Acid-phosphatase reaction in acute lymphoblastic leukaemia

Diagnostic significance of lysosomal enzymes in different types of leukemias

The activities of seven different leukocyte hydrolases were studied in 19 patients and ten controls. There was a strong positive correlation between the monocyte count and the activities of the lysosomal enzymes (N-acetyl-beta-glucosaminidase, alpha-fucosidase, beta-galactosidase, and alpha-mannosidase). High alpha-fucosidase and alpha-mannosidase activities were also found in the eosinophilic granulocytes. Using simple commercially available synthetic substrates, it is possible to study the activities of the lysosomal enzymes in different types of leukemias and to recognize the monocytic leukemias even when they present with very immature precursor cells in the peripheral blood.

Establishment and characterization of a new leukaemic T-cell line (Peer) with an unusual phenotype

We report the isolation and establishment in continuous culture of a human lymphoid cell line (Peer) from a case of T-leukemia. The Peer cell line lacks some typical cell-surface properties of T cells, namely sheep erythrocyte rosette formation and reactivity with two anti-T-cell sera, but has focal acid phosphatase and does express two other T-cell antigens, one defined by a monoclonal antibody, the other related to a T-cell subset (TH2). The cells are negative for B-cell markers (SmIg or cytoplasmic mu Fcgamma and C3 receptors, mouse erythrocyte rosettes) and EBV (EBNA). In addition, the Peer cell does not possess the typical phenotypic markers of "non-B, non-T" leukemia: cALL and Ia-like antigens, and the cytoplasmic hexosaminidase isoenzyme I, but is positive for terminal deoxynucleotidyl transferase by enzymatic and immunofluorescent criteria. The cell line requires exogenous L-asparagine for adequate growth in culture, a property known to be characteristic of certain T cells but not of B cells. The Peer cell line appears to have a maturation arrest at a developmental stage intermediate between the cortical thymocyte and a mature T-cell subset and to have lost some T-cell differentiation features.

Acute lymphoblastic leukemia. A comprehensive review with emphasis on biology and therapy

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. It is now curable in 60-70% of children. Most of the current understanding of the biology and treatment of ALL originates from studies of children. In adults, although much progress has been achieved, ALL is curable in only 20-35% of patients.

METHODS

A review of the biology and treatment of ALL from the English literature was performed.

RESULTS

Immunophenotypic and cytogenetic analyses of ALL have contributed to a more rational classification of ALL. These analyses have identified subgroups with poor prognosis or with different therapeutic requirements. Overall, 60-70% of adults with ALL have poor prognostic features, including older age, a high leukocyte count, non-T-cell immunophenotype, Ph-positive genotype, and longer time to achieve a complete remission. These patients have a cure rate of 20-25%, whereas those without these risk factors, have a 60-70% probability of survival. The use of more intensive induction regimens with growth factor support may improve survival rates. Also, intensive consolidation-intensification may improve survival rates. Most patients benefit from maintenance therapy, but the dose schedule must be optimized. Central nervous system (CNS) prophylaxis is beneficial, particularly for patients with a high risk for CNS relapse and when introduced early during induction of remission. Patients with high risk characteristics may benefit from allogeneic bone marrow transplantation (BMT) during first remission, and all other patients may benefit from it during first or subsequent relapse. Autologous BMT may be a valuable option for poor compliant patients.

CONCLUSIONS

Although the prognosis of patients with ALL has improved markedly during the past decades, newer strategies, including more dose-intensive therapy, the search for new drugs, and more target-specific therapy, are needed to improve the current cure rates.

T-cell receptor gene rearrangements in lymphoid and non-lymphoid leukaemias

Rearrangements of delta-, tau-, and beta- T-cell receptor (TcR) chain genes were analysed in 64 haematologic malignancies comprising T- and B-lineage acute lymphoblastic leukaemias (ALL), B-chronic lymphocytic leukaemias (CLL), acute myeloid leukaemias (AML) and acute undifferentiated leukaemias AUL). The TcR genes were rearranged in 5/6 T-ALL. In non-T-leukaemias the frequency of TcR gene rearrangements was higher in B-lineage ALL (8/11), although they were all detected in B-CLL (5/29), AML (1/16) and AUL (2/4). Immunoglobulin (Ig) gene rearrangements were observed in 1/6 T-ALL and 2/14 AML. The analysis of these gene configurations has a diagnostic application since it allows the definition of the clonality of malignant proliferation and although they are not lineage specific such configurations represent a further parameter to evaluate, together with the immunophenotype and morphology, in the assignment or exclusion of the differentiation lineage of the haematologic malignancies.

Prognostic significance of cytochemical analysis of leukemic M2 blasts

Cytochemical analysis of leukemic blasts from 46 patients with acute myeloblastic M2 leukemia (according to the FAB classification) was performed before and after cytostatic therapy, and compared with findings obtained in 20 age- and sex-matched control subjects. Cytochemical findings for myeloperoxidase (MPO), Sudan black B, acid phosphatase and alpha-naphthyl-acetate esterase (ANAE) were related to the achievement of the first complete remission (CR), i.e. data were compared after the patients had been divided into CR and non-CR groups. The analysis clearly showed that a high proportion of myeloperoxidase- and, to a lesser extent, Sudan black B-positive blasts before treatment may have constituted a significantly unfavourable prognostic factor.

