Effects of a novel synthetic retinoid on malignant glioma in vitro: inhibition of cell proliferation, induction of apoptosis and differentiation.

Among six synthetic retinoids tested, the retinoid 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) was highly efficient in inducing growth inhibition of 8MG-BA and GL-15 human glioblastoma cell lines, with growth arrest at the S phase of the cell cycle. CD 437 also induced apoptosis in these cells, with 8MG-BA being the most sensitive. In these cells, induction of apoptosis by CD437 has been related to the downregulation of Bcl-2 expression and to CPP32 activation, but not to p53 expression. The remaining non-apoptotic cells presented a morphological pattern of astroglial differentiation with overexpression of glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS). The mechanism of action of CD437, originally developed as a RARgamma agonist, is not yet elucidated. However, our results suggest that it acts through an increase of the expression of retinoid-inducible genes, such as RARbeta2 and/or RARalpha2.

Chimerism analysis by lineage-specific fluorescent polymerase chain reaction in secondary graft failure after allogeneic stem cell transplantation.

BACKGROUND: Chimerism analysis is essential in understanding the etiology of graft failure occurring after allogeneic stem cell transplantation. The detection of marrow and/or blood host cells suggests graft rejection, relapse of the underlying disease, or a state of stable mixed chimerism. However, complete donor chimerism may be observed in some cases. Our objective was to characterize, by a sensitive process of chimerism analysis, six cases of graft failure occurring after transplant. METHODS: Six cases of secondary graft failure, in which previous analysis had shown complete donor chimerism by standard polymerase chain reaction amplification of variable number of tandem repeats, were studied. In order to detect a minority population of recipient cells, we increased the sensitivity of the process by using fluorescent polymerase chain reaction and analyzing the origin of T, B, and natural killer lymphocytes at the time of graft failure. RESULTS: The complete donor origin of mononuclear cells and lymphocytic populations was confirmed with this method in five of six patients. In the remaining patient, diagnosis of graft failure was clarified by the detection of a previously undetected mixed chimerism, compatible with graft rejection. In the other five patients, graft rejection was thereby excluded and graft failure could be related to viral infection or to graft-versus-host disease. CONCLUSION: Our sensitive process of fluorescent lineage-specific chimerism analysis may help in distinguishing between graft rejection and other mechanisms of graft failure, which is essential for deciding appropriate therapy.

Pathologic interaction between megakaryocytes and polymorphonuclear leukocytes in myelofibrosis.

Idiopathic myelofibrosis (MF) is a myeloproliferative syndrome characterized by an increase in bone marrow collagen. Megakaryocytes (Mks), which store growth factors in their alpha granules, are known to be involved in the pathogenesis of MF. Previously, mice given bone marrow grafts infected with a retrovirus carrying murine thrombopoietin (TPO) complementary DNA developed a disease resembling human idiopathic MF. In this study, we used this murine model (TPO mice) to determine whether release of alpha granules is responsible for fibroblast activation and development of fibrosis. The intracellular trafficking of several alpha-granule proteins (von Willebrand factor, fibrinogen, and transforming growth factor beta (TGF beta), which are stored in the granule matrix; and alpha(IIb)beta(3) integrin and P-selectin (CD62p), which are located in the alpha-granule membrane) was studied with immune electron microscopy in bone marrow Mks from TPO mice. P-selectin immunolabeling increased consistently and was occasionally found lining the demarcation membrane system. Evidence of extensive emperipolesis was also found in TPO mouse Mks, involving almost exclusively neutrophil and eosinophil polymorphonuclear (PMN) cells with altered morphologic features. In parallel, the host Mks had myeloperoxidase-positive granules scattered in their cytoplasm, associated with marked ultrastructural cytoplasmic alterations and ruptured alpha-granule membranes. Similar observations were made in bone marrow biopsy specimens from 12 patients with idiopathic MF; indeed, there was an increased rate of emperipolesis involving mostly PMN cells, abnormal P-selectin expression, and mutual subcellular PMN and Mk alterations. This study indicates that in idiopathic MF, abnormal P-selectin distribution in Mks induces selective sequestration of PMN cells. This results in a release of alpha-granular proteins and growth factors, which in turn induces fibroblast activation and fibrosis deposition. (Blood. 2000;96:1342-1347)

Ex vivo expanded mobilized peripheral blood CD34+ cells accelerate haematological recovery in a baboon model of autologous transplantation.

