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IF 3.118; International audience; The assessment of minimal residual disease (MRD) in acute myeloblastic leukemia is of growing interest as a prognostic marker of patients' outcome. Multiparameter flow cytometry (MFC), tracking leukemia-associated immunophenotypic patterns, has been shown in several studies to be a useful tool to investigate MRD. Here, we report a multicenter prospective study which allowed to define a harmonized analysis strategy, as well as the efficacy of MFC MRD to predict outcome. This study included 276 patients, in 10 different MFC centers, of whom 268 had at least 1 MRD check point. The combination of a CD45, CD34, and CD33 backbone, with the addition of CD117, CD13, CD7, and CD15 in 2 five-color tubes allowed to define each patient's multiparameter immunophenotypic characteristics at diagnosis, according to a Boolean combination of gates. The same individual diagnosis gating strategy was then applied at each MRD time point for each patient. MRD levels were stratified according to log by log thresholds, from 5 × 10-2 (the classical morphological threshold to define remission) down to

The hematological reference values are very important for diagnostic orientation and treatment decision. The aim of this study was to establish hematological reference values for healthy adults in Togo. A total of 2571 voluntary blood donors participated to this study. Only 1349 subjects negative for HIV, HBV, HCV, malaria, and without hemoglobin abnormalities in electrophoresis and hypochromia on blood smear, were definitively retained for the study. Median hemoglobin level was higher in males than females (15.1 g/dL versus 13.0 g/dL, p=0.000). Median total WBC (4.2×109/L) and absolute neutrophil counts (1.6×109/L) were similar by gender. The median lymphocyte counts in males and females were, respectively, 2.1×109/L and 2.2×109/L (p=0.11). The median platelet count was lower in males than females (236×109/L versus 247×109/L, p=0.004). Our median values for RBC parameters differ from those of African countries probably because of our inclusion criteria which eliminate most cases with iron deficiency and/or thalassemia.

Resume La validation des resultats d'un hemogramme automatise suit une demarche precise qui consiste d'abord a eliminer des anomalies liees a la phase pre-analytique puis a detecter les pieges techniques lies a l'echantillon. En leur absence, toute alarme de l'automate associee ou non a une anomalie quantitative est une indication formelle a l'examen d'un frottis de sang lorsque le patient est vu pour la premiere fois afin de valider ou de modifier la formule de l'automate et de rechercher des anomalies qualitatives des differentes lignees. Dans des contextes cliniques particuliers signales par le prescripteur, l'analyse du frottis de sang peut meme etre necessaire en l'absence de ces anomalies.

Glioblastoma is a therapeutic challenge as a highly infiltrative, proliferative, and resistant tumor. Among novel therapeutic approaches, proteasome inhibition is very promising in controlling cell cycle and inducing apoptosis. This study investigated the effect of ritonavir, a protease inhibitor of the HIV and a proteasome modulator, on glioma cells. The hypothesis was that proteasome modulation, mainly by only inhibiting proteasome chymotrypsin-like activity, could be sufficient to control tumor progression. The experiments were done on a human glioblastoma-derived GL15 cell line and a rat nitrosourea-induced gliosarcoma 9L cell line. Culturing conditions included monolayer cultures, transplantations into brain slices, and transplantations into rat striata. The study demonstrates that ritonavir, by inhibiting the chymotrypsin-like activity of the proteasome, has cytostatic and cytotoxic effects on glioma cells, and can induce resistances in vitro. Ritonavir was unable to control tumor growth in vivo, likely because the therapeutic dose was not reached in the tumor in vivo. Nevertheless, ritonavir might also be beneficial, by decreasing tumor infiltration, in the reduction of the deleterious peritumor edema in glioblastoma.

BACKGROUND: This study evaluated the ability of a modified cell separator (Cobe Spectra Apheresis) system to isolate monocytes (MOs) by elutriation. The evaluation was performed in two independent international laboratories. The capacity of collected MOs to differentiate into dendritic cells (DCs) was also assessed. STUDY DESIGN AND METHODS: MNCs from platelet apheresis residues were elutriated on a modified cell separator (Cobe Spectra Apheresis system) using a custom disposable set. Cells were separated according to their size and density. Recovery and purity of the collected cell product were evaluated by impedance counting and flow cytometry. DCs were differentiated in culture from the elutriated MOs and characterized by their surface markers and stimulatory capacity in a mixed WBC reaction assay. RESULTS: Six apheresis mononuclear cell products were used by each laboratory. The separation was achieved in less than 1 hour. Collected MOs had the potential to differentiate into DCs. CONCLUSION: The modified cell separator is an easy and fast device to obtain highly enriched MOs with a DC differentiation potential. The system is closed and employs a single-use disposable set and is more amenable to good tissue practice. This method could become a valuable tool for DC-based active immunotherapy.

