[ICO-13 monoclonal antibodies to the differentiation antigen of human hemopoietic cells].

Monoclonal antibodies (Mab) ICO-13 of IgM isotype reacted in indirect surface immunofluorescence test with 88.5 +/- 3.4% of thymocytes and 7.1 +/- 2.4% of T cells, but failed to react with other peripheral blood cells from healthy donors. The antigen disappeared in cells stored at 4 degrees C overnight or at -196 degrees C in liquid nitrogen. The antigen detected by Mab ICO-13 was expressed on blast cells of acute lymphoblast leukemias and lymphomas. The antigen was absent in chronic lymphoblast leukemia and blast crisis of chronic myeloid leukemia.