Treatment of childhood acute lymphoblastic leukemia. Long-term results of the AIEOP-ALL 87 study

BACKGROUND AND OBJECTIVES

In March 1987 AIEOP started the AIEOP-ALL-87 study, based on the previous AIEOP-ALL-82. The aim of this new study was to evaluate, for all risk groups: a) the efficacy of treatment intensification achieved by adding a fourth drug (daunomycin) in the induction phase and a 3-drug reinduction phase for all risk groups; b) the impact of the addition of three doses of intrathecal methotrexate during cranial radiotherapy and extended exposure to weekly high-dose L-aspariginase during late intensification in high risk patients. We report the long-term results of the AIEOP ALL-87 study.

DESIGN AND METHODS

From 1987 to 1991, a total of 632 eligible and evaluable children (age 1 to < or =16 years) with non-B-cell acute lymphoblastic leukemia (ALL), were enrolled and stratified as follows: standard risk (SR, 79 patients, 12.5%) had WBC <10,000/mm3, age > or = 3 and <7 years, and FAB L1 morphology. The high risk (HR, 175 patients, 27.7%) group included patients with WBC > or =50,000/mm3 or FAB L3 morphology or T immunophenotype or acute undifferentiated leukemia (AUL) or leukemia-lymphoma syndrome. All the remaining patients formed the intermediate risk group (IR, 378 patients, 59.8%). All patients received a 4-drug induction therapy; intermediate-dose methotrexate was given to HR patients; cranial radiotherapy was given to IR and HR patients, while SR patients received extended intrathecal methotrexate; all patients received a 3-drug reinduction phase; high dose L-asparaginase (HD-L-ASP; E.Coli, Bayer) was given to HR patients; continuation therapy with 6-mercaptopurine, i.m. methotrexate, and monthly vincristine and prednisone pulses was given to all patients. Treatment duration was 2 years.

RESULTS

Six hundred and nineteen patients (97.9%) achieved complete remission. The remission rate was 98.7% in the SR group, 98.1% in the IR group, and 97.1% in the HR group. The overall 10-year survival and event-free survival (EFS) rates (SE) are 74.7% (1.8) and 62.8% (2.0) respectively; EFS rates by risk group are 67.5% (5.5) in SR, 62.8% (2.6) in IR, and 61.9% (3.8) for HR. The 10-year EFS for all eligible patients was 63.9% (1.9).

INTERPRETATION AND CONCLUSIONS

When compared to the results of the AIEOP-ALL-82 study, treatment intensification in the ALL-87 study has improved long-term survival and EFS from 66.4% and 53.6% to 74.7% and 62.8%, respectively. Failures were mostly due to marrow or extramedullary relapses suggesting that further treatment intensification, as being used in current therapeutic strategies, is appropriate, although patients relapsing after less intensive treatment may have better chances of rescue. These results, although obtained in a relatively large proportion of patients, in which infants were not included, indicate that the addition of high-dose L-asparaginase to a relatively non-intensive treatment may be of major benefit for HR patients and that the addition of intrathecal methotrexate during CRT, may improve the central nervous system-disease control with a marked reduction of nervous system relapses.

Monoclonal antibody panels for acute leukemia and myelodysplastic syndrome diagnosis. Results of a co-operative quality control group

