Forty-four patients with Ph positive leukemia (36 developing blast crisis after chronic phase and eight presenting in acute leukemia) were classified into subgroups on the basis of reactivity of blasts with an anti-serum made against non-T,non-B acute lymphoid leukemia (ALL+), levels of terminal transferase enzyme (TdT+) and morphology.
A 46-year-old female with chronic myelogenous leukemia (CML) in blast crisis was monitored for terminal deoxynucleotidyltransferase (TdT) activity of marrow and peripheral blood throughout the course of her illness.
These leukaemic cells retain their undifferentiated membrane characteristics C.M.L. patients in blast crisis who are A.L.L.-antigen-positive and have terminal transferase enzyme activity might benefit from therapy usually given in typical Philadelphia-chromosome-negative A.L.L.