Immunoelectron microscopical study of non-lymphocytic leukemic cells. Expressing human granulocyte antigen defined by...

The cells from 5 cases of non-lymphocytic leukemia were investigated by immunoelectron microscopy using an anti-granulocyte antibody, clone 1G10 (New England Nuclear), to clarify the nature of immature leukemic cells. Reaction products on the surface of the leukemic cells were composed of two layers, an inner translucent and an outer dense granular zone. Although non-leukemic cells of the granulocytic series in various stages of maturation between promyelocytes and neutrophils were all positive for the antigen-antibody reaction, non-neoplastic monocytes and lymphocytes were all negative. Using this method, it was possible to diagnose the undifferentiated leukemic cells that were negative for myeloperoxidase. Furthermore, the results of our present study suggest the possibility that the antibody 1G10 may be useful for distinguishing granulocytic cells from cells of monocytic lineage.