EXPRESSION OF AN ADHESION MOLECULE AND HOMING IN B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA .1. APPLICATION OF THE HEV-BINDING ASSAY TO A CLINICAL-SERIES

High endothelial venule (HEV)-binding of peripheral blood mononuclear cells (PBMCs) from 43 patients with B-cell chronic lymphocytic leukaem ia (B-CLL) was investigated with a HEV-binding in vitro assay. Immunop henotyping of HEV-adherent PBMCs proved that most of them belonged to the B-cell proliferation. B-CLL cells stringently expressed CD44 molec ules (Hermes-1, -3 and H90). The patients were subgrouped according to Binet's classification, as well as according to the organ manifestati ons, i.e. patients with B-cell monoclonal lymphocytosis of undetermine d significance (B-MLUS) and patients with lymphocytosis (LY), lymph no de enlargement (LN) and splenomegaly (SM). The HEV-binding activity of the cells was the highest in Binet stage A patients and in patients w ith B-MLUS (p<0.05 in B-MLUS versus B-CLL LY, LN, SM). Based on these findings it is suggested that B-CLL patients show not only a clinical and immunophenotypical heterogeneity, but a diverse function of adhesi on molecules.