Enzyme cytochemistry of unfixed leukocytes and bone marrow cells using polyvinyl alcohol for the diagnosis of leukemia

Cytochemical methods for the demonstration of enzyme activities in blood and bone marrow cells were systematically improved by the addition of an inert polymer, polyvinyl alcohol (PVA), to the incubation medium and by using optimized reaction media. The methods investigated were tetrazolium salt methods for lactate, glucose-6-phosphate, succinate and glutamate dehydrogenase, the indoxyl-tetrazolium salt method for alkaline phosphatase, the diaminobenzidine method for peroxidase, and diazonium salt methods for chloroacetate esterase, beta-glucosaminidase, beta-glucuronidase, acid phosphatase, and dipeptidylpeptidase II and IV. PVA in the media preserved the morphology of cells very well and prevented leakage of large molecules such as enzymes from the cells. Therefore, fixation or long periods of air-drying prior to incubation leading to substantial loss of enzyme activity could be avoided. A brief period of drying (2 min at 37 degrees C) of the cell preparations just before the incubation was sufficient for making the cells permeable. Localization of enzyme activities was very precise and precipitation of the final reaction product was confined to sites which are known to contain the enzyme under study (granules, mitochondria, lysosomes). These advantages advocate the use of PVA in haematological enzyme cytochemistry and especially for diagnosis of leukemia.

Genes for tumor markers are clustered with cellular proto-oncogenes on human chromosomes

We have analyzed the relative mapping positions of genes for polypeptides expressed abnormally in tumors (tumor markers) and cellular proto-oncogenes and find a remarkable degree of co-mapping of tumor marker genes with oncogenes in the human karyotype. We propose that aberrant expression of marker genes in tumors may be related to their proximity in the human genome to oncogenes expressed during the development of malignancy, and we suggest ways to test this hypothesis of concerted abnormal gene expression in mammalian tumor cells.

Immunocytochemical evidence of common-ALL antigen in null-ALL

4 cases of acute lymphoblastic leukaemia (ALL), diagnosed as null-ALL by indirect immunofluorescence using monoclonal antibodies, were similarly investigated using a sensitive immunoperoxidase method. The Avidin-Biotin system was employed. The immunoenzymatic results were in agreement with those obtained with immunofluorescence techniques for all antigens except common-ALL (C-ALL). The C-ALL antigen, recognized by the J5 antibody, was detected only by the immunoperoxidase method on cell membranes of the 4 ALL. This paper discusses the possibility of false negative results in testing for C-ALL antigen by conventional indirect immunofluorescence as suggested by refined immunocytochemical screening. Moreover, the ability of the immunoperoxidase system to identify antigens on cell membranes, even at very low density, is discussed. The clinical significance of the presence of C-ALL antigen at weak intensity in cases of null-ALL is also considered.

Phenotypic and ultrastructural characterization of a medullary thymocyte acute lymphoblastic leukemia with cellular procoagulant activity

The phenotypic and ultrastructural characterization of the blast cells from a T-cell acute lymphoblastic leukemia (T-ALL) that was associated with disseminated intravascular coagulation (DIC) is described. The bone marrow blasts were considered to represent neoplastic medullary thymocytes and were acid phosphatase (+), terminal deoxynucleotidyl transferase (-), acid alpha-naphthyl acetate esterase (-), E-rosette (+) at 4 degrees C and 37 degrees C, Fc- and C3-receptor (-), and cALLA-, Ia-, 9.6+, OKT3+, OKT4+, OKT6+/-, OKT8+, OKT10+. On transmission electron microscopic study, the predominant cell was 6 micron in diameter and possessed an irregular nucleus, moderate-sized nucleolus, marginated heterochromatin, abundant Golgi elements and granules, and prominent intermediate filaments. The cells were analyzed with normal and factor-deficient human plasmas and contained significant amounts of tissue factor-like procoagulant activity. This is the first report of a well-characterized medullary thymocyte T-ALL in which DIC was an accompanying feature, and the first demonstration of tissue factor-like procoagulant activity in acute lymphoblastic leukemia. In view of thrombohemorrhagic phenomena observed in association with other medullary thymocyte leukemias, these findings suggest that tissue factor-like procoagulant activity may be a characteristic of medullary thymocyte-derived lymphoid leukemias.

