SLe(x) expression of normal CD34 positive bone marrow haemopoietic progenitor cells.

We investigated sialylated Lewis x (sLe(x)) antigen expression on CD34 positive (CD34+) haemopoietic progenitors in the bone marrow of eight healthy volunteers using monoclonal antibodies. We found that in all the samples examined, CD34+ bone marrow progenitors strongly expressed the sLe(x) antigen. This contradicts previous publications which reported sLe(x) expression on malignant blast cells but not on normal CD34+ progenitor cells.