Analysis of clonal B-cell CD38 and immunoglobulin variable region sequence status in relation to clinical outcome for B-chronic lymphocytic leukaemia

Current Landscape of Ancillary Diagnostic Testing in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia and is a heterogeneous disease with variable patient outcomes. A multidisciplinary technical evaluation, including flow cytometry, immunohistochemistry, molecular and cytogenetic analyses, can comprehensively characterize a patient's leukemia at diagnosis, identify important prognostic biomarkers, and track measurable residual disease; all of which can impact patient management. This review highlights the key concepts, clinical significance, and main biomarkers detectable with each of these technical approaches; the contents are a helpful resource for medical practitioners involved in the workup and management of patients with CLL.

A Ferroptosis Molecular Subtype-Related Signature for Predicting Prognosis and Response to Chemotherapy in Patients with Chronic Lymphocytic Leukemia

Ferroptosis is a type of regulated cell death catalyzed by the iron-dependent accumulation of lipid hydroperoxides to lethal levels. Chronic lymphocytic leukemia (CLL) is a chronic lymphoproliferative disorder. However, the understanding of ferroptosis in CLL remains largely poor. In this study, we investigated the stratification and prognostic role of ferroptosis-related genes in CLL patients of ICGC cohort. We obtained fourteen genes with prognostic value by screening 110 ferroptosis-related genes (FRGs). Based on the expression profiles of these 14 genes, we classified CLL patients into two clusters. Most of the FRGs were highly expressed in cluster 1, and cluster 1 was associated with better overall survival (OS). Subsequently, we developed an eight-gene signature (TP63, STEAP3, NQO1, ELAVL1, PRKAA1, HELLS, FANCD2, and CDKN2A) by using LASSO analysis. This risk signature divided CLL patients into high- and low-risk groups. We used Cox regression analysis and ROC analysis demonstrated the risk signature was reliable and robust. And we validated the risk model in an external cohort (GSE22762). We also conducted enrichment analysis and genomic mutation analysis. Finally, we explored the potential effect of chemotherapy between the two risk groups. Our study contributed to understanding the role of ferroptosis in CLL and facilitated personalized and precision treatment.

Effect of CD38 on B-cell function and its role in the diagnosis and treatment of B-cell-related diseases

CD38 is a multifunctional receptor and enzyme present on the surface of B lymphocytes, which can induce B lymphocytes proliferation and apoptosis by crosslinking related cytokines to affect the function of B cells, thus affecting immune regulation in humans and promoting tumorigenesis. The level of CD38 expression in B cells has become an important factor in the clinical diagnosis, treatment, and prognosis of malignant tumors and other related diseases. Therefore, studying the relationship between CD38 expression on the surface of B cells and the occurrence of the disease is of great significance for elucidating its association with disease pathogenesis and the clinical targeted therapy. In this paper, we review the effects of CD38 on B-cell activation, proliferation, and differentiation, and elaborate the functional role and mechanism of CD38 expression on B cells. We also summarize the relationship between the level of CD38 expression on the surface of B cells and the diagnosis, treatment, and prognosis of various diseases, as well as the potential use of targeted CD38 treatment for related diseases. This will provide an important theoretical basis for the scientific research and clinical diagnosis and treatment of B-cell-related diseases.

Ectonucleotidases in Blood Malignancies: A Tale of Surface Markers and Therapeutic Targets

Leukemia develops as the result of intrinsic features of the transformed cell, such as gene mutations and derived oncogenic signaling, and extrinsic factors, such as a tumor-friendly, immunosuppressed microenvironment, predominantly in the lymph nodes and the bone marrow. There, high extracellular levels of nucleotides, mainly NAD⁺ and ATP, are catabolized by different ectonucleotidases, which can be divided in two families according to substrate specificity: on one side those that metabolize NAD⁺, including CD38, CD157, and CD203a; on the other, those that convert ATP, namely CD39 (and other ENTPDases) and CD73. They generate products that modulate intracellular calcium levels and that activate purinergic receptors. They can also converge on adenosine generation with profound effects, both on leukemic cells, enhancing chemoresistance and homing, and on non-malignant immune cells, polarizing them toward tolerance. This review will first provide an overview of ectonucleotidases expression within the immune system, in physiological and pathological conditions. We will then focus on different hematological malignancies, discussing their role as disease markers and possibly pathogenic agents. Lastly, we will describe current efforts aimed at therapeutic targeting of this family of enzymes.

Targeting CD38 Enhances the Antileukemic Activity of Ibrutinib in Chronic Lymphocytic Leukemia

PURPOSE

CD38 has emerged as a high-impact therapeutic target in multiple myeloma, with the approval of daratumumab (anti-CD38 mAb). The clinical importance of CD38 in patients with chronic lymphocytic leukemia (CLL) has been known for over 2 decades, although it's relevance as a therapeutic target in CLL remains understudied.

EXPERIMENTAL DESIGN

We investigated the biological effects and antitumor mechanisms engaged by daratumumab in primary CLL cells. Besides its known immune-effector mechanisms (antibody-dependent cell-mediated cytotoxicity, complement-dependent death, and antibody-dependent cellular phagocytosis), we also measured direct apoptotic effects of daratumumab alone or in combination with ibrutinib. In vivo antileukemic activity was assessed in a partially humanized xenograft model. The influence of CD38 on B-cell receptor (BCR) signaling was measured via immunoblotting of Lyn, Syk, BTK, PLCγ2, ERK1/2, and AKT.

RESULTS

In addition to immune-effector mechanisms; daratumumab also induced direct apoptosis of primary CLL cells, which was partially dependent on FcγR cross-linking. For the first time, we demonstrated the influence of CD38 on BCR signaling where interference of CD38 downregulated Syk, BTK, PLCγ2, ERK1/2, and AKT; effects that were further enhanced by addition of ibrutinib. In comparison to single-agent treatment, the combination of ibrutinib and daratumumab resulted in significantly enhanced anti-CLL activity in vitro and significantly decreased tumor growth and prolonged survival in the in vivo CLL xenograft model.

CONCLUSIONS

Overall, our data demonstrate the antitumor mechanisms of daratumumab in CLL; furthermore, we show how cotargeting BTK and CD38 lead to a robust anti-CLL effect, which has clinical implications.

Evaluation of CD38 expression in Sudanese patients with chronic lymphocytic leukemia

Objective

The objective of this study was to evaluate the cluster of differentiation-38 (CD38) expression in Sudanese patients with chronic lymphocytic leukemia (CLL) and to determine its association with clinical and laboratory characteristics of the disease.