Cell surface markers in leukemia: biological and clinical correlations

Recent advances in analysis of leukemic cell phenotypes using cell surface markers have provided important insights into leukocyte differentiation and the cellular origin of leukemia. In addition to the traditional cell surface markers, i.e., surface membrane immunoglobulin and receptors for sheep erythrocytes that define B and T lymphocytes, highly specific monoclonal antibodies have been developed that discriminate various stages of human lymphocyte and granulocyte differentiation. Explorations of the detailed phenotypes of leukemic cells in relation to normal hemopoietic differentiation reveal that consistent, composite phenotypes of different subclasses of lymphoid malignancies closely mimic those of corresponding normal cells at equivalent levels of maturation. This is exemplified in lymphoma cells (chronic lymphocytic leukemia of B or T type, Sezary Syndrome, immunocytoma) that resemble mature and immunocompetent T and B cells, in T cell acute lymphoblastic leukemia (T-ALL) (equivalent to thymus cells) and in non-T ALL (corresponding to lymphoid progenitor cells in the bone marrow). The major phenotypes documented in different leukemias represent the level of maturation arrest imposed on the dominant subclone; this is determined by, but not necessarily synonymous with, the target cell and associated clonogenic cell population in the leukemia. The clinical significance of immunodiagnosis of leukemia cell types becomes best evidenced in acute leukemias. Besides the improvement of diagnosis by using objective criteria, clinically useful subclassifications became evident: five major subtypes of ALL are now recognized, including unclassified or null ALL, common ALL, pre-B-ALL, B-ALL and pre-T/T-ALL. In addition to disclosing that ALL is an heterogeneous disease, such classifications have proved to be prognostically significant. This is exemplified in 248 children and 145 adults with ALL which were analysed for cell type and clinical data. In addition to their utility in leukemia classification, monoclonal antibodies that identify leukemia associated antigens are becoming used therapeutically, e.g., to lyse residual leukemia cells from remission bone marrows removed from leukemia patients before reinfusion. New approaches to the treatment of leukemia in which the objective is to encourage maturation of leukemia cells rather than to achieve leukemia eradication, can be monitored by phenotyping the alterations of the cell surface, and cell markers may hopefully be useful in identifying cell types that can be induced to differentiate.

Pattern of subtypes of acute lymphoblastic leukemia in India

Leukemic cells from 124 acute lymphoblastic leukemia (ALL) and 31 chronic lymphatic leukemia (CLL) were examined for sheep erythrocyte receptor (E), surface immunoglobulin (SIg) and their reactivity with a panel of monoclonal antibodies recognizing specific surface antigens including pan-T, Common ALL and Ia antigens. In acute lymphatic leukemia, 33% of patients reveal T-cell receptor associated with higher age group, mediastinal mass and high WBC count. Common ALL was predominant between 2 and 9-yr age group. Among chronic lymphatic leukemia, 2 patients were found to be T-CLL while 29 revealed presence of SIg. Ia antigen was detected in 44.4% of ALL and 64% fo CLL patients. The pattern of surface marker observed in our series may be related to our life style, socio-economic and environmental factors.

A comparative study of immunological and cytochemical profiles between adult and childhood acute lymphoblastic leukemias (ALLs): heterogeneity in adult common ALL

To investigate the biological differences between adult and childhood acute lymphoblastic leukemia (ALL), leukemic blasts from 33 patients with ALL (22 adults and 11 children) and from 11 patients in the lymphoid crisis of chronic myeloid leukemia (CML) were studied using cytochemical and immunological markers and also by the outcome of their treatment. The cytochemical studies showed that blasts from seven of the adult ALL patients were dense-granular-positive (DG-positive) for beta-glucuronidase, whereas the blasts from the children were negative except for one (with T-ALL). In the adults with common ALL (cALL), survival of patients DG-positive for this enzyme were significantly shorter than that of eight patients with a scattered granular pattern (p less than 0.05). The mean ratio between the percentage of blasts positive for cALL antigen (cALLA) to that of blasts positive for terminal deoxynucleotidyl transferase (TdT) in the adult group with cALL (0.6 +/- 0.3) was significantly lower (p less than 0.01) than in the group of children with cALL (1.1 +/- 0.2) or in the lymphoid-crisis group (1.5 +/- 1.0). These findings indicate that adult cALL consists of two distinct subpopulations, one with less differentiated phenotype (cALL-/TdT+) and the other with more (cALL+/TdT+). In contrast, the blast cells in childhood cALL and some patients in lymphoid crisis had a relatively homogeneous population with the latter phenotypes. The results suggest that the clonotypic cells in adult ALL, particularly in cALL, appear to be more immature than those in childhood ALL. The beta-glucuronidase patterns indicate a further heterogeneity in adult ALL.

Non-T, non-B childhood acute lymphoblastic leukemia. Correlation between cytochemical markers and first complete remission

The positivity for four cytochemical reactions, acid phosphatase (AcP), alpha-naphtyl acid acetate esterase (ANAE), beta-glucuronidase (BG), and N-acetyl beta-glucosaminidase (NABG) was correlated to first remission duration in 120 children affected with non-T, non-B acute lymphoblastic leukemia (ALL). The percentages of patients remaining in complete remission at 72 months were always higher for children whose blasts lacked these enzymatic reactions; however, a statistical difference was found only between BG+ and BG- ALL. It also appears that more complete enzymatic patterns of leukemic cells are associated with a poorer prognosis. The percentage of patients still in their first remission was 89% for leukemias with no cytochemical markers, 59% when one reaction was present, but less than 39% when two or more enzymes were detected in the blasts. It is noteworthy that the blasts of patients with more severe prognosis demonstrated a simultaneous positivity for AcP-ANAE or BG-NABG cytochemical reactions. The possible usefulness of these cytochemical markers to detect subsets of patients with different prognostic significance among non-T, non-B ALL is discussed.

