Enzyme and membrane markers in leukaemia: recent developments

Cutaneous T-Cell Acute Lymphoblastic Leukemia and the Expression Pattern of Terminal Deoxynucleotidyl Transferase Immunostaining in Mycosis Fungoides and Spongiotic Dermatitis

Background/Aims

T-cell acute lymphoblastic leukemia (T-ALL) is an uncommon, aggressive malignancy that rarely presents in the skin and is generally not considered as part of the differential diagnosis by dermatologists and dermatopathologists. We describe an unusual case of T-ALL presenting with folliculocentric, erythematous papules on the face, histologically resembling mycosis fungoides (MF). Immunostaining for terminal deoxynucleotidyl transferase (TdT) was positive in tumor cells, supporting the diagnosis of cutaneous involvement by T-ALL. TdT is a nuclear enzyme expressed by immature lymphoid malignancies, but the expression pattern of this marker is not well characterized in the skin. We aimed to assess TdT staining in skin biopsies with similar-appearing lymphocytic infiltrates.

Methods

We evaluated the immunostaining profile of TdT in a cohort of 23 patients, including 13 cases of MF and 10 cases of spongiotic dermatitis.

Results

The lymphocytes in the MF and spongiotic dermatitis cases lacked nuclear staining for TdT. Nonspecific, granular, cytoplasmic staining was observed in a small number of background cells.

Conclusions

TdT may assist dermatopathologists in discriminating malignant infiltrates of T-ALL from other conditions.

Development of a Simple Assay Method for Adenosine Deaminase via Enzymatic Formation of an Inosine-Tb3+ Complex

Adenosine deaminase (ADA), which catalyzes the irreversible deamination of adenosine to inosine, is related to various human diseases such as tuberculous peritonitis and leukemia. Therefore, the method used to detect ADA activity and screen the effectiveness of various inhibitor candidates has important implications for the diagnosis treatment for various human diseases. A simple and rapid assay method for ADA, based on the enzymatic formation of a luminescent lanthanide complex, is proposed in this study. Inosine, an enzymatic product of ADA with stronger sensitization efficiency for Tb³⁺ than adenosine, produced a strong luminescence by forming an inosine-Tb³⁺ complex, and it enabled the direct monitoring of ADA activity in real-time. By introducing only Tb³⁺ to adenosine and ADA in the buffer, the enhancement of luminescence enabled the detection of a low concentration of ADA (detection limit 1.6 U/L). Moreover, this method could accurately determine the inhibition efficiency (IC₅₀) of the known ADA inhibitor, erhythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), and the inhibition of ADA could be confirmed by the naked eye. Considering its simplicity, this assay could be extended to the high-throughput screening of various ADA inhibitor candidates.

Split aptamer based sensing platform for adenosine deaminase detection by fluorescence resonance energy transfer

In this paper, a split aptamer based fluorescence resonance energy transfer (FRET) platform was constructed for the determination of adenosine deaminase (ADA) activity by using gold nanoclusters (AuNCs) and gold nanoparticles (AuNPs). A single adenosine triphosphate (ATP) aptamer was split into two fragments (referred to as P1 and P2). P1 was covalently attached to the AuNCs at the 5' end (P1-AuNCs), and P2 was labeled with AuNPs at the 3' end (P2-AuNPs). In the presence of ATP, ATP bound with the two fragments with high affinity to link P1-AuNCs and P2-AuNPs together, thus the fluorescence of P1-AuNCs was quenched via FRET from P1-AuNCs to P2-AuNPs. With the addition of ADA, ATP was transformed into inosine triphosphate (ITP), and then P1 and P2 were released to cause the fluorescence recovery of the system. So a split aptamer based FRET platform for ADA detection can be established via the fluorescence intensity change of the system. This platform showed a good linear relationship between the fluorescence intensity and ADA concentration in the range of 2-120 U L^-1, and the limit of detection (LOD) was 0.72 U L^-1. Moreover, the detection of ATP in human serum sample demonstrated the accuracy and applicability of the method for ADA detection in real sample.

A Label-Free Fluorescent Assay for the Rapid and Sensitive Detection of Adenosine Deaminase Activity and Inhibition

Adenosine deaminase (ADA), able to catalyze the irreversible deamination of adenosine into inosine, can be found in almost all tissues and plays an important role in several diseases. In this work, we developed a label-free fluorescence method for the detection of adenosine deaminase activity and inhibition. In the presence of ADA, ATP has been shown to be hydrolyzed. The ATP aptamer was shown to form a G-quadruplex/thioflavin T (ThT) complex with ThT and exhibited an obvious fluorescence signal. However, the ATP aptamer could bind with ATP and exhibited a low fluorescence signal because of the absence of ADA. This assay showed high sensitivity to ADA with a detection limit of 1 U/L based on an SNR of 3 and got a good linear relationship within the range of 1–100 U/L with R² = 0.9909. The LOD is lower than ADA cutoff value (4 U/L) in the clinical requirement and more sensitive than most of the reported methods. This technique exhibited high selectivity for ADA against hoGG I, UDG, RNase H and λexo. Moreover, this strategy was successfully applied for assaying the inhibition of ADA using erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) and, as such, demonstrated great potential for the future use in the diagnosis of ADA-relevant diseases, particularly in advanced drug development.

