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) .

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 .

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.

Mutual benefits of B-ALL and HLDA/HCDM HLDA 9th Barcelona 2010.

The B-cell panel of the ninth HLDA was applied in a multicentre fashion to cryopreserved cells from 46 patients with acute lymphoblastic leukemia. The reagents were aliquoted and shipped to volunteer participants from the French Groupe d'Etude Immunologique des Leucémies (GEIL). All samples were tested in flow cytometry, and the results collected as of the strength of labeling of the leukemic clone as negative, weak or strong.

Immune recovery after fludarabine-cyclophosphamide-rituximab treatment in B-chronic lymphocytic leukemia: implication for maintenance immunotherapy.

Thirty B-cell chronic lymphocytic leukemia patients were treated with fludarabine-cyclophosphamide-rituximab (FCR) and immune cell counts (natural killer (NK) cells, CD4, CD8, Tgammadelta and monocytes) were monitored from the end of treatment (EOT) up to 36 months (M36). Moreover, nonleukemic peripheral blood lymphocyte cytotoxicity (PBL/CTC) as well as rituximab (RTX)-dependent PBL/CTC was also measured at the initiation of therapy, EOT and M12. These parameters were correlated with post-FCR monitoring of the minimal residual disease (MRD) level in blood using a four-color flow cytometry technique.

DNA Index in childhood acute lymphoblastic leukaemia: a karyotypic method to validate the flow cytometric measurement.

The DNA index (DI) is a prognostic factor in childhood acute lymphoblastic leukemia (ALL). The accuracy of DI measurement is important for treatment stratification: hyperdiploidy with DI > or = 1.16 is predictive of favorable prognosis whereas hypodiploidy is associated with poor prognosis.

Adverse prognostic significance of CD20 expression in adults with Philadelphia chromosome-negative B-cell precursor acute lymphoblastic leukemia.

The prognostic significance of CD20 expression in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has been mostly studied in children and yielded conflicting results. In 143 adults with Philadelphia chromosome-negative BCP-ALL treated in the multicentric GRAALL 2003 trial, CD20 positivity over 20% was observed in 32% of patients. While not influencing complete remission achievement, CD20 expression was associated with a higher cumulative incidence of relapse (CIR) at 42 months (P=0.

Extended diagnostic criteria for plasmacytoid dendritic cell leukaemia.

The diagnosis of plasmacytoid dendritic cell leukaemia (pDCL) is based on the immunophenotypic profile: CD4(+) CD56(+) lineage(neg) CD45RA(+)/RO(neg) CD11c(neg) CD116(low) CD123(+) CD34(neg) CD36(+) HLA-DR(+). Several studies have reported pDCL cases that do not express this exact profile or expressing some lineage antigens that could thus be misdiagnosed. This study aimed to validate pDCL-specific markers for diagnosis by flow-cytometry or quantitative reverse transcription polymerase chain reaction on bone marrow samples.

Peripheral blood natural killer cell count is associated with clinical outcome in patients with aaIPI 2-3 diffuse large B-cell lymphoma.

Background: Lymphocytopenia is a prognostic factor in Hodgkin's disease. In diffuse large B-cell lymphoma (DLBCL), data are much less established, in spite of numerous reports on immune system-lymphoma interactions. This study addresses the prognostic value of blood lymphocyte subsets at diagnosis in DLBCL.

A novel PAX5-ELN fusion protein identified in B-cell acute lymphoblastic leukemia acts as a dominant negative on wild-type PAX5.

We report a novel t(7;9)(q11;p13) translocation in 2 patients with B-cell acute lymphoblastic leukemia (B-ALL). By fluorescent in situ hybridization and 3' rapid amplification of cDNA ends, we showed that the paired box domain of PAX5 was fused with the elastin (ELN) gene. After cloning the full-length cDNA of the chimeric gene, confocal microscopy of transfected NIH3T3 cells and Burkitt lymphoma cells (DG75) demonstrated that PAX5-ELN was localized in the nucleus.