Acid phosphatase and acid esterase activity in neoplastic and non-neoplastic lymphoid cells. A semiquantitative evaluation related to immunological markers in 112 cases

Acid phosphatase (AcP) and acid alpha-naphthylacetate esterase (ANAE) were examined in lymphoid cells from 104 patients suffering from various lymphoproliferative disorders and from 8 healthy controls. Enzyme activities were evaluated by means of a scoring system. Scores of AcP and ANAE were higher in normal T cells than non-T cells. In comparison, the activated T cells in infectious mononucleosis showed increased AcP and decreased ANAE reaction. Malignant T lymphoblasts had a distinct granular AcP positivity in contrast to the faint reactivity observed in cALL blasts, whereas ANAE showed negative or weak reaction in both subsets. High scores and distinct staining patterns for both enzymes were found in T CLL and T prolymphocytic leukaemia, clearly different from the weak activities seen in B CLL, B PLL and some B cell lymphomas. The latter, too, could be distinguished by mutual differences in enzyme reactions. High AcP and ANAE scores were also found in hairy cell leukaemia, and the staining patterns together with the tartrate resistance firmly established the diagnosis. Thus, simultaneous determinations of AcP and ANAE can be of great value in the diagnosis of lymphoid malignancies.

Cytochemical distribution of dipeptidylaminopeptidase IV (DAP IV; EC-3.4.14.5) in T-lymphoblastic lymphoma/leukemia characterized with monoclonal antibodies

In human blood and bone marrow, dipeptidylaminopeptidase IV (DAP IV; EC 3.4.14.5) selectively occurs in T lymphocytes bearing Fc receptors for IgM. In the present study 35 cases of lymphoblastic lymphoma and leukemia were analysed for the specificity, incidence and reaction pattern of DAP IV. On the basis of immunohistochemical staining with monoclonal antibodies and enzyme cytochemical staining for acid phosphatase, 12 cases were classified as B-type neoplasms. In 23 cases T-cell properties were expressed to different extents, apparently reflecting different categories of maturation. Whereas B-cell lymphomas were invariably negative for DAP IV, seven of the 23 T-lymphoblastic lymphomas/leukemias showed this enzyme. Thus DAP IV is a highly specific marker for a distinct T-cell subpopulation, apparently irrespective of the stage of differentiation.

Cytochemical analysis of acid hydrolases expression during phorbol diester (TPA)-driven differentiation of B-chronic lymphocytic leukaemia cells in vitro

Four acid hydrolases, acid phosphatase (AP), alpha-naphthyl acetate acid esterase (ANAE), beta-glucuronidase (BG) and N-acetyl-beta-glucosaminidase (NABG) were determined cytochemically in B-chronic lymphocytic leukaemia (B-CLL) cells exposed in vitro to the tumor promoter 12-0-tetradecanoyl phorbol 13 acetate (TPA). TPA, which has been previously shown to induce B-CLL cells to mature towards plasmacytoid cells, results in the progressive expression of the enzymes tested in the cytoplasm of malignant cells, in particular AP and ANAE. Furthermore, the sensitivity to inhibitors and the pattern of reactivity of ANAE provide evidence for an enzyme subtype normally restricted to plasma cells. Thus, acid hydrolases--some of which showing plasma cell type of activity--are expressed during B-CLL cells differentiation induced in vitro. These results confirm the value of cytochemistry in subtyping B-cell malignancies.

Stereologic analysis of the ultrastructure in isolated human T and non-T lymphoid cells. II. Data on blasts in ALL; correlation with immunologic studies and FAB-morphology

Leukemic cells from 20 cases of acute lymphoblastic leukemia (ALL), examined for T and B markers and classified according to FAB guidelines, were analyzed by electron microscopy. Using stereologic methods a quantitative morphologic characterization of the average blast, assumed to be of clonal origin and thus representative of the whole population, was obtained within each subset. Comparative studies of the ultrastructure of the T, B and non-T, non-B blast on one hand and of the FAB category L1 and L2 on the other were performed. No differences of cell volumes, total cell surface areas, nuclear volumes and surface areas or volumes of nuclear compartments were observed between the immunologically defined subsets. Minor variations were seen in the cellular surface contour, the B blast tending to be more irregular than the T blast. Features most predictive of the immunologic cell type were abundant rough ER in B-derived ALL, increasing with plasmacytoid differentiation, and an increase in dense granules which were often clustered in the vicinity of a well-developed Golgi complex in T ALL. The light microscopic criteria of the FAB classification were nearly all confirmed at the EM-level except that nuclear irregularity was observed to the same degree in both categories. Other differences not related to the FAB scheme were encountered in the volumes of the Golgi complex and of the mitochondrial compartment. Objective criteria as quantitative estimates of cellular structures may contribute to an improved subclassification in ALL.

