A micromethod for determination of terminal deoxynucleotidyl transferase (TdT) in the diagnostic evaluation of acute leukemias

Enzymatic synthesis of fluorescent oligomers assembled on a DNA backbone

A number of research laboratories have investigated the properties of multichromophore molecules and their applications in materials science and in biotechnology. Previous approaches for preparing such molecules have involved traditional organic synthesis. Here we describe the one-step enzymatic synthesis of such a multichromophore species by using a DNA-polymerizing enzyme (terminal deoxynucleotidyl transferase (TdT)). We find that a nucleotide-like molecule with pyrene replacing the DNA base (dPTP) can be accepted as a substrate for this enzyme to produce discrete chromophores that have 3 or 4 pyrenes consecutively, depending on which anomer (alpha or beta) is used. Products were characterized by gel electrophoresis, mass spectrometry, and fluorescence. The reaction was found to change the fluorescence emission of the chromophore from a maximum at 375 nm (the monomer nucleotide) to 490 nm in the oligomeric product. This new green-white emission is consistent with the formation of a pyrene excimer between adjacent pyrene glycosides, which exhibit a large Stokes shift of 130 nm. The enzymatic synthesis of the pyrene excimer might have applications in homogeneous biological assays for DNA fragments, such as those that arise during apoptosis.

Solid phase synthesis of thymosin beta 9

Thymosin beta 9, a 41 residue thymic polypeptide, has been synthesized by a solid phase method. A modification of the low HF method was used to deprotect and cleave the peptide from the resin. Thymosin beta 9 was then obtained in analytically pure form by a one-step purification procedure in 32% yield. The activity of thymosin beta 9 in the terminal deoxynucleotidyl transferase assay was greater than calf thymus fraction 5, but comparable to thymosin beta 4. In contrast to thymosin alpha 1, neither beta 4 nor beta 9 was active in the rosette inhibition assay.

Relationship of Auer rods and chromosome findings to outcome in eighty-nine adults with acute nonlymphoblastic leukemia

We performed cytogenetic analyses using banding techniques on 89 adults with acute nonlymphoblastic leukemia prior to receiving protocol chemotherapy. The relationships of cytogenetic findings both to outcome and to other pretreatment variables (particularly the presence or absence of Auer rods) were analyzed. Patients were followed up to 90+ months. When patients were grouped according to cytogenetic findings (NN: all normal metaphases; AA: all abnormal metaphases; AN: both normal and abnormal metaphases; F: no evaluable metaphases; I: insufficient (less than three) metaphases) no significant differences were noted with regard to age, sex, terminal transferase positivity, complete remission rate, remission duration or survival. The marrow aspirates of patients with only normal (69%) metaphases or no evaluable metaphases (64%) were more likely to display Auer rods than specimens from individuals with only abnormal (26%) or a mixture of normal and abnormal (42%) metaphases (p = 0.03). The presence of Auer rods in the pretreatment marrow aspirate was associated with an increased complete remission rate (71% vs 41%, p = 0.004), median remission duration (12 months vs 9 months, p = 0.02), and median survival (13 months vs 4 months, p = 0.01). Using multivariable analyses, the presence or absence of Auer rods was the pretreatment factor that most significantly predicted response and survival in this group of patients. The presence of a normal karyotype in the initial cytogenetic preparation is associated with the presence of Auer rods. The finding of Auer rods in the initial bone marrow predicts greater response and longer survival in acute nonlymphoblastic leukemia.

Malignant histiocytosis with unusual features. Disseminated intravascular coagulation with severe hyperfibrinolysis, acute polyneuroradiculitis Guillain-Barré, and a unique chromosome abnormality

The case of a 25-year-old man with the characteristic features of malignant histiocytosis (proliferation of abnormal histiocytic cells with erythrophagocytosis, hepatosplenomegaly, increased serum acid phosphatase, hypercalcemia, and bone pain) is reported. Chromosome studies revealed a near tetraploid karyotype with a pair of marker chromosomes. A few hours after initiation of chemotherapy with cyclophosphamide, Adriamycin (doxorubicin), vincristine, and prednisolone (CHOP regimen), the patient developed an acute ascending paralysis. Cerebrospinal fluid (CSF) findings were consistent with a diagnosis of Guillain-Barré Syndrome. On the next day, disseminated intravascular coagulation (DIC) with severe hyperfibrinolysis occurred. After intensive chemotherapy, complete remission could be achieved.

Immunohistological demonstration of terminal transferase (TdT) in the age-involuted human thymus

By using a sensitive immunoperoxidase technique, serological determinants of terminal deoxynucleotidyl transferase (TdT, E. C. 2.7.7.31) were found in cortical lymphocytes of thymus biopsies of adult and aged persons (21-70 years) of both sexes. In contrast to biochemical determinations, specific immunohistological studies showed that TdT is continuously present in very large numbers of cortical thymic lymphocytes during human life, despite subtotal physiological involution of the thymus.

