Leukemic Mantle Cell Lymphoma Research Articles

Interference in HbA1c measurement: a case of electropherogram shift due to hyperleukocytosis leading to the discovery of leukemic mantle cell lymphoma

HbA1c is a pivotal biomarker in diabetes management, reflecting long-term glycaemic control. HbA1c is often measured with capillary electrophoresis, which generally is a very precise technique, but there can be interference, especially in the case of haemoglobin diseases. Thus, in patients with underlying conditions, the accurate measurement of HbA1c can be challenging. We present a case of special interference in a 74-year-old female patient referred to a HbA1c test, in whom the measurement was thought to be significantly affected by hyperleukocytosis and led to an unexpected diagnosis of leukemic low-grade lymphoma. This case report highlights the underrecognized potential interference of leukocytosis in HbA1c measurement. It underscores the importance of clinical vigilance when interpreting HbA1c results in patients with underlying haematological conditions.

Dissecting the Single Cell Landscape of Leukemic Mantle Cell Lymphoma

Introduction: Resistance to therapy remains a major challenge for Mantle Cell Lymphoma (MCL) patients, despite a diverse and expanding treatment landscape. There is thus a major need to better understand the mechanistic underpinnings of therapy resistance in order to optimize treatment selection. Given the advent of immunotherapies in recent years, there has been increasing evidence that not only tumor-intrinsic factors affect therapy resistance, but that tumor-immune cell interactions are an additional major contributor. In the context of MCL, such interactions have been poorly characterized, but hold the promise of identifying novel treatment approaches and better understanding resistance mechanisms to commonly applied therapies such as BTK inhibition. Methods: This study aimed to investigate the single-cell landscape of leukemic MCL using single-cell profiling of 26 patients and 10 healthy donors. In addition, we performed in vitro drug testing on a subset of patient samples (n=12; 6 treatments) to understand the effects of drugs on both tumor and immune cells in MCL . To comprehensively characterize the phenotypic and functional features of immune and tumor cells within a single-cell landscape, we employed high-dimensional full-spectrum cytometry. Therefore, we developed 5 high-dimensional panels covering markers to deeply interrogate T and NK cells, immune evasion and immune checkpoints, cytokines and cytotoxicity, cellular trafficking and intracellular signaling/phosphoproteome (covering >120 proteins). We combined this with single-cell RNA sequencing and a scalable and reproducible bioinformatics pipeline. To assess the disease specificity of the immune landscape, we also obtained single-cell data from other B-NHL including MZL and CLL (n=60 patients). Results: Our data indicate profound changes in the immune landscape, in particular in the T cell compartment of MCL patients. In this regard, multi-omics factor analysis (MOFA) confirmed a highly distinct T cell landscape in MCL patients, characterized by higher effector marker expression in conventional CD4+ and CD8+ T cells in addition to higher fraction of effector and effector memory T cells compared to healthy donors (Fig. 1A and B). Moreover, our analysis revealed a pronounced expansion of highly suppressive regulatory T cells (~5% of T cells) (Fig.1B). The emergence of this effector Treg (eTreg) subset in MCL patients might limit efficient anti-tumor immunity of CD8+ and conventional CD4+ T cells. Consistent with this, we observed a high fraction of several dysfunctional CD8+ T cells subsets. Notably, we found a remodeling of this eTreg subset in patients undergoing ibrutinib treatment leading to a less pronounced suppressive phenotype and concomitantly observed an increase of proteins crucial for cytotoxic function such as Granzyme B and Interferon-γ in effector T cells. We further sought to link tumor cell signatures with the healthy immune cell signatures in order to assess potential interactions and mechanisms of immune escape. As such, the tumor cell compartment (MCL cells) displayed high-expression of inhibitory immune checkpoint ligands such as PVR, HLA-G, CD70 and PD-L1 and antiphagocytic proteins such as CD47 and CD24, which may contribute to the dysfunctional T cell compartment. In line with this, our analysis revealed that high expression of the immune checkpoint ligand CD70 on malignant B cells was inversely associated with an activation module in CD4+ T cells, providing a potential axis contributing to immune escape, which may be leveraged for future therapeutic use. Finally, we identified tumor and immune cell signatures associated with in vitro drug response that may not only be useful for improving treatment selection, but also offer novel biological insights into potential mechanisms of treatment resistance. Conclusion: This study provides valuable insights into the single-cell landscape of leukemic MCL, offering crucial understanding of how tumor-immune cell interactions may contribute to disease progression and treatment resistance. The findings hold potential for therapeutic exploitation to eventually improve patient outcomes in Mantle Cell Lymphoma.