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.

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.

Cytochemical reactions in bovine and ovine lymphosarcoma

Cytochemical reactions with a panel of special stains were explored in peripheral blood and lymph node cells of animals with the adult, calf, and thymic types of bovine lymphosarcoma as well as lymphosarcoma in sheep induced with the bovine leukosis virus. These results were compared with normal lymphoid cells. Cytochemical methods included Sudan black B, periodic acid-Schiff, acid phosphatase and three esterases. Cells from ovine lymphosarcomas and a thymic type of bovine lymphosarcoma were distinctively positive to the alpha naphthyl acetate esterase reaction. These cytochemical reactions which were obtained with standard cytochemical methods should aid in the characterization and classification of lymphoproliferative disorders in animals, especially when combined with immunologic surface markers.

Cytochemistry and ultrastructure in lymphoma and leukemia: utility in the diagnosis of different leukemias and the recognition of subtypes of lymphoproliferative disorders

This review is based on the findings of multiparameter studies performed on cells obtained from over 200 cases of leukemia and illustrates the wide range of laboratory tests currently available for cell phenotype identification. Immunological techniques are not discussed and the review deals mainly with light and electron microscopic cytochemistry, transmission (TEM) and scanning electron microscopy (SEM). The importance of light microscopic cytochemistry is clearly demonstrated. In particular, paranuclear acid phosphatase, non-specific esterase (NSE) and diaminopeptidase staining are recommended as reliable T-cell markers. Ultrastructural identification of unclassified leukemic cells using techniques to detect myeloperoxidase, acid phosphatase, platelet peroxide (PPO) and NSE, is shown to be of great importance in cases of early myelo-monoblastic differentiation with negative light microscopic cytochemistry. SEM is also shown to be a reliable means of distinguishing lymphoid and non-lymphoid leukemia when some degree of differentiation is present. However SEM does not appear to contribute in the diagnosis of unclassified leukemia. The new scanning immunoelectron microscopy (SIEM) technique employing heteroantisera or monoclonal antibodies conjugated to latex microspheres (immunolatex) to detect surface receptors and specific antigens is also illustrated. This technique displays the topography of surface antigens on the cell surface of leukemic cells in 3-dimension and facilitates simultaneous visualization of the surface architecture of the labelled cells.

Acute lymphoblastic leukemia in children: current status, controversies, and future perspective

Disease-free survival (DFS) in childhood ALL is 60%, and survival in good, average, and poor prognostic groups defined by initial WBC and age is 90, 60, and 45%, respectively. Additional immunological, morphological, biochemical, cytokinetic, and cytogenetic factors have been identified, illustrating the heterogeneity of ALL and its derivation from malignant clones at various stages of differentiation and with varying rates of proliferation. Of biologic importance, these factors may refine further the characteristic features of clinically-determined prognostic groups. Multivariate analysis of large prospective trials with homogeneous therapy will be required to determine the independent prognostic importance of these factors. Current treatment strategies in ALL include (1) tailoring therapy and its intensity to prognostic groups; (2) multiple-drug combinations in induction; (3) early use of intrathecal (IT) methotrexate (MTX); (4) CNS prophylaxis with IT MTX alone in good prognosis patients and combined cranial radiation (CXRT), 1800 rads plus IT MTX, in average and poor prognosis patients. Current studies show a CNS relapse rate of 5% in all prognostic groups. Late neuropsychological defects caused by cranial XRT and IT MTX have prompted programs designed to reduce the potential late toxicity of CNS prophylaxis. More pronounced in younger children, these abnormalities include decreased IQ, visual-motor incoordination, poor performance in mathematics, and memory dysfunction. Until 1980, more intensive induction, consolidation, and maintenance therapy had failed to prolong DFS in children with a poor prognosis. In West Germany (Berlin-Frankfurt-Muenster protocol) a 70 to 75% DFS is seen in all patients regardless of initial WBC, suggesting that effective therapy will override prognostic factors. Ultra-high-dose MTX, without cranial radiation, is also showing promise in poor prognosis patients. Other issues include the optimal duration of therapy, the role of testicular biopsies, and prophylactic testicular radiation. Recent studies suggest that prognostic factors lose their significance after 2 years of continuous complete remission and that 2 years of maintenance therapy is adequate. Bilateral open-wedge testicular biopsies have identified occult testicular disease in 8 to 10% of males. A unified approach to children with leukemia/lymphoma, a group with a particularly poor prognosis, utilizing NHL-type therapy may be more effective than conventional ALL therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Invited review. Nervous system antigens

Some of the better characterized proteins (markers) of the nervous system are described. The availability of specific antibodies to these markers has allowed the localization and assay of the proteins in tissue and biological fluids. There is some evidence that autosensitization may occur. Clinical application of these markers includes the evaluation and prognostic significance after stroke and head injury. The diagnostic histopathological use of the markers in the investigation of various tumours is summarized.