The need for standardization criteria and result reproducibility in immunophenotyping hematological diseases has increased along with their clinical importance. Our group "Policentric Study Group on Immunological Markers", is composed of 40 laboratories. Its aim, over recent years, has been to find a standardized way of immunophenotypic analysis applicable to various hematological diseases. The objective of this study is to contribute to the debate concerning standardization of monoclonal antibody panels and immunophenotypic analysis procedures in acute leukemia (AL) and myelodysplastic syndrome (MDS), with the following targets: to improve interlaboratory reproducibility of the immunophenotyping data, and interpretative results; to study, with improved feasibility, correlation between immunophenotype and clinical or biological findings on a large number of AL and MDS cases; to verify the utility of the proposed monoclonal antibody panels for proper AL and MDS classification, and to detect minimal residual disease. In the field of AL and MDS our experience is based on about 1800 and 700 cases respectively analyzed over the last five years. Starting from these experiences and data of the literature we have elaborated the proposed panels of monoclonal antibodies and the methods of analysis. We have suggested a standardized immunophenotypic approach to study AL and MDS. In particular our work has focused on the gating strategy. This aims at drawing a gate of analysis having high purity and recovery, and on the choice of monoclonal antibody combinations for multiparametric analysis, particularly the normal antigen expression on each step of lineage differentiation or their clinically relevant aberrant expressions. A standardized criteria has become a necessary starting point in any kind of analytical process. In the field of acute leukemias and myelodysplastic syndromes the work of this polycentric group has focused on the pre-analytical and analytical steps to be taken in cytometric evaluation of hematological malignancies. The results obtained may contribute to reaching intra and inter-laboratory reproducibility.

Rapid detection of clonality in patients with acute lymphoblastic leukemia

BACKGROUND AND OBJECTIVES

Polymerase chain reaction (PCR) detection of clonal T-cell receptor (TCR) gamma and delta gene rearrangements is widely used in clonality assessment of lymphoid leukemias and lymphomas and for detection of minimal residual disease of acute lymphoblastic leukemia (ALL). Standard analyses for clonality assessment include Southern blotting or PCR-based detection of clonal TCR gene rearrangements. The latter consist of heteroduplex PCR analysis by separation of PCR products on non-denaturing polyacrylamide gel (PAGE). We describe a rapid and sensitive method to identify specific clonal rearrangements in PCR fragments obtained by amplification of TCRgamma and TCRdelta genes.

DESIGN AND METHODS

We applied a semi-automated electrophoretic technique (PhastSystem , Amersham Pharmacia Biotech) and compared it with standard homo-heteroduplex analysis in 21 cases of childhood acute lymphoblastic leukemia (ALL).

RESULTS

The results obtained for each sample analyzed by standard homo-heteroduplex detection were completely reproduced by the PhastSystem approach.

INTERPRETATION AND CONCLUSIONS

We conclude that heteroduplex analysis of TCR gene rearrangements using the semi-automated PhastSystem is a simple, rapid, cheap and highly reproducible method which can be used as an alternative to traditional analysis for detection of clonality.

Effect of protracted high-dose L-asparaginase given as a second exposure in a Berlin-Frankfurt-Münster-based treatment: results of the randomized 9102 intermediate-risk childhood acute lymphoblastic leukemia study--a report from the Associazione Italiana Ematologia Oncologia Pediatrica

PURPOSE

To assess in a randomized study the therapeutic effect of the addition of high-dose L-asparaginase (HD ASP) in the context of a Berlin-Frankfurt-Münster (BFM)-based chemotherapy regimen for intermediate risk (IR) childhood acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

From March 1991 to April 1995, a total of 705 patients, with 59% of the cohort of patients fewer than 15 years old, with newly diagnosed non-B ALL, enrolled onto the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) ALL-91 study, were assigned to the IR group. Patients in remission at the beginning of the reinduction phase were randomized either to the standard treatment (SD ASP arm) or the experimental treatment (HD ASP arm; weekly intramuscular administration of HD ASP 25,000 IU/m(2) repeated for a total of 20 weeks). Most of the patients (90%) were treated with Erwinia chrysanthemi L-asparaginase product.

RESULTS

Among the 610 patients randomized to the SD ASP arm (n = 322) or to the HD ASP arm (n = 288), relapse occurred at a median time of 24 months after randomization in 76 (24%) and in 64 children (22%), respectively. Most of the relapses occurred in the marrow (100 isolated, 21 combined). There was no significant difference between the disease-free survival in the two treatment arms (P =.64), with estimated values at 7 years from randomization of 72.4% (SE 3.1) v 75.7% (SE 2.6) in the SD ASP and HD ASP arms, respectively.