Differences in beta-adrenergic receptor density and adenylate cyclase activity between normal and leukaemic leukocytes

An identical class of high-affinity binding sites for the 125I-labelled beta-adrenergic antagonist hydroxybenzylpindolol, was identified on intact human normal and leukaemic peripheral blood leukocytes. On normal unfractionated lymphocytes, polymorphonuclear leukocytes, and monocytes, receptor density did not differ significantly (1200-1400 receptors per cell; P greater than 0.3), but it was higher on B- than on T-lymphocytes (P less than 0.05). In leukaemia, monocytic blast cells expressed highest receptor numbers, whereas very low receptor density was seen on the pathologic B-cells from chronic lymphocytic leukaemia. Among normal leukocytes, adenylate cyclase activation by hormones (isoproterenol, prostaglandin E1, histamine) and sodium fluoride was strongest in plasma membranes from monocytes, but very weak in polymorphonuclear leukocytes either due to uncoupling of hormone receptors from adenylate cyclase or to low catalytic activity. In T-cells, enzyme activity was significantly lower than in B-cells. Loss of adenylate cyclase sensitivity to hormones and fluoride occurred in leukaemic cells from chronic and acute lymphocytic leukaemia.

Distinct lymphoblastic and myeloblastic populations in TdT positive acute myeloblastic leukemia: evidence by double-fluorescence staining

Double-immunofluorescent staining for the enzyme terminal deoxynucleotidyl transferase (TdT) as a marker of primitive lymphoblasts, and for the VIM-D5 antigen as a differentiation antigen of the myeloid system gave direct evidence for distinct lymphoblastic and myeloblastic populations (mixed leukemic cell populations) in seven patients with acute leukemia. The percentage of malignant TdT positive cells contributing to a leukemic cell bulk with unequivocal signs of myeloid origin was between 10 and 80%. A defect at the level of a common progenitor cell giving rise to both the TdT and the VIM-D5 positive blast cell population is discussed.

Phenotypic changes in a case of blast crisis of CML: characterization by TdT, cytochemistry, and cytogenetics

Phenotypic changes in blast crisis of a case of Philadelphia chromosome (Ph1)-positive chronic myelogenous leukaemia were characterized by serial terminal transferase (TdT) determinations simultaneously related to cytochemical and cytogenetic data. At the onset of the blast crisis, 90% of the blast cells were acid phosphatase-positive (focal pattern), Ph1-positive, lymphoid cells. The TdT activity amounted to 29 units/10(8) mononuclear cells in the peripheral blood and to 57 units/10(8) mononuclear cells in the bone marrow. Therapy with vincristine and prednisone caused the elimination of the TdT-positive cell population. 4 months later, there was an increase in TdT-negative, myeloid blasts which was brought under control with busulfan. Cytogenetic analysis of the myeloid blasts still revealed Ph1 positivity in 100% of the metaphases examined and the lack of additional chromosomal abnormalities. A second relapse was again dominated by TdT-containing cells with the 46,XX,Ph1 karyotype. This time, the patient failed to achieve remission with vincristine and prednisone. Even though the TdT activity was markedly decreased, the lymphoid blast count remained elevated and the cells showed resistance to further therapy. This failure of morphology, cytochemistry as well as cytogenetics to distinguish between the individual phenotypes emerging during the course of blast crisis of CML characterized the TdT as a cell marker of important diagnostic and therapeutically prognostic value.

T-cell growth factor (interleukin 2) and terminal transferase activity in human leukemias and lymphoblastic cell lines

Mononuclear blood cells from patients with different types of leukemia, and from controls as well as cells from established lymphoblastic cell lines were analyzed with respect to terminal transferase (TdT) activity and T-cell growth factor (TCGF; Interleukin 2, IL-2), to determine the significance of TCGF production and response as functional markers for human leukemias. The data obtained so far suggest that the aberrant proliferation and lack of maturation observed in these leukemias may be associated with or be the result of a break-down in cellular-mediated control of proliferation.

Methods and clinical relevance of terminal deoxynucleotidyl transferase determination in leukemic cells

Terminal deoxynucleotidyl transferase (TdT) is a unique DNA polymerase which is only found in immature cells of lymphoid lineage (pre-T/pre-B). Because of this restricted distribution of TdT, biochemical and immunofluorescence techniques have been employed to determine the distribution of TdT phenotypes in human leukemias and lymphomas, showing high levels of TdT in approximately 95% of acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL), approximately 50% of patients with acute undifferentiated leukemia (AUL), approximately 10 of patients with acute nonlymphoblastic leukemia (ANLL), and approximately 30% of patients with chronic myeloid leukemia (CML) and other myeloproliferative (MPS) or myelodysplastic (MDS) syndromes in blast crisis. High levels of TdT activity are associated with a clinical response to remission inducing therapy with vincristine and prednisone in a high proportion of patients (50%-90%), irrespective of clinical and morphologic diagnosis. Preliminary studies furthermore suggest that TdT might serve as a sensitive indicator of subclinical disease in ALL in complete remission.