Different expression of adhesion molecules on CD34(+) cells in AML and B-lineage ALL and their normal bone marrow counterparts

The expression of adhesion molecules on CD34(+) cells in acute myeloid leuk emia (AML) and B-lineage acute lymphoblastic leukemia (B-lineage ALL) was c ompared with that on the myeloid and B-lymphoid CD34(+) cells in normal bon e marrow. Bone marrow aspirates of 10 patients with AML, 8 patients with B- lineage ALL and of 6 healthy volunteers were examined. The phenotype of the CD34(+) cells was determined with a double immunofluorescence method and f low cytometry. CD34(+) cells in AML and B-lineage ALL showed a lower expres sion of VLA-2 and VLA-3 and a higher expression of ICAM-1 and LFA-3 than th eir normal bone marrow counterparts. AML CD34(+) cells had less L-selectin but more VLA-5 on their surface membrane than normal myeloid CD34(+) cells. B-lineage ALL CD34(+) cells showed an overexpression of LFA-3. In individu al patients deficiencies or overexpression of the beta 1 integrin chain, VL A-4, PECAM-1 or HCAM also occurred. An abnormal adhesive capacity of the le ukemic cells may influence their proliferation, their localisation and apop tosis. An aberrant expression of adhesion molecules may be used for the det ection of minimal residual leukemia in these patients.