CONCLUSION

No advantage was observed for IR ALL children treated with BFM-based intensive chemotherapy who received protracted E chrysanthemi HD ASP during reinduction and the early continuation phase.

17q21-qter trisomy is an indicator of poor prognosis in acute myelogenous leukemia

A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patient's condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance.

Long-term results of the Italian Association of Pediatric Hematology and Oncology (AIEOP) acute lymphoblastic leukemia studies, 1982-1995

The first multicentric approach to childhood acute lymphoblastic leukemia (ALL) treatment in Italy started in the early 1970s when the Associazione Italiana di Ematologia ed Oncologia Pediatrica (AIEOP) was founded. Since then the AIEOP has conducted nationwide chemotherapy protocols. Results obtained in three different periods (1982-1986, 1987-1990, 1991-1995) are reported here. Treatment schedules have been characterized by a progressive intensification of systemic therapy and by a progressive substitution of protracted intrathecal therapy for cranial irradiation as central nervous system (CNS) preventive therapy. In the third period cranial radiotherapy (CRT) has been administered only to patients at high risk of relapse or with CNS involvement at diagnosis (about 15% of the overall population). A progressive improvement of therapeutic results, with a steady reduction of isolated CNS relapse rates have been obtained in the three periods considered here. The AIEOP experience shows that CRT can be safely omitted in non-high risk patients, unless they are T-ALL patients with WBC count at the diagnosis > or =100,000/mm3, and that intensification of treatment allows the improvement of overall results with a reduction of the impact of NCI prognostic criteria. Over the years, AIEOP has also continued to foster active cooperation at an international level. In the ongoing AIEOP ALL 2000 study, conducted in cooperation with the BFM group, patients are stratified according to the presence of translocations t(9;22) and t(4;11) and to treatment response (either initial steroid therapy or induction) or minimal residual disease). This cooperation will allow an adequate recruitment of patients to answer relevant randomized questions in the context of a study in which patients are stratified according to minimal residual disease findings.

Integrin expression and IgA nephropathy: in vitro modulation by IgA with altered glycosylation and macromolecular IgA

BACKGROUND

Signal transduction by mesangial cell (MC) integrins regulates cell growth and survival, extracellular matrix production, and organization. The aim of the study was to investigate human MC integrin modulation by differently glycosylated IgA and macromolecular IgA, which are thought to play a pathogenetic role in IgA nephropathy (IgAN).

METHODS

MCs were incubated with purified human polymeric IgA, heat-aggregated IgA, IgA glycoforms generated by enzymatic hydrolysis of saccharide residues and serum fractions from IgAN patients, and controls isolated by lectin affinity and containing IgA with peculiar glycan patterns. Integrins were quantitated by flow cytometry.

RESULTS

Cultured MCs highly expressed alphavbeta3 and some alpha3beta1; alphavbeta3 was up-regulated by matrix components (P < 0.02). In vitro desialylated and degalactosylated polymeric human IgA enhanced alphavbeta3 expression on cultured MCs (P < 0.001). Serum IgA glycoforms isolated from IgAN patients with high exposure of internal sugars, GalNAc, Neu5Ac2,6GalNAc, and Man enhanced alphav expression on cultured MCs more than healthy controls. CONCLUSIONS.: These data support the hypothesis that IgA glycation plays a role in modulating the cell-matrix interaction, and that this mechanism can be operating in IgAN.

Neural correlates of imaginal aggressive behavior assessed by positron emission tomography in healthy subjects

OBJECTIVE

Neurodegenerative or traumatic lesions of the frontal lobes often lead to abnormally aggressive behavior. The authors hypothesized that the imaginal evoking of scenarios involving aggressive behavior would be associated with a modulation of the functional activity in the human frontal cortex.