To address the value of ex vivo expanded haematopoietic cells for shortening cytopenia in autologous haematopoietic transplantation, we designed an ex vivo expansion protocol based on a cocktail of early acting cytokines and short-term culture and tested it in a baboon model. Expansion involved enriched CD34+ peripheral blood haematopoietic cells cultured for 6 d with a combination of FLT3-L, stem cell factor (SCF), thrombopoietin (TPO) and interleukin (IL)-3 (50 ng/ml each); CD34+ cells, granulocyte-macrophage colony-forming units (GM-CFU) and megakaryocytic colony-forming units (MK-CFU) were amplified, respectively, 10.5-, 20.5- and 17.9-fold. Baboons were submitted to a myeloablative regimen consisting of cyclophosphamide plus total body irradiation (TBI; 6 Gy) and were then grafted with either 2 x 106/kg unmanipulated CD34+ cells (control group, n = 4) or cells cultured from 2 x 106/kg CD34+ cells (expansion group, n = 4). No cytokines were administered after transplantation. All the animals engrafted. The mean times to white blood cell (WBC), granulocyte and platelet recovery were significantly shorter in the expansion group than in the control group: WBC (> 1 x 109/l) and neutrophil (> 0.5 x 109/l) recovery occurred on days 8 (range 6-9) and 9 (range 6-11), respectively, compared with days 12 (range 10-15) and 14 (range 11-16); platelets recovered (> 20 x 109/l) on day 9 (range 7-12) compared with day 13 (range 11-15) in the control group (P < 0.05). No toxicity was observed after reinfusion. No secondary hypoplasia was observed during more than 12 months of follow-up. Functions of both neutrophils and platelets produced from expanded cells were normal in terms of oxidative metabolism, chemotaxis and the bleeding time. This study shows that in comparison with unmanipulated cells peripheral blood haematopoietic cells expanded from similar doses of CD34+ cells, under the conditions defined here, accelerated both neutrophil and platelet recovery without impairing long-term haematopoiesis.

Formation of dense erythrocytes in SAD mice exposed to chronic hypoxia: evaluation of different therapeutic regimens and of a combination of oral clotrimazole and magnesium therapies.

We have examined the effect of hydroxyurea (HU), clotrimazole (CLT), magnesium oxide (Mg), and combined CLT+Mg therapies on the erythrocyte characteristics and their response to chronic hypoxia in a transgenic sickle mouse (SAD) model. SAD mice were treated for 21 days with 1 of the following regimens (administered by gavage): control (n = 6), HU (200 mg/d; n = 6), CLT (80 mg/kg/d, n = 5), Mg (1,000 mg/kg/d, n = 5), and CLT+Mg (80 and 1,000 mg/kg/d, respectively, n = 6). Nine normal mice were also treated as controls (n = 3), HU (n = 3), and CLT+Mg (n = 3). Treatment with HU induced a significant increase in mean corpuscular volume and cell K content and a decrease in density in SAD mice. Treatment with the CLT and Mg, either alone or in combination, also increased cell K and reduced density in SAD mice. After 21 days of treatment, the animals were exposed to hypoxia (48 hours at 8% O(2)) maintaining the same treatment. In the SAD mice, hypoxia induced significant cell dehydration. These hypoxia-induced changes were blunted in either HU- or Mg-treated SAD mice and were completely abolished by either CLT or CLT+Mg treatment, suggesting a major role for the Gardos channel in hypoxia-induced dehydration in vivo.

Poor lymphocyte recovery following CD34-selected autologous peripheral blood stem cell transplantation for non-Hodgkin's lymphoma.

