[Analysis of the enzyme terminal deoxyribonucleotidyl transferase in lymphoma and leukemia cells]

This work analyses the presence of terminal deoxynucleotidyl transferase (TdT) in neoplastic lymphoid cells from a series of malignant lymphomas and in leukemic cells from blood or bone marrow of patients with lymphoproliferative diseases. The studied cases were 63 patients with acute leukemias, 26 patients with chronic leukemias, 85 patients with lymphomas and 14 normal controls. The presence of TdT in the neoplastic cells was determined by optimized assays of enzymatic activity or by immunofluorescence test for TdT positive blasts. The fluorescence tests made use of anti-TdT antibodies specifically absorbed on cells containing the enzyme and then revealed by a second fluorescent antibody. Appreciable amounts of TdT were found in the white cells of blood or bone marrow from the following 25 out of 35 acute lymphoblastic leukemias (ALL) with modulations in the different phenotypes; 13 out of 14 acute undifferentiated leukemias (AUL); and 9 out of 15 blastic crises in chronic myelogenous leukemia (CMLbc). The enzyme was present in 12 out of 14 lymphomas of lymphoblastic type (LL); 2 B lymphoblastic lymphomas did not show any TdT positivity. The highest levels of TdT were detected in cells classified as immature lymphoblast or in their precursors. TdT was absent from normal lymph nodes from leukocytes of chronic lymphocytic leukemia (CLL) and chronic (CML) and acute myelogenous leukemia (AML). 2 out of 14 cases of AML showed a border-line positivity. A definite correlation between concentrations of enzymatic activity and percentage of immunofluorescent cells could not be established. We did not find a precise correlation between the TdT content of lymphoid blasts and other clinical prognostic indices.(ABSTRACT TRUNCATED AT 250 WORDS)