Terminal Deoxynucleotidyl Transferase, Tdt, as a Marker for Leukemia and Lymphoma Cells

Terminal deoxynucleotidyl transferase, TdT, was assayed in the mononucleate cells of blood and bone marrow from 121 patients with leukemias at the onset of disease and from 95 subjects with malignant lymphomas at diagnosis. This intracellular marker was also investigated by cytoimmunofluorescent tests in 17 other cases of initial leukemias and in 3 diagnosed lymphoblastic lymphomas. Generally, the TdT levels were significantly enhanced in the blasts of the following: acute undifferentiated leukemias; the more immature types of acute lymphoblastic leukemias i.e., the null, non-T non-B, common, early T and pre-B subgroups; a fraction of blastic crises in chronic myelogenous leukemias; and many lymphoblastic lymphomas. TdT might also be slightly increased in the mononucleate blood cells obtained from the most immature forms of acute myelogenous leukemias.

Relapses with changes in cell phenotypes were occasionally observed in previously TdT-positive leukemias as a result of clonal evolution of the disease. The leukemias with blasts containing high levels of TdT were usually responsive to treatment with corticosteroids and vincristine.

TdT is an oligoclonal marker characterizing several populations of undifferentiated or poorly differentiated blasts that tend to develop towards or along the lymphoid pathway. Together with specific immunological markers, this enzyme is useful to define the particular type of leukemic cells. It also serves to identify the quasi-lymphoblastic nature of the malignant clone, a helpful indication for the choice of therapy.

A gold nanoparticle-based label free colorimetric aptasensor for adenosine deaminase detection and inhibition assay

A novel strategy for the fabrication of a colorimetric aptasensor using label free gold nanoparticles (AuNPs) is proposed in this work, and the strategy has been employed for the assay of adenosine deaminase (ADA) activity. The aptasensor consists of adenosine (AD) aptamer, AD and AuNPs. The design of the biosensor takes advantage of the special optical properties of AuNPs and the interaction between AuNPs and single-strand DNA. In the absence of ADA, the AuNPs are aggregated and are blue in color under appropriate salt concentration because of the grid structure of an AD aptamer when binding to AD, while in the presence of the analyte, AuNPs remain dispersed with red color under the same concentration of salt owing to ADA converting AD into inosine which has no affinity with the AD aptamer, thus allowing quantitative investigation of ADA activity. The present strategy is simple, cost-effective, selective and sensitive for ADA with a detection limit of 1.526 U L(-1), which is about one order of magnitude lower than that previously reported. In addition, a very low concentration of the inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) could generate a distinguishable response. Therefore, the AuNP-based colorimetric biosensor has great potential in the diagnosis of ADA-relevant diseases and drug screening.

Serum adenosine deaminase activity in cutaneous anthrax

BACKGROUND

Adenosine deaminase (ADA) activity has been discovered in several inflammatory conditions; however, there are no data associated with cutaneous anthrax. The aim of this study was to investigate serum ADA activity in patients with cutaneous anthrax.

MATERIAL AND METHODS

Sixteen patients with cutaneous anthrax and 17 healthy controls were enrolled. We measured ADA activity; peripheral blood leukocyte, lymphocyte, neutrophil, and monocyte counts; erythrocyte sedimentation rate; and C reactive protein levels.

RESULTS

Serum ADA activity was significantly higher in patients with cutaneous anthrax than in the controls (p<0.001). A positive correlation was observed between ADA activity and lymphocyte counts (r=0.589, p=0.021) in the patient group.

CONCLUSIONS

This study suggests that serum ADA could be used as a biochemical marker in cutaneous anthrax.

Graphene oxide based fluorescent aptasensor for adenosine deaminase detection using adenosine as the substrate

We present a novel fluorescent aptasensor for simple and accurate detection of adenosine deaminase (ADA) activity and inhibition on the basis of graphene oxide (GO) using adenosine (AD) as the substrate. This aptasensor consists of a dye-labeled single-stranded AD specific aptamer, GO and AD. The fluorescence intensity of the dye-labeled AD specific aptamer is quenched very efficiently by GO as a result of strong π-π stacking interaction and excellent electronic transference of GO. In the presence of AD, the fluorescence of the GO-based probe is recovered since the competitive binding of AD and GO with the dye-labeled aptamer prevents the adsorption of dye-labeled aptamer on GO. When ADA was introduced to this GO-based probe solution, the fluorescence of the probe was quenched owing to ADA can convert AD into inosine which has no affinity to the dye-labeled aptamer, thus allowing quantitative investigation of ADA activity. The as-proposed sensor is highly selective and sensitive for the assay of ADA activity with a detection limit of 0.0129U/mL in clean buffer, which is more than one order of magnitude lower than the previous reports. Meanwhile, a good linear relationship with the correlation coefficient of R=0.9922 was obtained by testing 5% human serum containing a series of concentrations of ADA. Additionally, the inhibition effect of erythro-9-(2-hydroxy-3-nonyl) adenine on ADA activity was investigated in this design. The GO-based fluorescence aptasensor not only provides a simple, cost-effective and sensitive platform for the detection of ADA and its inhibitor but also shows great potential in the diagnosis of ADA-relevant diseases and drug development.