Positive selection of CD34+ cells in autologous grafts, designed to deplete tumour cells, also results in T-cell depletion. To assess the reconstitution of the different lymphocyte subsets and of the T-cell repertoire diversity following autologous transplantation of selected CD34+ peripheral blood stem cells (PBSC), we analysed sequential blood samples in eight patients autografted for advanced B-cell non-Hodgkin's lymphoma in a phase I-II pilot study. Although natural killer cell recovery was rapid, T- and B-cell recovery was delayed with a median of 110/microliters CD4+, 175/microliters CD8+ T cells and 45/microliters B cells at 12 months post-transplant. The naive CD45RA+ T-cell compartment was profoundly deficient up to 12 months for both CD4+ and CD8+ subsets. A transient expansion of memory CD8+CD45RO+ T cells consisting of an increased percentage of CD57+CD28- cells occurred within the first 3 months post-transplant, but the memory CD4+CD45RO+ T cells remained far below the normal value. The CD8+CD28+ T-cell subset did not recover. Using multiplex PCR analysis of the T-cell receptor gamma locus, we found that the repertoire diversity improved at 12 months after being poor and oligoclonal during the first 3 months post-transplant. As shown by monoplex PCRgamma analysis of every VJ combination, despite T-cell depletion of the graft, mature T cells were carried over with the selected CD34+ PBSC and contributed to the T-cell recovery after transplantation.

CD3 hyporesponsiveness and in vitro apoptosis are features of T cells from both malignant and nonmalignant secondary lymphoid organs.

There is a dogma in tumor immunology that tumor-infiltrating lymphocytes (TIL) are defective based on their lack of antitumoral efficacy in vivo and on impaired response to in vitro functional tests. However, TIL have been compared usually with peripheral blood T lymphocytes, raising doubts on the conclusions drawn. Therefore, we compared TIL from B cell non-Hodgkin's lymphomas (NHL) with T cells from nonmalignant secondary lymphoid organs. NHL-TIL were unresponsive to activation by immobilized anti-CD3 mAb, although bypassing T cell receptor (TCR)/CD3 signaling led to proliferation. The poor proliferative responses of NHL-TIL could not be explained by quantitative defects in TCRzeta expression. NHL-TIL underwent marked spontaneous apoptosis in vitro with loss of approximately 50% of cells after 24 h of culture. This was associated with downregulation of the antiapoptotic Bcl-xL and Bcl-2 proteins, whereas viable NHL-TIL maintained their expression. IL-2, anti-CD3/IL-2, and manipulation of the Fas/Fas-ligand death pathway had no effect on NHL-TIL survival. Apoptosis was not due to increased cell cycling, as NHL-TIL were quiescent, nonproliferating cells. T cells from inflammatory, nonmalignant tissues gave similar functional results to NHL-TIL, suggesting the existence of factors common to the microenvironment of these diverse pathologies. Thus, the quiescent, anergic phenotype of NHL-TIL cannot be attributed solely to tumor factors, but rather is a feature of T cells from chronic inflammatory lesions.

[In vitro detection of prostate cancer circulating cells by immunocytochemistry, flow cytometry and RT-PCR PSA]. / Détection in vitro des cellules circulantes dans le cancer de la prostate par immunocytochimie, cytométrie en flux et RT-PCR PSA.

OBJECTIVE: To evaluate 3 in vitro methods detection (immunocytochemistry, flow cytometry and RT-PCR PSA) of circulating prostate cancer cells from a model of uncap dilution in immortalised lymphocytes. METHODS: In vitro comparison of 3 techniques (immunocytochemistry, flow cytometry, RT-PCR PSA) was performed from a range of dilutions of LbCap cells in immortalised human lymphocytes (concentration range: 1 LnCap cell per 100 lymphocytes to 1 LnCap cell per 100 million lymphocytes). Cells were detected by anti-PSA (prostate specific antigen) and PAP (prostatic acid phosphatase) antibody by immunochemistry, by fluorescent linked antipancytokeratin antibody by flow cytometry and RT-PCR PSA. RESULTS: The limit of detection was 1 LnCap cell per 200,000 lymphocytes (1/2.10(5)) for immunochemistry, 1 LnCap cell per 1,000 lymphocytes (1/1.10(3)) for flow cytometry and 1 LnCap cell per 10 million lymphocytes (1/10(7)) for RT-PCR PSA. CONCLUSION: RT-PCR, due to its most perceptible limit of detection, appears to be the method of choice for the detection of prostatic epithelial cells. Immunocytochemistry has the advantage of providing a quantitative approach. Flow cytometry is limited by the limit of detection of the apparatus used. The prognostic significance of detection of circulating prostate cancer cells remains to be clarified, but the detection of these cells and their correlation with the primary tumour will provide a better understanding of metastatic phenomena.