HIGM syndrome caused by insertion of an AluYb8 element in exon 1 of the CD40LG gene.

A new mutation of the CD40LG gene that encodes the CD40 ligand molecule was characterized in a young patient harboring a hyper-IgM with immunodeficiency syndrome. Inactivation of CD40LG gene resulted from the insertion of an AluYb8 element in exon 1 responsible for a total deficiency of CD40 ligand expression by T lymphocytes. Maternal transmission of the X-linked mutation was confirmed by gene-specific polymerase chain reaction.

Expression of the myeloid-associated marker CD33 is not an exclusive factor for leukemic plasmacytoid dendritic cells.

A new entity of acute leukemia coexpressing CD4(+)CD56(+) markers without any other lineage-specific markers has been identified recently as arising from lymphoid-related plasmacytoid dendritic cells (pDCs). In our laboratory, cells from a patient with such CD4(+)CD56(+) lineage-negative leukemia were unexpectedly found to also express the myeloid marker CD33. To confirm the diagnosis of pDC leukemia despite the CD33 expression, we demonstrated that the leukemic cells indeed exhibited pDC phenotypic and functional properties.

Age-related phenotypic and oncogenic differences in T-cell acute lymphoblastic leukemias may reflect thymic atrophy.

Postnatal thymic involution occurs progressively throughout the first 3 decades of life. It predominantly affects T-cell receptor (TCR) alphabeta-lineage precursors, with a consequent proportional increase in multipotent thymic precursors. We show that T-acute lymphoblastic leukemias (T-ALLs) demonstrate a similar shift with age from predominantly TCR expressing to an immature (IM0/delta/gamma) stage of maturation arrest.

Chronic myeloid leukemia associated with B-cell chronic lymphocytic leukemia: evidence of two separate clones as shown by combined cell-sorting and fluorescence in situ hybridisation.

The simultaneous occurrence of Philadelphia positive chronic myeloid leukemia (Ph+ CML) and B-cell chronic lymphocytic leukemia (B-CLL) is a rare event which raises the possibility that the two malignant clones derive from a common, or distinct, malignant stem cells. In this study, we used combined CD19-based cell-sorting and fluorescence in situ hybridisation (FISH) to investigate whether or not the BCR-ABL fusion gene was present in the malignant B-cells of a patient who presented a Ph+ CML/B-CLL association. The CD19+ cells lacked the BCR-ABL rearrangement whereas all CD19-cells exhibited the fusion gene.

Clinical value of the quantitative expression of the three epitopes of CD34 in 300 cases of acute myeloid leukemia.

Background And Objectives: The various epitopes of the CD34 molecule have been classified according to their different sensitivities to enzymatic cleavage by neuraminidase, chymopapain and a glycoprotease from Pasteurella haemolytica. Although monoclonal antibodies have been developed that specifically identify these epitopes, few studies have evaluated the distribution and quantitative expression of such epitopes on leukemic blasts.

Design And Methods: We report here a prospective multicenter study in which we examined and quantified the expression of the 3 classes of CD34 on fresh leukemic blast cells from 300 cases of acute myeloid leukemia (AML).

Clinical and biologic features of CD4(+)CD56(+) malignancies.

CD4(+)CD56(+) malignancies are rare hematologic neoplasms, which were recently shown to correspond to the so-called type 2 dendritic cell (DC2) or plasmacytoid dendritic cells. This study presents the biologic and clinical features of a series of 23 such cases, selected on the minimal immunophenotypic criteria defining the DC2 leukemic counterpart, that is, coexpression of CD4 and CD56 in the absence of B, T, and myeloid lineage markers. Clinical presentation typically corresponded to cutaneous nodules associated with lymphadenopathy or spleen enlargement or both.

[Pseudo-periodic disease with hyperimmunoglobulinemia D: a never-ending story with probable prenatal onset].

Unlabelled: Diagnosis of inflammatory non-infectious diseases with a neonatal onset is often retrospective. It may lead to aggressive and iatrogenic procedures.