Adenosine deaminase in saliva as a diagnostic marker of squamous cell carcinoma of tongue

Tongue cancer is amongst the most common and fatal types of cancers in the world. The abnormalities in purine metabolism are characteristic features of many human tumors. Little is known about the correlation between the activities of key enzymes of purine nucleotide pathway and clinical indicators of tongue cancer invasiveness and aggressiveness. Fifty patients (M: F 25:25; mean age: 55.6 years (range 45-60; SD 1.8)) with diagnosed squamous cell carcinoma of the tongue (test group) and 30 normal subjects (M: F 15:15) without any systemic disease (control group) were recruited after obtaining informed consent. All patients were staged by the TNM classification. Salivary adenosine deaminase (ADA) activity was assessed in cancerous patients (test group) and normal healthy subjects (control group). Statistically significant differences between test and control groups were observed in salivary ADA (P < 0.001). Furthermore, serum ADA levels significantly increased as the disease stage progressed from stage I to stage III of squamous cell carcinoma of the tongue in both genders (P < 0.001). Salivary ADA might be used as a diagnostic tool for early detection of squamous cell carcinoma of tongue.

Establishment and characteristics of a T-cell acute lymphoblastic leukemia cell line, JK-T1, with a chromosomal translocation between 8q24 and 14q13

A human leukemia cell line, JK-T1, was established from the bone marrow of a 10-year-old boy with T-cell acute lymphoblastic leukemia. The origin of the leukemic cell line, JK-T1, was demonstrated by its chromosomal and immunologic similarity to the patient's fresh leukemic cells. Karyotypic analysis revealed 46,XY,del(6)(q?),t(8;14)(q24;q13),der(9)t(9;?)(q34;?). In JK-T1, neither rearrangement nor amplification of the c-myc gene was observed apparently because the breakpoint of chromosome 14 was not q11 but q13. JK-T1 was independent of interleukin 2 (IL-2) because of little production of IL-2, little IL-2 receptor (CD25) on the surface, and no response to exogenous IL-2. JK-T1 had lymphocyte function associated antigen-1 (LFA-1) (CD11a, CD18) on its surface and could adhere to the hematologic stromal layer. These characteristics of JK-T1 cell line are considered to be useful not only for evaluating the role of t(8;14) but also in studying the adhesion molecules of leukemia.

Establishment of a human T-acute lymphoblastic leukemia cell line with a (16;20) chromosome translocation

A new T-cell line, Loucy, was established from the peripheral blood of a patient with T-cell acute lymphoblastic leukemia (T-ALL). The surface marker analysis of the cell line is OKT3+, OKT4+, THB4+, J5 +/-, OKT6-, TdT-, and HLA-DR-, indicating stage IV in T-cell lineage. Karyotype analysis revealed 45,X,5q-,t(16;20)(p12;q13). The translocation between chromosomes 16 and 20 has not been previously detected in ALL. This cell line may be of value in evaluating the role of t(16;20) in the etiology of T-ALL.

Enzymatic imbalance in peripheral blood mononuclear cells isolated from individuals with anti-HIV antibodies

Plasma membrane-bound 5'-nucleotidase (5'-NT), gamma-glutamyltransferase (gamma-GT) and soluble deoxynucleotidyltransferase (TdT) were studied in peripheral blood cells (PBMN) of 35 individuals, 26 male and 9 female, with circulating anti-HIV antibodies. Twenty-six were drug abusers, 2 were drug abusers and homosexuals and 4 were homosexuals. Three did not fall into any risk group. The surface immunologic phenotype of cells stained with the fluorescent monoclonal antibodies Leu 5, Leu 3, Leu 2, Leu 12, Leu M3, Leu M1, anti-CALLA and anti-HLA-DR was delineated by flow cytometry. While the gamma-GT activity did not change, the lymphocyte 5'-NT activity was significantly less than normal in anti-HIV positive individuals and in anti-HIV negative drug abusers. TdT activity was detectable in 14 anti-HIV positive patients (40%), who did not have clinical AIDS. Of 8 patients with AIDS, 3 had a low level of TdT activity but 5 had cells completely devoid of TdT and 5'-NT activity. 5'-nucleotidase activity and the frequency of Leu 2 suppressor antigen bearing cells were the only independent variables that correlated with AIDS incidence.

Occurrence of particular isoenzymes in fresh and cultured leukemia-lymphoma cells. II. Hexosaminidase I isoenzyme

