The chronic lymphocytic leukemia (CLL) immunoglobulin repertoire is biased and characterized by the existence of subsets of cases with closely homologous ("stereotyped") complementarity-determining region 3 (CDR3) sequences. In the present series, 201 (21.9%) of 916 patients with CLL expressed IGHV genes that belonged to 1 of 48 different subsets of sequences with stereotyped heavy chain (H) CDR3. Twenty-six subsets comprised 3 or more sequences and were considered "confirmed." The remaining subsets comprised pairs of sequences and were considered "potential"; public database CLL sequences were found to be members of 9 of 22 "potential" subsets, thereby allowing us to consider them also "confirmed.

Appropriate cancer care requires a thorough understanding of the natural history of the disease, including the cell of origin, the pattern of clonal evolution, and the functional consequences of the mutations. Using deep sequencing of flow-sorted cell populations from patients with chronic lymphocytic leukemia (CLL), we established the presence of acquired mutations in multipotent hematopoietic progenitors. Mutations affected known lymphoid oncogenes, including BRAF, NOTCH1, and SF3B1. NFKBIE and EGR2 mutations were observed at unexpectedly high frequencies, 10.7% and 8.3% of 168 advanced-stage patients, respectively. EGR2 mutations were associated with a shorter time to treatment and poor overall survival. Analyses of BRAF and EGR2 mutations suggest that they result in deregulation of B-cell receptor (BCR) intracellular signaling. Our data propose disruption of hematopoietic and early B-cell differentiation through the deregulation of pre-BCR signaling as a phenotypic outcome of CLL mutations and show that CLL develops from a pre-leukemic phase. SIGNIFICANCE:The origin and pathogenic mechanisms of CLL are not fully understood. The current work indicates that CLL develops from pre-leukemic multipotent hematopoietic progenitors carrying somatic mutations. It advocates for abnormalities in early B-cell differentiation as a phenotypic convergence of the diverse acquired mutations observed in CLL. Cancer Discov; 4(9); 1088-1101

One hundred and twenty-nine patients with chronic lymphocytic leukemia (CLL) followed in our outpatient department for periods ranging from 6 months to 13 years were divided into five anatomico-clinical stages: stage 0 (peripheral and bone marrow lymphocytosis); stage I (stage 0 + lymph node enlargement); stage I1 (stage 0 + palpable spleen); stage 111 (stage I + 11); and stage IV (anemia or thrombocytopenia) . Analysis of actuarial survival curves revealed the following: 1) median survival of the entire population exceeded 114 months; 2) there was no difference between the curves of stage 0 and stage I patients, 3) there was a significant difference between survival for stage 111 and IV patients as compared with stages 0, I and I1 (p < 0.01); and 4) median survival for stage I11 and stage IV was 70 months; and 23 months, respectively. Age did not appear to be a prognostic factor. Prognosis was poorer in male patients and in those with a high initial lymphocyte count (50,000/mma), but this was due to the higher incidence of stages 111 and IV in this population ( p <

Diagnosis of PIOL is often made months or years after the initial onset of ocular symptoms. Cytology remains the gold standard for diagnosis. However, measurement of IL-10 in the AH is a good screening test to reduce diagnostic delays.

Ligation of CD47 triggers caspase-independent programmed cell death (PCD) in normal and leukemic cells. Here, we characterize the morphological and biochemical features of this type of death and show that it displays the hallmarks of type III PCD. A molecular and biochemical approach has led us to identify a key mediator of this type of death, dynamin-related protein 1 (Drp1). CD47 ligation induces Drp1 translocation from cytosol to mitochondria, a process controlled by chymotrypsin-like serine proteases. Once in mitochondria, Drp1 provokes an impairment of the mitochondrial electron transport chain, which results in dissipation of mitochondrial transmembrane potential, reactive oxygen species generation, and a drop in ATP levels. Surprisingly, neither the activation of the most representative proapoptotic members of the Bcl-2 family, such as Bax or Bak, nor the release of apoptogenic proteins AIF (apoptosis-inducing factor), cytochrome c, endonuclease G (EndoG), Omi/HtrA2, or Smac/DIABLO from mitochondria to cytosol is observed. Responsiveness of cells to CD47 ligation increases following Drp1 overexpression, while Drp1 downregulation confers resistance to CD47-mediated death. Importantly, in B-cell chronic lymphocytic leukemia cells, mRNA levels of Drp1 strongly correlate with death sensitivity. Thus, this previously unknown mechanism controlling caspase-independent type III PCD may provide the basis for novel therapeutic approaches to overcome apoptotic avoidance in malignant cells.

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Key Points• ROSA KIT WT is a new human SCF-dependent FceRI-positive mast cell line that converts to SCF-independence by KIT D816V-transfection.• The FceRI-positive ROSA KIT D816V clone is a major tool for studying cellular aspects of mastocytosis and responses to targeted drugs.In systemic mastocytosis (SM), clinical problems arise from factor-independent proliferation of mast cells (MCs) and the increased release of mediators by MCs, but no human cell line model for studying MC activation in the context of SM is available. We have created a stable stem cell factor (SCF) -dependent human MC line, ROSA -derived tumors did not show mediator-related symptoms, and KIT D816V-positive MCs obtained from patients with SM did not show increased IgE-dependent histamine release or CD63 upregulation. Our data show that KIT D816V is a disease-propagating oncoprotein, but it does not activate MCs to release proinflammatory mediators, which may explain why mediator-related symptoms in SM occur preferentially in the context of a coexisting allergy. ROSA KIT D816V may provide a valuable tool for studying the pathogenesis of mastocytosis and should facilitate the development of novel drugs for treating SM patients. (Blood. 2014;124(1):111-120)

on behalf of the ANRS HC-13 Lympho-C Study Group Hepatitis C virus (HCV) infection increases the risk of B-cell non-Hodgkin lymphomas (B-NHL). Antiviral treatment (AT) can induce hematological responses in patients with marginal zone lymphomas (MZL). The ANRS HC-13 Lympho-C study aimed at a better understanding of the impact of AT on HCV associated B-NHL. This multicentric study enrolled 116 HCV-positive patients with B-NHL between 2006 and 2012. Cytological and histological samples were collected for centralized review. At lymphoma diagnosis, median age was 61 years and gender ratio M/F was 1. Cytohistological distribution was marginal zone lymphoma (MZL) n 5 45 (39%), diffuse large B-cell lymphoma (DLBCL) n 5 45 (39%), and other types n 5 26 (22%). MZL patients had more frequent detection of rheumatoid factor (68% vs. 35%; P 5 0.001) and more frequently mixed cryoglobulinemia (74% vs. 44%; P 5 0.021) than patients with DLBCL. Among patients receiving AT, a sustained virologic response was achieved in 23 of 38 (61%) patients with MZL and in 9 of 17 (53%) with DLBCL (P 5 0.42). Three-year overall survival (OS) and progression-free survival were 78% 95%CI and 64% , respectively, without difference between cytohistological groups. Outcome analysis showed a favorable association between OS and AT in all patients (P 5 0.05) and in the subgroup of MZL patients only (P 5 0.04). Our data support that AT improves the outcomes of HCV-associated NHLs. The impact of new AT regimen with protease inhibitor needs to be investigated in this setting. [clinicalTrials.gov Identification number NCT01545544]Am.