Results

We conducted a cross-sectional study on 99 patients diagnosed with CLL in Khartoum Oncology Hospital in Khartoum, Sudan. Immunophenotyping and CD38 expression levels were measured with four-color flowcytometry. The results of physical examination and blood analyses were used for assigning a modified Rai clinical staging system. The collected data were analyzed using the Statistical Package for the Social Science, version 22 (SPSS Inc., Chicago, IL, USA). According to our findings, the frequencies of 7%, 20%, and 30% cutoff levels of CD38 expressions were 68.7%, 41.4%, and 36.4% respectively. CD38 cutoff level of 7% showed a significant association with hemoglobin concentration (P = 0.04), whereas other cutoff levels showed insignificant results. All the three cutoff levels showed insignificant associations with the other clinical and laboratory variables. In conclusion, the CD38 expression at a cutoff level of 7% seems to be more valuable clinically than higher cutoff levels in Sudanese CLL patients.

A phase 2 study of ofatumumab (Arzerra®) in combination with a pan-AKT inhibitor (afuresertib) in previously treated patients with chronic lymphocytic leukemia (CLL)

AKT plays a centralized role in tumor proliferation and survival and is aberrantly activated in chronic lymphocytic leukemia (CLL). In this phase 2 trial, 30 relapsed/refractory CLL patients were treated with combination afuresertib, a novel oral AKT inhibitor, and ofatumumab for 6 months, followed by afuresertib maintenance for 12 months. We aimed to achieve deeper and more durable responses, without requiring long-term continuous treatment. Treatment was generally well tolerated but respiratory infections were common, with 18% severe requiring hospitalization. Hematologic toxicities were manageable (grade 3-4 neutropenia 39%). At a median follow-up of 13.4 months, overall responses were 50% (complete responses 3.6%). Median progression-free survival was 8.5 months and overall survival 34.8 months. Combination therapy with ofatumumab and afuresertib is active and well tolerated, but does not appear to lead to durable responses and may not provide additional benefit over single-agent ofatumumab in relapsed/refractory CLL. Novel agent combinations are currently undergoing intense investigation.

Morphological, immunophenotypic, and genetic features of chronic lymphocytic leukemia with trisomy 12: a comprehensive review

Chronic lymphocytic leukemia is an extremely heterogeneous disease and prognostic factors such as chromosomal abnormalities are important predictors of time to first treatment and survival. Trisomy 12 is the second most frequent aberration detected by fluorescence in situ hybridization at the time of diagnosis (10-25%), and it confers an intermediate prognostic risk, with a median time to first treatment of 33 months and a median overall survival of 114 months. Here, we review the unique morphological, immunophenotypic, and genetic characteristics of patients with chronic lymphocytic leukemia and trisomy 12. These patients carry a significantly higher expression of CD19, CD22, CD20, CD79b, CD24, CD27, CD38, CD49d, sIgM, sIgk, and sIgλ and lower expression of CD43 compared with patients with normal karyotype. Circulating cells show increased expression of the integrins CD11b, CD18, CD29, and ITGB7, and of the adhesion molecule CD323. Patients with chronic lymphocytic leukemia and trisomy 12 frequently have unmutated IGHV, ZAP-70 positivity, and closely homologous stereotyped B-cell receptors. They rarely show TP53 mutations but frequently have NOTCH1 mutations, which can be identified in up to 40% of those with a rapidly progressive clinical course.

Cytomegalovirus infection does not impact on survival or time to first treatment in patients with chronic lymphocytic leukemia

Human cytomegalovirus (HCMV) is a widely prevalent herpes virus which establishes a state of chronic infection. The establishment of CMV‐specific immunity controls viral reactivation and leads to the accumulation of very large numbers of virus‐specific T cells which come to dominate the immune repertoire. There is concern that this may reduce the immune response to heterologous infections and HCMV infection has been associated with reduced survival in elderly people. Patients with chronic lymphocytic leukemia (B‐CLL) suffer from a state of immune suppression but have a paradoxical increase in the magnitude of the CMV‐specific T cell and humoral immune response. As such, there is now considerable interest in how CMV infection impacts on the clinical outcome of patients with B‐CLL. Utilizing a large prospective cohort of patients with B‐CLL (n = 347) we evaluated the relationship between HCMV seropositivity and patient outcome. HCMV seropositive patients had significantly worse overall survival than HCMV negative patients in univariate analysis (HR = 2.28, 95% CI: 1.34–3.88; P = 0.002). However, CMV seropositive patients were 4 years older than seronegative donors and this survival difference was lost in multivariate modeling adjusted for age and other validated prognostic markers (P = 0.34). No significant difference was found in multivariate modeling between HCMV positive and negative patients in relation to the time to first treatment (HR = 1.12, 95% CI: 0.68–1.84; P = 0.65). These findings in a second independent cohort of 236 B‐CLL patients were validated. In conclusion no evidence that HCMV impacts on the clinical outcome of patients with B‐CLL was found. Am. J. Hematol. 91:776–781, 2016. © 2016 Wiley Periodicals, Inc.

CD38 in Hairy Cell Leukemia Is a Marker of Poor Prognosis and a New Target for Therapy

Hairy cell leukemia (HCL) is characterized by underexpression of the intracellular signaling molecule RhoH. Reconstitution of RhoH expression limits HCL pathogenesis in a mouse model, indicating this could represent a new therapeutic strategy. However, while RhoH reconstitution is theoretically possible as a therapy, it is technically immensely challenging as an appropriately functional RhoH protein needs to be specifically targeted. Because of this problem, we sought to identify druggable proteins on the HCL surface that were dependent upon RhoH underexpression. One such protein was identified as CD38. Analysis of 51 HCL patients demonstrated that 18 were CD38-positive. Interrogation of the clinical record of 23 relapsed HCL patients demonstrated those that were CD38-positive had a mean time to salvage therapy 71 months shorter than patients who were CD38-negative. Knockout of the CD38 gene in HCL cells increased apoptosis, inhibited adherence to endothelial monolayers, and compromised ability to produce tumors in vivo. Furthermore, an anti-CD38 antibody proved effective against pre-existing HCL tumors. Taken together, our data indicate that CD38 expression in HCL drives poor prognosis by promoting survival and heterotypic adhesion. Our data also indicate that CD38-positive HCL patients might benefit from treatments based on CD38 targeting.

KLKB1 mRNA overexpression: A novel molecular biomarker for the diagnosis of chronic lymphocytic leukemia

OBJECTIVES

Plasma kallikrein, also known as Fletcher factor or kallikrein B1 (KLKB1), is a serine endopeptidase, like its homologs tissue kallikrein and kallikrein-related peptidases (KLKs). Its physiological role is to catalyze the release of kinins and other vasoactive peptides. Several KLKs have been proposed as putative tumor biomarkers with significant diagnostic and/or prognostic value in human malignancies arising from solid tumors; the most prominent example is the worldwide use of KLK3 (prostate-specific antigen, PSA) in prostate cancer diagnostics. The aim of this study was to analyze KLKB1 mRNA expression in B-cell chronic lymphocytic leukemia (CLL) patients and to examine its diagnostic value as a novel molecular biomarker in CLL.