Purine metabolism in childhood acute lymphoblastic leukemia: biochemical markers for diagnosis and chemotherapy

Adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), 5'nucleotidase (5'NT), ecto-5'NT, hypoxanthine-guanine phosphoribosyltransferase(HGPRT), adenine phosphoribosyltransferase(APRT), adenosine kinase(AK), AMP deaminase (AMPD) and adenylate kinase(AdKin) activities were assayed in leukemic cells from bone marrow and/or peripheral blood of 43 newly diagnosed children with acute lymphoblastic leukemia(ALL). These enzyme activities have been investigated in relation to some immunological markers. ADA activity was higher in E-rosette positive leukemia(E+ ALL), while HGPRT, APRT, PNP, 5'NT, ecto-5'NT and AdKin activities were found to be lower in E+ ALL as compared to E- ALL. In common ALL (cALL) antigen positive leukemia, mean ADA activity was significantly lower as compared to cALL- leukemia, whereas PNP, 5'NT, ecto-5'NT and AdKin activities were significantly higher. cALL cells with cytoplasmic immunoglobulin M(IgM) heavy chains were found to have mean 5'NT activities twice as high as cALL cells lacking cytoplasmic IgM heavy chains. In two patients who had surface immunoglobulins on their cell membranes, low 5'NT activities were found. When measuring enzyme activities after 2-4 days of prednisone monotherapy, only mean ADA and HGPRT activities decreased in non-B, non-T ALL. These decreases were not significant in T-ALL patients. Mean enzyme activities in the leukemic cells of five patients with relapse were comparable to those in newly diagnosed patients, except for 5'NT, which was found to be within the activity range of control peripheral blood lymphocytes. It is concluded that ADA and AdKin activities are suitable as markers for E+ ALL and cALL+ leukemias respectively. 5'NT might help to distinguish between cALL cells having and lacking pre-B characteristics. Since 5'NT activity may also be decreased in B-ALL, it is not suitable as a T-ALL marker. Enzymes of purine metabolism in leukemic relapse need further investigation.

Symposium: classification of leukemia. 1. The classification of acute leukemia

Two main forms of acute leukemia have been recognized by the French-American-British (FAB) group: myeloid (AML) and lymphoblastic (ALL). Some types of AML can be diagnosed on well prepared bone marrow films stained with May-Grünwald-Giemsa. Poorly differentiated types, myeloblastic (M1) and monoblastic (M5PD), need confirmation by positive cytochemical reactions (Sudan Black B, myeloperoxidase and non-specific esterase). There are 2 sub-types of promyelocytic leukemia: M3 typical, hypergranular and M3 variant, microgranular. The M3 variant has a more acute course, higher WBC and may require cytochemistry to demonstrate promyelocytic differentiation. Electron microscopic cytochemistry can also help in the classification of difficult AML cases; the 'platelet-peroxidase' reaction, for example, is essential for the diagnosis of megakaryoblastic leukemia, a disorder often presenting as 'acute' myelosclerosis. Three morphological types are seen in ALL: L1, predominantly in children, L2, more frequently in adults, and the relatively rare L3 or Burkitt type. Immunological and enzyme markers (ALL and la antigens, terminal transferase, etc.) help define the cell phenotype: (1) non-B, non-T ALL with 3 forms (common, null and pre-B), (2) T-ALL, related to but distinct from T-lymphoblastic lymphoma, and (3) B-ALL, usually with L3 morphology, There is growing evidence that the FAB morphological types correlate with prognosis in ALL independently of other factors. The immunologically defined types also correlate with prognosis but not as an independent variable.

Existence of tartrate-resistant acid phosphatase activity in differentiated lymphoid leukemic cells

Acid phosphatase (AcP) in neoplastic cells from various lymphoid leukemias was examined. In the cytochemical studies, tartrate-resistant AcP (T-rAcP) activity was observed in the neoplastic cells from well-differentiated lymphoid leukemias such as adult T-cell leukemia (ATL), B-cell chronic lymphocytic leukemia (B-CLL), T-cell chronic lymphocytic leukemia (T-CLL), and hairy-cell leukemia (HCL). T-rAcP activity was also detected in a small number of leukemic cells obtained from T-cell acute lymphoblastic leukemia (T-ALL), while it was not detected in the neoplastic cells from null-ALL, macroglobulinemia, and multiple myeloma (MM). In the electrophoretical studies, fraction 1 (F-1), F-3, F-3b, and F-4 were completely tartrate-sensitive, while F-2 was partially resistant and F-5 was completely resistant. T-rAcP activity (F-5) was observed in ATL cells, B-CLL cells, and HCL cells, while it was not detected in ALL cells, macroglobulinemia cells, and MM cells. The present study indicates that T-rAcP activity is observed not only in HCL cells but also in the well-differentiated lymphoid cells such as ATL cells, B-CLL and T-CLL cells except the most highly differentiated forms of B-cells of MM and macroglobulinemia.