METHOD

Regional cerebral blood flow (rCBF) determinations by positron emission tomography and psychophysiological measures of emotional responsivity were obtained in a group of 15 young healthy volunteers with good visual imagery abilities and no history of abnormal behavior while they imagined the same scenario with four variations involving emotionally neutral behavior and aggressive behavior.

RESULTS

Compared to the imagined neutral scenario, the imagined scenarios involving aggressive behavior were associated with significant emotional reactivity and rCBF reductions in the ventromedial prefrontal cortex, suggesting that a functional deactivation of this cortical area occurs when individuals respond to the eliciting of imagined aggressive behavior.

CONCLUSIONS

These results in healthy subjects further expand previous findings from animal and human studies by providing an in vivo functional demonstration of the involvement of the orbitofrontal cortex in the expression of aggressive behavior. They are also consistent with the hypothesis that a functional alteration of this cortical region may be present in individuals with pathological aggressive behavior.

Quantitative multiparametric immunophenotyping in acute lymphoblastic leukemia: correlation with specific genotype. I. ETV6/AML1 ALLs identification

The t(12;21)(p13;q22) fusion gene is the most frequent genetic lesion described in precursor B cell acute lymphoblastic leukemia (ALL) of childhood occurring in a quarter of cases. This gene rearrangement is associated with a good outcome presenting a high response rate to chemotherapy. In spite of its potential clinical relevance, the t(12;21) translocation usually goes undetected with conventional cytogenetic procedures. In the present study we utilized an objective flow cytometric approach (multiparametric quantitative analysis) for the phenotypic characterization of this type of ALL. We studied a total of 74 precursor B-ALL children, including 21 t(12;21)+ and 53 t(12;21)- cases. Our results show that the t(12;21)(p13;q22)+ ALLs display a higher intensity of CD10 (P = 0.0016) and HLADR (P = 0.005) expression together with lower levels of the CD20 (P = 0.01), CD45 (P = 0.01), CD135 (P = 0.003) and CD34 (P = 0.03) antigens as compared to the t(12;21) cases. Moreover, as regards CD34 expression, we observed a more heterogeneous antigen expression within individual patients with higher coefficients of variation (median of 202 vs 88, P = 0.0001). A multi-variate analysis disclosed that with the immunophenotypic approach used identification of t(12;21)+ cases can be achieved with a sensitivity of 86% and a specificity of 100%. We conclude that childhood precursor B-ALL carrying the t(12;21) translocation display characteristic phenotypic features which could provide a rapid, simple, sensitive and specific screening method to select for those cases that should undergo confirmatory molecular analysis.

Aloe-emodin is a new type of anticancer agent with selective activity against neuroectodermal tumors

Here we report that aloe-emodin (AE), a hydroxyanthraquinone present in Aloe vera leaves, has a specific in vitro and in vivo antineuroectodermal tumor activity. The growth of human neuroectodermal tumors is inhibited in mice with severe combined immunodeficiency without any appreciable toxic effects on the animals. The compound does not inhibit the proliferation of normal fibroblasts nor that of hemopoietic progenitor cells. The cytotoxicity mechanism consists of the induction of apoptosis, whereas the selectivity against neuroectodermal tumor cells is founded on a specific energy-dependent pathway of drug incorporation. Taking into account its unique cytotoxicity profile and mode of action, AE might represent a conceptually new lead antitumor drug.

Differential amygdala responses to winning and losing: a functional magnetic resonance imaging study in humans

The amygdala has been shown to respond to many distinct types of affective stimuli, including reward and punishment feedback in animals. In humans, winning and losing situations can be considered as reward and punishment experiences, respectively. In this study, we used functional magnetic resonance imaging (fMRI) to measure regional brain activity when human subjects were given feedback on their performance during a simple response time task in a fictitious competitive tournament. Lexical stimuli were used to convey positive 'win' or negative 'lose' feedback. The frequency of positive and negative trials was parametrically varied by the experimenters independently from the subjects' actual performance and unbeknownst to them. The results showed that the parametric increase of winning was associated with left amygdala activation whereas the parametric increase of losing was associated with right amygdala activation. These findings provide functional evidence that the human amygdala differentially responds to changes in magnitude of positive or negative reinforcement conveyed by lexical stimuli.

