Surface markers and prognostic factors in acute lymphoblastic leukemia

JAK3 mutations and mitochondrial apoptosis resistance in T-cell acute lymphoblastic leukemia

Resistance to mitochondrial apoptosis predicts inferior treatment outcomes in patients with diverse tumor types, including T-cell acute lymphoblastic leukemia (T-ALL). However, the genetic basis for variability in this mitochondrial apoptotic phenotype is poorly understood, preventing its rational therapeutic targeting. Using BH3 profiling and exon sequencing analysis of childhood T-ALL clinical specimens, we found that mitochondrial apoptosis resistance was most strongly associated with activating mutations of JAK3. Mutant JAK3 directly repressed apoptosis in leukemia cells, because its inhibition with mechanistically distinct pharmacologic inhibitors resulted in reversal of mitochondrial apoptotic blockade. Inhibition of JAK3 led to loss of MEK, ERK and BCL2 phosphorylation, and BH3 profiling revealed that JAK3-mutant primary T-ALL patient samples were characterized by a dependence on BCL2. Treatment of JAK3-mutant T-ALL cells with the JAK3 inhibitor tofacitinib in combination with a spectrum of conventional chemotherapeutics revealed synergy with glucocorticoids, in vitro and in vivo. These findings thus provide key insights into the molecular genetics of mitochondrial apoptosis resistance in childhood T-ALL, and a compelling rationale for a clinical trial of JAK3 inhibitors in combination with glucocorticoids for patients with JAK3-mutant T-ALL.

Prognostic significance of cell surface phenotype in acute lymphoblastic leukemia

Context:

To find out the phenotypic character of lymphoblasts of acute lymphoblastic leukemia (ALL) patients in our study cohort and their possible effect on the prognosis.

Aims:

To investigate the phenotype in ALL in our demographic population and to prognosticate various upfront current protocols employed in our hospital.

Settings and Design:

The study spanned over a period of 4 years with retrospective and prospective data of January 2008 through December 2011.

Materials and Methods:

159 patients of all age groups were enrolled for the study, of which flow cytometry was done in 144 patients.

Statistical Analysis Used:

Analysis was done using the variables on SPSS (statistical package for social sciences) software on computer. Survival curves were estimated by method of Kaplan-Meir.

Results:

Majority of the patients were of B-cell (68.1%) and 30.6% patients were of T-cell lineage. Of these, 80.6% patients were having cALLa positivity. Complete remission (CR) was achieved in 59.1%, 16.4% relapsed, and 20.1% patients died.

Conclusions:

Phenotyping has become an important and integral part of diagnosis, classification, management and prognosticating in ALL. B-cell has been found to have a better survival over T-cell lymphoblastic leukemia. cALLa antigen positivity has good impact in achieving CR in only B-cell lineage, myeloid coexpression has no significant effect on the outcome. BFM (Berlin-Frankfurt-Münster) based protocols though showed a higher CR and survival vis-a-vis UKALL-XII. However, patients enrolled in former group being of low risk category and lesser in numbers cannot be compared statistically with a fair degree of confidence.

Classification of lymphoid neoplasms: the microscope as a tool for disease discovery

In the past 50 years, we have witnessed explosive growth in the understanding of normal and neoplastic lymphoid cells. B-cell, T-cell, and natural killer (NK)-cell neoplasms in many respects recapitulate normal stages of lymphoid cell differentiation and function, so that they can be to some extent classified according to the corresponding normal stage. Likewise, the molecular mechanisms involved the pathogenesis of lymphomas and lymphoid leukemias are often based on the physiology of the lymphoid cells, capitalizing on deregulated normal physiology by harnessing the promoters of genes essential for lymphocyte function. The clinical manifestations of lymphomas likewise reflect the normal function of lymphoid cells in vivo. The multiparameter approach to classification adopted by the World Health Organization (WHO) classification has been validated in international studies as being highly reproducible, and enhancing the interpretation of clinical and translational studies. In addition, accurate and precise classification of disease entities facilitates the discovery of the molecular basis of lymphoid neoplasms in the basic science laboratory.

The prognostic significance of morphological features in childhood acute lymphoblastic leukaemia

A consecutive series of 209 children with acute lymphoblastic leukaemia (ALL) presenting to a regional referral unit between 1970 and 1977 was studied. The following morphological features in the initial bone marrow were recorded: blast size, percentage periodic acid-Schiff (PAS) and oil-red-O (ORO) positivity, percentage of blasts with vacuoles, and acid phosphatase positivity. The blasts were also coded according to the FAB (L13) classification. When analysed separately, increasing blast size was significantly related to the length of first remission (P = 0.01). However, this was almost entirely due to its association with the FAB L2 type of disease which also had a highly significant influence on length of first remission (P less than 0.0001) independent of all other factors. Patients with L3 disease had blasts with heavy vacuolation, ORO positivity and displayed monoclonal surface immunoglobulin and their prognosis was very poor. The percentage of vacuolated blasts and ORO positivity otherwise showed no influence on prognosis. Fine granularity of PAS staining in lymphoblasts showed no prognostic value but the trend of longer remission duration with increase in percentage of PAS coarse granularity and blocks, was statistically significant (P = 0.006). This relationship was partly due to a correlation with the presence of mediastinal mass and L2 disease, but was still independent of all other prognostic factors. In a smaller number (39) of the series of patients on whom cell surface markers were available, we were unable to demonstrate a correlation between T-derived blasts and the L1 and L2 classification; but there was a strong correlation with polar acid phosphatase positivity in T-derived blasts.

