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The sensitivity of terminal deoxynucleotidyl transferase (TdT) assay methods was examined by using a mixture of the TdT-positive lymphoblastic leukemia cell line NALM-18 and the TdT-negative erythroleukemia cell line K-562. The biochemical assay could detect TdT activity in the mixture containing NALM-18 cells at concentrations of more than 10 percent. The immunofluorescent (IF) method could detect positive cells in the mixture containing NALM-18 cells at concentrations of more than 1 percent. Furthermore, an approximately 10(5)-fold increase in sensitivity was obtained by the combination of RT-PCR and subsequent Southern blotting, as compared to biochemical assay. In many leukemia cases the expression of TdT-mRNA corresponded well to that of TdT protein. However, in some patients with leukemia, only TdT-mRNA was detectable by RT-PCR without any expression of TdT protein. A PCR-based technique enables us to detect TdT transcripts at the highest sensitivity, but does not allow the characterization of each positive cell. IF analysis is simple and sensitive, but may sometimes cause nonspecific reactions. All these techniques have some advantages and some faults, therefore, the results obtained from clinical studies using these techniques should be interpreted with caution.

Terminal deoxynucleotidyl transferase (TdT) was purified from calf thymus and a monoclonal antibody-producing clone was produced by the fusion of mouse myeloma cells and spleen cells of mice immunized with the purified enzyme. The antigens recognized by an immunoadsorbent column revealed TdT, whose molecular weight was 62 kDa. The extensive study of TdT in 196 patients with hematological disorders was done. The results from immunofluorescent analysis corresponded well to the results of biochemical assays of this enzyme. This monoclonal antibody will provide a useful means for the survey of leukemia and lymphoma patients.

Myeloperoxidase (MPO)- and Sudan Black B-not more than 3%-positive, esterase staining-negative, lymphoid, megakaryocyte lineage and erythroid surface marker-negative and electron microscopic platelet peroxidase-negative acute leukemia (AL) was diagnosed as acute undifferentiated leukemia (AUL), and myeloid marker (CD13, CD33), electron microscopic MPO (EMMPO), and DNA analysis of immunoglobulin heavy chain and T cell receptor as well as chemotherapy and its reactivity were examined. Of 239 cases of AL, 10 (4.2%) were AUL, and of these 10 cases, 9 were CD13 or CD33-positive AML-MO (MO) cases. Of 9 cases examined for EMMPO, 4 (44%) were positive, and of 3 cases of MO subjected to DNA analysis, 1 and 1 showed rearrangements of immunoglobulin heavy chain and T cell receptor beta chain, respectively. Of 6 cases of MO on myeloid induction therapy, 1 and 1 showed complete remission (CR) and partial remission (PR), respectively, each having lymphoid genotype, and 4 showed no remission (NR), being 3 of them EMMPO-positive. Of 2 cases on lymphoid induction therapy, 1 and 1 showed CR and NR, respectively, the former being EMMPO-positive MO. BHAC-EM therapy with behenoyl cytosine arabinoside, VP-16 and mitoxantrone performed on 2 cases refractory to any one of both these myeloid and lymphoid induction therapies led to CR in all these 2 cases.

A total of 8,316 barbers were followed up from 1976 to 1987 to examine the relations between hair dye use and deaths from hematopoietic disorders. The follow-up rate was about 95%. Three leukemia deaths and two malignant lymphoma deaths were observed in this cohort. The observed deaths were less than the expected number calculated from age- and sex-specific mortality of the general population in Japan (3.8 and 3.0, respectively). No deaths from aplastic anemia or the other hematopoietic disorders were observed.

The relation between terminal deoxynucleotidyl transferase (TdT) activity, glucocorticoid (GC) receptors and the effect of vincristine-prednisolone (VP) therapy on fresh leukaemia cases was examined. Five of 6 TdT+ leukaemias showed high levels of GC receptors and a favourable response to VP therapy, whereas 1 acute lymphoblastic leukaemia (ALL) and 3 of chronic myelogenous leukaemia (CML) cases in blast crisis with no TdT activity showed low level of GC receptors and poor response to VP therapy. Significant correlation (r = 0.821, P less than 0.01) was observed between TdT activity and the number of GC receptor sites in these cases. X2 test showed significant difference (P less than 0.01) between TdT+ and TdT- leukaemias in the effect of VP. A significant difference (P less than 0.01) was also observed between VP-effective and ineffective leukaemias in the number of GC-receptor sites by unpaired t test. Therefore GC receptors may be responsible for the effect of VP on TdT+ leukaemias.

A new cell line of human erythroleukemia cells differentiates spontaneously so that 30% of the cells are always hemoglobinized. Erythropoietin did not affect the percentage of such cells but stimulated the cell growth, indicating that the cells have functioning receptors. Binding of human recombinant radioiodinated erythropoietin to the receptors was specific. The bound ligand was internalized into cells at 37 degrees C but not at 15 degrees C. Scatchard analysis showed two classes of binding sites. Covalent binding of erythropoietin to its receptors yielded two products detected on sodium dodecyl sulfate-polyacrylamide gels electrophoresed under reducing conditions. Under non-reducing conditions, these species disappeared and larger products appeared.

Sialyltransferase activity in blasts from acute lymphoblastic leukemia (ALL) was markedly lower (1.68 +/- 1.23 pmol/mg protein) than those (6.18 +/- 2.22 pmol/mg protein) of lymphocytes from normal volunteers (t less than 0.001). On the contrary, enzyme activity was significantly increased in blasts (1.21 +/- 0.38 pmol/mg protein) from acute non-lymphoblastic leukemia, compared to the level (0.53 +/- 0.32 pmol/mg protein) of mature granulocytes (t less than 0.001). In TdT-negative CML in blast crisis, sialytransferase activity (2.11 +/- 0.88 pmol/mg protein) was significantly higher than those of mature granulocytes (t less than 0.001), whereas no significant difference in the enzyme activity was noted between the blasts from TdT-positive CML in blast crisis and from ALL. In TdT-positive ALL cases, there was an inverse relationship (r = -0.85, t less than 0.01) between sialytransferase activity and terminal deoxynucleotidyl transferase (TdT) activity of the blasts. Therefore, sialytransferase in leukocytes may be a unique enzyme in which changes in activity relate to the differentiation or malignant transformation of leukocytes.

The level of sialyltransferases activity in leukemic blasts from acute lymphoblastic leukaemia (ALL) cases was significantly lower (3.29±2.09 pmoles/5× 107 cells or 1.77 ± 1.16 pmoles/mg protein) than those (18.80 ± 4.91 pmoles/5 × 107 cells or 7.72 ±1.75 pmoles/mg protein) of mature lymphocytes from normal volunteers (t<0.001). An inverse relationship between the level of sialyltransferases activity and the level of terminal transferase (TdT) activity was seen in blasts from eight TdT-positive ALL cases. No significant difference was observed in the level of sialyltransferases activity between ALL and cells of chronic myclogenous leukemia (CML) in blast crisis. Short term culture of ALL blast cells with 12-0-tetradecanoylphorbol-13-acetate (TPA) at the concentration of 10-6M to 10-9M caused a marked increase in sialyltransferases activity. In one of these three ALL cases the population of TdT-positive cells and the TdT activity of the blasts decreased significantly after culture with TPA. These results suggest that biochemical differentiation of leukemic lympho blasts has been induced by the addition of TPA, although morphological changes were not observed. Sialyltransferases activity may be a useful indicator for the analysis of differentiation of lymphocytes. [ABSTRACT FROM AUTHOR]