DESIGN AND METHODS

Total RNA was isolated from peripheral blood mononuclear cells of sixty-nine patients previously diagnosed with CLL and thirty-one healthy blood donors. After cDNA preparation, a sensitive and cost-effective quantitative real-time PCR (qRT-PCR) methodology was developed and applied for KLKB1 mRNA quantification. Last, we carried out a biostatistical analysis to assess the clinical significance of KLKB1 mRNA expression.

RESULTS

According to our findings, KLKB1 mRNA expression is significantly higher in CLL patients than in healthy blood donors. Furthermore, KLKB1 mRNA levels are negatively correlated with CD38 expression, an established prognostic biomarker in CLL. Most importantly, KLKB1 mRNA expression possesses important diagnostic value, distinguishing very efficiently CLL patients from non-leukemic population.

CONCLUSIONS

KLKB1 mRNA expression is a putative molecular biomarker in CLL, meriting investigation in large cohorts of CLL patients and non-leukemic controls.

Cytogenetic prioritization with inclusion of molecular markers predicts outcome in previously untreated patients with chronic lymphocytic leukemia treated with fludarabine or fludarabine plus cyclophosphamide: a long-term follow-up study of the US intergroup phase III trial E2997

Fludarabine (F) and cyclophosphamide (C) remain backbones of up-front chemotherapy regimens for chronic lymphocytic leukemia (CLL). We report long-term follow-up of a randomized F vs. FC trial in untreated CLL (#) . With median follow-up of 88 months, estimated median progression-free survival (PFS) was 19.3 vs. 48.1 months for F (n = 109) and FC (n = 118), respectively (p < 0.0001), and median overall survival (OS) was 88.0 vs. 79.1 months (p = 0.96). In multivariable analyses, variables associated with inferior PFS and OS respectively were age (p = 0.002, p < 0.001), Rai stage (p = 0.006, p = 0.02) and sex (p = 0.03, PFS only). Del(17)(p13.1) predicted shorter PFS and OS (p < 0.0001 for each), as did del(11q)(22.3) (p < 0.0001, p = 0.005, respectively), trisomy 12 with mutated Notch1 (p = 0.003, p = 0.03, respectively) and unmutated IGHV (p = 0.009, p = 0.002, respectively), all relative to patients without these features. These data confirm results from shorter follow-up and further justify targeted therapies for CLL.

Chemoimmunotherapy for relapsed/refractory and progressive 17p13-deleted chronic lymphocytic leukemia (CLL) combining pentostatin, alemtuzumab, and low-dose rituximab is effective and tolerable and limits loss of CD20 expression by circulating CLL cells

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients with purine analog refractory disease or TP53 dysfunction still have limited treatment options and poor survival. Alemtuzumab-containing chemoimmunotherapy regimens can be effective but frequently cause serious infections. We report a Phase II trial testing the efficacy and tolerability of a short-duration regimen combining pentostatin, alemtuzumab, and low-dose high-frequency rituximab designed to decrease the risk of treatment-associated infections and to limit the loss of CD20 expression by CLL cells. The study enrolled 39 patients with progressive CLL that was either relapsed/refractory (n = 36) or previously untreated with 17p13 deletion (17p13-) (n = 3). Thirteen (33%) patients had both 17p13- and TP53 mutations predicted to be dysfunctional, and eight patients had purine analog refractory CLL without TP53 dysfunction. Twenty-six (67%) patients completed therapy, with only five (13%) patients having treatment-limiting toxicity and no treatment-related deaths. Twenty-two (56%) patients responded to treatment, with 11 (28%) complete responses (four with incomplete bone marrow recovery). Median progression-free survival was 7.2 months, time to next treatment was 9.1 months, and overall survival was 34.1 months. The majority of deaths (82%) were caused by progressive disease, including transformed diffuse large B-cell lymphoma (n = 6). Correlative studies showed that low-dose rituximab activates complement and natural killer cells without a profound and sustained decrease in expression of CD20 by circulating CLL cells. We conclude that pentostatin, alemtuzumab, and low-dose high-frequency rituximab is a tolerable and effective therapy for CLL and that low-dose rituximab therapy can activate innate immune cytotoxic mechanisms without substantially decreasing CD20 expression.

Infectious lymphadenitis in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma: a rare, but important, complication

The differential diagnosis of rapidly progressive or symptomatic lymphadenopathy in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) includes infectious lymphadenitis. We studied 286 (9%) of 3040 patients with CLL seen between 2003 and 2012 at Mayo Clinic Rochester who had 356 diagnostic lymph node biopsies to evaluate rapidly progressive or symptomatic lymphadenopathy. Most (85.4%) biopsies showed progressive CLL, 8.9% a second lymphoid malignancy, 3.9% infectious lymphadenitis, 1.1% reactive adenitis and 0.6% non-hematological malignancies. Of the 12 patients (14 biopsies) with infectious lymphadenitis, five patients had never been treated for their CLL, and seven had a specific microbiological diagnosis (herpes simplex n=3, Cryptococcus neoformans n=1, Mycobacterium n=1, coagulase negative Staphylococcus n=2). We conclude that infectious lymphadenitis is a rare complication of CLL with clinical characteristics similar to progressive CLL and transformation to a more aggressive lymphoma. Early recognition and antimicrobial therapy treatment of infectious lymphadenitis can be highly effective in these patients.

Five important advances in hematopathology

CONTEXT

Hematopathology is a dynamic field that has always been on the frontier of clinical research within the scope of pathology. Several recent developments in hematopathology will likely affect its practice clinically.

OBJECTIVE

To review 5 important recent advances in hematopathology: (1) detection and prognostic implication of MYC in diffuse large B-cell lymphomas, (2) determining origin and prognosis through immunoglobulin gene usage in mature B-cell neoplasms, (3)detecting minimal residual disease in multiple myeloma, (4) using genome-wide analysis in myelodysplastic syndromes, and (5) employing whole-genome sequencing in acute myeloid leukemias.

DATA SOURCES

Literature review and the authors' experiences in an academic center.

CONCLUSIONS

These advances will bring hematopathology into a new molecular era and help us to better understand the molecular, pathologic mechanisms of lymphomas, leukemias, myelomas, and myelodysplastic syndromes. They will help us to identify diagnostic and prognostic markers and eventually provide new therapeutic targets and treatments for these diseases.