Prognostic significance of cell surface markers in childhood acute lymphoblastic leukaemia

Examination of surface markers on leukaemic blasts from 51 children with ALL revealed that ALL is a heterogeneous disease. The majority (68%) of patients with ALL lack surface markers (null leukaemia); 28% could be classed as T cell as they form rosettes with sheep RBC and 4% have been shown to possess surface immunoglobulins and hence are classed as B cells. The children with null cell leukaemia have a better prognosis than T and B cell types.

Molecular classification of cancer: class discovery and class prediction by gene expression monitoring

Although cancer classification has improved over the past 30 years, there has been no general approach for identifying new cancer classes (class discovery) or for assigning tumors to known classes (class prediction). Here, a generic approach to cancer classification based on gene expression monitoring by DNA microarrays is described and applied to human acute leukemias as a test case. A class discovery procedure automatically discovered the distinction between acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) without previous knowledge of these classes. An automatically derived class predictor was able to determine the class of new leukemia cases. The results demonstrate the feasibility of cancer classification based solely on gene expression monitoring and suggest a general strategy for discovering and predicting cancer classes for other types of cancer, independent of previous biological knowledge.

History and classification of human leukemia-lymphoma cell lines

Continuous human leukemia-lymphoma cell lines have become indispensable tools in hematological research since the establishment of the first human lymphoma cell line Raji in 1963. We summarize here historical landmarks in the establishment of unique leukemia-lymphoma-derived cell lines from the various cell lineages; their special importance in hematopoietic research is emphasized. The first cell lines were derived from African Burkitt lymphomas and were found to integrate the Epstein-Barr virus in their genome leading to the discovery and isolation of this virus. However, it was later recognized that not every cell line derived from a patient with leukemia-lymphoma represents a malignant cell line as residual normal B-lymphocytes can also be immortalized by EBV infection. During the following 20-30 years many other types of hematopoietic cell lines, commonly derived from hematopoietic neoplasms, were established. These panels of cell lines now span almost the whole spectrum of hematopoietic cell lineages (except for dendritric cells) and the various distinct stages of differentiation along the respective cell axes. From early on, cell lines became important tools for basic and clinical hematological research, initially mainly in the field of immunology, but later expanding to other areas also. It became apparent that leukemia-lymphoma cell lines are of monoclonal origin, are arrested at a discrete maturational stage during differentiation in each lineage, and show sustained and growth factor-independent or -dependent unlimited proliferation. Categorization of cell lines might best be based on the physiological stages of hematopoietic differentiation in the various cell lineages. For an adequate classification, detailed characterizations of both the cell lines and the primary cells from which the cell lines originated are absolutely mandatory. In summary, the availability of large numbers of continuous leukemia-lymphoma cell lines has greatly facilitated clinical and immunobiological studies of normal and malignant hematopoiesis. Human leukemia-lymphoma cell lines will continue to provide exquisite model systems for many biomedical disciplines.

Adverse prognostic features in 251 children treated for acute myeloid leukemia

Potential predictors of event-free survival (EFS) were assessed in 251 consecutively diagnosed children treated for acute myeloid leukemia (AML) on three successive clinical trials. The lack of significant differences in 4-year EFS for these studies (20% +/- 4%, 29% +/- 4%, and 20% +/- 7%) permitted combined analysis of presenting features. Splenomegaly (P = .002), coagulation abnormalities (P = .001), leukocyte count > or = 10 x 10(9)/L (P = .002), and age > 14 years (P = .01) were statistically significant predictors of a poorer EFS by univariate analysis and retained significance in multivariate analysis. Age < 2 years and monocytic leukemias (often cited as adverse factors in AML) showed no prognostic influence in this study. The estimated relative risk of failure for a child with a single adverse feature at diagnosis was at least 1.4 times greater than that for a patient with no adverse features. For children with two or more adverse features, the relative risk increased by more than threefold. These clinical variables, alone or in combination, may identify important subgroups of patients with AML at high risk for failure and for whom improved or alternative therapies are especially important.

Immunological classification of childhood acute lymphoblastic leukemia

Seven hundred and forty-four newly diagnosed patients with acute leukemias between 1978 and 1990 were classified on the basis of immunological phenotypes. The majority of the patients were enrolled in the Tokyo Children's Cancer Study Group (TCCSG) studies. The incidence of subclassification of acute leukemias in this study was as follows: 522 patients with ALL (70%), 139 patients with ANLL (18%), 29 patients with biphenotypic leukemia, 8 patients with Ph1-positive acute leukemia (Ph1-AL), and 45 patients with infant leukemia. ALLs were classified into common ALL (cALL, 77%), T-ALL (15%), B-ALL (4%), and unclassified ALL (3%). The incidence of ALL subtypes in this study reflected those of TCCSG. Biphenotypic leukemias were categorized into 4 groups as follows; 1) cALL with positive myelomonocytic antigen(s) (N = 11), 2) unclassified ALL with positive myelomonocytic antigen(s) (N = 5), 3) ANLL with positive B-lymphoid antigen(s) (N = 4), and 4) acute leukemia with positive T-lymphoid and myeloid antigen(s). Infant leukemias were classified into ALL type (N = 27) and ANLL type (N = 18). In this present study, clinical features and immunological phenotypes of the acute leukemias with a poor prognosis, i.e. biphenotypic leukemia, Ph1-AL, and infant leukemia are analyzed and discussed.

