Post-remission intervention with alemtuzumab or rituximab to eradicate minimal residual disease in chronic lymphocytic leukemia: where do we stand?

The introduction of purine nucleoside analogs, later in combination with alkylating moieties and anti-CD20 immunotherapy, has profoundly improved the response rate and response duration in patients with chronic lymphocytic leukemia (CLL). The quality of clinical response following treatment may be improved to a level where residual leukemic cells become undetectable. As patients with this type of response appear to have extended survival rates, minimal residual disease (MRD) eradication is considered a new objective in CLL treatment with the aim of improving progression-free survival (PFS) and potentially overall survival (OS). This review therefore aims to overview the prognostic value of MRD eradication in CLL, the role of post-remission intervention with "passive" immunotherapy (alemtuzumab or rituximab) so as to eliminate persistent MRD or prevent MRD relapse, the impact of these strategies on disease-free survival and their possible adverse consequences. The data indicate a potential for post-remission alemtuzumab or rituximab to prolong PFS in CLL, although more investigations and longer follow-up are required before MRD-guided strategies can be recommended outside of clinical trials

Evaluation of paroxysmal nocturnal hemoglobinuria screening by flow cytometry through multicentric interlaboratory comparison in four countries.

OBJECTIVES: Paroxysmal nocturnal hemoglobinuria (PNH) is currently diagnosed by flow cytometry; although highly sensitive, its interpretation and reporting appear as critical as its technique. Thus, we developed a quality control scheme for the French-speaking region based on the international recommendations for PNH screening. METHODS: After a topical workshop, we proposed a 1-year, two-step survey program to any volunteering French-speaking clinical laboratory. The first survey consisted of sending raw data files to evaluate gating and the interpretation strategy of each center. The second stipulated sending fresh whole-blood samples to evaluate the whole process and its practice. RESULTS: Forty-nine participants from voluntary centers returned results for each of the two successive surveys. On virtual survey, 27% reported false-positive PNH created by immature granulocytes, whereas the minor PNH clone was not detected by 9%. On fresh survey, 63% of centers used at least the same six-color combination (CD24, CD14, CD33, CD15, CD45, and fluorescent aerolysin), and nearly 70% of participants were able to perform a sensitivity test less than 0.1% on neutrophils. All participants detected the major PNH clone, yet 16% returned false-positive results for the non-PNH clone case. CONCLUSIONS: We succeeded in rallying numerous French-speaking clinical laboratories for both surveys and in harmonizing the technical practice by highlighting common pitfalls

À propos d’un cas de leucémie plasmocytaire primitive à IgE

International audienceWe report here a case of primitive plasma cell leukemia with immunoglobulin (Ig) E. IgE myeloma is an exceptional variant of multiple myeloma, with a very poor prognosis. Its biological diagnosis requires specific analyzes in order to detect IgE gammopathy. Plasma cell leukemia (PCL) is also a very rare and very severe form of multiple myeloma. There are two variants: primitive PCL (pPCL) occurring de novo and secondary PCL (sPCL), evolution of a preexisting myeloma. Its diagnosis is essentially biological since it is defined by a blood plasmocytosis greater than 2 G/L or 20% of the leucocytes.Nous rapportons ici un cas de leucémie plasmocytaire primitive à immunoglobulines (Ig) E. Le myélome à IgE est une variante exceptionnelle du myélome multiple, associée à un pronostic très péjoratif. Son diagnostic biologique nécessite la réalisation d’analyses spécifiques pour la mise en évidence d’une gammapathie à IgE. La leucémie à plasmocytes (LP) est également une forme très rare et grave du myélome multiple. Il en existe deux variantes : la LP primitive (LPp) survenant de novo et la LP secondaire (LPs), évolution d’un myélome préexistant. Le diagnostic de la LP est essentiellement biologique puisqu’elle est définie par l’existence d’une plasmocytose circulante supérieure à 2 G/L ou 20 % des leucocytes

A primitive plasma cell leukemia with immunoglobulin (Ig) E

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Down-regulation of CXCR4 and CD62L in Chronic Lymphocytic Leukemia Cells Is Triggered by B-Cell Receptor Ligation and Associated with Progressive Disease