The isoenzyme profiles of hexosaminidase (N-acetyl-beta-D-glucosaminidase) were analyzed by isoelectric focusing on horizontal polyacrylamide thin-layer gel with special emphasis on the intermediate isoenzyme (Hex I). The expression of Hex I was examined in 87 leukemia-lymphoma cell lines, in 14 B-lymphoblastoid cell lines, in 441 cases of leukemia-lymphoma (specimens containing 80% or more tumor cells), in 22 leukemia cell lines and in 14 cases of leukemia that had been treated with phorbolesters (TPA) for induction of differentiation, and in the mononuclear cell preparations separated from peripheral blood, lymph node, thymus, bone marrow, tonsil, liver, and spleen specimens from normal donors. Hex I was detected in the leukemia cell lines arrested at early, immature or at late, mature stages of B- and T-cell differentiation, but not in cell lines blocked at intermediate stages of maturation. Most myelomonocytic leukemia cell lines and the erythroleukemia cell lines showed Hex I, whereas the B-lymphoblastoid cell lines were negative for this marker. During induction of differentiation, the expression of Hex I was lost in 13 of 15 leukemia cell lines that were originally Hex I-positive. Among the panel of the "fresh" leukemia-lymphoma cells, Hex I was found predominantly in cases of acute lymphoblastic leukemia and acute myeloblastic/monoblastic leukemia, but rarely or not at all in the mature T-, B- or myeloid malignancies. However, two out of two cases of multiple myeloma were Hex I-positive, and the Hex I expression could be induced by TPA in three of six B-cell chronic lymphocytic leukemia cases. Chronic myelocytic leukemia cells remained Hex I-negative during induction of differentiation. Hex I-positivity was not detected in the cell preparations from normal tissues, and peripheral blood indicating that the normal cellular counterpart of the Hex I-positive tumor cells are present at only low percentages within the respective cell populations. It is suggested that Hex I is a marker of early lymphoid and myeloid hematopoiesis that is no longer expressed in intermediate stages of lymphoid differentiation and in later or terminal stages of myeloid differentiation, but that is again detectable in terminally differentiated B-cells. Further studies will focus on identification and isolation of normal Hex I-positive cells.

Phenotyping of malignant hematopoietic cells. Analysis of 1200 cases of leukemia-lymphoma

1255 cases of leukemia-lymphoma were tested between 1972 and 1984 by multiple marker analysis. Routine leukemia phenotyping was performed using standard morphological and cytochemical techniques in combination with clinical and histo-pathological information; the main emphasis was put on immunological surface marker analysis using erythrocyte rosette assays, TdT and a large panel of poly- and monoclonal antibody tests. The 1255 cases were divided into these major types and subtypes: 349 cases of ALL and related immature T- and Burkitt-lymphomas (cALL, pre B-ALL, B-ALL and Burkitt-lymphomas, T-ALL and immature, mostly leukemic T-lymphomas, Null-ALL), 454 cases of mature T- and B-cell malignancies (T-CLL, mycosis fungoides, Sezary-syndrome, T-lymphomas, B-CLL, hairy cell leukemia, multiple myeloma, B-lymphomas), 263 cases of acute myeloid leukemias (AML, AMMoL/AMoL), 182 cases of chronic myeloid leukemias (CML in chronic phase, CMoL, CML in blast crisis), 6 cases of erythroleukemia and 1 case of megakaryoblastic leukemia. A simplified classification scheme which has been used in our laboratories is presented. Phenotyping is of diagnostic, prognostic and therapeutic relevance, most evidently for patients with ALL. Routine leukemia phenotyping should be performed with highly standardized techniques and reagents and by combining information from several fields in the multiple marker analysis. New areas of leukemia research might become very useful for the routine procedure of phenotyping.

Reactivity patterns of monoclonal antibodies positive on myelomonocytic leukemia cells as defined by esterase isoenzyme analysis

The reactivity with monoclonal antibodies (MoAbs) specific for myelomonocytic cells and the expression of a particular esterase isoenzyme were analyzed in 159 cases of acute myeloid leukemias. The incidence of positivity of 16 MoAbs (MCS-2, MCS-1, OKM1, My-1, Leu-M1, Leu-M3, CA-2-38, MY4, MY7, MY8, MY9, VIM-D2, VIM-D5, Mo1, Mo2, 63D3) was studied using the indirect immunofluorescence technique. A carboxylic esterase isoenzyme which can be inhibited completely and selectively by sodium fluoride (NaF) was demonstrated by isoelectric focusing on horizontal polyacrylamide gels. This NaF-sensitive isoenzyme indicated the monocytic origin of the blast cells as it is specific for this cell lineage. Prior to the immunological-isoenzymatic analysis all cases were categorized into two subtypes according to morphological criteria of the FAB classification system: 147 cases of AML (FAB M1-3) and 12 cases of AMMoL/AMoL (FAB M4/5). However, 15 out of 147 cases of AML expressed the NaF-sensitive isoenzyme and were therefore assigned to the group AMMoL/AMoL. Likewise, 1 case, diagnosed morphologically as AMMoL, was negative for this marker isoenzyme and was assigned to the other leukemia subtype. The incidence of reactivity varied widely for the MoAbs tested regarding the overall results on all cases and the positivity of cases of either AML or AM-MoL/AMoL. The MoAbs were grouped into four classes depending on the pattern of reactivity with myeloblastic or monoblastic or both subtypes of acute myeloid leukemia. The MoAbs MCS-2, MY7, Leu-M1, and MY9 detected the vast majority of cases with either myelocytic or monocytic involvement (group-I: "pan-myelomonocytic" reactivity). The MoAbs MCS-1, OKM1, VIM-D5, and Mo1 showed a predominance in their staining pattern for monocytic variants, but were also positive on a substantial percentage of nonmonocytic cases (group-II: predominantly reactive with monocytic, but also myelocytic cases). The MoAbs Leu-M3, MY4, VIM-D2, Mo2, and MY8 reacted with the large majority of AMMoL/AMoL cases and with a small number of AML cases (group-III: monocyte-"specific" reactivity). The MoAbs of group-I are useful in differentiating acute lymphoid from acute myeloid leukemias. The MoAbs of group-III, and to a lower extent those of group-II, will be of considerable value in the subtyping of acute myeloid leukemias. The results show that accuracy of leukemia classification might not always be achieved by morphology alone, but that immunological and biochemical aspects should be included as well, and several MoAbs are very useful tools for classification and subtyping of acute myeloid leukemias.

