Abstract
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.