Individual and combined effect of granulocyte-macrophage colony-stimulating factor and prolactin on maturation of dendritic cells from blood monocytes under serum-free conditions

Prolactin (PRL) shares structural and functional features with haemopoietic factors and cytokine peptides. Dendritic cells (DC) are involved in both initiating the primary and boosting the secondary host immune response and can be differentiated in vitro from precursors under the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) plus other factors. Because PRL has been shown to functionally interact with GM-CSF, we have addressed its role on GM-CSF-driven differentiation of DC. Monocytic DC precursors from peripheral blood mononuclear cells (PBMC) were enriched either by adhesion to a plastic surface or CD14-positive selection and cultured for 7 days in serum-free medium containing GM-CSF, interleukin (IL)-4 and PRL, alone or in combination. Cells with large, veiled cytoplasm, expressing major histocompatibility complex (MHC) class II and the costimulatory molecules CD80, CD86 and CD40 and lacking the monocyte marker CD14, were considered as having the phenotype of cytokine-generated DC. Functional maturation was assessed by proliferation and interferon-gamma (IFN-gamma) release of allogeneic T lymphocytes. Physiological (10-20 ng/ml) concentrations of PRL interacted synergistically with GM-CSF and the effect was similar to that induced by IL-4 on GM-CSF-driven DC maturation. When used alone, the physiological concentrations of PRL were inhibitory, whereas higher concentrations (80 ng/ml) were stimulatory. The synergistic effect of PRL may in part be caused by its ability to counteract the down-modulation of the GM-CSF receptor observed in serum-free conditions. These data provide further evidence of the significance of PRL in the process of T lymphocyte activation.

The calculating brain: an fMRI study

To explore brain areas involved in basic numerical computation, functional magnetic imaging (fMRI) scanning was performed on college students during performance of three tasks; simple arithmetic, numerical magnitude judgment, and a perceptual-motor control task. For the arithmetic relative to the other tasks, results for all eight subjects revealed bilateral activation in Brodmann's area 44, in dorsolateral prefrontal cortex (areas 9 and 10), in inferior and superior parietal areas, and in lingual and fusiform gyri. Activation was stronger on the left for all subjects, but only at Brodmann's area 44 and the parietal cortices. No activation was observed in the arithmetic task in several other areas previously implicated for arithmetic, including the angular and supramarginal gyri and the basal ganglia. In fact, angular and supramarginal gyri were significantly deactivated by the verification task relative to both the magnitude judgment and control tasks for every subject. Areas activated by the magnitude task relative to the control were more variable, but in five subjects included bilateral inferior parietal cortex. These results confirm some existing hypotheses regarding the neural basis of numerical processes, invite revision of others, and suggest productive lines for future investigation.

Stem cell factor is not essential for cell survival and proliferation of soft tissue sarcoma of neuroectodermal origin

BACKGROUND AND OBJECTIVE

Stem cell factor (SCF), and its receptor (c-kit) play key roles in the expansion and differentiation of hematopoietic progenitor cells, in melanoblasts and primordial germ cells, making it possible that SCF and c-kit are involved in neoplastic processes deriving from these cells. C-kit has been described to be expressed at different levels in neuroblastoma and in soft tissue sarcoma of neuroectodermal origin, and seems to be required for survival processes. In this study we investigate how c-kit expression is regulated and whether a SCF autocrine loop is essential for survival of sarcoma cell lines.

DESIGN AND METHODS

C-kit modulation and internalization was evaluated incubating cells with rhSCF. Cell differentiation and proliferation experiments were performed to test whether c-kit expression is related to cell cycle progression or to differentiation processes. Cell cultures were treated with neutralizing antibody and antisense oligonucleotides in order to assess the possible significance of the SCF autocrine loop.