Rearrangements of the tal-1 locus as clonal markers for T cell acute lymphoblastic leukemia

Normal and aberrant immune receptor gene assembly each produce site-specific DNA rearrangements in leukemic lymphoblasts. In either case, these rearrangements provide useful clonal markers for the leukemias in question. In the t(1;14)(p34;q11) translocation associated with T cell acute lymphoblastic leukemia (T-ALL), the breakpoints on chromosome 1 interrupt the tal-1 gene. A site-specific deletion interrupts the same gene in an additional 26% of T-ALL. Thus, nearly one-third of these leukemias contain clustered rearrangements of the tal-1 locus. To test whether these rearrangements can serve as markers for residual disease, we monitored four patients with T-ALL; three of the leukemias contained a deleted (tald) and one a translocated (talt) tal-1 allele. These alleles were recognized by a sensitive amplification/hybridization assay. tald alleles were found in the blood of one patient during the 4th mo of treatment but not thereafter. Using a quantitative assay to measure the fraction of tald alleles in DNA extracts, we estimated that this month 4 sample contained 150 tald copies per 10(6) genome copies. The patient with t(1;14)(p34;q11) (talt) leukemia developed a positive assay during the 20th mo of treatment. By standard criteria, all four patients remain in complete remission 11-20 mo into treatment. We conclude that tal-1 rearrangements provide useful clonal markers for approximately 30% of T-ALLs.

Childhood acute lymphoblastic leukemia: results of the Austrian Cooperative Study Group with the ALL A 84 protocol

We prospectively treated 127 children with ALL with a risk-adapted regimen. All patients received the identical induction-consolidation therapy. The early maintenance included intermediate dose methotrexate in patients with standard risk (n = 79) and medium risk (n = 39). In addition patients with high risk (n = 6) received high dose ARA-C followed by L-asparaginase. Intensification treatment and prophylactic cranial irradiation was also tailored according to the risk group. Treatment duration was 2 years. Complete remission was achieved in 97.6% of all patients. Treatment-related toxicity accounted for one death in complete remission. The probability of event-free survival (pEFS) for the combined group was 72% at a median follow-up of 42 months. The pEFS was higher in patients with standard risk (SR) than in patients with medium risk (MR) (80% versus 65%; p less than 0.05) at 30 months, but attenuated in the follow-up evaluation at 42 months (76% versus 63%; p less than 0.1). The number of high-risk patients was too small for statistical evaluation. Relapse within the first 18 months after diagnosis indicated a poor prognosis and was more common in patients with MR than in patients with SR. The immunophenotype of the leukemic cells was not found to constitute an independent risk factor after treatment has been risk-adapted. Patients with an initial white blood cell count of more than 50 X 10(9)/l had a worse prognosis than patients with a lower white blood cell count (p less than 0.01).

Laboratory and clinical applications of monoclonal antibodies for leukemias and non-Hodgkin's lymphomas

Important insights into leukocyte differentiation and the cellular origins of leukemia and lymphoma have been gained through the use of monoclonal antibodies that define cell surface antigens and molecular probes that identify immunoglobulin and T-cell receptor genes. Results of these studies have been combined with markers such as surface membrane and cytoplasmic immunoglobulin on B lymphocytes, sheep erythrocyte receptors on T lymphocytes, and cytochemical stains. After using all of the aforementioned markers, it is now clear that acute lymphoblastic leukemia (ALL) is heterogeneous. Furthermore, monoclonal antibodies that identify B cells, such as the anti-CD20 and anti-CD19 antibodies in combination with studies of immunoglobulin gene rearrangement, have demonstrated that virtually all cases of non-T-ALL are malignancies of B-cell origin. At least six distinct subgroups of non-T-ALL can now be identified. T-ALL is subdivided by the anti-CD7, anti-CD5, and antibodies that separate T lymphocytes subsets into three primary subgroups. Monoclonal antibodies are also useful in the subclassification of non-Hodgkin's lymphoma, and certain distinct markers can be correlated with morphological classification. Although monoclonal antibodies are useful in distinguishing acute myeloid from acute lymphoid leukemias, they have less certain utility in the subclassification of acute myelogenous leukemia (AML). Attempts to subclassify AML by differentiation-associated antigens rather than by the French-American-British (FAB) classification are underway in order to document the potential prognostic utility of surface markers. Therapeutic trials using monoclonal antibodies in leukemia and lymphoma have been reported. Intravenous infusion of unlabeled antibodies is the most widely used method; transient responses have been demonstrated. Antibodies conjugated to radionuclides have been quite successful in localizing tumors of less than 1 cm in some studies. Therapy trials with antibodies conjugated to isotopes, toxins, and drugs have shown promise. Purging of autologous bone marrow with monoclonal antibodies and complement in vitro has been used in ALL and non-Hodgkin's lymphoma; preliminary data suggest that this approach may be an effective therapy and may circumvent many of the obstacles and toxicities associated with in vivo monoclonal antibody infusion.

Immunological subtypes of acute lymphoblastic leukemia in north India

Pretreatment immunologic marker analysis in 152 adult and childhood patients of ALL and ALL/lymphoma employing multiple monoclonal antibodies and hetero-antisera revealed three major subgroups, i.e. T-ALL (37.7%), N-ALL (33.1%) and C-ALL (21.5%). The early age peak was absent, males predominated in all the subgroups and T-ALL had increased incidence of thymic mass. Leucocyte counts of 50,000 X 10(6)/l were equally frequent in the three groups. T-ALL showed marked heterogeneity by showing a variety of markers such as T-helper/inducer, T-suppressor/cytotoxic, p-24, Ia and CALLA. These results show a high prevalence of unfavourable prognostic factors in ALL in our geographic region which might be related to socioeconomic and/or environmental factors.