Use of positron emission tomography-computed tomography in the management of patients with chronic lymphocytic leukemia/small lymphocytic lymphoma

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) cells typically have low 2-deoxy-2-[(18)F]fluoro-d-glucose (FDG) avidity, and patients with CLL have an increased risk of developing FDG-avid aggressive lymphomas, second malignancies and infections. We hypothesized that FDG positron emission tomography-computed tomography (PET-CT) of the trunk is a sensitive method of detecting these complications in patients with CLL. Of the of 2299 patients with CLL seen in the Division of Hematology at Mayo Clinic Rochester between 1 January 2006 and 31 December 2011, 272 (11.8%) had 526 PET-CT scans and 472 (89.7%) of these were reported as abnormal. Among the 293 (55.7%) PET-CT scans used for routine evaluation of CLL, the PET component was of clinical value in only one instance. In contrast, in 83 (30.5%) patients, PET-CT scans used to evaluate new clinical complications localized high FDG-avidity lesions for biopsies. This resulted in clinically relevant new diagnoses in 32 patients, including those with more aggressive lymphoma (n = 16), non-hematological malignancies (n = 8) and opportunistic infections (n = 3). Twenty-seven patients had high FDG-avidity CLL, which was associated with prominent lymph node proliferation centers, an increased frequency of poor prognostic factors (17p13 deletion, unmutated immunoglobulin heavy chain variable gene [IGHV], expression of ZAP-70 and CD38) and a shorter overall survival. We conclude that FDG PET scans should not be used for routine surveillance of patients with CLL. However PET-CT scans are sensitive, but not specific, for detection of aggressive lymphomas, other cancers and systemic infections in patients with CLL.

Induced resistance to ofatumumab-mediated cell clearance mechanisms, including complement-dependent cytotoxicity, in chronic lymphocytic leukemia

Ofatumumab (OFA), a human CD20-targeting mAb, kills B lymphocytes using the innate immune system including complement-dependent cytotoxicity (CDC). The efficacy of OFA in patients with chronic lymphocytic leukemia (CLL) is limited by drug resistance, which is not well characterized. To better understand mechanisms of resistance, we prospectively studied CLL cells isolated from blood samples collected before and after in vivo exposure to the initial dose of OFA therapy in 25 patients undergoing their first treatment for progressive CLL. As previously reported, OFA therapy rapidly decreased the absolute lymphocyte count, CD20 expression by CLL cells, and serum complement levels. We now show that after administration of the first dose of OFA, there was a modest rebound in the absolute lymphocyte count and serum complement levels, but substantial ongoing loss of CD20 expression by CLL cells. These post-OFA treatment CLL cells were highly resistant to OFA-mediated CDC but retained sensitivity to alemtuzumab-mediated CDC in vitro. Posttherapy serum OFA levels correlated inversely with both the amount of pretreatment circulating cell-bound CD20 and with the decrease in this value following treatment. In vitro OFA-mediated CDC did not predict clinical responses, and the patients with first-dose reactions to OFA did not have markers of increased complement activation in vivo. We propose that optimal efficacy of CD20- targeted therapy for CLL requires determining an mAb dose size and frequency that optimizes CLL killing without exceeding the capacity of the cytotoxic mechanisms and thus minimizes loss of CD20 expression in the surviving CLL cells.

CD38 as a prognostic marker in CLL

Cell-surface expression of CD38 in CLL has been recognised recently as a marker of progressive disease and poor outcome. In contrast to traditional staging systems, CD38 is able to identify progressive cases at an early stage. Measurement of CD38, in conjunction with other novel prognostic factors such as p53 and ZAP-70 helps to identify patients who might benefit from early and more intensive therapy. In addition, CD38 positivity can predict unmutated IgVH gene mutation status in most cases. These features, together with its easy applicability, render CD38 a valuable tool in the routine diagnostics of CLL. Questions remaining to be clarified about CD38 include the incidence and significance of its variations during the course of the disease, the optimal method to define CD38 positivity and the impact of different methodologies on results. Only after these issues are resolved can the definitive place of CD38 be defined in the diagnostics of CLL.

Molecular analysis of immunoglobulin genes reveals frequent clonal relatedness in double monoclonal gammopathies

Monoclonal gammopathies (MGs) are hematological diseases characterized by high levels of a monoclonal immunoglobulin (Ig) or M-protein. Within this group are patients with more than one M-protein, referred to as double MGs (DMGs). The M-proteins in DMG patients may have different heavy chain (HC) isotypes that are associated with different light chains (LCs), or different HCs that are LC matched. In this study, we examined the clonal relatedness of the M-proteins in the latter type in a cohort of 14 DMG patients. By using PCR, we identified 7/14 DMG patients that expressed two Ig HC isotypes with identical Ig HC variable (IGHV), diversity (IGHD), joining (IGHJ), and complementarity determining region (HCDR3) sequences. Two additional DMG patients had two Ig transcripts using the same IGHV, IGHD and IGHJ genes but with slight differences in variable region or HCDR3 mutations. LC analysis confirmed that a single LC was expressed in 3/7 DMG patients with identical HC transcripts and in the two DMGs with highly similar transcripts. The PCR findings were confirmed by immunofluorescence for HC and LC expression. Clonally related HC-dissimilar/LC-matched DMGs may occur often and defines a new subtype of MG that may serve as a tool for studies of disease pathogenesis.

Double productive immunoglobulin sequence rearrangements in patients with chronic lymphocytic leukemia

The immunoglobulin heavy chain variable (IGHV) gene mutational status represents a major prognostic marker in chronic lymphocytic leukemia (CLL). Usually, the prognostic implications of IGHV gene analysis can be reliably ascertained but, occasionally, double productive rearrangements have been detected. Clinical presentation and biological features of such cases are unknown. Sixty patients with morphologically and phenotypically monoclonal CLL but double productive IGHV rearrangements were retrospectively identified by mRNA analysis from three Hematology Institutions. Clinical and biological features and survival of these 60 patients were compared with a control group of patients with CLL and single IGHV rearrangement. A prospective registry was used to assess the epidemiology of double productive IGHV among incidental patients with CLL. Using standard criteria to define IGHV-mutated (M) or unmutated (U) cases, 39 of the 60 patients (65%) with double productive IGHV rearrangement had concordant status (23 MM, 16 UU), while 21 (35%) had discordant IGHV status. As compared with M patients, the MM ones had lower CD38 expression, more favorable cytogenetics and more indolent clinical behavior. Cases with UU had similar characteristics of U patients. Discordant cases presented with adverse prognostic features and had an aggressive clinical behavior requiring early treatment, similar to U patients. The prevalence of double IGHV was 3.1%. Patients with CLL with double concordant mutational status (MM or UU) have a clinical course similar to that of the corresponding single IGHV status, while those exhibiting discordant status represent a high risk population. This may help correct stratification within clinical trials.