Objective: Polymorphonuclear cell functions frequently are impaired in critically ill patients, and restoration of normal functions could help to prevent nosocomial infections. The aim of this study was to evaluate the effects of pretreatment with granulocyte colony-stimulating factor (G-CSF) on bacterial pneumonia induced 48 hrs after peritonitis (cecal ligation and puncture [CLP]) in rats. Design: Controlled animal study. Setting: Research laboratory of an academic institution. Subjects: Male Sprague-Dawley rats. Interventions: First, the CLP model was characterized. Second, alveolar endotoxin instillation allowed us to evaluate the ability of neutrophils to migrate to airspaces after CLP was assessed. In the last set of experiments, CLP was followed by G-CSF treatment as a preventive therapy for subsequent bacterial superinfection induced by alveolar Pseudomonas aeruginosa instillation. Measurements and Main Results: CLP induced a brief increase in proinflammatory cytokines (tumor necrosis factor-α, interleukin-1β) at the 6th hr followed by a longer-lived anti-inflammatory response (interleukin-10 increase from days 1 to 3) in plasma, compared with healthy rats. Impaired neutrophil migration to alveolar spaces denoting immunoparalysis was evidenced after endotracheal endotoxin instillation following CLP, compared with non-CLP rats challenged with endotoxin. No such impairment was found when G-CSF (100 μg/kg: glycosylated recombinant human G-CSF, Lenograstim) was given before endotoxin. G-CSF (100 μg/kg 24 and 48 hrs after CLP) given before endotracheal P. aeruginosa instillation increased bacterial clearance, as shown by P. aeruginosa counts in both bronchoalveolar lavage (8.9 x 10 3 ± 2.8 x 10 3 colony-forming units/mL vs. 3.3 x 10 4 ± 1.5 x 104 colony-forming units/mL with saline) and lung tissue (4.2 x 105 ± 1.0 x 105 colony-forming units/g vs. 1.5 x 10 6 ± 0.6 x 10 6 colony-forming units/g with saline). Furthermore, G-CSF pretreatment kept P. aeruginosa clearance in CLP rats similar to that in non-CLP rats challenged with P. aeruginosa. Conclusion: These results suggest that G-CSF (Lenograstim) may enhance host defenses in rats with peritonitis and immunoparalysis.

OBJECTIVE Granulocyte colony-stimulating factor is widely prescribed to hasten recovery from cancer chemotherapy-induced neutropenia and has been reported to induce pulmonary toxicity. However, circumstances and mechanisms of this toxicity remain poorly known. DESIGN To reproduce a routine situation in cancer patients receiving chemotherapy, we investigated the mechanisms underlying granulocyte colony-stimulating factor-induced exacerbation of alpha-naphthylthiourea-related pulmonary edema. SETTING Laboratory research unit. SUBJECTS Male specific-pathogen-free Sprague-Dawley rats. INTERVENTIONS The effects of granulocyte colony-stimulating factor given alone or after alpha-naphthylthiourea used to induce acute lung injury were investigated. MEASUREMENTS AND MAIN RESULTS Lung injury was assessed based on neutrophil sequestration (myeloperoxidase activity in lung tissue) and influx into alveolar spaces (bronchoalveolar lavage fluid cell quantification) and on edema formation (wet/dry lung weight ratio) and alveolar protein concentration into bronchoalveolar lavage fluid. Tumor necrosis factor-alpha and interleukin-1beta were measured in serum, lung homogenates, and isolated alveolar macrophage supernatants. In control rats, granulocyte colony-stimulating factor (25 microg/kg) significantly elevated circulating neutrophil counts without producing alveolar recruitment or pulmonary edema. alpha-Naphthylthiourea significantly increased the wet/dry lung weight ratio (4.68 +/- 0.04 vs. 4.38 +/- 0.07 in controls, p=.04) and induced alveolar protein leakage. Adding granulocyte colony-stimulating factor to alpha-naphthylthiourea exacerbated pulmonary edema, causing neutrophil sequestration in pulmonary vessels, significantly increasing lung myeloperoxidase activity (12.7 +/- 2.0 mOD/min/g vs. 1.1 +/- 0.4 mOD/min/g with alpha-naphthylthiourea alone; p

The tal-1 gene encodes a basic helix-loop-helix (bHLH) transcription factor required for primitive and definitive hematopoiesis. Additionally, ectopic activation of thetal-1 gene during T lymphopoiesis occurs in numerous cases of human T-cell acute lymphoblastic leukemia. With the use of transgenic mice, we show that, in adult hematopoiesis, constitutive expression of TAL-1 protein causes disorders in the hematopoietic lineages that normally switch off tal-1 gene expression during their differentiation process. Myelopoiesis was characterized by a moderate increase of myeloid precursors and by Sca-1 antigen persistence. Although no lymphoid leukemia was observed, T lymphopoiesis and B lymphopoiesis were severely impaired. Transgenic mice showed reduced thymic cellularity together with a decrease in double-positive cells and a concurrent increase in the single-positive population. B cells exhibited a differentiation defect characterized by a reduction of the B-cell compartment most likely because of a differentiation block upstream of the intermediate pro-B progenitor. B cells escaping this defect developed normally, but transgenic splenocytes presented a defect in immunoglobulin class switch recombination. Altogether, these results enlighten the fine-tuning of TAL-1 expression during adult hematopoiesis and indicate why TAL-1 expression has to be switched off in the lymphoid lineages.

