title: Prognostic significance of terminal deoxynucleotidyl transferase activity in acute nonlymphoblastic leukemia.
abstract: Bone marrow and/or peripheral blood samples from 133 (75%) of a total of 177 consecutive previously untreated protocol patients with acute nonlymphoblastic leukemia (ANLL) were analyzed for terminal deoxynucleotidyl transferase (TdT) activity at the time of presentation. Twenty-nine (22%) were found to exhibit TdT activity (greater than or equal to 0.10 U/10(8) cells, TdT+) as measured in a biochemical microassay. There were no differences between TdT+ as compared with TdT-negative (TdT-) patients with respect to age, sex, French-American-British (FAB) classification, or the presence of Auer's rods. Remission induction rates were higher for the TdT- patients, with 68% v 48% for the TdT+ patients (P = .05). TdT- patients also experienced longer remissions (P = .003) than TdT+ patients, especially in the Auer's rod-positive subgroup (P = .002). None of five patients with TdT+ ANLL treated with vincristine and prednisone as initial therapy achieved complete remission; all required induction regimens containing daunorubicin or amsacrine in combination with cytosine arabinoside and 6-thioguanine. It is concluded that TdT activity in ANLL indicates biphenotypia or lineage infidelity and is associated with a poor prognosis on chemotherapy protocols currently used for the treatment of ANLL.
mesh_terms: D001853:Bone Marrow / Q000201:enzymology; D004796:Clinical Enzyme Tests; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism*; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D005500:Follow-Up Studies; D006801:Humans; D007938:Leukemia / Q000201:enzymology* / Q000503:physiopathology; D011379:Prognosis
chemical_list: D004254:DNA Nucleotidyltransferases; D004253:DNA Nucleotidylexotransferase