RESULTS

In vitro SCF stimulation induces c-kit down-regulation; this phenomenon could be connected with receptor internalization, and new protein synthesis is necessary for its re-expression. The cell proliferation arrest in G0/G1 does not modify c-kit expression while down-regulation of c-kit was demonstrated after cells had been treated with differentiating agents. SCF neutralization does not influence either the S phase or apoptosis in sarcoma cell lines.

INTERPRETATION AND CONCLUSIONS

In sarcoma cell lines, c-kit is regulated by differentiation processes; moreover our results suggest that c-kit activity, but probably not the SCF autocrine loop, is essential for survival of these cell lines.

Clinically useful information provided by the flow cytometric immunophenotyping of hematological malignancies: current status and future directions

BACKGROUND

At present, immunophenotyping of hematological malignancies represents one of the most relevant clinical applications of flow cytometry. In recent years, its use has extended from clinical research to diagnostic laboratories. The aim of this report is to critically review the type of information provided by the flow cytometric immunophenotyping of hematological malignancies and its clinical impact as well as to highlight its potential future applications.

METHODS

The currently available information, including that provided by different international consensus groups on the phenotypic characterization of hematologic malignancies, was reviewed. Additionally, recent reports on the immunophenotypic analysis of hematological malignancies published in hematology, oncology, pathology, immunology, and cell biology journals were also analyzed.

RESULTS

A careful review of the literature showed that in spite of the well-established utility of immunophenotyping for the diagnosis, classification, prognostic stratification, and monitoring of hematological malignancies, only a small part of the information on the immunophenotypic characteristics of pathological hemopoietic cells has been used routinely. Specific and sensitive identification of neoplastic cells and their accurate enumeration and phenotypic characterization represent the major aims of these procedures. Similarities between leukemic and healthy cells allow the establishment of the lineage and maturation stage of the pathologic cells, this information being of great utility for the diagnosis, classification, and prognostic evaluation of different subtypes of hematological malignancies. On the other hand, the phenotypic aberrations displayed by leukemic cells could allow the selection of cases carrying specific genetic abnormalities in which further confirmatory molecular studies will be performed.

CONCLUSIONS

The information provided by the flow cytometric immunophenotyping of hematological malignancies is of great clinical utility, with a major challenge for the near future being the standardization of technical procedures, data interpretation, and reporting.

The c-kit receptor and its ligand stem cell factor in childhood malignant lymphoid precursors

The c-kit receptor (CD117) and its ligand stem cell factor (SCF) play an important role in the development, differentiation, and survival of normal and malignant hematopoietic cells. The aim of this work is to review the cellular distribution of this receptor and the effect of SCF on the hematopoietic system, particularly among lymphoid lineage, either in normal or malignant cell progenitors. We examined reports and results in the field and articles or abstracts published in journals covered by MEDLINE. Additionally, we evaluated CD117 expression on fresh blast cells of 376 newly diagnosed cases of childhood acute lymphoblastic leukemia (ALL) that were referred to centers affiliated with the Italian Association for Pediatric Hematology and Oncology (AIEOP). In view of our data, approximately 11% of ALL are CD117 positive. In particular, this receptor can be expressed in 10% and 11.5% of T-lineage and B-lineage ALL, respectively. Its expression is associated with an intermediate/mature phenotype in T-lineage ALL, whereas in B-lineage ALL, the majority of the positive cases are classified as early B ALL. The effect of SCF on malignant hematopoiesis and its potential clinical uses are reviewed.

The role of the anterior prefrontal cortex in human cognition

Complex problem-solving and planning involve the most anterior part of the frontal lobes including the fronto-polar prefrontal cortex (FPPC), which is especially well developed in humans compared with other primates. The specific role of this region in human cognition, however, is poorly understood. Here we show, using functional magnetic resonance imaging, that bilateral regions in the FPPC alone are selectively activated when subjects have to keep in mind a main goal while performing concurrent (sub)goals. Neither keeping in mind a goal over time (working memory) nor successively allocating attentional resources between alternative goals (dual-task performance) could by themselves activate these regions. Our results indicate that the FPPC selectively mediates the human ability to hold in mind goals while exploring and processing secondary goals, a process generally required in planning and reasoning.