Myelodysplastic syndromes (MDSs) are heterogeneous diseases of bone marrow (BM) cell precursors for which immunophenotypic characterization is still considered irrelevant despite the accuracy and sensitivity of flow cytometry techniques. The aim of this study was to determine whether immunophenotypic abnormalities could be defined In MDSs and could correlate with the French-American-British classification and cytogenetics. Analysis was performed on 275 BM samples (207 MDS patients, 68 controls) and 25 control blood samples. immunophenotyping was based on a primary gating of blast cells, monocytes, and granulocytes according to CD45 antigen expression and side scatter light diffraction. Immunophenotypic hierarchical clustering was performed to analyze the results, The data obtained show that (1) immunophenotypic clustering partly discriminates patients with refractory anemia with excess blasts/refractory anemia with excess blasts in transformation (RAEB/RAEB-T), chronic myelomonocytic leukemia (CMML), and refractory anemia/refractory anemia with ring sideroblasts (RA/RARS) for CD45(lo) blast cells and patients with RA/CMML, RARS, and RAEB/RAEB-T for CD45(hi)/side scafter(hi) (SShi) granulocytes; (2) the most discriminating markers were CD16, CD34, CD36, CD38, CD71, and HLA-DR for blast cells and CD11b, CD13, CD33, CD36, CD38, CD71, and HLA-DR for CD45(hi)/SShi granulocytes; (3) clusters related to CD34 expression were associated with high levels of blast cells on BM smear; (4) clusters related to high levels of CD36 expression on CD45(lo) blast cells and CID45(hi)/SShi granulocytes were associated with a poor International Prognosis Scoring System score; and (5) high levels of CD71 expression on CD45(hi)/SShi granulocytes were associated with the RARS category. These results show a close relationship between Immunophenotypic abnormalities and BM dysplasia and suggest that flow cytometry could be a future tool for the characterization of MDSs. (C) 2002 by The American Society of Hematology.

Resume L'immunophenotypage est devenu un examen indispensable au diagnostic des leucemies aigues lymphoides comme myeloides. L'introduction du marqueur du CD45 permet une meilleure individualisation des populations cellulaires et une precision accrue du fenetrage des blastes. Le phenotype immunologique des LA permet de definir plusieurs sous-groupes, dont certains sont correles a des anomalies cytogenetiques et/ou moleculaires. Il identifie certaines formes rares de LA. Le phenotypage systematique des LA a egalement pour interet de detecter des phenotypes blastiques aberrants, qui pourront servir au suivi de la maladie residuelle par cytometrie en flux.

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. Secondary graft failure, the occurrence of pancytopenia after initial engraftment of an allogeneic transplant, is often a diagnostic problem. Recipients of T cell-depleted marrow may be particularly at risk for graft failure (1, 2), but it may be seen in recipients of unmodified, HLA-identical or nonidentical, marrow (3, 4). Immunologically mediated graft rejection, secondary lack of sustained marrow engraftment, and relapse of the underlying disease are the main diagnoses to be considered in this situation. Chimerism analysis is necessary to distinguish among these possibilities, if relapse is not apparent in marrow morphology. In some cases, the detection of residual host cells by chimerism analysis may represent a small number of malignant host cells not evident on marrow slides (5, 6). In other cases, the detection of residual host cells suggests either graft rejection (7) or a state of long-term stable mixed chimerism (8). To distinguish between these possibilities, the degree and evolution of mixed chimerism, determined by serial analysis over time, may be helpful. In contrast, the persistence of complete donor chimerism favors secondary lack of engraftment, as a result of infection (especially cytomegalovirus), the toxic effect of drugs, or graft-versus-host disease (GVHD) (9, 10). The sensitivity of detection of recipient cells is the essential parameter of chimerism analysis in this setting (11). A minority population of recipient cells could be undetected against a background of donor cells if an insensitive process is used. The suitable process of chimerism analysis must be applicable to the small number of cells that can be collected from hypocellular blood or marrow at the time of graft failure. Our objective was to study cases of secondary graft failure with a sensitive method of chimerism analysis. We retrospectively studied six patients, in whom previous analysis had shown complete donor chimerism using standard polymerase chain reaction (PCR) amplification of variable number of tandem repeat (VNTR) sequences. In order to detect a minority population of recipient cells, we sought to increase the sensitivity of the process by using fluorescent primers and automated GeneScan analysis of PCR products. In five patients, we applied this method separately to lymphocytic T-, B-, and natural killer (NK) cell subpopulations, sorted at the time of graft failure. We also examined the potential etiologies of graft failure and the impact of therapy on achieving subsequent engraftment.