Effective therapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone chemotherapy with obinutuzumab for follicular lymphoma in leukemic phase

The patient, a 56-year-old lady, also exhibited numerous lymphadenopathy, hepatosplenomegaly, hyperleukocytosis (167,200/µl, aberrant lymphocytes 91.5%), and fever. A lymph node biopsy revealed follicular lymphoma (FL), grade 1. Peripheral blood tumor cells did not express CD10, which was a distinctive characteristic of the lymph node specimen. To prevent tumor lysis syndrome (TLI), CHOP was delivered without an anti-CD20 antibody, but afterward, residual lymphoma cells were found in peripheral blood (>80%). As a result, obinutuzumab (Obi) was given on day 8 following the second round of CHOP, and the tumor cells in the peripheral blood vanished without any major side effects like TLI. She underwent six chemotherapy sessions before receiving maintenance therapy with Obi and achieving a full metabolic response. According to reports, leukemic FL exhibits negative CD10 expression in peripheral blood lymphoma cells, while leukemic mantle cell lymphoma also shows this trait. Therefore, it is important not to confuse the two types in diagnosis. Leukemic FL with significant leukocytosis is reportedly uncommon and has a bad prognosis. Our case indicates that CHOP with Obi would be a good alternative for cases like yours, however, there have been a few cases recorded. Further case accumulation or investigation is warranted.

Updates in the treatment of mantle cell lymphoma: A Canadian expert framework

Mantle cell lymphoma (MCL) is a B cell Non-Hodgkin Lymphoma that develops in the mantle zone of the lymph node. It is more common in men and is usually diagnosed at an advanced stage with involvement of lymph nodes, bone marrow, and potentially the gastrointestinal tract. MCL accounts for 5–10% of all new NHL cases per year in Canada, which is estimated at 11,400 for 2022. While most patients respond to initial treatment, relapses occur early and MCL generally shows a variable response to subsequent treatments, often with limited duration of benefit. Two main subtypes of MCL can be distinguished that arise from in situ MCL lesions. The most common subtype, classic MCL, arises from these cells with limited or no immunoglobulin heavy chain variable region (IGHV) mutations. Cells from this subtype express SOX11, are genetically unstable, and have naïve B cell-like characteristics. Classic MCL is more often nodal and extranodal and may eventually progress to aggressive blastoid or pleomorphic MCL. The other subtype, leukemic non-nodal MCL, arises from cells that have undergone IGHV somatic hypermutations, do not express SOX11, and exhibit characteristics of memory B cells. This subtype can have an indolent clinical behavior for a long time, often several years, but frequently acquires TP53 and other mutations and progresses to a more aggressive subtype. Treatment options have expanded significantly over the past decades, with improvements in both overall survival (OS) and progression-free survival (PFS) compared to earlier treatment eras. This Canadian expert framework aims to discuss the management considerations for patients with MCL, and will present both front-line treatment options as well as those for relapsed and refractory disease.

Whole-Genome Analysis of Histone Modifications Reveals New Insights into the Biology and Clinical Behavior of Mantle Cell Lymphoma Subtypes