Myelodysplastic syndrome, juvenile myelomonocytic leukemia, and acute myeloid leukemia associated with complete or partial monosomy 7. European Working Group on MDS in Childhood (EWOG-MDS)

We reviewed the clinical features, treatment, and outcome of 100 children with myelodysplastic syndrome (MDS), juvenile myelomonocytic leukemia (JMML), and acute myeloid leukemia (AML) associated with complete monosomy 7 (-7) or deletion of the long arm of chromosome 7 (7q-). Patients with therapy-induced disease were excluded. The morphologic diagnoses according to modified FAB criteria were: MDS in 72 (refractory anemia (RA) in 11, RA with excess of blasts (RAEB) in eight, RAEB in transformation (RAEB-T) in 10, JMML in 43), and AML in 28. The median age at presentation was 2.8 years (range 2 months to 15 years), being lowest in JMML (1.1 year). Loss of chromosome 7 as the sole cytogenetic abnormality was observed in 75% of those with MDS compared with 32% of those with AML. Predisposing conditions (including familial MDS/AML) were found in 20%. Three-year survival was 82% in RA, 63% in RAEB, 45% in JMML, 34% in AML, and 8% in RAEB-T. Children with -7 alone had a superior survival than those with other cytogenetic abnormalities: this was solely due to a better survival in MDS (3-year survival 56 vs 24%). The reverse was found in AML (3-year survival 13% in -7 alone vs 44% in other cytogenetic groups). Stable disease for several years was documented in more than half the patients with RA or RAEB. Patients with RA, RAEB or JMML treated with bone marrow transplantation (BMT) without prior chemotherapy had a 3-year survival of 73%. The morphologic diagnosis was the strongest prognostic factor. Only patients with a diagnosis of JMML fitted what has previously been referred to as the monosomy 7 syndrome. Our data give no support to the concept of monosomy 7 as a distinct syndrome.

Cytofluorimetric analysis of CD34 cells

The cytofluorimetric enumeration of CD34-positive cells is a useful method for measuring haematopoietic stem cells. The large variation of results between different laboratories, in multicenter quality control studies, could be due to multiple technical problems. CD34 analysis must be performed in whole blood and the NH4Cl or the NH4Cl-derived reagents give the best results in the lysis procedure. The monoclonal antibody for CD34 detection must be a class III, if possible PE-conjugated. Any differences were found in the absolute CD34 count using different analysis protocols: Milan, ISHAGE, Dutch, or a commercial kit, when the sample is fresh and in good viable condition. The multiparametric approach, using three or four colours simultaneously, could be required in scoring apheresis products from patients with CD34-positive blast cells (ie ALL of B cell origin) and in deciding the optimum time to start the leukapheresis, choosing, with an equal CD34 number, the moment at which the highest number of more immature progenitor cells (CD38-negative or dim, CD90-positive) is present.

Prognostic value of minimal residual disease in acute lymphoblastic leukaemia in childhood

BACKGROUND

Sensitive techniques for detection of minimal residual disease (MRD) at degrees of one leukaemic cell per 10(3)-10(6) cells (10(-3)-10(-6)) during follow-up of children with acute lymphoblastic leukaemia (ALL) can provide insight into the effectiveness of cytotoxic treatment. However, it is not yet clear how information on MRD can be applied to treatment protocols.

METHODS

We monitored 240 patients with childhood ALL who were treated according to national protocols of the International BFM Study Group. 60 patients relapsed and the patients in continuous complete remission (CCR) had a median event-free follow-up of 48 months. Bone-marrow samples were collected at up to nine time points during and after treatment. Standardised PCR analysis of patient-specific immunoglobulin and T-cell receptor gene rearrangements and TAL1 deletions were used as targets for semiquantitative estimation of MRD. Amount of MRD was classed as 10(-2) or more, 10(-3), and 10(-4) or less.