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)

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 × 106/kg unmanipulated CD34+ cells (control group, n = 4) or cells cultured from 2 × 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 × 109/l) and neutrophil (> 0·5 × 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 × 109/l) on day 9 (range 7–12) compared with day 13 (range 11–15) in the control group (P

Resume La possibilite de prelever les progeniteurs hematopoietiques du sang circulant, de les mobiliser apres administration de chimiotherapie et/ou de facteurs de croissance associee a la generalisation des cytokines recombinantes a modifie depuis une dizaine d'annees les techniques de greffe de moelle osseuse. Qu'il s'agisse d'auto ou d'allogreffes, les cytphereses pratiquees apres un traitement de mobilisation sont de plus en plus utilisees comme greffon aux depens des prelevements medullaires. De nombreuses equipes ont montre que la reconstitution hematologique etait plus rapide qu'avec les greffons medullaires, reduisant ainsi la periode d'applasie medullaire et par consequent les temps d'hospitalisation et les couts de la greffe. La selection positive des cellules CD34 + offre des possibilites de purge soit des cellules tumorales contaminantes dans le autogreffes, soit des lymphocytes T afin de minimiser le risque de reaction du greffon contre l'hote dans les allogreffes. La selection positive est le point de depart d'autres axes de recherche en therapie cellulaire: expansion ex vivo, obtention de cellules differenciees, amplification de cellules immuno-competentes, therapie genique.

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.

Dense, dehydrated red blood cells (DRBCs) are a characteristic feature of sickle-cell disease (SCD). DRBCs play a role in the pathophysiology of SCD acute and chronic organ damage because of heightened tendency to undergo polymerization and sickling because of their higher hemoglobin S concentration. Relations between red cell density (assessed with phthalate density-distribution profile method) and several hematologic, biochemical, genetic parameters, and clinical manifestations were studied in a large cohort of homozygous patients. The percentage of DRBCs was significantly higher in patients who experienced skin ulcers, priapism, or renal dysfunction. Presence of α-thalassemia deletions was associated with fewer DRBCs. A multivariable analysis model showed DRBCs to be positively associated with hemolytic parameters such as lactate dehydrogenase and bilirubin and negatively with fetal hemoglobin. The percentage of DRBCs decreased by 34% at 6 months of hydroxycarbamide (xydroxyurea) therapy. Thus, DRBCs are associated with specific clinical manifestations and biologic markers and may be a useful addition to the biologic and clinical evaluation of patients with SCD, because they can easily be measured in a hematocrit tube.

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).

Hydroxyurea-derived clinical and biological benefits and safety were retrospectively studied for 123 adult patients from 2 sickle cell disease referral centers during a total follow-up of 654 patient-years and total hydroxyurea exposure of 549 patient-years. Fifty-six adverse events occurred (incidence: 12%/patient-year), with leg ulcers being the most frequent. Adverse events could arise at any time and were usually reversible. No malignancy was observed. Clinical and biological benefits of our cohort were similar to those previously reported. Based on this relatively long retrospective study, the risk/benefit ratio for moderate hydroxyurea doses was satisfactory.

Background: Tacrolimus and cyclosporin inhibits the activity of calcineurin, a serine/threonine phosphatase that is involved in many physiological and pathological pathways. However, the baseline calcineurin phosphatase activity (CPA) measured before the transplant is unknown. In this study, we determine baseline CPA in liver transplant (LT) candidates and explore some factors that might modify it. Patients and methods: Thirty-two consecutive LT candidates (25 men, seven women, average age 53.4 years) were included. Seven millilitres of whole blood was collected from each patient. CPA was determined in lymphocytes quantifying a dephosphorylated peptide phosphorylated previously (D-L-D-V-P-I-P-G-R-F-D-R-R-V-S-V-A-A-E) by high-performance liquid chromatography. The relationship between CPA and the quantitative variables was tested according to Pearson's correlation. A two-way analysis of variance was performed to test the independent role of categorical parameters in CPA. Results: The median CPA was significantly lower in LT candidates than in healthy volunteers [179.2 (146.9–226.3) vs 247.8 (220.9–292.5) pmol/min/106 peripheral blood mononuclear cell (PBMC), respectively, P=0.0002]. CPA was also significantly lower in alcoholic cirrhosis (152.2 vs 211.1 pmol/min/106 PBMC, P=0.04) and in the presence of hepatocellular carcinoma (HCC) (152.0 vs 213.5 pmol/min/106 PBMC, P=0.0074) compared with other liver diseases. A two-way analysis of variance showed that these parameters were independently associated with lower CPA (P=0.05 for alcohol and P=0.0056 for HCC respectively). Conclusion: This pilot study showed a lower CPA in patients with AC and HCC. This phenomenon may contribute towards lowering the risk of acute rejection in these patients after LT and, on the other hand, may increase the risk of de novo cancers.