Acute lymphocytic leukemia: correlation of clinical features with immunocytochemical classification

Many immunologic studies of acute lymphocytic leukemia (ALL) during the past decade have demonstrated the close correlation of immunologic phenotypes of ALL subclasses with the clinical presenting features and prognosis. However, the clinical application of conventional immunologic techniques had been very limited because of the requirement of a fresh sample to prepare the mononuclear cell suspensions for study. We studied 81 cases of ALL using immunoperoxidase stain for nuclear terminal deoxynucleotidyl transferase (TdT) and immunoalkaline phosphatase stain for surface markers (using monoclonal antibody J5 for common ALL antigen [CALLA], Leu-1 for pan-T antigen, and B1 for pan-B antigen) on air-dried smears. The cases were classified as common ALL (TdT+, CALLA+, pan-T-, and pan-B-) (41 cases), null-ALL (TdT+, CALLA-, pan-T-, and pan-B-) (19 cases), T-ALL (TdT+, CALLA-, pan-T+, and pan-B-) (nine cases), B-ALL (TdT-, CALLA-, pan-T-, and pan-B+) (six cases), pre-B-ALL (TdT+/-, CALLA+, pan-T-, and pan-B+) (four cases), or pre-T-ALL (TdT+, CALLA+, pan-T+, and pan-B-) (two cases). This subtyping of ALL correlated well with known clinical presenting features, prognosis, chromosome analysis in 35 cases with an abnormal clone, and conventional immunologic typing in 38 cases. The data suggest that these simple and practical immunocytochemical stains can be used for immunologic subclassification of ALL.

Multiparameter characterization of L3 leukemia cell populations

Multiparameter analysis of 14 consecutive patients with L3 cell populations (FAB classification) in bone marrow showed consistently high mean cellular RNA content but heterogeneity with respect to percent cels in S- and G2M-phases of the cell cycle, cell surface phenotype, cytogenetic abnormalities, cellular DNA content, and nuclear activities of terminal deoxynucleotidyl transferase. Five of the 14 patients had the characteristic profile of L3 leukemia with high RNA content, a typical t(8;14) or t(8;22) translocation, low Tdt, B-cell surface phenotype, pseudodiploid modal number of chromosomes, high proliferation and normal DNA index. The remaining 9 patients had features thought to be unusual and they were very heterogeneous. Median survival time from time of diagnosis was 115 days with no patient alive after 474 days. The survival times exhibited excellent correlation with a parametric model assuming exponential distribution. Accordingly, the presence of abnormal DI predicted for decreased, and the presence of t(8;14) or pseudodiploidy was associated with increased survival rates. However, due to the small number of patients in this study, generally applicable conclusions should be drawn only from a collection of larger numbers of cases of this rare type of leukemia.

Clinical studies of autografting in acute lymphocytic leukaemia

The role of autologous marrow transplantation has been reviewed in this chapter. The transplantation results in first remission are difficult to interpret due to the prognostically heterogeneous patient population transplanted and the ever-changing natural history of first complete remission due to more aggressive conventional-dose chemotherapy regimen. The biological role of marrow purging, i.e. elimination of leukaemic cells from the graft, is yet unclear. It is the opinion of the authors that studies in second and subsequent remission can resolve burning issues such as the efficacy of various high-dose conditioning regimens and of different methods of elimination of leukaemic cells such as procedures based on immunological methods, monoclonal antibodies and on differences in sensitivity of stem cells and leukaemic cells to in vitro chemotherapy. It may well be that a large number of patients is needed and, therefore, a multi-centre study is indicated.

The human T-cell leukemias: clinical, cytomorphologic, immunophenotypic, and genotypic characteristics

The distribution of the conventional lymphoid cell markers on T lymphocytes and the principal panels of monoclonal antibodies used to recognize distinctive T-lymphocyte-associated differentiation antigens are discussed. These reagents have been used to probe the early and late stages of T-cell differentiation, and a hypothetical schema of T-cell differentiation has been constructed. Application of these reagents to the investigation of neoplastic T cells has resulted in the determination of the subset of origin and the stage of differentiation of the neoplastic cells in T-cell-derived lymphoproliferative malignancies. Recent advances in molecular biology have made possible the Southern blot hybridization analysis of DNA extracted from neoplastic T cells for patterns of T-cell-receptor gene rearrangements. Examination of these patterns in benign and malignant T and non-T cell has provided the basis for the use of T-cell-receptor gene rearrangements as specific genetic markers of T-cell lineage, clonality, and differentiation. These and other advances have resulted in the delineation of a new category of T-cell neoplasia, the adult T-cell leukemia/lymphoma syndrome. They have also demonstrated that the majority of clinically indolent neoplasms composed of large granular lymphocytes in so-called T gamma-lymphoproliferative disease are monoclonal proliferations. Further phenotypic, functional, and genotypic analyses of the T-cell malignancies should provide better understanding of T-lymphocyte differentiation and heterogeneity. Such studies should also lead to better clinicopathologic correlations and greater understanding of the basis for the clinical diversity of the T-cell-derived lymphoproliferative malignancies.