FINDINGS

MRD negativity at the various follow-up times was associated with low relapse rates (3-15% at 3 years), but five-fold to ten-fold higher relapse rates (39-86% at 3 years) were found in MRD-positive patients. The distinct degrees of MRD appeared to have independent prognostic value (p [trend]<0.001) at all separate time points, especially at the first two time points (at the end of induction treatment and before consolidation treatment). At these two time points a high degree of MRD (> or = 10(-2)) was associated with a three-fold higher relapse rate when compared with patients with a low degree of MRD (< or = 10(-4)). At later time points (including the end of treatment) even a low degree of MRD was associated with a poor outcome. Positivity in patients in CCR after treatment was rare (< 1%). With the combined MRD information from the first two follow-up time points, it was possible to recognise three different risk groups--55 (43%) were in a low-risk group and had a 3-year relapse rate of only 2% (95% CI 0.05-12%); 19 (15%) were in a high-risk group and had a relapse rate of 75% (55-95%); and 55 (43%) were in an intermediate-risk group and had a 3-year relapse rate of 23% (13-36%).

INTERPRETATION

Our collaborative MRD study shows that monitoring patients with childhood ALL at consecutive time points gives clinically relevant insight into the effectiveness of treatment. Combined information on MRD from the first 3 months of treatment distinguishes patients with good prognoses from those with poor prognoses, and this helps in decisions whether and how to modify treatment.

Clinical relevance of CD10 expression in childhood ALL. The Italian Association for Pediatric Hematology and Oncology (AIEOP)

BACKGROUND AND OBJECTIVE

Previous studies have considered the prognostic significance of CD10 expression in childhood acute lymphoblastic leukemia (ALL) and showed its linkage to a more favorable prognosis. The aim of this study was to assess the independent significance of CD10 expression in a large population of ALL patients.

DESIGN AND METHODS

We revised the independent clinical relevance of CD10 expression in 2038 children with acute lymphoblastic leukemia (ALL), who were consecutively entered in 4 sequential trials of the Italian Association for Pediatric Hematology and Oncology (i.e. AIEOP studies 82, 87, 88, 91); 1142 were males and 896 females, age ranged between 1 and 14 years (yrs) at diagnosis. Of the whole group, 1471 children (72.2%) were defined as having standard risk, 567 (27.8%) as having a high risk.

RESULTS

CD10 was detected in blast cells from 1706 of 1784 (95.6%) patients with B-lineage ALL and 46 of 254 (18.1%) with T-cell ALL. In the B-lineage subgroup CD10 expression was associated with presenting features such as age < 9 yrs and inclusion in the standard risk category. No significant differences were found between CD10+ and CD10- cases in T-lineage ALL, concerning presenting features, except for FAB L2 in the former group. We compared the event-free survival (EFS) rates for patients with T-ALL or B-lineage ALL, regarding CD10 positivity, overall and by individual study. Patients with T-ALL fared worse than those with B-lineage ALL (5 and 10 yrs EFS: 46.8% vs. 68.5% and 44.5% vs. 63.7% respectively, p = 0.0001). In multivariate analysis of B-lineage subgroup poorer EFS was associated with male sex, higher WBC (> or = 20 x 10(9)/L), age > 9 yrs. Only WBC > or = 20 x 10(9)/L and age > 9 yrs were parameters linked to poorer EFS in the T-lineage subgroup. Finally, we compared EFS rates for four groups of patients categorized as having high or standard risk, and according to CD10+ and CD10- expression. High-risk patients fared statistically worse than standard risk patients both in the CD10- and in the CD10+ groups (42% vs. 50.7% and 63.6% vs. 66.8%, respectively).

INTERPRETATION AND CONCLUSIONS

CD10 expression does not have independent prognostic significance in either the larger subgroup of B-ALL patients or in T-cell ALL.