[Hemolysis and schizocytosis, malabsorption and the "folate trap": unusual semiological peculiarities associated with vitamin B12 deficiency]. / Hémolyse et schizocytose, malabsorption et "piège à folates": à propos de particularités sémiologiques mal connues des carences en vitamine B12.

INTRODUCTION: Hemolysis and red cell fragmentation accompanying vitamin B12 deficiency may misdirect the diagnosis. Signs of malabsorption and abnormalities related to folic acid metabolism characterized by discrepancies between folic acid normal serum levels and erythrocytic folic acid levels may also exist. EXEGESIS: We report the occurrence of hemolysis and red cell fragmentation mimicking microangiopathic hemolytic anemia, malabsorption and folic acid deficiency in the course of vitamin B12 deficiency. Appropriate replacement therapy corrected all abnormalities. CONCLUSION: An association between hemolysis, malabsorption and folic acid deficiency should lead physicians to search for signs of vitamin B12 deficiency.

Successful cryopreservation of purified autologous CD34+ cells: influence of freezing parameters on cell recovery and engraftment.

Conventional hematopoietic stem cell cryopreservation methods use a DMSO concentration of 10%. However, cells manipulated ex vivo may require more refined freezing protocols adapted to the specific cell suspension. In this retrospective study, we evaluated the results obtained with CD34+ cells purified from peripheral blood of 39 patients on the CEPRATE SC System and frozen in 7.5% DMSO with a view to transplantation. The post-freezing recovery of progenitor cells was 89.4 +/- 27.87% for CD34+ cells, 59.13 +/- 36.93% for CFU-GM, and 53.49 +/- 40.71 for BFU-E. Neither the purity of the suspension nor the nucleated cell density during freezing was predictive of cell recovery. No difference was observed between cells stored in vials and bags. Thirty-seven patients transplanted with the concentrated CD34+ fraction received 4.46 x 10(6) CD34+ cells/kg and 33.04 x 10(4) CFU-GM/kg. The median time to granulocyte (>0.5 x 10(9)/l) and platelet (>50 x 10(9)/l) engraftment was 11 and 13 days, respectively. Only cell density and the infused number of CD34+ cells and CFU-GM were significantly related to hematological recovery. Our data suggest that purified CD34+ cells can be successfully cryopreserved in 7.5% DMSO and may represent a first step in establishing freezing parameters for selected CD34+ cells.

Multicentric evaluation of the MDR phenotype in leukemia. French Network of the Drug Resistance Intergroup, and Drug Resistance Network of Assistance Publique-Hôpitaux de Paris.