Terminal deoxynucleotidyl transferase activity in childhood leukemia

The activity of terminal deoxynucleotidyl transferase (Tdt) was measured in mononuclear cells of 70 children with acute leukemia, in whom raised levels of Tdt were noted at diagnosis, relapse, or during remission. Serial measurements of Tdt activity were related to the percentage of blasts in the bone marrow and the clinical course of children both during therapy and after its completion. The Tdt values did not predict relapse in children with acute lymphoblastic leukemia nor did the quantitative determination correlate with the percentage of blasts in the bone marrow.

Biochemical enzyme analysis in acute leukaemia

This report summarises the current knowledge regarding the clinical utility of biochemical enzyme markers for both diagnostic and therapeutic purposes in acute leukaemia. The enzymes studied most extensively in this field are terminal deoxynucleotidyl transferase, adenosine deaminase, 5'-nucleotidase, purine nucleoside phosphorylase, and acid phosphatase, esterase, hexosaminidase isoenzymes. For each enzyme, the quantitative and qualitative characteristics in various immunologically defined subclasses of acute leukaemia are described. The quantitative evaluation of enzyme activities represents an adjunctive classification technique which should be incorporated into the multivariate analysis, the "multiple marker analysis." By qualitative characterisation pronounced heterogeneity of leukaemia subsets is uncovered. The application of 2'-deoxycoformycin, a specific inhibitor of adenosine deaminase, and the potential usefulness of two other enzymes as targets for treatment with selective agents is discussed. The concept that gene products expressed at certain developmental stages of normal cells can similarly be detected in leukaemic cells (which therefore seem to be "frozen" or "arrested" at this particular maturation/differentiation stage) is supported by the results obtained in enzyme studies. Besides their practical clinical importance for classification and treatment of acute leukaemias, biochemical enzyme markers constitute a valuable research tool to disclose biological properties of leukaemic cells.

Isoenzyme studies in human leukemia-lymphoma cell lines--IV. Lactate dehydrogenase

Isoelectric focusing (IEF) in horizontal polyacrylamide gels has been used to separate lactate dehydrogenase (LDH) isoenzymes in 97 human permanent hematopoietic cell lines (85 leukemia-lymphoma cell lines and 12 'normal' B-lymphoblastoid cell lines). Maximally 8 LDH bands were seen; the electrophoretically detectable bands 4 and 5 could be separated by IEF into 2 and 3 isoenzymes, respectively. The LDH patterns have been found to vary both in number of isoenzymes and in relative intensity in different cell lines depending upon the stage at which arrest of differentiation occurred. These differences can be used to analyse and distinguish different cell lines. The method should provide a valuable supplement to the enzymatic phenotyping and complete characterization of fresh and cultured leukemias and for the monitoring of phenotypic changes occurring during induction of differentiation.

Lysosomal isoenzyme profiles used to classify a case of acute undifferentiated leukaemia

Lysosomal enzyme activities and isoenzyme profiles were measured in lymphoid and non-lymphoid leukaemic cells from childhood patients. High activities, especially of beta-hexosaminidase and alpha-mannosidase, were associated with leukaemic cells of myeloid or monocytic origin. Leukaemic cells from two children with acute myeloid leukaemia had a relative reduction in the B isoenzyme of beta-hexosaminidase activity, whereas in patients with non T, non B cell acute lymphoblastic leukaemia, intermediate beta-hexosaminidase isoenzymes were expressed. A patient is described on whom conventional marker studies were either negative or equivocal, but lysosomal enzyme markers were consistent with a myeloid leukaemia. This observation was supported by the clinical course of this patient.

