Significance of PHA induced clonogenic cells in chronic myeloid leukemia and early acute myeloid leukemia.

A technique for cloning myeloblastic leukemic cells in semi-solid agar, after prior PHA stimulation, was studied in all phases of chronic myeloid leukemia. Phytohemagglutinin responsive cells were found in blast crisis and accelerated phase. In a small number of patients in the benign phase of their disease, colony growth with PHA was detected. A group of patients with early acute leukemia was also examined by this technique. The incidence of PHA colonies appeared to correlate with the progression of the disease. The potential application of this assay for early detection of leukemic clones and possible prediction of the rapidity of progression of the leukemic process is discussed.