The wide discrepancies in the frequency of 'positive' samples for multidrug resistance (MDR) phenotype within the same type of tumor observed in the literature justified the need for the definition of consensus recommendations. To define standard techniques of MDR phenotype measurement, we ran a large multicentric evaluation of the different methods available. Thirty-six French centers participated in the study, and 742 samples of 2-10 x 10(6) viable cells were sent by overnight express mail between December 1993 and February 1996. The same batches of MRK16, 4E3 and UIC2 were used. Nineteen samples of leukemia (12 AML, 1 ALL, 6 lymphoproliferative syndromes) and six leukemic cell lines with different levels of MDR expression were tested. Five meetings reached agreement concerning the guidelines for each technique, except immunocytochemistry. The 19 fresh samples were tested by each center using one to four techniques among cytofluorometry, immunocytochemistry, functional tests and RT-PCR. Five samples were diagnosed as 'negative' according to local criteria, with few discordant results (0 to 16% of 'positive' results). For all the 14 remaining samples, large discrepancies were observed from center to center, and from one technique to another. No correlations could be found between techniques. Flow cytometric analysis of cells already exposed to MRK16 or control IgG2A, fixed in paraformaldehyde and sent to centers did not reduce the discrepancies between centers in two of the four samples with moderate expression, emphasizing the role of histogram interpretation. The use of alternative monoclonal antibodies (4E3 and UIC2) did not reduce the discrepancies observed. In a second step, the K562 parental cell line, a low resistant subline (K562/HHT100, x7 resistance index to DNR) and a high resistant subline (K562/HHT300, x125 resistance index to DNR) were sent blindly three times, with an increasing level of recommendations for flow cytometry. Dramatic improvements were observed in cytometric results when the result was expressed as the ratio of arithmetic mean of fluorescence of antibody (10 microg of MRK16)/arithmetic mean of fluorescence of control (10 microg IgG2A): the proportion of expected results increased from 61 to 100% for K562, and from 37 to 85% for K562/HHT100. For uptake and drug efflux measurements, the use of 1 h uptake of 0.1 microM of rhodamine, followed by 1 h efflux +/-10 microM of verapamil, permitted an increased reproducibility of the technique from 71 to 100% for K562 and K562/HHT100. Whatever the technique used, concordant results were obtained for K562/HHT300. The immunocytochemistry, using several antibodies (MRK16, JSB1 and C219) gave many non-interpretable results (44%), due to a frequent high background and discordant results between antibodies in the same centers, and discordant conclusions between centers. The group does not recommend this technique for circulating tumoral cells.

A new c-kit mutation in a case of aggressive mast cell disease.

Systemic mast cell disease (SMCD) is a disorder characterized by a mast cell proliferation in various tissues. Mast cells express the c-kit proto-oncogene. A few cases of c-kit mutations have been described in SMCD. We report an aggressive SMCD in a patient who presented with a bone marrow infiltration by abnormal mast cells. Molecular studies of mast cell DNA and RNA revealed a new c-kit heterozygous mutation (Asp820Gly). This mutation leads to a drastic amino-acid change and is located close to the highly oncogenic Asp816Val. These findings suggest that the Asp820Gly has a potential role in c-kit activation.

[Detection of circulating epithelial cells in prostate cancer]. / Détection des cellules épithéliales circulantes dans le cancer de la prostate.

INTRODUCTION: The prostate cancer, which is the second cause of cancer, is in constant increase. This is linked to the ageing of population which is in fact a medical and socioeconomic problem. The curative therapeutic attitude of the localized prostate cancer are either wath-full waiting, radiotherapy or radical prostatectomy. With the actual clinical and radiological techniques of stadification, 40% of the localized prostate cancer are extraglandular on the prostatectomy specimen. Recently, the RT-PCR seems to be a more specific and sensitive technique to detect circulating epithelial cells compared to others techniques (immunocytochemistry or flow cytometry). The detection of these circulating cells, would be correlated to the anatomopathologic stage. The use of RT-PCR as a tool of molecular stadification should be considered. METHODS: This study evaluates and compares with in vitro pattern, the different techniques of separation (ficoll, gradient, osmotic shock) and detection (immunocytochemistry, flow cytometry and RT-PCR). RESULTS: The ficoll gradient is the best technique of cellular separation preserving cellular morphology and RNA. The detection level are 1 cell LnCap per 40,000 lymphocytes cell by immunocytochemistry, 1/1000 by flow cytometry, 1/10,000 to 1/1,000,000 by RT-PCR. CONCLUSION: The RT-PCR with its low detection level and its high specificity, is the best technique of detection of epithelial circulating cells in localized stage. The advantage of immunocytochemistry is its simplicity. Its use for circulating cells caracterization can be considered for metastatic stage.

Modulation of erythrocyte potassium chloride cotransport, potassium content, and density by dietary magnesium intake in transgenic SAD mouse.