Multimarker phenotypic characterization of adult and childhood acute lymphoblastic leukaemia: an Italian multicentre study

A multicentre phenotypic study was carried out in Italy combining conventional immunological techniques with monoclonal antibody (MoAb) analysis in 190 cases of adult and childhood acute lymphoblastic leukaemia (ALL), in an attempt to define better the lineage relationship of the neoplastic cells. Of the 140 children evaluated, 79.3% expressed the common ALL (cALL) antigen (all analyses performed by MoAb), 11.4% were T-ALL and 9.3% were non-T, non-B, non-common ('null') ALL. The proportion of adult cALL cases was slightly lower (64% of the 50 cases studied) than that of childhood ALL, whilst the incidence of T-ALL was significantly higher in adults than in children (26% v. 11.4%, P less than 0.05). Because of the high proportion of cALL cases, the incidence of 'null' ALL in adult patients was similar (10%) to that of children, and lower than previously reported. The recognition of early pre-T-ALL cases (T1+, RFT2+, T10+, T6-, T11-, E-) contributed to the overall low proportion of 'null' ALL; prior to the use of MoAb, such cases would probably have been classified as undifferentiated acute leukaemia or 'null' ALL. The search for B-cell-related markers showed that the incidence of pre-B-ALL cases (cytoplasmic immunoglobulin positive cases) was similar in adults and in children (25.6% and 32%, respectively). Furthermore, the great majority of cases studied expressed the BA-1 antigen (92.8% of adults and 79% of children), whilst the BA-2 antigen was found in 53% of cases (tested only in children), confirming a hierarchy in the expression of B-cell related markers in cALL: BA-1, BA-2, CyIg. Several of the 'null' cases also expressed the BA-1 antigen on a variable proportion of cells, pointing to a possible B-cell origin of the blasts. This multicentre study shows that both in adult and in childhood ALL the combined use of conventional immunological markers and of a panel of MoAb allows identification of the cell lineage of the great majority of cases, thus reducing the number of 'null' ALL. Furthermore, these findings suggest that practically all cases of ALL belong either to the T or to the B cell compartment and that the neoplastic cells appear blocked at different levels along the lymphoid differentiation pathway.

Immunodiagnosis and immunotherapy of childhood malignancies

Recent advances in immunologic techniques have allowed the generation of monoclonal antibodies against antigens on tumor cells and their normal counterparts. Monoclonal antibodies useful for diagnosing and defining subtypes of acute leukemias and neuroblastoma have been prepared, although the prognostic significance of the subtypes defined by such antibodies remains to be determined. The usefulness of these reagents for therapeutic purposes either ex vivo, in association with autologous bone marrow transplantation, or in vivo, as carriers of cytotoxic agents, is currently under investigation.

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.

Surface marker analysis of acute lymphocytic leukaemia in Taiwan, Republic of China

Acute lymphocytic leukaemia (ALL) is heterogeneous in clinical characteristics and immunological properties. Standard surface marker analysis has enabled us to subclassify 121 cases of ALL into four subtypes, i.e. T-ALL, common ALL, null ALL and B-ALL. We have also tried to correlate these subtypes with their clinical characteristics. Our patients had younger ages with a mean age of 13.75. A slight male predominance was observed. There were consistently higher incidences in northern Taiwan in each subtype, but no significant differences in incidences between rural and urban areas. Although there were high incidences of L1 type cell in each immunological subtype, there was no correlation between FAB classification and each subtype, nor did morphologic features relate to cellular origins. Clinical manifestations revealed significantly high incidence of CNS involvement and thymic mass in T-ALL. Hepatosplenomegaly was more common and complete remission rate was higher in children with ALL than in adults.

Immunodiagnosis of childhood ALL with monoclonal antibodies to myeloid and lymphoid associated antigens

Sixty-five cryopreserved leukemic samples from children diagnosed and treated as having acute lymphocytic leukemia (ALL) were retrospectively examined for the presence of lymphoid and myeloid associated antigens by indirect immunofluorescence using monoclonal antibodies. Expectedly, the majority of these specimens expressed antigens known to be expressed on lymphoid, and not myeloid malignancies. These included the common acute lymphoblastic leukemia antigen (CALLA), the p32 B-cell associated antigen, and T-cell associated antigens. Leukemic cells from the 8 remaining patients expressed antigens known to be present on both myeloid and lymphoid leukemias. These included HLA/DR, and the antigens identified by BA-1 and BA-2. Cells from 2 of these 8 patients reacted with antibodies that define antigens present on normal and malignant myeloid cells. Both specimens reacted with 1G10, an anti-granulocyte antibody, and one reacted with 5F1 which reacts with monocytes, nucleated red blood cells, megakaryocytes and platelets. One of these patients relapsed while receiving ALL therapy, and the morphology of her leukemic cells became characteristic of acute monocytic leukemia (AMoL). The second patient failed ALL therapy but responded to standard acute nonlymphocytic leukemia (ANLL) therapy, clearing her peripheral blasts. Thus these studies confirm that cell surface phenotyping with monoclonal antibodies can recognize ALL cells that express myeloid rather than lymphoid associated antigens and demonstrate that the malignant cells display a clinical behavior consistent with the diagnosis of ANLL.

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.

Absence of prognostic significance of skeletal involvement in acute lymphocytic leukemia and non-Hodgkin lymphoma in children

Over a period of 6 years 88 children with acute lymphocytic leukemia and malignant non-Hodgkin lymphoma were treated according to the West-Berlin protocol. In 72 children skeletal surveys were performed initially and these showed leukemic bone changes in 31 patients. Follow-up was obtained in 70 patients for up to 8 years after diagnosis: 20 of these patients died and of these 8 showed initial skeletal involvement. In 17 children relapses occurred and 10 of them had bone lesions at first presentation. There was no significant correlation between the extent of the skeletal involvement and the survival time as calculated by life table analysis.