Isoenzyme studies in human leukemia-lymphoma cell lines--1. Carboxylic esterase

The isoenzyme patterns of carboxylic esterase (E.C. 3.1.1.1) were studied in 74 proven human leukemia-lymphoma and 12 normal B-lymphoblastoid cell lines. These cell lines have been extensively phenotyped using poly- and monoclonal antibodies. Esterase isoenzymes were separated by isoelectric focusing and visualized by histo-cytochemical techniques. No leukemia-specific or (except for monocytes) blood cell type-specific isoenzyme or isoenzyme pattern could be detected. The monocytic element in some cell lines was characterized by a strong isoenzyme band which could be selectively and completely inhibited by sodium fluoride. The enzyme phenotypes were stably expressed in all subcultures of a given cell line and did not appear to have any cell cycle dependency. The leukemia-lymphoma cell lines have been subclassified into four major groups according to immunological parameters: T-cell, B-cell, myelomonocytic and non-T, non-B-cell. On the basis of immunological data the T-cell lines were assigned to five stages of differentiation. The number and staining intensity of the isoenzymes increased with differentiation of the T-cells paralleling the expression of immunological markers. The B-cell leukemia-lymphoma cell lines were divided into pre B-, B-, Burkitt lymphoma, multiple myeloma and hairy cell leukemia cell lines. Substantial variability among the isoenzyme patterns was detected ranging from immature profiles of pre B-cell lines to complete isoenzyme repertoires of multiple myeloma cell lines. No significant difference was seen between the isoenzymes of mature B-cell lines and normal B-lymphoblastoid cell lines. The most prominent feature seen in myelomonocytic cell lines was the monocytic band indicating a monocytic origin and separating the 'monocytoid' from the 'pure myeloid' cell lines. Considerable heterogeneity in the isoenzyme patterns was observed in the non-T, non-B cell groups which comprised erythroleukemia cell lines and cell lines arrested at a very early stage of lymphoid differentiation. These latter cell lines together with some T- and B-cell lines shared the common characteristics of positivity for cALLA, TdT and Ia antigens and an immature, incomplete isoenzyme profile. The results support the notions of maturation arrest and normal gene expression in leukemic cell populations. Furthermore, the importance of biochemical studies as part of the multiple marker analysis could be demonstrated.

Leukemic cell differentiation in childhood leukemias. Analysis by enzyme markers

Enzyme marker analysis has become a valuable tool in leukemia research, especially as a part of the so-called multiple marker analysis which combines several disciplines for characterization of leukemia cells. In this study the qualitative activities of three enzyme markers were determined in leukemic cells from pediatric patients with acute leukemias: acid phosphatase (E.C. 3.1.3.2), carboxylic esterase (E.C. 3.1.1.1) and hexosaminidase (E.C. 3.2.1.30). The leukemia subtypes displayed different types of isoenzyme patterns. No additional isoenzyme was found that was not observed in normal blood cells, nor a single isoenzyme specific for a leukemia subtype. The biochemical profiles illustrated the existence of subsets in cALL, T-ALL and AML. The enzymologic polymorphism and the immunologic heterogeneity seen in leukemia subclasses have led together to an extended classification scheme of leukemias as well as to model schemes of normal hematopoietic cell differentiation. Despite former and constantly published assumptions there are still no specific markers of leukemia cells.

Chronic myelomonocytic leukemia: value of touch preps

(CMML) Chronic myelomonocytic leukemia is not an uncommon leukemia occurring in elderly individuals. Cutaneous manifestations are unusual and portend a poorer prognosis. Touch imprints from a skin punch biopsy may help to quickly confirm clinical suspicions of an underlying leukemia or lymphoma.

Ph1-positive acute myelocytic leukemia with high TdT levels

The authors have determined TdT levels in a case of Ph1-positive AML. Peripheral blood cells and bone marrow cells taken during the various phases of the disease were examined. Liquor cells were analyzed when symptomatic central nervous system involvement occurred. High TdT levels were found in all of the phases of the disease including the liquor. TdT eluted at various isoelectric points indicating a shifting of the activity to greater molarity during progress of the disease. Two different forms of TdT were present in the liquor. The authors speculate about the existence of a relation between TdT levels and Ph1-positive leukemia. They point out the importance of TdT levels as functional criterion of remission in acute leukemia. Finally, the existence of different forms of TdT could be the expression of a clonal selection caused by therapy or of a spontaneous clonal competition.

Correlation of lysosomal enzyme abnormalities in various forms of adult leukaemia

Lysosomal enzyme activities were studied in cells derived from the following types of leukaemia: chronic myeloid, acute myeloid, acute myelomonocytic, acute monocytic, non-T, non-B cell acute lymphoblastic, T-cell acute lymphoblastic, B-cell chronic lymphocytic and T-cell chronic lymphocytic. Activities of beta-hexosaminidase and alpha-mannosidase were significantly higher in cells from acute monocytic and acute myelomonocytic leukaemias, and somewhat higher in the other myeloid leukaemias, when compared with control granulocytes. Activities of beta-hexosaminidase, alpha-mannosidase, alpha-fucosidase, beta-glucuronidase and acid phosphatase were markedly lower in B cells of chronic lymphocytic leukaemia when compared with control or other leukaemic lymphoid cells. On isoelectric focusing abnormal patterns of beta-hexosaminidase, alpha-mannosidase and beta-glucuronidase activities were commonly found in myeloid and non-T, non-B cell leukaemias. All patients with acute myeloid leukaemia exhibited a relative decrease in the B form of beta-hexosaminidase activity. The results described show that studies on lysosomal enzymes may assist in the classification of different types of leukaemia.

Hypercalcemia and diffuse osteolytic lesions in the acute phase of chronic myelogenous leukemia. A possible relation between lymphoid transformation and hypercalcemia

A patient with blastic crisis of chronic myelogenous leukemia (CML) is presented. The acute phase was localized in the lymph nodes and bones, causing severe osteolytic lesions and hypercalcemia. The blast cells were undifferentiated in light microscopy and by histochemical stains. As viewed under electron microscopy, a considerable proportion of the blast cells were of myeloid origin, while immunologic markers and cytogenetics indicated a lymphoid origin. It seems plausible that the patient had a mixed myeloid-lymphoid blast crisis, but that the lymphoid blasts were responsible for the severe osteolytic lesions and the hypercalcemia.