Comprehensive assessment of potential multiple myeloma immunoglobulin heavy chain V-D-J intraclonal variation using massively parallel pyrosequencing

Multiple myeloma (MM) is characterized by the accumulation of malignant plasma cells (PCs) in the bone marrow (BM). MM is viewed as a clonal disorder due to lack of verified intraclonal sequence diversity in the immunoglobulin heavy chain variable region gene (IGHV). However, this conclusion is based on analysis of a very limited number of IGHV subclones and the methodology employed did not permit simultaneous analysis of the IGHV repertoire of non-malignant PCs in the same samples. Here we generated genomic DNA and cDNA libraries from purified MM BMPCs and performed massively parallel pyrosequencing to determine the frequency of cells expressing identical IGHV sequences. This method provided an unprecedented opportunity to interrogate the presence of clonally related MM cells and evaluate the IGHV repertoire of non-MM PCs. Within the MM sample, 37 IGHV genes were expressed, with 98.9% of all immunoglobulin sequences using the same IGHV gene as the MM clone and 83.0% exhibiting exact nucleotide sequence identity in the IGHV and heavy chain complementarity determining region 3 (HCDR3). Of interest, we observed in both genomic DNA and cDNA libraries 48 sets of identical sequences with single point mutations in the MM clonal IGHV or HCDR3 regions. These nucleotide changes were suggestive of putative subclones and therefore were subjected to detailed analysis to interpret: 1) their legitimacy as true subclones; and 2) their significance in the context of MM. Finally, we report for the first time the IGHV repertoire of normal human BMPCs and our data demonstrate the extent of IGHV repertoire diversity as well as the frequency of clonally-related normal BMPCs. This study demonstrates the power and potential weaknesses of in-depth sequencing as a tool to thoroughly investigate the phylogeny of malignant PCs in MM and the IGHV repertoire of normal BMPCs.

Prognostic impact of serum 25-hydroxivitamin D [25(OH)D] concentrations in patients with lymphoid malignancies

The incidence of lymphoid malignancies has been increasing rapidly. Despite growing evidence for a relationship between serum 25-hydroxivitamin D [25(OH)D] concentrations and solid tumor risk, far less is known about the relationship between 25(OH)D and the risk of hematologic malignancy. This study aimed to assess the prognostic relevance of serum 25(OH)D concentrations in patients with B chronic lymphocytic leukemia (B-CLL) and non Hodgkin's lymphoma (NHL). The study was carried out on 195 newly diagnosed patients (75 B-CLL and 120 NHL) as well as 30 normal healthy controls. For all patients and normal controls serum 25(OH)D concentrations were assayed by enzyme-linked immunosorbent assay. Serum 25(OH)D levels were significantly lower in B-CLL and NHL patients as compared with normal controls (P = 0.00 for both). Also, there are significant associations between serum 25(OH)D levels and positive CD 38, positive ZAP 70 as well as Binet stages (χ(2) = 16.071, 16.644, 21.134 respectively; P = 0.00 for all) in the B-CLL patient group. Moreover, there are significant associations between serum 25(OH)D status and international prognostic index (IPI), performance status (χ(2) = 6.994, 9.212, P = 0.02, 0.01 respectively), but not with clinical stages (χ(2) = 3.115, P = 0.539) in NHL. Multivariate analysis revealed that 25(OH)D insufficiency is an independent poor prognostic factor in both B-CLL and NHL patient groups. In conclusion, 25(OH)D insufficiency is an independent poor prognostic factor in patients with B-CLL and NHL. 25(OH)D might be a therapeutic target in lymphoid malignancies.

Complement dependent cytotoxicity in chronic lymphocytic leukemia: ofatumumab enhances alemtuzumab complement dependent cytotoxicity and reveals cells resistant to activated complement

Complement dependent cytotoxicity (CDC) is an important mechanism of action for monoclonal antibodies (mAbs) used in the treatment of chronic lymphocytic leukemia (CLL). We hypothesized that alemtuzumab (ALM) mediated CDC would be increased by the addition of ofatumumab (OFA). CLL cells from 21 previously untreated patients with progressive disease were tested in vitro for mAb binding, complement activation and CDC. The subpopulation of CDC resistant CLL cells was examined for levels of C3b and C5b-9 binding, and expression of complement regulatory proteins. OFA significantly increased complement activation and CDC in ALM-treated CLL cells, suggesting that combining ALM and OFA could improve clinical outcome in patients with CLL. Approximately 10% of CLL cells were resistant to CDC because of lower levels of complement activation or decreased cytotoxicity of activated complement. Improvement of clinical responses will require determining the mechanisms of CDC resistance and developing methods to overcome this problem.

Predicting survival in chronic lymphocytic leukemia

There is increasing interest in the use of prognostic markers that may predict survival and guide management in patients diagnosed with the early stages of chronic lymphocytic leukemia (CLL). Currently, the most important traditional prognostic factors include clinical staging, lymphocyte doubling time and β2-microglobulin/thymidine kinase; and the most important novel markers include karyotypic aberrations (typically assessed by FISH probes or CpG oligonucleotide karyotyping) and IgVH mutation status. Although each of these factors have individually shown significant correlations with survival, there is increasing appreciation that the most complete information may be obtained by using a combination of several factors in prognostic normograms or models. In this article, we review the current state-of-the-art with regards to CLL prognostic factors and discuss how they can be applied in the clinic.

CD38 and chronic lymphocytic leukemia: a decade later

This review highlights a decade of investigations into the role of CD38 in CLL. CD38 is accepted as a dependable marker of unfavorable prognosis and as an indicator of activation and proliferation of cells when tested. Leukemic clones with higher numbers of CD38(+) cells are more responsive to BCR signaling and are characterized by enhanced migration. In vitro activation through CD38 drives CLL proliferation and chemotaxis via a signaling pathway that includes ZAP-70 and ERK1/2. Finally, CD38 is under a polymorphic transcriptional control after external signals. Consequently, CD38 appears to be a global molecular bridge to the environment, promoting survival/proliferation over apoptosis. Together, this evidence contributes to the current view of CLL as a chronic disease in which the host's microenvironment promotes leukemic cell growth and also controls the sequential acquisition and accumulation of genetic alterations. This view relies on the existence of a set of surface molecules, including CD38, which support proliferation and survival of B cells on their way to and after neoplastic transformation. The second decade of studies on CD38 in CLL will tell if the molecule is an effective target for antibody-mediated therapy in this currently incurable leukemia.

Hematologist/oncologist disease-specific expertise and survival: lessons from chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL)

BACKGROUND

The impact of physicians' disease-specific expertise on patient outcome is unknown. Although previous studies suggest a survival advantage for cancer patients cared for at high-volume centers, these observations may simply reflect referral bias or better access to advanced technologies, clinical trials, and multidisciplinary support at large centers.

METHODS

We evaluated time to first treatment (TTFT) and overall survival (OS) of patients with newly diagnosed chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) at a single academic center based on whether they were cared for by a hematologist/oncologist who subspecializes in CLL (CLL hematologist) or a hematologist/oncologist with expertise in other areas (non-CLL hematologist).

RESULTS

Among 1309 newly diagnosed patients with CLL cared for between 1999 and 2009, 773(59%) were cared for by CLL hematologists and 536 were cared for by non-CLL hematologists. Among early-stage patients (Rai 0-I), median TTFT (9.2 vs 6.1 years; P < .001) and OS (10.5 years vs 8.8 years; P < .001) were longer for patients cared for by CLL hematologists. For all patients, OS was superior for patients cared for by CLL hematologists (10.5 years vs 8.4 years; P = .001). Physician's disease-specific expertise remained an independent predictor of OS after adjusting for age, sex, stage, and lymphocyte count at diagnosis. Patients seen by a CLL hematologist were also more likely to participate in clinical trials (48% vs 16%; P < .001).

