[Paediatric case report of an acquired autoimmune thrombotic thrombocytopenic purpura]. / Purpura thrombotique thrombocytopénique acquis auto-immun chez l'enfant: à propos d'1 cas.

UNLABELLED: Thrombotic thrombocytopenic purpura (TTP), when accompanied by regenerative anaemia with schizocytosis, thrombopenia and neurological manifestations, is a disease whose main characteristic is the absence of the von Willebrand factor (vWF) cleaving protease. The two types of TTP are distinguishable by the presence or absence of antiprotease inhibitors, which are, respectively, either acquired or constitutional. The acquired autoimmune form is most frequently observed in adults. OBSERVATION: An adolescent with a previous history of moderate, isolated thrombopenia first showed symptoms of TTP at the age of 14. Positive antiprotease inhibitors in combination with a degeneration of protease activity confirmed the diagnosis of acquired autoimmune TTP. A treatment consisting of daily plasma exchange led to rapid improvement; however, a failed attempt to space out plasma exchanges necessitated the introduction of 4 weekly injections of Rituximab beginning on day 40, which was successful. Indeed, since the second injection of Rituximab on day 51, the number of platelets stabilized at a normal level, thereby allowing for the complete cessation of plasma exchange. At this writing - day 89 - the patient remains in persistent remission. CONCLUSION: Given the different therapeutic and prognostic implications of the 2 types of TTP in child patients, it is mandatory to end at an accurate biological diagnosis: whereas the constitutional form is effectively treated with plasma injections, the acquired form, while initially requiring plasma exchange, often necessitates the use of immunosuppressors during acute or relapse phase. The present study concerns a paediatric case of acquired TTP treated successfully with Rituximab during an acute dependant phase.

Fine characterization of childhood and adult acute lymphoblastic leukemia (ALL) by a proB and preB surrogate light chain-specific mAb and a proposal for a new B cell ALL classification.

The expression of the surrogate light chain (psiL) - made of the lambda-like (or lambda5) and the VpreB proteins - is a B cell-specific maturation marker. Using an anti-human VpreB mAb (4G7), we recently identified in human normal bone marrows, proB and preB cells that express the psiH-psiL proB (proBCR) and the mu-psiL preB (preBCR) receptors, respectively. In the present study, FACS and biochemical analysis confirm the broad proB and preB reactivity of the 4G7 mAb that contrasts with the narrow specificity of other available anti-psiL reagents for preB cells. This mAb was used to explore intracytoplasmic and cell surface expression of the VpreB protein on a series of 92 precursor B cell ALLs (from 40 child and 52 adult patients), in combination with 24 other mAbs. The major result concerns the identification within proB (or BI) and common (or BII) ALLs, of proBCR and proBCR+ ALLs that express the VpreB in the cytoplasm or at the cell surface, respectively. The percentage of ALLs within these two VpreB sub-groups differ considerably between the ALL origin. In the pediatric series, ALLs present in the majority a proBCR+ phenotype whereas we observed a proBCR+ phenotype for adult ALLs. Based on VpreB expression, and in combination with other published data, we propose a refined classification for precursor B cell ALLs.

Detection of plasminogen activator inhibitor-1 (PAI-1) mRNA in human megakaryocytes by in situ hybridization.

Platelets have been described to contain a large proportion of the circulating plasminogen activator inhibitor type 1 (PAI-1) which is released on platelet activation. This protein could be taken up by platelets from the plasma or synthesized by megakaryocytes (MKs). Recently, PAI-1 mRNA has been detected in a human megakaryoblastic leukemia cell line (MEG-01) by the polymerase chain reaction (PCR). However, a direct-demonstration of its presence in normal human MKs is lacking. In order to prove directly the megakaryocytic origin of platelet PAI-1, the MEG-01 cell line, human bone marrow enriched in MKs, and bone marrow smears from allogeneic bone marrow transplantation donors were investigated for the presence of PAI-1 mRNA using in situ hybridization (ISH). Specimens of bone marrow were first stained with May-Grünwald Giemsa (MGG) for cell identification according to their morphology. Subsequently, the same slides were used for ISH. PAI-1 mRNA was clearly demonstrated in the MEG-01 cell line and in MKs, and its presence correlated with the detection of PAI-1 antigen by immunocytochemistry. PAI-1 mRNA was also detected in morphologically characterized mature granulocytes of marrow samples.