Analysis of isoenzyme patterns of acid phosphatase in acute leukemias

The status of acid phosphatase isoenzymes was evaluated in cells of patients with acute lymphocytic leukemias or lymphomas by analytical isoelectric focusing in polyacrylamide gels (IEF) on horizontal thin-layer slabs. The isoenzyme patterns were correlated with routine immunological cell surface markers and the relationship of enzyme activity to specific immunological subclasses of ALL is discussed. By isoelectric focusing up to five isoenzyme groups (I-V) containing several isoenzyme were observed. No leukemia specific or additional isoenzyme could be demonstrated. This biochemical characterization showed a marked heterogeneity within two major immunologic subgroups indicating that various differentiation stages of cell maturation could be involved in cALL and T-ALL. According to their degree of maturation along T-cell differentiation axis the leukemic cells displayed no enzyme activity, weak isoenzyme bands or the incomplete or complete isoenzyme pattern seen with normal lymphocytes from human tonsils which were used as controls. The investigation of specific enzymatic patterns can lead to a further definition of subsets of acute leukemias and give insight into lymphopoietic differentiation.

Comparison of purine degradative enzymes and terminal deoxynucleotidyl transferase in T cell leukaemias and in normal thymic and post-thymic T cells

Adenosine deaminase (ADA), ecto 5' nucleotidase (5'NT), purine nucleoside phosphorylase (PNP) and terminal deoxynucleotidyl transferase (TdT) were measured in the cells of patients with acute or chronic T cell leukaemia and compared with normal putative prothymocytes (large, blast-like cortical thymocytes), cortical and medullary thymocytes and peripheral blood T lymphocytes. Distinct patterns of enzyme activities were found in the individual types of T cell leukaemia. Mean ADA, TdT and 5'NT activities in thymic acute lymphoblastic leukaemia (Thy-ALL) were 41.9 u/10(8) cells, 31.1 u/10(8) cells and 4.7 u/10(6) cells respectively; in chronic T cell leukaemia they were 7.1 u/10(8) cells, 0.6 u/10(8) cells and 18.1 u/10(6) cells respectively. Mean PNP activity was similar between these two groups of leukaemia (68.6 u/10(6)cells in Thy-ALL and 77.9 u/10(6) cells in chronic T cell leukaemia). The activities of these four enzymes in OKT4+ chronic T cell leukaemia did not differ significantly from those in the OKT8+ chronic T cell leukaemia cases. The activities of TdT, ADA, PNP and 5'NT in Thy-ALL closely resembled those in normal immature thymocytes, and in the chronic T cell leukaemias showed a similar pattern of enzyme activities to that of mature T lymphocytes. These findings are consistent with surface phenotypic studies of T cell malignancies which suggest that different T cell leukaemias represent malignant proliferation of T cell clones arrested at different stages of T cell differentiation. They also demonstrate the value of biochemical markers in defining the different subtypes of acute and chronic leukaemia.

Isoenzyme studies in human leukemia -- III. beta-Hexosaminidase (E.C. 3.2.1.30)

Enzymologic profiles of beta-hexosaminidase (N-acetyl-beta-D-glucosaminidase, E.C.3.2.1.30) were studied in cells from childhood acute leukemias and lymphomas. By analytical isoelectric focusing or disc electrophoresis the beta-hexosaminidase activity was separated into its components A, B, I and C. The isoenzyme patterns were correlated with immunologic cell surface marker characteristics found on the investigated leukemic cells. In all cases of T-ALL the beta-hexosaminidase forms A and B were observed, an enzyme pattern similar to that found in normal lymphocytes. Seven out of 11 cases with cALL, three of six cases with AML and one case of AUL displayed the intermediate component (Hex I). Marked heterogeneity within the immunologically classified subgroup cALL was reflected in different enzyme patterns of the cALL samples. These biochemical phenotypes may indicate the different maturation and differentiation status of cells expressing the same immunologic surface markers.

Isoenzyme studies in human leukemia -- II. Carboxylic esterase (E.C. 3.1.1.1.)

Isoelectric focusing analysis of esterase activity (E.C. 3.1.1.1.) has been carried out on polyacrylamide gel slabs of a variety of immunologically defined acute leukemia subtypes. Distinct isoenzyme bands and isoenzyme groups have been identified and characterized biochemically with regard to their features for substrate specificity, pH optimum and inhibition experiments. The esterase isoenzyme patterns permitted the distinction between acute myeloid and non-myeloid leukemias. Acute lymphocytic leukemias localized by their immunological profile along the T-cell axis exhibited a readily recognizable isoenzyme group (T group). Reproducible differences in isoenzyme patterns were observed in childhood common ALL which indicate that the immunologically determined entity cALL displays a clear heterogeneity with respect to biochemical profiles of enzyme markers. These results suggest that further combined biochemical and immunological characterization may significantly contribute to a better understanding of lymphopoietic and leukemic cell differentiation.

