Immunoglobulins on the surface of blast cells in human acute leukemia.

By means of the direct fluorescent antibody technique it was shown that malignant cells in acute lymphoblastic leukemia do not, as a rule, bear immunoglobulins on the cell surgace (43 of 45 cases). During complete remission the number of Ig-positive cells corresponds to the number of Ig-positive cells in normal lymphocyte populations. During incomplete remission as well as during incomplete remission as well as during intensive chemotherapy, the lymphocyte-like cells are evidently malignant, since they do not contain a normal number of Ig-positive lymphocytes. In acute myeloblastic leukemia (AML) and acute myelomonoblastic leukemia (AMML), lymphocytes distribute normally according to the number of Ig-positive and Ig-negative in 34 of 38 cases. AMML blast cells were Ig-positive in nine of ten cases. The data are discussed in the light of current concepts about the presence of a common precursor cell of granulocytes and monocytes.