Glycophorin A as a cell surface marker of early erythroid differentiation in acute leukemia.

We show here that the leukemic blast cells from three patients of a total of 15 subsequently diagnosed as having acute leukemia express on their surface the major red cell sialoglycoprotein, glycophorin A (GP-A). This was demonstrated (1) by indirect immunofluorescence using rabbit anti GP-A anti-serum and (2) by immune precipitation of GP-A from surface radiolabelled leukemic cells. Since GP-A is exclusively present on erythroid cells and their precursors, these findings indicate that a higher proportion of the blast leukemias than previously recognized show features of early erythroid differentiation.