T-lymphoblastic leukaemia and aspartate aminotransferase

AST levels from 11 untreated children with T-ALL were found to be significantly higher than those from 74 children with non-T disease. The enzyme was not related to haemoglobin or bilirubin levels nor to the presence of hepatosplenomegaly in any of the patients. It was correlated with the white cell count, but only in the T-cell group and not the remainder. It was also correlated with a parallel (but lesser) rise in ALT, but again only in the T-cell group. The blast cells themselves contained little or no transaminase activity, so it is probable that T-ALL produces more extramedullary tissue damage than non-T disease.

Enzymecytochemical heterogeneity of human chronic T-lymphocytic leukemia as demonstrated by reactivity to dipeptidylaminopeptidase IV (DAP IV; EC 3.4.14.4)

The observation that the dipeptidylaminopeptidase IV (DAP IV; EC 3.4.14.4) occurs exclusively in T mu lymphocytes, stimulated the following study on cases of chronic lymphocytic leukemias. Thirty cases of human chronic lymphocytic leukemia were subjected to the DAP IV reaction in addition to the usually applied cytochemical and immunological tests (acid alpha-naphthyl acetate esterase, acid phosphatase, rosetting with sheep erythrocytes and surface Ig). DAP IV activity was measured directly in normal granulocytes, monocytes, B and T lymphocytes as well as in lymphocyte suspensions of leukemic cases. On a cytochemical level granulocytes, monocytes, B lymphocytes and all 24 cases of B-CLL were found to be DAP IV negative, though some of the latter showed positive reactions for AcE and AcP. From the six cases of T-CLL, five were positive to DAP IV cytochemically. No discrepancies were observed between cytochemical and biochemical results. It is concluded that DAP IV is a reliable and easy to perform marker for T mu lymphocytes and their neoplasias. The results have been interpreted as further evidence for a clonal nature of T-cell neoplasias.

Subclassification in acute lymphoblastic leukaemia: acid phosphatase reaction and immunological markers in relation to clinical features. A comparative study of 44 patients

A prospective, comparative study of cytochemical and immunological markers and clinical features was undertaken in 44 patients with ALL (children and adults). 12 patients (27%) had T-ALL, 1 patient (2%) B-ALL and 31 patients (71%) (non-T, non-B)-All. E-rosetting lymphoblasts ranged from 35 to 96% (median: 61), highest when AET-treated SRBC were used as indicator cells. All 12 E-rosette positive cases were strongly acid phosphatase (AcP)-positive, showing a homogeneous pattern of distinct granular AcP-activity in more than 85% of the lymphoblasts (median: 96%) significantly different from the median of 26% granulated blasts found in (non-T, non-B)-ALL cases. Counting blasts with granular AcP-activity proved to be both easier than using a scoring system for the AcP-reaction and more efficient in terms of discriminating ability between the subgroups. Significant clinical and haematological features characterizing the T- and AcP-positive cases included: (1) Predominance of young adult men, (2) presence of a mediastinal mass, (3) involvement of skin and serous membranes, (4) only slightly affected haemoglobin concentration at presentation, (5) difficulty in obtaining complete remission, (6) shorter duration of first complete remission and (7) shorter survival rate. It is confirmed that AcP-staining of lymphoblasts is an easy, reproducible and inexpensive method for identifying the T-cell variety of ALL.

Auer bodies in acute lymphocytic leukaemia and B-cell lymphoma: evidence for a common progenitor of myeloid and lymphoid cells?

In a patient with acute lymphocytic leukaemia (pre-T ALL) and another patient with leukaemic generalization of B-cell lymphoma Auer bodies were found in a few immature cells. The diagnosis in both cases was based on clinical grounds, morphology, cytochemistry, and immunological marker analysis of the blasts. Auer bodies are known to be a marker of high significance for acute non-lymphocytic leukaemias. Therefore the findings described suggest mixed leukaemias with either T-cell or B-cell predominance. It provides further evidence for the existence of a common progenitor of myeloid and lymphoid cells.

Cytochemistry and membrane markers in acute lymphatic leukaemia (ALL)

136 patients suffering from ALL were subdivided into 5 subtypes (C-ALL, C/T-ALL, pre-T-ALL, B-ALL) according to rosetting tests and using specific antisera directed against membrane antigens. In addition, leukaemic blasts of all patients were investigated according to morphological and cytochemical criteria. In APh and ANAE, indices and the percentages of cases showing a granular staining pattern were high in pre-T- and in T-ALL, but low in C/T- and in C-ALL. PAS-staining, conversely, was more pronounced in C/T- and C-ALL. APh proved to be more discriminative for recognition of the T- and pre-T-ALL subgroups than ANAE, but ANAE-cytochemistry may be useful to detect contaminating normal T-lymphocytes in ALL. Receptors for C3 were more frequent in C- and in T-ALL than in C/T- and in pre-T-ALL, receptors for Fc were distributed equally among all subtypes. Positively of C3- and Fc-receptors was not correlated with cytochemical results. Morphological criteria were not sufficient for subclassification of ALL; the combination of APh- and PAS-staining, however, is valuable to differentiate between C-subgroups and T-subgroups.