CONCLUSIONS

Physician disease-specific expertise appears to influence outcome in patients with CLL. To the greatest extent possible, patients should be cared for by a hematologist/oncologist expert in the care of their specific malignancy. When not possible, practice guidelines developed by disease-specific experts should be followed.

Monoclonal and polyclonal serum free light chains and clinical outcome in chronic lymphocytic leukemia

Free light chains (FLCs) are the most commonly detected paraproteins in chronic lymphocytic leukemia (CLL). We examined the types of FLC abnormalities and prognostic utility of the FLC assay compared with standard prognostic biomarkers in a prospective cohort of 339 patients with newly diagnosed CLL. Three types of FLC abnormalities were identified: monoclonal elevated FLC (elevated κ and/or λ with abnormal FLC ratio), polyclonal elevated FLC (elevated κ and/or λ with normal FLC ratio), and ratio-only FLC abnormality (normal range κ and λ with abnormal FLC ratio). One hundred sixty-five patients (49%) had a FLC abnormality with approximately equal distribution among monoclonal elevation, polyclonal elevation, and ratio-only abnormality. All FLC abnormalities were associated with poor time to first treatment: monoclonal FLC (hazard ratio [HR], 4.99; 95% confidence interval [CI], 2.94-8.48), polyclonal FLC (HR, 2.40; 95% CI, 1.24-4.64), ratio-only FLC (HR, 2.57; 95% CI, 1.40-4.69). Monoclonal FLC and polyclonal FLC were associated with poor overall survival compared with patients with normal FLC. Results remained significant after adjusting for Rai stage. The FLC assay is a simple, widely available clinical test with similar prognostic utility as routinely used prognostic biomarkers for CLL. Among persons with FLC abnormalities, the type of abnormality affects prognostic significance.

Acute liver failure because of chronic lymphocytic leukemia: case report and review of the literature

Infiltration of the liver by hematologic malignancies is an uncommon cause of liver failure. B-Cell chronic lymphocytic leukemia (cll) is a usually indolent disease that may infiltrate the liver, but based on a review of the literature, has never been reported to induce acute liver failure. Here, we describe the case of a 78-year-old woman with acute liver failure secondary to infiltration with cll being unresponsive to chemotherapy and causing death. This case is notable because of its atypical presentation and ultimate poor prognosis.

Prospective study of clinical and biological prognostic factors at diagnosis in patients with early stage B-cell chronic lymphocytic leukemia

Retrospective series have reported many clinical and biological significant prognostic factors in chronic lymphocytic leukemia (CLL). We describe a prospective cohort of 135 patients with CLL homogeneously studied at diagnosis for prognostic factors. Biological variables analyzed were CD38 and ZAP-70 expression, fluorescence in situ hybridization (FISH) for 13q-, +12, 11q-, and 17p-, and conventional cytogenetics. Univariate and multivariate analysis for progression-free survival (PFS) were performed in patients with early stage (Rai 0-1) CLL. CD38 was positive in 42 (31.6%) patients and ZAP-70 in 47 (35.9%). The most frequent FISH finding was isolated 13q- in 50 (38.5%) patients, and 17p- -was found in 11 (8.4%). Among 135 patients, 114 (84.4%) were Rai 0-1 at diagnosis and 39 (28.9%) presented adenopathies. With a median follow-up of 39 months, the presence of lymphadenopathy in patients with Rai 0-1 stage CLL was the only significant variable for predicting PFS in multivariate analysis (odds ratio [OR] 7, 95% confidence interval [CI] 2.2-22, p = 0.001). When only biological factors were analyzed, CD38 expression (OR 3.2, 95% CI 1.1-9.3, p = 0.03) and 17p- (OR 3.5, 95% CI 0.95-13.1, p = 0.05) correlated with worse PFS. A longer follow-up is necessary to analyze the prognostic value of these variables regarding overall survival.

Progressive but previously untreated CLL patients with greater array CGH complexity exhibit a less durable response to chemoimmunotherapy

To better understand the implications of genomic instability and outcome in B-cell chronic lymphocytic leukemia (CLL), we sought to address genomic complexity as a predictor of chemosensitivity and ultimately clinical outcome in this disease. We used array-based comparative genomic hybridization (aCGH) with a one-million probe array and identified gains and losses of genetic material in 48 patients treated on a chemoimmunotherapy clinical trial. We identified chromosomal gain or loss in ≥6% of the patients on chromosomes 3, 8, 9, 10, 11, 12, 13, 14, and 17. Higher genomic complexity, as a mechanism favoring clonal selection, was associated with shorter progression-free survival, and predicted a poor response to treatment. Of interest, CLL cases with loss of p53 surveillance showed more complex genomic features and were found both in patients with a 17p13.1 deletion and in the more favorable genetic subtype characterized by the presence of 13q14.1 deletion. This aCGH study adds information on the association between poor trial response and increasing genetic complexity as CLL progresses.

Single-agent lenalidomide in the treatment of previously untreated chronic lymphocytic leukemia

PURPOSE

Lenalidomide is an oral immunomodulatory drug with multiple effects on the immune system and tumor cell microenvironment leading to inhibition of malignant cell growth. Based on encouraging reports of lenalidomide in relapsed and refractory chronic lymphocytic leukemia (CLL), we investigated the first-line use of single-agent lenalidomide in CLL.

PATIENTS AND METHODS

Using a starting dose of lenalidomide 10 mg/d for 21 days of a 28-day cycle and weekly 5-mg dose escalations to a target of 25 mg, we encountered severe toxicities (tumor lysis, fatal sepsis) in the first two patients enrolled. The study was halted and the protocol amended to a more conservative regimen: starting dose of lenalidomide 2.5 mg with monthly escalations to a target dose of 10 mg, and extended tumor lysis prophylaxis and monitoring. Gene expression profiles from patient samples before and after 7 days of lenalidomide were performed.

RESULTS

Twenty-five patients were enrolled on the amended protocol. No further tumor lysis events were reported. Tumor flare was common (88%) but mild. Grade 3 to 4 neutropenia occurred in 72% of patients, with only five episodes of febrile neutropenia. The overall response rate was 56% (no complete responses). Although rapid peripheral lymphocyte reductions were observed, rebound lymphocytoses during the week off-therapy were common. Lenalidomide-induced molecular changes enriched for cytoskeletal and immune-related genes were identified.

CONCLUSION

Lenalidomide is clinically active as first-line CLL therapy and is well-tolerated if a conservative approach with slow dose escalation is used. A lenalidomide-induced molecular signature provides insights into its immunomodulatory mechanisms of action in CLL.

Age at diagnosis and the utility of prognostic testing in patients with chronic lymphocytic leukemia

BACKGROUND

A study was undertaken to analyze the survival of chronic lymphocytic leukemia (CLL) patients relative to age-matched individuals in the general population and determine the age-stratified utility of prognostic testing.

