ADHESION MOLECULE EXPRESSION ON CD34(-ANEMIA BONE-MARROW() PROGENITORCELLS FROM NORMAL AND APLASTIC)

Aplastic: anaemia (AA) is a disease of bone marrow failure. Evidence h as been produced for both a stem cell and a stromal ci:ll defect in th is disease. The contribution of deficient or defective cell adhesion m olecules (CAMs) has not been determined. CAMs have been shown to be im portant in stern cell-stromal cell interactions and maintenance of hae mopoiesis. In this study the expression of CAMs (LFA-1, LFA-3, ICAM-1, VLA-4, CD44, sLe(x) and L-selectin) on CD34(+) progenitor cells from 10 normal donors and eight patients with AA was investigated using dou ble immunofluorescence. There was no significant difference in the per centage of CD34(+) cells that were CAM(+) between normal and AA bone m arrow, suggesting that abnormal CAM expression on AA progenitor cells is not responsible for nor contributes to the pathogenesis of the dise ase. However, these findings do not exclude abnormal CAM function on p rogenitor cells, or abnormal expression or function of CAM ligands or counterreceptors on AA stromal cells.