During the early post-transplantation period, the limitations of monitoring current tacrolimus dose with classic pharmacokinetics (PK) have been demonstrated in liver-transplant recipients. Evaluation of the pharmacodynamics (PD) using calcineurin activity (CNA) has been proposed to optimize tacrolimus dosing. The aim of the present study was to determine the time of maximal inhibition of CNA, to explore the relation between exposure to tacrolimus and CNA, and to analyze its variability. Blood was drawn from 14 patients 0, 2, 3, 4, 6, and 9 hours after tacrolimus intake on post-transplantation days 8, 21, and 90 to measure blood tacrolimus concentrations using the EMIT 2000 assay and CNA in peripheral blood mononuclear cells. Tacrolimus and CNA data were obtained for 33 blood-sample collection sessions and analyzed using a population approach. Three models were built to describe tacrolimus PK, CNA kinetics, and the relationships between the area under the CNA-time curve (AUC12effCNA) and AUC12Tacrolimus or CminTacrolimus. Coagulation factor V and whole/split liver graft were identified as covariates influencing tacrolimus clearance. Indeed, apparent tacrolimus clearance rose by 14% when factor V increased by 10% and was threefold higher in patients with whole-liver grafts. The median maximal inhibition of CNA was reached 4 hours after tacrolimus intake on days 8, 21, and 90 and represented an 18% drop in CNA compared with activity at drug intake. The variability of the PK-PD relationship was minimal when using AUC12Tacrolimus. The large variability of the PD parameters (coefficient of variation was 89%) that linked AUC12effCNA to AUC12Tacrolimus indicates that monitoring tacrolimus concentrations may not be adequate to control CNA. Measuring CNA in peripheral blood mononuclear cells 4 hours after tacrolimus intake during the first 3 months after liver transplantation could be a means to improve tacrolimus monitoring and thereby avoid acute graft-rejection episodes.

In Drosophila, the RING finger protein d-Goliath was originally identified as a transcription factor involved in the embryo mesoderm formation [Bouchard, M.L., Cote, S., 1993. The Drosophila melanogaster developmental gene g1 encodes a variant zinc-finger-motif protein. Gene 125, 205-209]. In mouse, the m-Goliath mRNA level was shown to be increased in growth factor withdrawal-induced apoptosis of myeloid cells [Baker, S.J., Reddy, E.P., 2000. Cloning of murine G1RP, a novel gene related to Drosophila melanogaster g1. Gene 248, 33-40]. Due to its putative function of transcription factor in apoptosis, we cloned the human cDNA for h-Goliath and characterized the expression of the protein in blood and bone marrow cells. The human protein of 419 aa (44 kDa) contains a protease-associated domain, a transmembrane domain and a RING-H2 motif. This structure classifies h-Goliath as a new member of a human family of ubiquitin ligases with GRAIL (gene related to anergy in lymphocytes) as founder. This E3 ligase controls the development of T cell clonal anergy by ubiquitination [Anandasabapathy, N., Ford, G.S., Bloom, D., Holness, C., Paragas, V., Seroogy, C., Skrenta, H., Hollenhorst, M., Fathman, C.G., Soares, L., 2003. GRAIL: an E3 ubiquitin ligase that inhibits cytokine gene transcription is expressed in anergic CD4+ T cells. Immunity 18, 535-547]. In vitro ubiquitination studies support the E3 ubiquitin ligase activity of h-Goliath. In human, the protein is expressed under 3 isoforms, a major one at 28 kDa and two others at 46 and 55 kDa. These proteins come from a common precursor (44 kDa) as we observed using in vitro transcription-translation. Using immunohistochemistry on blood or bone marrow smears, of healthy or leukemia samples, we found that the protein expression was restricted to the cytoplasm of progenitors and fully differentiated leukocyte populations. We did not observe any modification of h-Goliath expression or localization in leukemia. In these cells, this new E3 ubiquitin ligase protein does not seem associated with a differentiation state of the cell or with apoptosis.

International audience; Erythropoietic protoporphyria is an inherited disorder of heme biosynthesis caused by partial ferrochelatase deficiency, resulting in protoporphyrin (PP) overproduction by erythrocytes. In humans, it is responsible for painful skin photosensitivity and, occasionally, liver failure due to accumulation of PP in the liver. The ferrochelatase deficiency mouse mutation is the best animal model available for human erythropoietic protoporphyria. The original description, based on mice with a BALB/cByJCrl genetic background, reported a disease resembling the severe form of the human disease, with anemia, jaundice, and liver failure. Using congenic strains, we investigated the effect of genetic background on the severity of the phenotype. Compared with BALB/cByJCrl, C57BL/6JCrl mice developed moderate but increasing anemia and intense liver accumulation of PP with severe hepatocyte damage and loss. Bile excretory function was not affected, and bilirubin remained low. Despite the highest PP concentration in erythrocytes, anemia was mild and there were few PP deposits in the liver in SJL/JOrlCrl homozygotes. Discriminant analysis using six hematologic and biochemical parameters showed that homozygotes of the three genetic backgrounds could be clustered in three well-separated groups. These three congenic strains provide strong evidence for independent genetic control of bone marrow contribution of PP overproduction to development of liver disease and biliary PP excretion. They provide a tool to investigate the physiological mechanisms involved in these phenotypic differences and to identify modifying genes.