Prevention of erythrocyte dehydration is a potential therapeutic strategy for sickle cell disease. Increasing erythrocyte magnesium (Mg) could inhibit sickle cell dehydration by increasing chloride (CI) and water content and by inhibiting potassium chloride (K-CI) cotransport. In transgenic SAD 1 and (control) C57BL/6 normal mice, we investigated the effect of 2 weeks of diet with either low Mg (6 +/- 2 mg/kg body weight/d) or high Mg (1,000 +/- 20 mg/kg body weight/ d), in comparison with a diet of standard Mg (400 +/- 20 mg/ kg body weight/d). The high-Mg diet increased SAD 1 erythrocyte Mg and K contents and reduced K-CI cotransport activity, mean corpuscular hemoglobin concentration (MCHC), cell density, and reticulocyte count. SAD 1 mice treated with low-Mg diet showed a significant reduction in erythrocyte Mg and K contents and increases in K-CI cotransport, MCHC, cell density, and reticulocyte counts. In SAD 1 mice, hematocrit (Hct) and hemoglobin (Hb) decreased significantly with low Mg diet and increased significantly with high-Mg diet. The C57BL/6 controls showed significant changes only in erythrocyte Mg and K content, and K-CI cotransport activities, similar to those observed in SAD 1 mice. Thus, in the SAD 1 mouse, changes in dietary Mg modulate K-CI cotransport, modify erythrocyte dehydration, and ultimately affect Hb levels.

Combination therapy of erythropoietin, hydroxyurea, and clotrimazole in a beta thalassemic mouse: a model for human therapy.

beta thalassemia (beta thal) in DBA/2J mice is a consequence of the spontaneous and complete deletion of the beta major globin gene. Homozygous beta thal mice have clinical and biological features similar to those observed in human beta thal intermedia. Erythrocytes in human beta thal are characterized by a relative cell dehydration and reduced K+ content. The role of this erythrocyte dehydration in the reduced erythrocyte survival, which typifies the disease, has not previously been evaluated. We examined for 1 month the effects on the anemia and the erythrocyte characteristics of beta thal mice of daily treatment with either clotrimazole (CLT), an inhibitor of red blood cell (RBC) dehydration via the Gardos channel, or human recombinant erythropoietin (r-HuEPO), or hydroxyurea (HU). The use of either r-HuEPO or HU induced a significant increase in hemoglobin (Hb), hematocrit (Hct), erythrocyte K+ and a decrease in percent reticulocytes, suggesting improved erythrocyte survival. CLT alone decreased only mean corpuscular hemoglobin concentration (MCHC) and cell density and increased cell K+. Thus, though the Gardos channel plays a major role in cell dehydration of murine beta thal erythrocyte survival. Combination therapy with r-HuEPO plus HU produced no incremental benefit beyond those of single drug therapy. However, addition of CLT to r-HuEPO, to HU, or to combined r-HuEPO plus HU led to statistically significant increase in Hb, Hct, and erythrocyte K+ compared with any of the regimens without CLT. These results suggest that CLT not only inhibits erythrocyte dehydration, but also potentiates the erythropoietic and cellular survival responses to r-HuEPO and HU.

[Cytology of acute leukemia]. / Cytologie des leucémies aiguës.

Cytological analysis of peripheral blood and bone marrow films is a quick and simple method for diagnosis of acute leukemia. In association with cytochemistry techniques it allows the rapid identification and subsequent classification of most types of acute myeloid leukemias. Although morphological analysis can suggest the diagnosis of an acute lymphoblastic leukemia, it is necessary to have the corroborating evidence of immunological markers for confirmation. In addition, ultrastructural studies contribute to the identification of rare forms of acute myeloid leukemias (minimally differentiated, megakaryoblastic). Cytological studies have also proven useful for the follow-up activities of confirming complete remission and detecting relapses.

Loss of TAL-1 protein activity induces premature apoptosis of Jurkat leukemic T cells upon medium depletion.