Enumeration of cytoplasmic mu immunoglobulin positive acute lymphoblastic leukemia cells by flow cytometry: comparison with fluorescence microscopy

The pre-B phenotype of childhood acute lymphoblastic leukemia, in which the mu immunoglobulin molecule is expressed in the cytoplasm of the blast cells, has been shown to have independent prognostic significance. Patients with this phenotype of the disease tend to have a poorer outcome on contemporary treatment regimens than do those with the other B-precursor phenotypes. For these clinical studies, the detection of the pre-B phenotype has depended upon fluorescent-microscope based techniques. A flow-cytometry based technique for the detection of the cytoplasmic mu immunoglobulin molecule is presented here and the results compared in detail with those of fluorescent microscopy. The results show that the two techniques are equivalent. The flow cytometry method has the advantage of a standardized control, is less labor intensive, and is observer-independent.

Childhood acute lymphoblastic leukemia with natural killer activity. Clinical and cellular features of three cases

Leukemic cells from 3 of 28 children with acute lymphoblastic leukemia (ALL) had natural killer (NK) activity against K562 and Molt-3, but not against Raji as determined by the 4-hour 51Cr release assay at a 40:1 effector:target ratio; the highest percent lysis against K562 in each patient ranged from 55.9% to 147.4% of the normal lymphocyte value and that against Molt-3 from 28.0% to 127.9%. Their leukemic cells were nonphagocytic, nonadherent, and negative for nonspecific esterase. Leukemic cells from two of them displayed similar morphologic and immunologic features. The cells had a round nucleus, and were E-receptors (E)+, Leu-5+, IgG-Fc+, Ia+, OKM1+ or OKM1-, T-cell antigens-, B markers-, and monocyte antigen-, indicating their NK cell origin. The other patient's cells were characterized by the irregularly shaped nucleus, and were E+, Leu-5+, IgG-Fc+, T+, OKT6+, Leu-2a+, and OKM1+. The presence of E which are identical to E of T-cells and a high density of T-cell antigens including OKT6 on the cells suggested their T-cell nature. Of the three patients, two without thymic enlargement had leukemic cells of NK cell origin, and the other one with the symptom leukemic cells of the T-cell lineage, the clinical feature probably reflecting the cell lineage of their leukemic cells.

Immunologic phenotypes of diffuse, aggressive, non-Hodgkin's lymphomas. Correlation with clinical features

The immunologic phenotypes of 59 cases of diffuse, aggressive, non-Hodgkin's lymphomas were determined using a battery of immunologic and cytochemical techniques. Included were cases of diffuse, large cell "histiocytic," mixed cell, undifferentiated non-Burkitt's. Burkitt's lymphoma, lymphoblastic lymphoma, and mycosis fungoides/Sézary's syndrome were excluded from this study since these are distinct clinicopathologic entities with well-recognized immunologic phenotypes. The immunotype could be determined in 57/59 (97%) cases tested: 31 of 59 cases (53%) were B-cell type, 25 of 59 (42%) were peripheral T-cell type, and one was true histiocytic. Two cases had no detectable markers and were called "null cell." This relatively high frequency of peripheral T-cell lymphomas in an American series previously has not been observed and may be a result of progressive improvements in immunologic techniques. Monoclonal anti-T cell antibody staining was performed in 11 T-cell cases and corroborated the findings using spontaneous E-rosette formation. Eight of the T-cell lymphomas had a helper cell phenotype whereas one had a suppressor cell phenotype and two could not be subclassified. All B-cell lymphomas in this series possessed monoclonal surface immunoglobulin detected by direct immunofluorescence of viable cells. Enzyme cytochemistry profiles only partially correlated with immunotype and were not believed to be helpful in the determination of specific phenotypes. There were no significant differences between the B-cell and T-cell diffuse aggressive lymphomas with respect to sex, constitutional symptoms, stages, sites of extranodal involvement, complete remission rate, or survival when they were studied prior to the initiation of aggressive therapy. Although immunotyping can be successfully performed in essentially all cases of diffuse, aggressive non-Hodgkin's lymphomas, to date, the authors have been unable to demonstrate that immunotype alone has an independent prognostic effect.

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.

Pediatric oncology group utilization of immunologic markers in the designation of acute lymphocytic leukemia subgroups: influence on treatment response

The clinical application of blast cell immunophenotype testing is important in childhood ALL for the following reasons. (1) Knowledge of the immunologic group is important in predicting prognosis. Prognostic grouping may prove to be accomplished best by using a combination of traditional risk factors and immunologic phenotyping. However, definition of traditional risk factors may vary within the immunologic groups of ALL. (2) In assessing the relative effectiveness of different treatment regimens for children with ALL it is important to make comparisons among patients within the same major immunologic groups of ALL. (3) Identification of specific immunologic groups of patients within ALL may help in designing therapy for each group. The POG has already made preliminary attempts in this direction for T-ALL and B-ALL. However, leukemia species-specific therapy is still only a long-range goal. Laboratory research must endeavor to identify additional biologic characteristics peculiar to each major immunologic group of ALL. These characteristics may dictate therapeutic maneuvers in the future.

Superoxide dismutase activity in leukemic blasts of children with acute leukemia

Superoxide dismutase activity was determined in leukemic blasts of 24 patients with acute leukemia and was correlated to its type. The activity was significantly lower in five patients with T cell or B cell leukemia, and there was a wide range of distribution in 15 patients with non-T, non-B cell leukemia. Manganese superoxide dismutase activity was significantly lower in all types of acute lymphoblastic leukemia than in normal mononuclear leukocytes. Both total and manganese superoxide dismutase activities in acute myeloblastic leukemia, however, were significantly higher than those in normal polymorphonuclear leukocytes. The prognosis in patients with a low superoxide dismutase activity in leukemic blasts seemed to be poorer. Determination of superoxide dismutase activity in leukemic blasts may have a prognostic value in the management of children with acute leukemia.