Mutations of the AML1 gene are frequent molecular abnormalities in minimally differentiated acute myeloblastic leukemia (M0 AML), a rare type of AML. In this retrospective multicenter study, morphologic, immunophenotypical, cytogenetic, and molecular features of 59 de novo M0 AML cases were analyzed and correlated to AML1 mutations. Point mutations of AML1 gene were observed in 16 cases (27%). They were correlated with higher white blood cell (WBC) count (P =.001), greater marrow blast involvement (P =.03), higher incidence of immunoglobulin H/T-cell receptor (IgH/TCR) gene rearrangement (P

Methionine depletion in the human cell line CCRF-CEM through the action of recombinant methioninase (rMETase), a methionine-cleaving enzyme, was previously demonstrated to produce a strong cytotoxic synergistic effect with fluorouracil (FUra) throughout a broad range of concentrations of FUra and rMETase, including subcytotoxic levels of rMETase. Potentiation was associated with a decrease in free thymidylate synthase from preexisting levels. To further investigate the action of rMETase on CCRF-CEM cells, in the present study we explored the effects of rMETase as a single agent on DNA methylation levels and DNA synthesis, which may be changed as a result of deprivation of methionine. Cells treated with rMETase under subcytotoxic conditions contained significantly lower levels of genomic methylated DNA than did control cells, as demonstrated by incorporation of the methyl radical of [methyl-(3)H]S-adenosylmethionine in DNA and by use of methylation-sensitive arbitrarily primed PCR. DNA hypomethylation produced by rMETase was of similar magnitude as that produced with the DNA methyltransferase inhibitor 5-azacytidine. Cells exposed to rMETase synthesized significantly more DNA than did untreated cells. Incorporation of [6-3H]thymidine and [6-3H]2'-deoxyuridine in these cells was augmented over that in control by mean factors of 1.78 and 2.36, respectively. Increased 3H nucleoside incorporation resulted in greater numbers of nuclear grains as demonstrated by autoradiography. The increase in DNA synthesis induced by rMETase is likely to result from enhancement of DNA repair because it was not accompanied by differences in cell cycle phase distribution or in total DNA content as determined by flow cytometry. We hypothesize that potentiation of FUra cytotoxicity by rMETase may result from increased inhibition of thymidylate synthase, together with DNA hypomethylation and enhanced DNA repair that could be involved in cell responses to drug-induced damage.

The reciprocal t(4;11)(q21;q23) is often described in acute lymphoblastic leukemia (ALL). In some cases, variant or complex t(4;11) has been detected in ALL by cytogenetic analysis, but to our knowledge no molecular study has been reported in these variant translocations. We describe a 27-year-old woman suffering from pre–B-cell ALL with an unusual rearrangement between chromosomes 4 and 11. Because this complex rearrangement involved the 11q23 chromosome band known to be associated with poor prognosis, we performed fluorescence in situ hybridization, Southern blot, and reverse transcription polymerase chain reaction analyses. This confirmed myeloid lymphoid leukemia gene rearrangement and showed the presence of MLL/AF4 fusion transcript. These results showed the importance of molecular analysis that allowed minimal residual disease monitoring in this patient.

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% O2) 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.

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.