METHODS

All 2487 patients diagnosed with CLL between January 1995 and June 2008 and cared for in the Mayo Clinic Division of Hematology were categorized by age at diagnosis and evaluated for differences in clinical characteristics, time to first treatment, and overall survival (OS).

RESULTS

Among Rai stage 0 patients, survival was shorter than the age-matched general population for patients aged <55 years (P < .001), 55 to 64 years (P < .001), and 65 to 74 years (P < .001), but not those aged ≥75 years at diagnosis (P = not significant). CD38, IGHV mutation, and ZAP-70 each predicted time to first treatment independent of stage for all age groups (all P < .04), but had less value for predicting OS, particularly as age increased. IGHV and fluorescent in situ hybridization (FISH) predicted OS independent of stage for patients aged <55 years (P ≤ .001), 55 to 64 years (P ≤ .004), and 65 to 74 years (P ≤ .001), but not those aged ≥75 years. CD38 and ZAP-70 each predicted OS independent of stage for only 2 of 4 age categories. Among Rai 0 patients aged <75 years, survival was shorter than the age-matched population only for IGHV unmutated (P < .001) patients or those with unfavorable FISH (P < .001).

CONCLUSIONS

Survival of CLL patients aged <75 years is shorter than the age-matched general population regardless of disease stage. Among patients aged <75 years, the simple combinations of stage and IGHV or stage and FISH identifies those with excess risk of death relative to the age-matched population. Although useful for predicting time to first treatment independent of stage for patients of all ages, prognostic testing had little utility for predicting OS independent of stage among patients aged ≥75 years.

Vitamin D insufficiency and prognosis in chronic lymphocytic leukemia

Vitamin D insufficiency is common globally and low levels are linked to higher cancer incidence. Although vitamin D insufficiency is related to inferior prognosis in some cancers, no data exist for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We evaluated the relationship of 25(OH)D serum levels with time-to-treatment (TTT) and overall survival (OS) in newly diagnosed CLL patients participating in a prospective cohort study (discovery cohort) and a separate cohort of previously untreated patients participating in an observational study (confirmation cohort). Of 390 CLL patients in the discovery cohort, 119 (30.5%) were 25(OH)D insufficient. After a median follow-up of 3 years, TTT (hazard ratio[HR] = 1.66; P = .005) and OS (HR = 2.39; P = .01) were shorter for 25(OH)D-insufficient patients. In the validation cohort, 61 of 153 patients (39.9%) were 25(OH)D insufficient. After a median follow-up of 9.9 years, TTT (HR = 1.59; P = .05) and OS (HR 1.63; P = .06) were again shorter for 25(OH)D-insufficient patients. On pooled multivariable analysis of patients in both cohorts adjusting for age, sex, Rai stage, CD38 status, ZAP-70 status, immunoglobulin heavy chain variable (IGHV) gene mutation status, CD49d status, and cytogenetic abnormalities assessed by interphase fluorescent in situ hybridization testing, 25(OH)D insufficiency remained an independent predictor of TTT (HR = 1.47; P = .008), although the association with OS was not significant (HR = 1.47; P = .07). Vitamin D insufficiency is associated with inferior TTT and OS in CLL patients. Whether normalizing vitamin D levels in deficient CLL patients would improve outcome merits clinical testing.

Prognostic factors in chronic lymphocytic leukemia-what do we need to know?

Of all leukemias, chronic lymphocytic leukemia (CLL) shows the highest variability in its clinical presentation and course. CLL can present as an aggressive and life threatening leukemia or as an indolent form that will not require treatment over decades. The currently available clinical staging systems for CLL are simple and inexpensive but lack accuracy to predict disease progression and survival on an individual basis. The increased understanding of the key events of molecular pathogenesis has provided a plethora of novel molecular and biological factors that correlate with the outcome of CLL. This Review provides a concise discussion of the most important discoveries and gives guidance on how to implement novel prognostic tools in the clinical management of CLL by applying the criteria of evidence, relevance, and simplicity to the selection of prognostic markers.

Statin and non-steroidal anti-inflammatory drug use in relation to clinical outcome among patients with Rai stage 0 chronic lymphocytic leukemia

Statins and non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed medications. In vitro studies suggest that statins and NSAIDs may have potential as anticancer therapies in low-grade non-Hodgkin lymphomas including chronic lymphocytic leukemia (CLL), and a recent observational study found statin use was associated with improved event free survival in patients with follicular lymphoma. Other studies have suggested that statins reduce the efficacy of rituximab by inhibiting binding to CD20. We therefore conducted an observational cohort study of 686 patients with newly diagnosed Rai stage 0 CLL to evaluate whether statin or NSAID use was related to their clinical outcome or influenced the efficacy of rituximab therapy. At diagnosis, 136 (20%) patients took statins and 230 (34%) scheduled daily aspirin, ibuprofen, or naproxen. No difference in time to treatment was observed based on statin or NSAID use. Among patients receiving a rituximab-containing first-line therapy, no difference in time to salvage treatment was observed based on statin use. Although previous studies suggested statins may improve event free survival among patients with follicular lymphoma, we find no impact of statins on time to initial therapy in this large study of patients with Rai stage 0 CLL. The in vitro observation that statins reduce rituximab efficacy does not appear to have clinical significance in CLL care.

Platelet-derived growth factor (PDGF)-PDGF receptor interaction activates bone marrow-derived mesenchymal stromal cells derived from chronic lymphocytic leukemia: implications for an angiogenic switch

Malignant cells are capable of influencing the microenvironment in a manner that facilitates tumor cell survival. Bidirectional crosstalk between chronic lymphocytic leukemic (CLL) cells and marrow-derived mesenchymal stromal cells (MSCs) activates both cell types. In this study, we observed that the conditioned medium (CM) obtained from CLL cells was able to induce Akt activation in MSC. Subsequent studies investigated the mechanism of MSC activation mediated by CLL-CM. Platelet-derived growth factor receptors (PDGFRs) were selectively activated in MSCs by CLL-CM and found to be critical receptors for CLL-CM-driven MSC proliferation and MSC Akt activation. The known ligands of PDGFR, platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF), were detected in CLL-CM, but PDGF was the predominant ligand involved in the CM-mediated PDGFR activation. Both PDGF and VEGF were found to be elevated in the plasma of CLL patients with a positive association for high-risk factors and more advanced stage. Finally, we demonstrated that PDGF induced MSC VEGF production through a phosphatidylinositol 3-kinase (PI3K)-dependent mechanism. These results show that PDGF-PDGFR signaling influences at least the MSC in the microenvironment of CLL and may play a role in the induction of an angiogenic switch known to be permissive for disease progression.

