOHYDRATES IN B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA AND MONOCLONAL LYMPHOCYTOSIS OF UNDETERMINED SIGNIFICANCE

The L-selectin mediated adhesion of freshly isolated peripheral blood mononuclear cells (PBMCs) to phosphonomonoester core polysaccharide (P PME) and fucoidin derivatized gels was investigated in seven cases of monoclonal lymphocytosis of undetermined significance (B-MLUS) and 12 cases of chronic lymphocytic leukaemia: B-CLL, patients with periphera l lymphocytosis (LY-patients), lymph node enlargement (LN-patients) an d splenomegaly (SM-patients). PBMCs isolated from the peripheral blood of 10 healthy donors served as controls. The binding to PPME and fuco idin correlated well (n = 19, P = 0.01). Adhesion of PBMCs from B-MLUS and B-CLL showed a greater variability than controls. A higher number of cells, on average, bound to PPME and fucoidin derivatized polyacry lamide gels in B-MLUS than in B-CLL. However, the differences observed were not statistically significant. In four cases with B-CLL, the sti mulatory effect of interferon-alpha on the function of L-selectin and some other accessory molecules was also studied. The increased binding of PBMCs to immobilized analogue molecules (PPME, fucoidin) and to hi gh endothelial venules (HEVs) in the in vitro HEV-binding assay suppor ts the notion that interferon-alpha not only increases the expression of the adhesion molecules, but also results in an enhanced adhesive fu nction.