Acute myeloid leukemias (AML) represent a vast and complex group of diseases where numerous molecular lesions have been and keep being described. From the immunophenotypic point of view, probably because of the variety of cells in the myeloid lineage, a rather large variety also exists. The detection of minimal residual disease (MRD) in such conditions therefore meets the challenge of tracking the proper anomaly and correctly separate leukemic cells from their normal counterparts. In an oligocentric project initiated in France in late 2006, ten cytometry platforms and six molecular biology laboratories collaborated to detect MRD concomitantly in flow and with molecular techniques. The flow cytometry part of this work is reported here. A total of 307 consecutive patients were tested at diagnosis with a comprehensive common panel allowing for the detection of immature markers and potential leukemia-associated immunophenotypic patterns. Follow-up samples were planned to be obtained after induction and at the end of treatment, with an optional control before the second consolidation. In fine, 274 patients had at least one point of follow up. All samples were tested in a technique of whole bone marrow lysis no wash, avoiding any cell loss. The flow cytometry panel comprised ten five-colors tubes, all containing CD45 as gating marker. A newly developed strategy was devised to analyse MRD data. The approach of the GTLLF (Arnoulet, Cytometry part B, 2011) was first applied to properly identify mature polymorphonuclears, monocytes and lymphocytes, allowing for a negative Boolean selection of immature cells in the region dubbed “bermudes” by this group. Focusing on this area, each combination of the four markers tested together with CD45 was then displayed in a total of six biparametric histograms. For each of them, on the diagnosis sample, quadrant gates were constructed so that the lower left one contained no blast cells. A Boolean operation was then designed to exclude all these six areas, thereby combining the positive blasts present in the three other parts of each quadrant. The resulting population was visualized on a CD45/side scatter biparametric histogram to check that the cells appeared as a focused cluster at a precise position. The same strategy was then applied for each patient’s consecutive samples, always checking whether any cells identified with this protocol displayed the scattered pattern of cells engaged in maturation (no MRD) or constituted a focused population without maturation (positive MRD). The amount of MRD was then calculated taking into account as denominator the whole population of nucleated cells in the sample (excluding debris on a live gate). As internal control a specific feature of the Kaluza software was used to merge samples obtained for a given patient in order to display on the same worksheet the diagnosis and follow up samples using the principal component separation provided by the “radar” tool of this software. This original method proved to be easily applicable and provide a consistent help for MRD interpretation. All patients could be assessed for MRD with only two of the ten tubes used. These contained the following combinations : CD15, CD13, CD33, CD34, CD45 and CD7, CD117, CD33, CD34, Cd45. At diagnosis, any combination of expression of CD13, CD33, CD117 and CD34 could be observed, the percentage of positive cases for each of these antigens being respectively 86%, 89%, 81% and 58%. As a whole, 93% of the follow-up samples (MRD) tested contained less than 5% of cells with an immunophenotype comparable to that of diagnosis. This figure was 77% for less than 1% and 43% for less than 0.1%. The strategy devised for files analysis was easily applicable for all patients except those with myelomonocytic leukemia. For some of them, separation of the blasts from the monocytic compartment could be problematic in regenerating bone marrow samples. In conclusion, the flow cytometry part of this multicenter study allowed to establish that the combination of CD45 with CD13, CD33, CD117 and CD34 with the additional information provided by CD5 and CD7 represents a quasi-universal panel, now easy to implement on instruments with 8 or 10 detectors, for the detection of MRD in multiparameter in flow cytometry. Moreover, a powerful strategy of listmodes analysis was developed allowing for the direct comparison of several samples from the same patients and/or of a given sample and normal (control) bone marrow. Disclosures: No relevant conflicts of interest to declare.

2115 [][1] Introduction VOC, the most common manifestation of SCD, is the first cause of death, particularly when complicated by an acute chest syndrome (ACS) or multiorgan failure.1,2 Vichinsky et al3 found that nearly half their patients included for ACS were initially hospitalized for VOC. However, no data are available on follow-up differences between patients hospitalized for uncomplicated VOC and those who will develop ACS. We report the preliminary analytical results of blood samples drawn on days 1, 2 and 4 of hospitalization for VOC and at steady state from patients enrolled in the more comprehensive PRESEV study. Methods This prospective, monocenter, observational trial included homozygous SCD patients, ≥18 years old with severe VOC requiring admission to our university hospital's Adult Sickle-Cell Referral Center. This study was conducted in accordance with the Declaration of Helsinki principles, Good Clinical Practice guidelines, and local laws and regulations. Severe VOC was defined as pain or tenderness, affecting at least 1 part of the body, e.g. limbs, ribs, sternum, head (skull), spine and/or pelvis, that required opioids and was not attributable to other causes. ACS was defined as the association of 2 criteria among chest pain, radiologic infiltrate and auscultatory abnormality. Patients could be enrolled in the trial more than once if their hospitalizations were separated by ≥1 months. Exclusion criteria were: ACS on day of inclusion, pregnancy, hospitalization for >24 h, chronic blood-exchange transfusion (BET), transfusion impossibility, severe complication requiring transfusion at admission, proven sepsis, surgery

Some patients present borderline features between acute myeloid leukemia (AML) and typical myelodysplastic syndromes (MDS): an excess of blasts insufficient to conclusively diagnose AML, yet above the figures usually compatible with MDS or the presence of Auer rods associated with a moderate excess of blasts. This presents considerable difficulties in diagnosis and management. The authors studied 28 such cases using the French-American-British Co-operative Group (FAB) classification, which groups them into a separate category termed "refractory anemia with excess of blasts in transformation" (RAEB-T). This was found to be a heterogenous group. Certain patients (4/28) had a previously established myelodysplasia, but most presented directly as RAEB-T. Two very different pictures emerged: a few patients (4/28) were young, with presentation and evolution similar to classic AML, for whom combination chemotherapy was effective; the majority (20/28) were older, with more varied clinical and cytologic presentation, for whom chemotherapy was of little effect and who presented a picture resembling classic RAEB with a median survival of 10 months.