Transcriptional activation of the tal-1 gene occurs in -30% of patients with T cell Acute Lymphoblastic Leukemia and is therefore likely to be involved in human T cell leukemogenesis. However, the TAL-1 protein functional properties involved in this process have not been assessed so far. We have derived a clonal subline of the Jurkat T cell line which produced solely a mutant truncated form of TAL-1 protein. Sequencing of genomic DNA and cDNAs showed that the only transcribed tal-1 allele of this mutant subline harbored a G nucleotide insertion at codon 270. The resulting frameshift modifies TAL-1 residues 272-278 and creates a stop at codon 279. Although the deletion of the 53 carboxy-terminal residues of the TAL-1 protein did not directly affect the TAL-1 basic helix-loop-helix domain (residues 185-243), it had drastic effects on TAL-1 functional properties, since the mutant subline exhibited a dramatic decrease of protein binding activity to the TAL-1 DNA consensus sequence. Growth curves indicated that the mutant subline exhibited premature apoptosis upon medium depletion or serum reduction when compared with the parental cells. However, no difference between Jurkat and the mutant subline was observed in etoposide- or Fas/APO-1-triggered apoptosis. Stable expression of the mutant TAL-1 protein in Jurkat cells resulted in a phenotype that was similar to that of the mutant Jurkat subline, indicating that the TAL-1 mutant protein behaved like a dominant negative mutant and that the premature apoptosis of the mutant subline upon medium depletion was the consequence of the loss of TAL-1 protein activity.

Immunophenotype of adult acute lymphoblastic leukemia, clinical parameters, and outcome: an analysis of a prospective trial including 562 tested patients (LALA87). French Group on Therapy for Adult Acute Lymphoblastic Leukemia.

The aim of the multicentric trial LALA87 was to test the efficacy of different postremission therapies in adults (15 to 60 year olds) with acute lymphoblastic leukemia (ALL). An immunologic subclassification based on surface marker expression was proposed. Among the 562 tested patients, 511 were assigned either to the B lineage (361 cases, 63%) or to the T lineage (150 cases, 26%). T-ALL were significantly associated with male sex, age less than 35 years, mediastinal mass, central nervous system involvement, high white blood cell count, and low anemia. In a univariate and multivariate analysis, T-cell leukemia had a more favorable outcome than B-cell leukemia with respective median disease-free survivals (DFSs) of 28 and 14 months (P < .005). However, the type of postremission therapy modifies the value of the immunophenotype prognostic factor. In the chemotherapy arm, T-ALL patients (26 patients) had a more favorable outcome than B-ALL patients (57 patients) (P < .003). In the autologous bone marrow transplantation (ABMT) arm, the apparent better outcome of T-ALL patients (35 T/50 B) did not reach statistical significance (P = .2) and there was no difference in the allogeneic bone marrow transplantation (alloBMT) arm (37 T/71 B: P = .9). In the B-cell-lineage leukemias, subclassification by stages and myeloid antigen coexpression (10%) were not associated with different prognosis. CD10+ T-ALL (31 patients) were associated with a better DFS compared with the CD10- T-ALL (73 patients) with respective median DFS, not reached and 18.5 months (P = .04).

An expert system for the interpretation of flow cytometric immunophenotyping data.

The development of high-grade non-Hodgkin's lymphomas in HIV-positive patients and patients with acquired immune deficiency syndrome (AIDS) is a well known phenomenon. The proper classification of these neoplasms often requires a multiparameter approach, including the interpretation of a large panel of immunologic markers analyzed by flow cytometry. The availability of individuals with the required expertise to properly interpret these marker studies is limited. For this reason, we have designed an expert system to automate the analysis of immunophenotyping panels in both HIV-related and non-HIV-related hematopoietic neoplasms. The expert system, which we call "Professor Fidelio", runs on IBM-compatible computers under Windows 3.0. The system is designed to accept any number of markers studied from a repertoire of 35 markers. Professor Fidelio functions on the basis of heuristic classification of defined diagnostic patterns. Nine specific patterns (Stem Cell, Myeloid and/or Monocytic, Erythroid, Megakaryocytic, Immature B-cell, Immature T-cell, Mature B-cell, Mature T-cell, and Plasma cell) and one "non-specific" pattern have been agreed upon. Fidelio's knowledge base contains the definitions of each of these patterns and the heuristics for excluding patterns when an incomplete panel of markers is performed. The inference engine interprets the findings (including the age of the patient) and reports the patterns which are matched, the differential diagnosis, the suggested diagnosis from the list of differentials if the marker studies are specific, and recommendations for additional tests which may be valuable in establishing the diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)