Introduction: Mantle cell lymphoma (MCL) is a mature B-cell neoplasm characterized by the t(11;14)(q13;q32) leading to cyclin D1 overexpression. Two major clinico-biological subtypes of MCL have been recognized, conventional (cMCL) and leukemic non-nodal MCL (nnMCL), being the former clinically more aggressive than the latter. Although these subtypes have been well characterized at the genomic level, the genome-wide landscape of histone modifications is widely unknown. Aim: To explore whether an integrative multiomic analysis of chromatin marks and gene expression may help us to better understand the biology and clinical behavior of cMCL and nnMCL. Methods: We carried out 2 profiling strategies. On the one hand, we performed ChIP-seq for H3K27ac, which marks active regulatory elements, in a series of 52 MCL cases, and we also profiled chromatin accessibility by ATAC-seq in 28 of these cases. On the other hand, we performed ChIP-seq for 6 histone modifications with complementary functions (H3K4me1, H3K4me3, H3K27ac, H3K36me3, H3K27me3 and H3K9me3) in purified neoplastic cells of 3 cMCL and 3 nnMCL, and we mined ChIP-seq data from normal B cell subpopulations. Additionally, we analyzed previously published expression data from 44 MCL profiled by Affymetrix U219 microarrays. Clinical data were available for most cases. Data were analyzed using a battery of computational and statistical approaches. Results: An initial unsupervised principal component analyses of the H3K27ac and ATAC-seq data revealed 2 main clusters corresponding to cMCL and nnMCL, indicating that the chromatin landscape is markedly different between the 2 MCL subtypes. A supervised differential analysis of H3K27ac data between cMCL and nnMCL showed extensive differences, mostly associated with increased H3K27ac in cMCL. Putting the data in the context of normal B cell subpopulations, we identified 746 de novo active regions in cMCL and 126 in nnMCL (LFC>1, FDR ≤0.05). Interestingly, more than 60% of these regions were enhancers according to the chromatin states analysis (derived from the integration of 6 histone modifications), and the majority of them presented an open chromatin configuration. This chromatin activation patterns correlated with transcriptional differences between cMCL and nnMCL. Analyzing the target genes of these regions, we identified 167 and 20 upregulated genes in cMCL and nnMCL, respectively. Upregulated genes in cMCL were linked to cellular processes related to cell cycle and cell proliferation according to gene ontology analysis. Analyzing the transcription factor binding motifs present in the ATAC-seq peaks among the de novo active H3K27ac regions in cMCL, we observed an enrichment in specific transcription factor families such as Krüppel-like family (KLF) and E2F. However, there was no significant enrichment in any transcription factor family among nnMCL de novo active regions. Moreover, although the cMCL-associated de novo H3K27ac signature was common to all cMCL cases, we did observe varying H3K27ac levels among cases. We then explored whether H3K27ac levels could be associated with clinical features in cMCL. In fact, we identified 100 specific regions whose increased H3K27ac levels were significantly associated with shorter overall survival, leading to the identification of two subgroups of cMCL with markedly different clinical behavior. Conclusions: The results obtained with this multilayer chromatin analysis confirm that MCL is a heterogeneous disease showing widespread differences between the 2 subtypes. cMCL present a clear de novo chromatin activation associated with upregulation of key genes involved in cMCL pathogenesis, while nnMCL cases seem to be characterized by the absence of this signature and an overall chromatin profile more similar to normal B cells. Moreover, the level of activation in regulatory regions in cMCL seems to be related with the clinical outcome of the patients, with more activation associated with shorter overall survival.

Mutations of ATM Confer a Risk of Inferior Survival in Patients with TP53-wild Type Mantle Cell Lymphoma