Patient: A 6-year-old boy was suffering, since birth, from recurrent febrile attacks including rashes, gastrointestinal manifestations and inflammatory joint involvement.

22q11 deletion in DGS/VCFS monozygotic twins with discordant phenotypes.

22q11.2 deletion is a common genetic disorder characterised by a wide spectrum of clinical manifestations. To date no simple genotype-phenotype correlation has been established.

Acute basophilic leukaemia and translocation t(X;6)(p11;q23).

We report two infants with acute basophilic leukaemia associated with a t(X;6)(p11;q23) as the sole abnormality. Morphologic evidence of basophilic lineage was provided by light and electron microscopy. Both patients also had a similar presentation on diagnosis, characterized by clinical signs consistent with a hyperhistaminaemia syndrome, i.

Minimally differentiated erythroleukaemia (AML M6 'variant'): a rare subset of AML distinct from AML M6. Groupe Français d'Hématologie Cellulaire.

We describe eight cases of erythroleukaemia distinct from FAB-AML M6, which demonstrate minimal erythroid differentiation not associated with a myeloblastic component. Three infants (including a Down's syndrome) and two adults presented with a de novo leukaemia. One case was preceded by an untreated refractory anaemia with excess of blasts and one by polycythaemia vera.

Optimization of immunohistochemical detection of P-glycoprotein in chronic lymphoid disorders.

To optimize the immunohistochemical detection of the multidrug resistance (MDR)-associated P-glycoprotein (P-gp) in chronic lymphoid disorders, the authors compared the sensitivity of three different monoclonal antibodies (MoAb) directed against P-gp (C219, JSB-1, and MRK 16) by using the APAAP technique on four tissue preparations obtained from lymphoid tumors: Cryostat sections, ModAMEX processed sections, frozen cytospin preparations, and fresh cytospin preparations. Tumor samples were obtained from patients with previously treated chronic lymphocytic leukemia (6 cases) or non-Hodgkin's malignant lymphoma (4 cases). Lymph nodes (n = 9), spleen (n = 3), and blood (n = 5) were analyzed.

De novo acute leukemia with a sole 5q-: morphological, immunological, and clinical correlations.

The 5 q deletion is frequently found in myelodysplastic syndromes and acute non lymphoid leukemia, but this anomaly is usually found in secondary diseases and associated with many other chromosomal aberrations. This report describes four cases of "de novo" acute leukemia with a sole 5q- anomaly. They had no cytological, genetic or clinical characteristics of secondary disorders.

Hairy cell transformation of a B-cell chronic lymphocytic leukemia: a morphological, cytochemical, phenotypic and molecular study.

The normal counterparts of the B cells found in hairy cell leukemia (HCL) are not known. We report here a detailed morphological, cytochemical, immunological and molecular analysis of a patient with B-cell chronic lymphocytic leukemia (B-CLL) who later in the course of his disease developed hairy cell leukemia. We speculate that hairy cell transformation of B-CLL might be related to an in vivo protein kinase C mediated cellular activation of B-CLL cells.

Enhancement of ricin A chain immunotoxin activity by perhexiline on established and fresh leukemic cells.

In the perspective of increasing the clinical potential of ricin A chain immunotoxins (RTA-ITs), perhexiline (Pex) and four structural analogues (Pex 2, Pex 3, Pex 7, and Pex 11) were evaluated for their ability to enhance RTA-IT activity in vitro. Only perhexiline significantly enhanced the cytotoxic activity of anti-CD5 RTA-ITs, T101 and T101-F(ab')2, on CEM III cell line (30- to 2000-fold), and of anti-HLA-DR RTA-IT, HNC-241, on both RAJI cell line (greater than 100-fold) and two immortalized cell lines originating from patients suffering from B-cell chronic lymphocytic leukemia, EHEB and FS2 D5 (10-fold). On 16 consecutive fresh B-cell chronic lymphocytic leukemia cell samples, significant T101-F(ab')2 RTA-IT and HNC-241 RTA-IT enhancement was observed with perhexiline which was comparable to that of NH4Cl and monensin.