Activation of plasminogen activator inhibitor-1 synthesis by phorbol esters in human promyelocyte HL-60--roles of PCKbeta and MAPK p42.

HL-60 cells treated by PMA develop the monocyte adherent phenotype and synthesize plasminogen activator inhibitor type-1 (PAI-1). We focused our study on the identification of the PMA-activated protein kinase C (PKC) isoform and its downstream transduction pathway activating PAI-1 synthesis. Acquisition of the monocytic phenotype was evidenced by cell adherence (90-95%) and a sharp increase of CD 36 and receptor for urokinase plasminogen activator (uPAR) surface expression. Ro 31-8220, a specific inhibitor of PKC, prevented PMA-induced PAI-1 synthesis (mRNA and protein levels) and cell adhesion. To identify the PKC isoform, we took advantage of the HL-525 cell line, an HL-60 cell variant deficient in PKCbeta gene expression. This defect prevents PMA to induce the differentiation process. HL-525 stimulated by PMA did not synthesize PAI-1 nor become adherent. However, in HL-525 cells either pretreated by retinoic acid that reinduces PKCbeta gene expression or transfected with PKCbeta cDNA, PMA significantly activated PAI-1 synthesis and adhesion of cells. Immunoblotting of active Mitogen Activated Protein Kinase (MAPK) p42/p44 in HL-60 cells showed a preferential and sustained activation of the p42 isoform by PMA over the p44 isoform. Ro 31-8220 significantly attenuated this activation. PD 098059 and U0126, both highly specific MEK inhibitors, efficiently prevented PMA-induced PAI-1 synthesis (mRNA and protein levels) and cell adhesion whereas SB203580, a specific inhibitor of stress-activated MAPK p38, did not. Results obtained from HL-60 and HL-525 cells indicate that the PMA-activated transduction pathway of uPAR expression involves a PKC isoform other than PKCbeta. In conclusion, we propose that the pathway PKCbeta-MEK-MAPK p42 is a potential linear route for PAI-1 synthesis leading to morphological changes and adherence linked to PMA-induced differentiation in HL-60 cells.

Interleukin-2 induces chemotactic deficiency in patients with onco hematologic malignancies and autologous bone marrow transplantation.

Unusual gram positive bacteremia has been reported in non granulopenic patients receiving recombinant human interleukin-2 (IL-2) suggesting a beneficial effect of anti gram positive prophylaxis in such patients. We report here studies on granulocyte functions examined during the course of high dose IL-2 therapy (16 to 24 million IU/m2/days for 11 to 18 days) administered during a period of 35 days in 14 patients including 4 solid tumors, 5 chronic myeloid leukemias, 4 recipients of autologous bone marrow transplant (ABMT) and 1 recipient of syngeneic bone marrow transplant. Neutrophils functions were studied before IL-2 administration (d 0), after the first cycle (d 8) and after the third cycle (d 36). Nylon fiber adherence, superoxide production, random migration, phagocytosis, nitroblue tetrazolium reduction, lysozyme and elastase release were not impaired significantly throughout therapy. However N-Formyl-Methionyl-Leucyl-Phenylalanine (FMLP) stimulated chemotaxis of granulocytes, normal before therapy, was significantly impaired as early at d 8 and severely inhibited at d 36 (p less than 0.001). Three septicemia, one corynebacteria parvum septicemia and two gram-negative septicemia despite normal neutrophil counts and oxacillin or Penicillin G plus Pefloxacin prophylaxis, occurred among the 14 patients studied. Although neutrophil functions were not more depressed in transplanted patients than in the other non transplanted patients, special attention should be paid to such patients in whom delayed immune reconstitution could increase the risk of sepsis.

Clinical and biological effects of gamma interferon and the combination of gamma interferon and interleukin-2 after autologous bone marrow transplantation.

Interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) have shown synergistic immunomodulatory and anti-tumor effects in preclinical studies. The present study was designed to assess the effects of the combination of these cytokines after autologous bone marrow transplantation (ABMT). Ten patients received rIFN-gamma alone and 13 patients the combination of rIFN-gamma + rIL-2. Patients received transplants because of lymphoma (10 patients), acute leukemia (3 patients) or solid tumors (10 patients). Immunotherapy was started at a median of 67 days after ABMT. All patients received either 5 x 10(6) (8 pts) or 10 x 10(6) IU/m2 (16 pts) rIFN-gamma by subcutaneous injection 3 times weekly for 14 weeks. rIL-2 therapy consisted of 5 cycles of continuous intravenous infusion of 12 x 10(6) IU/m2/day starting 1 week after administration of rIFN-gamma. In the rIFN-gamma group, toxicity was mild and some biological changes were seen (NK/LAK activation, increase of phagocytosis and of NBT reduction). The combination of rIFN-gamma with rIL-2 did not increase the usual rIL-2 toxicity. NK/LAK cytotoxicity was strongly activated after the first cycle of rIL-2 and was maintained until the end of therapy. Granulocyte chemotaxis was defective after cycle 1 but recovered thereafter. We conclude that the administration of rIFN-gamma + rIL-2 is feasible after ABMT. Our data suggest that the combination may have prolonged the immunologic activation provided by rIL-2 and some improvement of the deleterious effects of rIL-2 on granulocyte functions was achieved. Controlled studies are warranted to assess the impact of this strategy on biological response and patient outcome.

New parameters in erythrocyte counting. Value of histograms.

In this report we rate a new, third-generation automated hematology system (Technicon Instruments H-1) that can furnish a full range of values, including erythrocyte parameters and a leukocyte differential count. Particular attention is focused on erythrocyte morphometric parameters, including measurement of cell size and hemoglobin content on a cell-by-cell basis. We assess the usefulness of new parameters derived from these measurements, such as mean corpuscular volume and red blood cell distribution width, which characterize cell size, and mean corpuscular hemoglobin concentration, and hemoglobin distribution width, which characterize cell hemoglobinization in evaluating normal and abnormal subjects. The value of these parameters in classifying anemias is assessed in our patient population that includes those with iron deficiency anemias and thalassemias, as well as other forms of anemia.

[Extreme hypogammaglobulinemia disclosing large granular lymphocytes with hepatosplenorenal infiltration]. / Hypogammaglobulinémie extrême révélant une leucémie à grands lymphocytes granuleux avec infiltration hépato-spléno-rénale.

We report a case of large granular lymphocytosis, or chronic "natural killer" lymphocytosis, a newly described entity. We were able to demonstrate the proliferative character of the disease by the finding of karyotype abnormalities. This case was remarkable for the pre-existence, for at least three years, of severe hypogammaglobulinaemia, for the very slow course of the proliferative process and for the progressive and tumoral infiltration of the spleen and liver, then kidney.

[Prognostic factors in cancer of the endometrium and therapeutic indications]. / Facteurs de pronostic dans le cancer de l'endomètre et indications thérapeutiques.

Between 1970 and 1979, 270 patients were treated at Fondation Bergonie for carcinoma of the endometrium (169, for the whole treatment). The cases were classified according to the FIGO staging system. The mean age of the patients was 62.2, with a range from 31 to 95. 62% of patients had stage I carcinoma, 16% stage II, 18% stage III and 4% stage IV. The operability rate, according to the patients ages was considered a main factor in the prognosis. The 5 years survival was 64% for stage I, 60% for stage II, 47% for stage III and 0% for stage IV. Histologic grade of the tumor and depth of myometrial invasion are also important prognosis factors; both influencing survival. This study compared with others, provides the main prognosis factors: age and operability, stage of the tumor, histologic grade, depth of myometrial invasion and pelvic and/or para-aortic lymph nodes involvement. The authors conclude by specifying the indications for treatment.

[Anemia and dysmyelopoiesis with marker chromosome and transferrin receptor anomaly]. / Anémie et dysmyélopoïèse avec chromosome marqueur et anomalie du récepteur de la transferrine.

A 64-year old man presented with microcytic hypochromic aplastic acquired anemia without iron depletion. His bone marrow was hypercellular with dyserythropoiesis and no stainable iron deposits. 59 Fe incorporation by erythroblasts was reduced, and the karyotype revealed an aneuploidy with marker chromosome. After study of transferrin receptor with specific antibody, we conclude that the receptor presents a functional defect.