Fifty-seven patients in initial phase of acute promyelocytic leukemia (APL) were treated in the same department with heparin infusion, platelet transfusions, and two related induction regimens both including cytosine arabinoside and daunorubicin. Clinical and biological findings at presentation were studied. The complete remission (CR) rate was 53%. Twenty-seven patients (47%) died during the initial course of the disease, either before day 5 (early death [ED], n = 7) or after day 5 (death in aplasia [DA], n = 20). Most ED was due to intracerebral hemorrhage (6/7), especially when large hemorrhages had been seen on fundus oculi examination. Most DA was due to multivisceral failure (9/20). No correlation was found between initial disseminated intravascular coagulation (DIC) and death. However, the worsening of coagulation parameters during induction therapy, with or without initial DIC, significantly increased the occurrence of renal and respiratory failure which were particularly frequent during the first month. The median duration of survival was short (3.5 months) and the median duration of CR (11 months) was similar to that of other acute myeloid leukemias treated with the same regimens. The possible causes of the high mortality observed during the initial courses of APL and the possible benefit of a more graduate induction chemotherapy are discussed.

Twenty patients (17 women, three men) with mediastinal diffuse large-cell lymphoma with sclerosis are reported. At the time of diagnosis, the disease was confined to supradiaphragmatic areas in all patients but two, who had kidney involvement (seven were stage I, 11 were stage II, and two were stage IV). A B-cell phenotype was demonstrated in nine of the 11 cases that were analyzed for cell lineage. All patients received an anthracyclin-containing regimen followed by mantle radiotherapy. Analysis of pretreatment characteristics showed that only the extent of disease influences outcome. Moreover, achievement of complete remission (CR) after chemotherapy appears to be a major prognostic factor. Two-year survival was better in patients who reached CR after chemotherapy than in those who did not (100% versus 9%; p less than 0.0001). Overall 2-year and 7-year survival rates were 50% and 33%, respectively. Therefore, localized mediastinal large cell lymphoma with sclerosis should be considered a high-risk subtype of non-Hodgkin's lymphoma in which standard treatment approaches are unsuccessful.

Twenty-two patients with Stage III and IV follicular non-Hodgkin's lymphoma were treated for 8 months by a chemotherapy regimen alternating between two different four-drug combinations (doxorubicin, teniposide, cyclophosphamide, prednisone; vincristine, cyclophosphamide, CCNU, prednisone). The overall response rate (complete and partial remission) was 68%. The complete remission rate was 23%. Twenty patients are alive, 50% of them are free of disease progression (median follow-up 76 months). It is concluded that our chemotherapy regimen is not satisfactory and that new therapeutic approaches are needed.

SUMMARY In toxic epidermal necrolysis (TEN), as in the ‘epidermal type’ of erythema multiforme, the necrotic epidermis is infiltrated with mononuclear cells. We studied the epidermal infiltrate in seven cases of TEN. About half the cells obtained from pieces of cleaved epidermis dissociated by trypsin were non-epithelial. On cytologic analysis, 80% of these foreign cells exhibited markers of macrophages, 15% were granulocytes and only 5% were lymphocytes (almost exclusively OKT8 T lymphocytes). Semi-thin sections of early prenecrotic lesions showed exocytosis of mononuclear cells within the epidermis with features of satellite cell necrosis and formation of colloid bodies. Almost all these mononuclear cells were macrophages as evidenced by endogenous peroxidase-positive granules. These findings suggest that some kind of macrophage-mediated cytotoxicity may play a role in the necrosis of epidermal cells during TEN.

The characteristics of severe neutropenia with delayed onset following administration of rituximab were evaluated in 293 consecutively patients treated for B-cell malignancies between Oct. 1996 and Feb. 2004. Eighteen episodes of severe neutropenia were identified between 2 to 36 weeks after rituximab, delivered alone in 4 cases or combined to chemotherapy in 14 other cases. At the time of occurrence of neutropenia, 10 patients had completed treatment and were in complete remission and 8 were still on therapy. All patients had a normal neutrophil count before rituximab treatment. In 4 cases, neutropenia was complicated by fever requiring hospitalisation. Among the18 patients [diffuse large B-cell lymphoma: 12, follicular lymphoma: 3, mantle cell lymphoma: 1, post transplant lymphoproliferative disorder: 1, chronic lymphocytic leukemia (CLL): 1], 8 had previouly been treated with high-dose therapy followed by autologous stem-cell transplantation. None of the known causes of neutropenia were found. Neutropenia was associated with selective marrow depletion of neutrophil precursors in all episodes. The peripheral blood lymphocyte subset repartition was documented in 16 cases; a severe B lymphopenia was observed in all except one - patient with CLL - and CD4+ lymphopenia was seen in 13. T-cell clonality was studied in 8 cases and was positive in 5. Parvovirus B19 DNA was not detected in the 11 tested cases. Tests for antineutrophil antibodies were positive in 5 cases; no hemolytic anemia, autoimmune thrombocytopenia or large granular natural killer lymphocytosis were observed. Filgrastim was given to 4 patients only. The median time of neutrophil recovery for the entire group was 14 days (range: 2–180). The mechanism of this rare event already reported (Saikia et al. Ann. Oncol 2002, Voog et al. NEJM 2003, Chaiwatanatorn et al. BJH 2003, Lemieux et al. BMT 2004) remains to be established. Since it seems to be more frequent in patients who have received extensive prior chemotherapy (8/18), it is tempting to speculate that cumulative immunosuppression might favor the development of such an event.