Background: Despite improved approaches to prognostication in mantle cell lymphoma (MCL), the impact of specific genomic aberrations is not well-described beyond TP53, which is well recognized as a high-risk marker across malignancies and widely assessed at time of diagnosis. However, since outcomes in patients without TP53 aberrations can be highly variable and difficult to predict, additional molecular markers are needed to identify patients who are at high risk for early relapse and inferior OS (Bond et al, Blood Adv 2021). In this study, we used comprehensive whole exome and transcriptome sequencing to genomically assess the prognostic impact of recurrent abnormalities in patients with MCL with and without TP53 aberrations. Methods: The Atlas of Blood Cancer Genomes (ABCG) project is a worldwide effort to systematically profile the genetic alterations and expression changes in all blood cancers. We recruited MCL patients with detailed clinical data available and subjected their tumors to whole exome and transcriptome sequencing. TP53-aberrant cases were identified from the genomic and diagnostic data. Progression-free survival (PFS) and overall survival (OS) were measured from the date of diagnosis until date of progression/relapse or death (PFS) or death (OS) using the Kaplan-Meier method and statistical comparisons by the logrank test. Results: Whole exome and whole transcriptome sequencing was performed successfully for 252 patients with MCL. Consistent with previous descriptions of the disease, median age at diagnosis was 65 years (range: 32-96), and 73% of patients were male. Seventy-five percent of patients had stage IV disease, and MIPI score was high, intermediate, or low in 34%, 34%, and 32% of patients, respectively. Ki67 proliferative index was ≥30% in 48% of patients with available data (n=115). Most patients received commonly used MCL therapies. Of the 185 patients for whom first-line treatment was known, 28% received bendamustine-containing regimens, 42% received cytarabine-containing regimens, and the remaining 30% received other regimens. Twenty-one percent of patients underwent autologous stem cell transplant consolidation as part of first-line therapy. Seventeen percent of patients had blastoid or pleomorphic histology, and 3% had leukemic non-nodal type MCL. Median PFS for the entire cohort was 41 months, and median OS was 138 months. As expected, patients with a confirmed TP53 abnormality (n=39) had inferior median OS compared to TP53-WT patients (n=84; 39 months vs 138 months, p<0.001). Recurrent mutations identified in TP53-aberrant and TP53-WT patients are presented in Figure 1. Among TP53-WT patients, the following genes were mutated in ≥10% of cases: ATM (45%), KMT2D (23%), PTPN13 (13%), NOTCH1 (13%), NSD2 (11%), and SPEN (10%). Incidence of ATM mutations in TP53-aberrant patients was 21% and was less common in patients with TP53 mutations (14%) rather than deletions (30%). Presence of an ATM mutation (median variant allele frequency 43%; range 15-96%) in TP53-WT patients was associated with inferior median PFS (38 months vs 138 months for ATM WT, p=0.023) (Figure 2); median OS was also shorter in patients with ATM mutations (104 vs 138 months, p=0.035). Although the incidence of ATM mutations was lower in TP53-aberrant patients, there was no significant association between ATM mutation and PFS or OS in that subgroup. Conclusions: To our knowledge, this study represents the largest genomic characterization of clinical outcomes in MCL patients. These findings suggest a pathogenic role for ATM mutations in patients with TP53-WT MCL and provide molecular insights into their heterogeneous outcomes. Although ATM mutations have been previously shown to be mutually exclusive with TP53 mutations (Mareckova et al, Leukemia & Lymphoma 2019), to our knowledge this is the first study that shows prognostic differences by ATM mutation status among TP53-WT patients. Our data indicate that ATM mutations are a significant prognostic factor and should be assessed at diagnosis along with TP53. Further clinical investigation of ATM mutations in TP53-WT MCL patients will be important to determine how this molecular marker may inform risk stratification and treatment approaches. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Complex Structural Variation Associated with Enhancer Hijacking and Loss of Tumor Suppressors in Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a rare, incurable mature B-cell lymphoma that can have either an aggressive or indolent clinical course. The hallmark aberration of MCL is the t(11;14)(q13;q32) translocation that places CCND1 under control of the immunoglobulin heavy chain (IGH) locus resulting in its constitutive expression. CCND1/IGH translocation occurs in nearly all MCL cases and arises during VDJ recombination. Whole genome sequencing (WGS) of MCLs has shown the prevalence of additional structural variations (SV), particularly in tumors with poor outcome. Complex rearrangements, such as chromothripsis and chromoplexy have been observed in MCL but their role in lymphomagenesis has not been determined. We hypothesized that some of these complex rearrangements afford a selective advantage to the tumor by disrupting tumor suppressor genes or by placing oncogenes in proximity to regulatory elements in cis, thereby resulting in ectopic expression.We performed WGS on tumor DNA extracted from 106 RCHOP-treated MCL patients. Matching ribosomal-depleted RNA-seq data was available for all tumor samples. Gene expression count values were obtained using Salmon and counts were normalized