Methodological aspects of minimal residual disease assessment by flow cytometry in acute lymphoblastic leukemia: A French multicenter study.

Background: Minimal residual disease (MRD) assessment provides a powerful prognostic factor for therapeutic stratification in acute lymphoblastic leukemia (ALL). Multiparameter flow cytometry (MFC) has the potential for a rapid and sensitive identification of high risk patients. Our group has previously published that MRD levels analyzed by clone specific Ig/TcR-QPCR and MFC were concordant at a sensitivity of 10-4 . Here we report the MFC methodological aspects from this multi-center experience. Methods: MRD was assessed by MFC in 1030 follow-up samples from 265 pediatric and adult patients with de novo ALL treated in the FRALLE, EORTC or GRALL clinical trials. MRD assessment as applied by the eight participating MFC laboratories is described in detail regarding cell preparation, leukemia-associated immunophenotype (LAIP) markers and data analysis. Samples were obtained from bone marrow (BM) and peripheral blood (PB). Immunostaining was performed after erythrocyte lysis or Ficoll enrichment. Results: This study confirms the applicability of MFC-based MRD assessment in 97% of patients with ALL at the 10-4 cut-off. MRD values after Ficoll enrichment and erythrocyte lysis were found comparable. Higher MRD values were obtained in BM than in PB, especially for B-lineage ALL. Conclusions: Measurement of MRD by MFC at the 10-4 cut-off is applicable within a few hours for almost all patients and using a comparable analytical strategy allows for multicenter collaborative studies. The method can be introduced in a strategy aimed at defining the risk of failure of patients with childhood or adult ALL. © 2014 Clinical Cytometry Society.

Flow cytometry and IG/TCR quantitative PCR for minimal residual disease quantitation in acute lymphoblastic leukemia: a French multicenter prospective study on behalf of the FRALLE, EORTC and GRAALL.

Minimal residual disease (MRD) quantification is widely used for therapeutic stratification in pediatric acute lymphoblastic leukemia (ALL). A robust, reproducible, sensitivity of at least 0.01% has been achieved for IG/TCR clonal rearrangements using allele-specific quantitative PCR (IG/TCR-QPCR) within the EuroMRD consortium. Whether multiparameter flow cytometry (MFC) can reach such inter-center performance in ALL MRD monitoring remains unclear. In a multicenter study, MRD was measured prospectively on 598 follow-up bone marrow samples from 102 high-risk children and 136 adult ALL patients, using IG/TCR-QPCR and 4/5 color MFC. At diagnosis, all 238 patients (100%) had at least one suitable MRD marker with 0.01% sensitivity, including 205/238 samples (86%) by using IG/TCR-QPCR and 223/238 samples (94%) by using MFC. QPCR and MFC were evaluable in 495/598 (83%) samples. Qualitative results (<0.01% or ≥0.01%) concurred in 96% of samples and overall positivity (including <0.01% and nonquantifiable positivity) was concurrent in 84%. MRD values ≥0.01% correlated highly (r(2)=0.87) and 69% clustered within half-a-log(10). QPCR and MFC can therefore be comparable if properly standardized, and are highly complementary. MFC strategies will benefit from a concerted approach, as does molecular MRD monitoring, and will contribute significantly to the achievement of 100% MRD informativity in adult and pediatric ALL.

Immunolabelling and flow cytometry as new tools to explore dysferlinopathies.

Dysferlinopathies are autosomal recessive muscular dystrophies caused by DYSF mutations, which lead to a reduced amount or a complete lack of dysferlin. One step in dysferlinopathies diagnosis consists in Western blot analysis of proteins extracted from muscle biopsy, or blood monocytes. We have taken advantage of dysferlin expression in monocytes to develop a whole blood flow cytometry (WBFC), using antibodies directed against dysferlin. Six patients were submitted to WBFC analysis and immunofluorescence analysis on monocytes. Results obtained are correlated to Western blot from monocytes and muscle biopsies. The possible usefulness of this flow cytometry analysis in routine diagnosis is presented.