Terminal deoxynucleotidyl transferase activity and B cell markers in chronic myelogenous leukemia blast crisis

Early relapse of acute lymphoblastic leukemia is not predictable by serial biochemical assays of terminal transferase activity in cells from peripheral blood

Serial samples of peripheral blood were collected from 37 children with acute lymphoblastic leukemia (ALL) in remission. Activity of terminal transferase (TdT) was assayed by a biochemical technique. False positive results were obtained infrequently (approx. 1%), in contrast to experience with bone marrow analyses. However, early relapse of disease was not predictable in ALL by repeated measurement of TdT in circulating mononuclear cells during remission.

Detection of circulating 'terminal transferase-positive' cells does not predict relapse in acute lymphoblastic leukemia

Serial samples of peripheral blood were obtained from 35 children with ALL over a period of 18 months. The mononuclear cells were examined for TdT by indirect immunofluorescence using an unpurified anti-calf thymus TdT as the primary antibody. This analysis failed to distinguish those children who were destined to relapse (n = 9) from those who remained in continuous complete remission. Rather, the exhibition of fluorescence was linked to the co-existence of infection, with a negative predictive value of 0.91. Putative 'TdT-positive' cells were concentrated in the T-lymphocyte fraction and the very process of E-rosette formation seemed to contribute to this phenomenon. It appears as if the anti-TdT reagent recognizes not only TdT but also a variety of antigens which are expressed on or in immature and activated lymphocytes.

Sialyltransferase activity in leukemia

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.

Terminal deoxynucleotidyl transferase activities and glucocorticoid receptors in leukaemia

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.

Acute lymphocytic leukemia and complement receptors. (A study of 45 cases)

The expression of complement receptors (C3R) associated or not to sheep erythrocyte receptors (ER) and surface membrane immunoglobulins (SmIg) was determined on lymphoblasts of 45 patients with acute lymphocyte leukemia (ALL) at onset and/or in the first relapse. We found C3R simultaneously expressed with ER or SmIg on lymphoblasts of T cell ALL and B cell ALL. Lymphoblasts were positive for C3R in absence of ER and SmIg only in three patients in the hematological relapse. We stress the importance to find C3R as independent marker on ALL cells at onset and in subsequent relapses.