Abstract Progressive cases of B-cell chronic lymphocytic leukemia (CLL) are frequently associated with lymphadenopathy, highlighting a critical role for signals emanating from the tumor environment in the accumulation of malignant B cells. We investigated on CLL cells from 30 untreated patients the consequence of B-cell receptor (BCR) triggering on the membrane expression of CXCR4 and CD62L, two surface molecules involved in trafficking and exit of B-lymphocytes from lymph nodes. BCR stimulation promoted a strictly simultaneous down-regulation of CXCR4 and CD62L membrane expression to a variable extent. The variable BCR-dependent decrease of the two proteins was strikingly representative of the heterogeneous capacity of the CLL cells to respond to BCR engagement in a given patient. Functionally, cells down-regulating CXCR4 and CD62L in response to BCR engagement displayed a reduction in both migration toward CXCL12 and adhesion to lymphatic endothelial cells. Remarkably, the ability of CLL cells to respond to BCR ligation was correlated with unfavorable prognostic markers and short progression-free survival. In conclusion, BCR signaling promotes decrease of CXCR4 and CD62L membrane expression in progressive cases only. These results are consistent with the hypothesis that BCR-mediated signaling pathways favor accumulation of a proliferative pool within the lymph nodes of progressive CLL cases. [Cancer Res 2009;69(16):6387–95

Angiogenic factors could help us to define patients obtaining complete response with undetectable minimal residual disease in untreated CLL patients treated by FCR: results from the CLL2010FMP, a FILO study

International audienceAngiogenesis is in a constant balance between pro and anti-angiogenic factors. Neoangiogenesis, implicated in metastatic spreading is characterized in solid cancers, but fairly new in chronic lymphocytic leukemia (CLL). We hypothesize that secretion of angiogenic factors could be correlated to the pathogenesis of CLL, and therefore predict the outcome of patients. We investigated concentrations of 22 cytokines and chemokines in 137 non-del 17p B-CLL patients, treated with a fludarabine-cyclophosphamide-rituximab (FCR)-based regimen. We constructed a biomarker index defining different risk groups based on lymphocyte count, the intensity of CD20 antigen on CD19+ cells, Ang-2, and PDGF-BB plasma concentrations at diagnosis. Four groups were defined, exhibiting specific molecular signatures and correlated with progression-free survival of patients. Our results suggest that we can determine at diagnosis of non-del 17p B-CLL patients, those with a very high probability of progression-free survival, independently of IGVH mutational status and residual disease at the end of treatment

The degree of BCR and NFAT activation predicts clinical outcomes in chronic lymphocytic leukemia

International audienceAbstract B-cell antigen receptor (BCR)–mediated signaling plays a critical role in chronic lymphocytic leukemia (CLL) pathogenesis and gives an in vitro survival advantage to B cells isolated from patients with unfavorable prognostic factors. In this study, we undertook to elucidate the signaling intermediates responsible for this biologic alteration. In responding cells only, in vitro BCR engagement triggers global phosphorylation of Syk, activation of phospholipase Cγ2, and intracellular calcium mobilization, reflecting competency of BCR signaling. The calcium–calcineurin-dependent transcription factor NFAT2 is up-regulated and to some extent constitutively activated in all CLL B cells. In contrast, its DNA-binding capacity is enhanced on IgM stimulation in responding cells only. NFAT inhibition using the VIVIT peptide prevents induction of CD23 target gene and IgM-induced survival, converting responding cells to unresponsive status. At the opposite, ionomycin-induced NFAT activity allows survival of nonresponding cells. These results demonstrate that the functional heterogeneity relies on variability of protein levels establishing BCR-dependent thresholds and NFAT-dependent activation. Finally, status of the BCR-NFAT pathway for each patient reveals its relevance for CLL clinical outcome and points out to BCR-NFAT intermediates as promising functional therapeutic targets

Enhanced immune-regulatory B cells function in progressive chronic lymphocytic leukemia patients.

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