Abstract

The expression of lineage specific surface antigens on granulocytes and monocytes was quantitated using monoclonal antibodies in 16 healthy adults and 21 patients with myelodysplastic syndromes. In nine of 19 patients the granulocytes showed a decrease in myeloid or an increase in monocyte antigen expression or both. In 11 of 19 patients the monocytes showed a decreased expression of monocyte antigens or an increase in myeloid antigens or both. The data suggest that in the myelodysplastic syndromes the granulocyte-macrophage progenitors do not develop along two divergent lines but differentiate with the emergence of dual characteristics.