Mediastinal mass in acute lymphoblastic leukemia

Patients with acute lymphoblastic leukemia who have a mediastinal mass at the time of diagnosis are said to have a poor prognosis. However, many factors which may not be independent contribute to the success of treatment. We compared the disease characteristics and results of therapy in children having large mediastinal masses and lymphoblastic leukemia without mediastinal mass. Patients with a mediastinal mass had less evidence of marrow failure but were burdened with considerably more leukemic cells as measured by peripheral blood white count and extent of lymphadenopathy. Since the presence of mediastinal mass was strongly associated with these and other poor prognostic characteristics, we used multivariate techniques to determine which characteristics were independently associated with an increased risk for relapse. White count, extent of lymphadenopathy, age, and sex were significant predictors of early relapse, but when controlled for these variables the presence of a mass did not predict prognosis.

Adult T-cell lymphoma leukemia in Western countries

A new T-cell disorder has recently emerged: the so-called adult T-cell lymphoma leukemia (ATLL) initially described in Japan. Subsequently, ATLL cases were recognized in patients from the Caribbean. We summarize the clinical and hematological features of 19 published cases from Western countries, in addition to a new case we encountered. The leukemic cells display characteristic morphological features and a T3+T4+T8-T6- surface antigenic phenotype. Overall survival is of short duration, but remission could be obtained in our case despite a subsequent relapse in skin and CNS. Geographic clusters of ATLL cases have led to the discovery of the possible role of a new retrovirus, HTLV, in the genesis of this rare malignancy.

E-rosette positive acute lymphoblastic leukaemia in adolescents and adults

E-rosetting of leukaemic blast cells is one of the markers of T-cell acute lymphoblastic leukaemia (ALL). In children, E+ ALL has a bad prognosis. In adults, data are scarce. This report provides information on 25 E+ ALL adult patients who have a minimum follow-up time of 36 months. Twenty-two of 25 patients (88%) achieved complete remission (CR) (median duration 16 months), and six of them were alive, relapse-free, and off therapy after 36-81 months, with a 26% projected 6-year relapse-free survival. In 97 patients with E-SmIg- ALL, who were treated at the same Institutions, over the same period of time, and by the same modalities, the outcome of therapy was almost identical: CR 80%, median duration of first CR 15 months, projected 6-year relapse-free survival 15%. The white blood cell (WBC) count at presentation influenced significantly and to the same degree first CR length in both E+ and E- cases. In this adult series, WBC count was not as high as in children. Moreover, a high Hb concentration, a very high WBC count, lymphadenomegaly, and mediastinal involvement, were found more frequently in adolescents and young adults than in adults. Based on these data, it is suggested that in adults E-rosetting as such is not a marker of a poorer prognosis, that some of the typical features of children E+ ALL weaken with age, and that in adults the disease can have a less aggressive character.

Relevance of monoclonal antibodies in the diagnosis of unusual T-cell acute lymphoblastic leukaemia

3 cases of adult acute lymphoblastic leukaemia (ALL), the T-cell nature of which was identified only using a panel of monoclonal antibodies (MoAb), are described. All cases were E-rosette negative, surface immunoglobulin (SmIg) negative, common ALL (CALLA) antigen negative, terminal deoxynucleotidyl transferase (TdT) positive, and acid phosphatase positive. The T-cell origin of the blasts was demonstrated by the positivity with RFA-1, a MoAb which detects an antigen of MW 65-69000 present on the membrane of thymocytes and mature T-lymphocytes. In addition, 2 of the 3 cases were positive with OKT6, which recognizes cortical thymocytes. MoAb directed against more mature T lineage cells (OKT3, OKT4, OKT8, OKT11A) were consistently negative (less than or equal to 12%). These findings indicate that the use of a combination of MoAb is important in detecting individual cases of T-ALL, which otherwise might be classified as undifferentiated acute leukaemia or null-ALL. MoAb detecting a T-cell antigenic determinant of MW 65-69000 (e.g. RFA-1, OKT1, Leu1) appear the most specific reagents for T-ALL.

Results of treatment of high risk childhood acute lymphoblastic leukemia

Sixteen children with high risk acute lymphoblastic leukemia (ALL) who had one or more of the following risk factors: white cell count over 50 X 10(9)/liter, mediastinal mass, age under 2 or over 10 years, extramedullary involvement, or T-cell markers, were treated by a new protocol. All attained complete remission and 11 are still in their continuous first remission for 6-53 months. High activity of adenosine deaminase (ADA) in the leukemic cells seems to be an independent risk factor, as in the high ADA level group, 4 out of 7 patients relapsed and died, while none of the 8 patients with low ADA levels relapsed or died.

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)

Intermittent combination chemotherapy with or without bacillus Calmette-Guérin for treatment of acute lymphoblastic leukemia of childhood