T lymphoblastic leukaemia and the central nervous system

Of 100 children and adolescents with lymphoblastic leukaemia (ALL) seen over a 6-year period, 25 developed clinically evident infiltration of the central nervous system (CNS), despite early treatment with cranial radiotherapy and intrathecal methotrexate. Nine of these 25 had the features of T ALL, though there were only 17 such patients overall. Not only did those with T ALL get CNS disease more frequently, but they did so much sooner after diagnosis (P less than 0.001) and more commonly had associated facial palsies (P less than 0.05). The tendency to develop CNS infiltration appeared to be significantly related to the possession of T-cell markers (P less than 0.02), but not to the diagnostic white cell count (P = 0.37). These findings suggest that current CNS prophylactic therapy is ineffective in most patients with T ALL.

Nucleoside phosphorylase activity in normal and leukemic cells

Nucleoside phosphorylase (NP) activity was assayed in normal peripheral blood lymphocytes, mature and immature thymocytes fractionated by peanut agglutinability, CLL lymphocytes, and ALL lymphoblasts to determine applicability as an enzymatic cell marker. Circulating lymphocytes had the highest activity, immature thymocytes the lowest, and mature thymocytes were intermediate in NP level. This suggests an increase in NP activity with T-cell maturation. CLL lymphocytes showed very low activity, confirming previous reports. However, the NP activity of the lymphoblasts of 40 patients with B, T, and non-B, non-T ALL was similar to that of normal peripheral blood lymphocytes and could not be used to discriminate between these subgroups of ALL.

Regulation of human T-cell proliferation: T-cell growth factor and isolation of a new class of type-C retroviruses from human T-cells

The discovery, characterization, and purification of human T-cell growth factor (TCGF) has led to the establishment of continuously growing T-lymphoblast cell lines from normal people and from patients with certain T-cell neoplasias. In contrast to normal T-cells, neoplastic mature T-cells respond directly to TCGF, requiring no prior lectin or antigen in vitro activation. The transformed T-cell lines have phenotypic characteristics consistent with the neoplastic cells of their disease of origin. A novel retrovirus, human T-cell lymphoma-leukemia virus (HTLV), has been isolated from the fresh and cultured cells of two of these patients. Subsequent characterization of this virus has shown that it is not significantly related to any known animal retrovirus, is not an endogenous (genetically transmitted) virus of man, and so far has been associated only with fresh or cultured T-cells from patients with T-cell neoplasia. These results suggest that HTLV infected some mature T-cells of some people and that it might be involved in some neoplasias involving these cells.

The association of eosinophilia with lymphoblastic leukaemia or lymphoma: a study of seven patients

Seven patients with hypereosinophilia in association with a lymphoblastic malignancy are described. The eosinophilia preceded or was present at diagnosis in all patients. Eosinophil counts fell during complete remission but rose significantly before or during relapses in five patients. Hypogranular and sometimes Pelger-eosinophils were seen in five cases. Surface and enzyme markers defined the malignancy in six cases as common-ALL (three), T-ALL (two) and T-lymphoblastic lymphoma (one). Although a diagnosis of eosinophilic leukaemia or acute myeloid leukaemia with eosinophil differentiation was considered in three patients, cytochemical and ultrastructural studies failed to show any evidence of myeloid differentiation in the blast cells. The bone marrow karyotype was normal in the four patients studied. All seven patients had one or more relapses and six died 6-62 months from diagnosis. Severe complications of the hypereosinophilic syndrome developed in one patient. As T-lymphocytes have been shown to be involved in the induction of eosinophilia in rodents, it is suggested that the hypereosinophilia in these patients was induced by eosinopoietic stimuli produced by lymphoblasts.

Lymphoblastic lymphoma/leukemia with convoluted nuclei: the question of its relation to the T-cell lineage studied in 13 patients

This work is devoted to the analysis of the nature of lymphoblastic lymphoma/leukemia with convoluted nuclei which were initially described by Barcos and Lukes. Ultrastructural, cytochemical, and immunologic features of tumor cells were investigated in patients chosen according to known morphologic criteria. Through results of the E rosette test, the patients were divided into two groups (E+ and E-). In the E+ group, the predominant features were sex (only men), the mediastinal localization, and the focal positivity of the acid phosphatase reaction. Cytotoxicity tests with rabbit antihuman T-lymphocyte anti-serum confirmed the results of the E rosette test in the 3 patients of the E+ group who were tested and were also positive in 2 patients from the E- group (1 of these 2 patients had the characteristics found in the E+ group and can thus be related to this group; the other patient had none of these characteristics). This raises the question of a leukemia arising from a less differentiated T-cell but this interpretation is limited by the specificity of the anti-T-serum. Ultrastructural study defines more precisely the convoluted aspect but does not at present allow a distinction between the two groups.