Nasal T-cell lymphoma as a type of so-called "lethal midline granuloma"

Six cases were described in which an initial clinical diagnosis of "rhinitis gangrenosa progressiva" or lethal midline granuloma was made. The histological examinations of their surgical and autopsy specimens proved that their nasologic diseases could all be identified as malignant lymphoma arising from the nasal cavity, showing the general histologic characteristics reported for T-cell lymphomata derived from peripheral T-cells. This histologic observation was then confirmed by immunofluorescence studies using various antisera directed toward either human T- or B-cell-surface antigens. These studies clearly demonstrated that their malignant cells bore human Ly-l-like antigen but lacked human TL-like and Ia-like antigens as well as surface-bound immunoglobulins, indicating their peripheral T-cell origin. These data may suggest that so-called "rhinitis gangrenosa progressiva" or lethal midline granuloma contains at least two distinct disease categories, one of which is Wegener's granulomatosis, and the other of which is nasal T-cell lymphoma as described herein.

Nucleoside incorporation into DNA and RNA in acute leukaemia: differences between the various leukaemia sub-types

The incorporation of the labelled deoxyribonucleosides 3H-deoxythymidine (3H-TdR), H3-deoxycytidine (3H-CdR), 3H-deoxyadenosine (3H-AdR), 3H-deoxyguanosine (3G-GdR), 3H-deoxyuridine (3H-UdR) and of labelled uridine (3H-UR) into DNA and RNA was studied in bone marrow (BM) and peripheral blood (PB) cells from 10 normal donors and 11 patients with acute myeloblastic leukaemia, 13 with acute non-T non-B common ALL (c-ALL) and seven with thymic acute lymphoblastic leukaemia. 3H-TdR incorporation was highest into the DNA of normal BM cells, 3H-CdR into DNA in Thy-All and 3H-UdR into DNA of c-ALL cells. Purine deoxynucleoside (3H-AdR and 3H-GdR) incorporation was highest in AML cells and they were incorporated mainly into RNA indicating that before utilization they are partially degraded from the deoxyribose to the corresponding ribose form. In all but three leukaemia samples, the 3H-UdR/3H-TdR incorporation ratio was above the range found in normal bone marrow, suggesting the leukaemic cells are more dependent than a normal mixed marrow cell population on the de novo pathway of thymidylate synthesis. The incorporation of nucleosides by peripheral blood cells was usually much lower than by the corresponding bone marrow cells, irrespective of blast percentage.

Isozyme distribution of hexokinase, phosphofructokinase and pyruvate kinase in lymphocytes from patients with chronic lymphocytic leukemia

The enzyme activities and isozyme distribution of the three glycolytic regulator enzymes hexokinase, phosphofructokinase and pyruvate kinase were studied in lymphocytes of patients with chronic lymphocytic leukemia. Isozyme distribution patterns were determined by kinetic measurements, electrophoresis and immunoprecipitation. The CLL lymphocytes were different from normal non-T lymphocytes with respect to hexokinase residual activity in the presence of glucose-1,6-P2, pyruvate kinase residual activity in the presence of alanine, and phosphofructokinase activity after stimulation by glucose-1,6-P2. No differences could be discerned in enzyme activities between the CLL and the normal T and non-T lymphocytes.

The use of enzyme marker analysis for subclassification of acute lymphocytic leukemia in childhood

Subclassification of acute lymphocytic leukemias in childhood by multiple marker analysis has proven the heterogeneity of this disease and this methodology has led to a better understanding of the cell-biological basis of ALL. Enzyme markers have become important tools in multiple marker analysis. This is especially true for TdT, purine metabolic enzymes, hexosaminidase I, acid phosphatase and carboxylic esterases. In spite of sophisticated methods and encouraging results multiple marker analysis has not been totally satisfactory in defining patients at risk. The same is true for a risk score established by clinical data. More efforts in the future are necessary for combining multiple marker analysis, cytogenetics, proliferation characteristics, basic clinical findings and the final outcome of the disease in these patients. Beyond that this kind of leukemia research will help to clarify the pathobiological basis of human leukemia and to develop new specific therapeutic modalities.

Studies of terminal deoxynucleotidyl transferase in normal and neoplastic human cells

Optimized biochemical assays and cytoimmunofluorescence tests were used to detect terminal deoxynucleotidyl transferase, TdT, in malignant cells of 36 leukemias and 75 lymphomas from patients not receiving chemotherapy. TdT was virtually absent from normal lymph nodes and from leukocytes of chronic lymphocytic leukemia, CLL, taken as controls. Its quantitative distribution in the neoplasms matched the current knowledge. Appreciable amounts of TdT were found in all the 10 lymphomas of lymphoblastic type, LL, and in the white blood cells of: 16 out of 19 acute lymphoblastic leukemia, AAL, perhaps with modulation in the various phenotypes; 2 out of 3 acute undifferentiated leukemias, AUL; and 3 out of 7 blastic crises in chronic myelogenous leukemia, b.c. CML. Biochemical and cytoimmunological analyses yielded concordant responses and even roughly comparable estimates in the same patients. TdT immunofluorescence was clearly nuclear in most cells and was cytoplasmic occasionally. Definite correlations between concentrations of enzymatic activity and percentage of immunofluorescent cells could not e established. Further detailed work will be required to identify putative subgroups in TdT-positive blast populations.