Fludarabine followed by alemtuzumab consolidation for previously untreated chronic lymphocytic leukemia: final report of Cancer and Leukemia Group B study 19901

The humanized anti-CD52 monoclonal antibody alemtuzumab is an effective therapy for chronic lymphocytic leukemia (CLL). We examined the impact of alemtuzumab treatment after initial fludarabine treatment for feasibility and safety. Patients (N = 85) with previously untreated symptomatic CLL received fludarabine (25 mg/m(2)/day) for 5 days every 4 weeks for four cycles followed by 2 months of observation. Patients with stable disease or better response then received alemtuzumab 30 mg three times weekly for 6 weeks either intravenously (IV; cohort 1; N = 39) or subcutaneously (SC; cohort 2; N = 20). Of the 85 evaluable patients enrolled on our study, four (5%) attained a complete response (CR) and 43 (51%) attained a partial response after fludarabine induction for an overall response rate (ORR) of 55%. Thirty-nine patients received IV alemtuzumab for consolidation with improvement in CR to 27% and ORR to 73%. Twenty patients received SC alemtuzumab consolidation with improvement in CR to 17% and ORR to 69%. Toxicity from IV alemtuzumab included infusion-related reactions and infection. Mild local inflammation was common from SC alemtuzumab but there were virtually no systemic side effects. Nine of 59 (15%) patients had cytomegalovirus (CMV) infections; one patient died. The administration of alemtuzumab as consolidation therapy following an abbreviated fludarabine induction is feasible but requires close monitoring for CMV infection and other infectious events.

Immunoglobulin heavy chain variable region gene usage and mutational status of the leukemic B cells in Iranian patients with chronic lymphocytic leukemia

The mutational status of the immunoglobulin variable region heavy chain genes (IGHV) is an important prognostic marker in chronic lymphocytic leukemia (CLL). The data accumulated in the literature has largely been derived from studies conducted on Caucasian Western populations. Little is known about Asian CLL patients. In this study the IGHV genes usage and somatic hypermutation status have been investigated in 87 Iranian CLL patients. Based on a cut-off of 98% nucleotide sequence homology, 64.4% and 35.6% of the patients expressed mutated and unmutated IGHV genes, respectively, with most non-progressive patients being in the mutated group (35/44 vs 19/40; P = 0.009). Progression-free survival (PFS) and time to first treatment (TTFT) were significantly higher in our mutated and non-progressive patients compared to unmutated and progressive subtypes, respectively. The most frequently used IGHV gene was IGHV3-7 (12.6%) followed by IGHV3-30 (11.4%), IGHV3-48 (9.2%), IGHV4-39 (6.9%), and IGHV1-8 (6.9%) genes, which taken together comprised nearly half of the IGHV genes expressed in the Iranian CLL patients. Of the IGHV genes, IGHV3-7 was significantly over-represented in non-progressive compared to progressive CLL patients (P = 0.036), whereas IGHV1-69 and IGHV1-2 were expressed at a higher frequency in unmutated compared to mutated CLL patients (P < 0.03). Comparison of IGHV gene usage in our patients with that of Western CLL patients revealed significant differences in expression of IGHV1-69, IGHV3-7, IGHV3-21, and IGHV4-34 genes. Analysis of the IGHV third complementary determining region (HCDR3) sequences revealed a high frequency use of certain HCDR3 motifs, such as YYYGMDV, in our samples. These findings imply contribution of antigen selection and regional (ethnic/geographic) parameters in the leukomogenesis of CLL.

Bi-directional activation between mesenchymal stem cells and CLL B-cells: implication for CLL disease progression

It was hypothesized that contact between chronic lymphocytic leukaemia (CLL) B-cells and marrow stromal cells impact both cell types. To test this hypothesis, we utilized a long-term primary culture system from bone biopsies that reliably generates a mesenchymal stem cell (MSC). Co-culture of MSC with CLL B-cells protected the latter from both spontaneous apoptosis and drug-induced apoptosis. The CD38 expression in previously CD38 positive CLL B-cells was up-regulated with MSC co-culture. Upregulation of CD71, CD25, CD69 and CD70 in CLL B-cells was found in the co-culture. CD71 upregulation was more significantly associated with high-risk CLL, implicating CD71 regulation in the microenvironment predicting disease progression. In MSC, rapid ERK and AKT phosphorylation (within 30 min) were detected when CLL B-cells and MSC were separated by transwell; indicating that activation of MSC was mediated by soluble factors. These findings support a bi-directional activation between bone marrow stromal cells and CLL B-cells.

Intrinsic and extrinsic factors influencing the clinical course of B-cell chronic lymphocytic leukemia: prognostic markers with pathogenetic relevance

B-cell chronic lymphocytic leukemia (CLL), the most frequent leukemia in the Western world, is characterized by extremely variable clinical courses with survivals ranging from 1 to more than 15 years. The pathogenetic factors playing a key role in defining the biological features of CLL cells, hence eventually influencing the clinical aggressiveness of the disease, are here divided into "intrinsic factors", mainly genomic alterations of CLL cells, and "extrinsic factors", responsible for direct microenvironmental interactions of CLL cells; the latter group includes interactions of CLL cells occurring via the surface B cell receptor (BCR) and dependent to specific molecular features of the BCR itself and/or to the presence of the BCR-associated molecule ZAP-70, or via other non-BCR-dependent interactions, e.g. specific receptor/ligand interactions, such as CD38/CD31 or CD49d/VCAM-1. A putative final model, discussing the pathogenesis and the clinicobiological features of CLL in relationship of these factors, is also provided.

Phase I trial of daily oral Polyphenon E in patients with asymptomatic Rai stage 0 to II chronic lymphocytic leukemia

PURPOSE

To define the optimal dose of Polyphenon E for chronic daily administration and tolerability in patients with chronic lymphocytic leukemia (CLL).

PATIENTS AND METHODS

Previously untreated patients with asymptomatic Rai stage 0 to II CLL were eligible for participation. Polyphenon E with a standardized dose of epigallocatechin-3-gallate (EGCG) was administered using the standard phase I design with three to six patients per dose level (range, 400 to 2,000 mg by mouth twice a day). Trough plasma EGCG levels were measured 1 month after initiation of therapy. Response was classified using the National Cancer Institute (NCI) Working Group (WG) Criteria.

RESULTS

Thirty-three eligible patients were accrued to dose levels 1 to 8. The maximum-tolerated dose was not reached. The most common adverse effects included transaminitis (33%, all grade 1), abdominal pain (30% grade 1, 0% grade 2, and 3% grade 3), and nausea (39% grade 1 and 9% grade 2). One patient experienced an NCI WG partial remission. Other signs of clinical activity were also observed, with 11 patients (33%) having a sustained > or = 20% reduction in absolute lymphocyte count (ALC) and 11 (92%) of 12 patients with palpable adenopathy experiencing at least a 50% reduction in the sum of the products of all nodal areas during treatment. Trough plasma EGCG levels after 1 month of treatment ranged from 2.9 to 3,974 ng/mL (median, 40.4 ng/mL).

CONCLUSION

Daily oral EGCG in the Polyphenon E preparation was well tolerated by CLL patients in this phase I trial. Declines in ALC and/or lymphadenopathy were observed in the majority of patients. A phase II trial to evaluate efficacy using 2,000 mg twice a day began in November 2007.