Seventy-four children ranging in age from 6 months to 17.5 years with acute lymphoblastic leukemia newly diagnosed between 1976 and 1979 were entered on a study incorporating intermittent chemotherapy with or without the addition of bacillus Calmette-Guérin (BCG). The chemotherapy program consisted of induction with vincristine, dexamethasone, and intrathecal methotrexate, intensification with adriamycin and asparaginase, central nervous system treatment with cranial irradiation and intrathecal methotrexate, and continuation treatment with 5-day courses of combination chemotherapy administered every three weeks. The first phase of continuation therapy incorporated vincristine, adriamycin, 6-mercaptopurine, and dexamethasone. In the second phase, oral methotrexate was substituted for the adriamycin in non-T-cell patients; in T-cell patients, cytosine arabinoside or cyclophosphamide and methotrexate in alternating cycles were substituted for the adriamycin and asparaginase was added. Total duration of therapy was approximately 2.5 years. Connaught BCG was administered by Heaf gun on days 8 and 15 of each 3-week cycle for the first 8 months of treatment in approximately one-third of the patients. Actuarial disease-free survival with a median follow-up of 59 months shows no difference in outcome between the BCG and non-BCG poor-risk patients. However, there is an improvement in disease-free survival of BCG-treated good- and average-risk girls (P = 0.04). While patients were actively receiving BCG there was also a trend toward the development of fewer significant infections than when patients were not receiving BCG (P = 0.85). Toxicities from BCG administration included satellite rashes, local tenderness, lymphadenopathy, secondary infection, and residual scars. Overall disease-free survival by actuarial analysis is 60% at 6 years; for patients with unfavorable prognostic features it is 40%. In this trial the addition of BCG prolonged the disease-free survival of girls with good- and average-risk prognostic features and also may have decreased the susceptibility to infection while it was being administered. However, the benefit does not appear sufficient to warrant its routine use, especially in view of the toxicities encountered.

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.

Immunological types of lymphoproliferative disorders in a cohort: a 4-year study

Immunological testing of malignant cells and serum from most cases of lymphoproliferative disorders (LPD) allows the cell type to be characterised as of B, T or "null" lymphocyte origin. Regional differences in the incidence of neoplasms of these types have been reported. Furthermore, most published series have drawn cases from referral institutions rather than the general population. In order to determine the true incidence of a cohort we surveyed an entire population, that of Tasmania, an island state of Australia with a population of 410,000, during a defined period, the years 1977-1980 inclusive, for the occurrence of LPD. A total of 248 cases was discovered, made up of 133 cases of non-Hodgkin's lymphoma (NHL), 30 of chronic lymphocytic leukaemia (CLL), 18 of acute lymphoblastic leukaemia (ALL), 54 of multiple myeloma (MM), eight of macroglobulinaemia (MGA) and five others. We identified B lymphocytes by the presence of surface membrane immunoglobulin (Smlg) and their ability to rosette with mouse red blood cells, and T lymphocytes by their ability to rosette with sheep red blood cells. Laboratory testing was performed in 201 (81%) of the cases and characterisation of the cell of origin as of B, T or "null" type was successful in 158 (64%). Of these 158, 136 (86%) were B, 4 (3%) T, and 18 (11%) "null". On B cell subtyping by heavy and light chain lg analysis the Tasmanian series, compared with other reports, had an apparent paucity of B-CLL, MM and MGA of lambda subtype (57 k to 12 lambda, k:lambda ratio 4.8:1) and an unusual incidence of B-CLL with the double lg heavy chain combination M+G. Surveys of this type may help to point to environmental or other factors important in the aetiology of LPD.

Electron microscopic detection of periodate reactive complex carbohydrates in human T and B lymphocytes

The periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) technique, which has the same cytochemical significance as PAS staining of light microscopy, was undertaken to reveal the distribution of complex carbohydrates with vicinal glycols in human lymphocytes in several conditions at the ultra-structural level. The PA-TCH-SP method stained the clustered and the scattered cytoplasmic granules, Golgi apparatus and glycogen particles of lymphocytes. In the buffy coat, the lymphocytes with the clustered cytoplasmic granules contained less glycogen particles compared with the lymphocytes without the clustered cytoplasmic granules. The majority of T-lymphocytes separated from the venous blood possessed PA-TCH-SP positive clustered cytoplasmic granules, but glycogen particles were scanty or negligible, while B lymphocytes were rich with glycogen particles but had scanty clustered cytoplasmic granules. The T and B cell-derived cultured cell lines had a similar reactivity to the peripheral T and B cells.

Sex differences in prognosis of childhood T-cell leukemia

Bone marrows of 41 untreated children and adolescents with acute lymphocytic leukemia were studied by combined immunologic and histochemical methods at the time of diagnosis. Eleven were classified as T-cell lymphoblastic leukemias (27%) on the basis of cytochemical stains and E-rosette assay. The patients in this group has low median age of 8 years, relatively low median WBC of 13.4 x 10(3)/cc, 6/11 were female, and only 2/5 males had a mediastinal mass. The girls had a lower median age than boys (7 vs 9 years), none had mediastinal masses or extramedullary involvement, and their survival was greater than 27 months compared to 14 months for the boys (P less than 0.01). All patients were enrolled and treated on the (then) currently active CCSG protocols for ALL. This study emphasizes the fact that not all patients with T-cell ALL have poor prognosis, that sex could be an important factor affecting survival, and that the difference in survival could not be adequately explained by differences in the initial WBC.

Acute lymphoblastic leukemia subtypes in Israel: the Sheba medical center experience

During the period from 1978 to 1981, 52 patients with ALL were diagnosed and treated at the Chaim Sheba Medical Center. Using standard cell markers to subtype the blasts, 49 of the patients could be classified: 16 were found to be T-cell ALL, 10 common ALL, five null ALL, four pre-B and 14 were partially characterized as non-B, non-T. Analysis of the series revealed two distinctive features: high prevalence (30%) of T-cell ALL among both Jews and Arabs and a high proportion, two-thirds, of high risk patients due to high initial WBC counts, unfavourable age or T-cell characteristics. The minimal incidence of ALL among the Gaza Strip Arab children during the study period is 4:100,000, which is close to the incidence in the Western world. During previous years the leukemia incidence in the Gaza Strip was very low while the most common lymphatic malignancies were Burkitt tumor and other non-Hodgkin lymphomas.