using the DESeq2 method. Structural variants were identified using a consensus between GRIDSS and Manta and these were analyzed to identify the topology of complex rearrangements using JaBbA. This allows the annotation of rearrangements such as chromothripsis and chromoplexy and enables the detection of genes near new regulatory elements through complex (multi-breakpoint) rearrangements. We supplemented this analysis by including 57 published classical and non-nodal leukemic MCL genomes.Chromothripsis and chromoplexy were observed in 8 and 12 tumors, respectively. The majority of the genomes were associated with isolated structural variations such as large deletions, inversions and reciprocal translocations were more common. Six genes (BCL10, TRAF6, TRAF3, MAP3K7, BTK, RELB) coding for canonical and non-canonical NFκB signaling proteins were found rearranged to within 1Mbp of a naïve B-cell super-enhancer region. The TRAF6 rearrangement was part of a chromothripsis and chromoplexy event involving both chr9 and chr11. A separate chromothripsis example involving chr1 placed each of BCL10 and NOTCH2 within 100-200kbp of super-enhancers. A 1Mbp region containing RELB was amplified and inserted into chr19p approximately 150kbp downstream a super-enhancer. An 800kbp deletion brought MAP3K7 to within 400kbp of a super-enhancer. DAZAP1, a gene known to be recurrently mutated in MCL, was translocated upstream to within 300kbp of a super-enhancer by t(5;19)(p13.3;p15.33). TRAF3 was translocated 400kbp upstream a super-enhancer by t(14;20)(q32.32;q13.13). None of the aforementioned SVs were associated with a detectable increase in expression of the affected gene. In contrast, we identified one genome in which the MYC oncogene was relocated 500kbp upstream of a super-enhancer via an unbalanced t(4;8)(q21.23;q24.21) translocation. In this case, MYC expression was in the 95 th percentile of MYC expression across the cohort. Focal deletions and amplifications were also found affecting lymphoma driver genes. Focal amplifications affecting 3q (34 tumors) and 5p (9 tumors), were among the most common recurrent events. These respectively affect the TERC and TERT genes, both involved in telomerase function. All tumors with TERT amplifications also showed TERC amplifications. TERC and TERT were expressed higher on average in amplified tumors than in unamplified tumors. Two tumors showed focal deletions affecting the 3‘ end of BIRC3. The focal deletion in one tumor was found to span to the 3‘ end of BIRC2 resulting in a BIRC2/BIRC3 fusion. Aberrant splicing across the two genes was evident in matching tumor RNA-seq data.Complex rearrangements in MCL have been found to link distant super-enhancer elements with a variety of lymphoma oncogenes. We noted a recurrence of such events affecting known regulators of NFκB signaling. We are using nanopore-based long-read PromethION sequencing to validate the structure of the derivative chromosome in these cases. Although these genes were not detectably overexpressed, deregulation of genes may be occurring by other means. The full extent of deregulation of NFκB and other oncogenic pathways will be revealed as complex rearrangements are studied in additional MCL tumors. DisclosuresCoyle: Allakos, Inc.: Consultancy. Melnick: Epizyme: Consultancy; Daiichi Sankyo: Research Funding; Sanofi: Research Funding; Janssen Pharmaceuticals: Research Funding; Constellation: Consultancy; KDAC Pharma: Membership on an entity's Board of Directors or advisory committees. Scott: BC Cancer: Patents & Royalties: Patent describing assigning DLBCL COO by gene expression profiling–licensed to NanoString Technologies. Patent describing measuring the proliferation signature in MCL using gene expression profiling. ; AstraZeneca: Consultancy; Abbvie: Consultancy; NanoString Technologies: Patents & Royalties: Patent describing measuring the proliferation signature in MCL using gene expression profiling.; Rich/Genentech: Research Funding; Celgene: Consultancy; Incyte: Consultancy; Janssen: Consultancy, Research Funding. Morin: Epizyme: Patents & Royalties; Celgene: Consultancy; Foundation for Burkitt Lymphoma Research: Membership on an entity's Board of Directors or advisory committees.

The pathologic diagnosis of mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a mature B-cell non-Hodgkin lymphoma usually characterized by t(11;14) (q13;q32), or CCND1 translocation and Cyclin D1 over expression. A very small subset of MCL may lack the t(11;14) (q13;q32) translocation and Cyclin D1 over expression, but show alternative translocations involving CCND2 and CCND3, and over expression of SOX11. In general, MCL has been considered a very aggressive and incurable lymphoma and patients with MCL usually have a poor prognosis. However, indolent variants, including in situ mantle cell neoplasm and the recently recognized leukemic non-nodal MCL do exist. In recent years, genome-wide molecular genetic studies have revealed a characteristic MCL genetic profile. This review will focus on the pathologic diagnosis of MCL using the traditional morphological and immunophenotypic strategies combined with cytogenetic characteristics and recently identified molecular profile. Morphological subtypes, immunophenotypic variants, recently recognized indolent variants, as well as MCL risk stratification will also be discussed.

Pathology and Diagnosis of Mantle Cell Lymphoma

Mantle Cell Lymphoma (MCL) is a rare type of B-cell non-Hodgkin lymphoma (NHL), characterised by an aggressive clinical course and a poor prognosis that remains incurable for the majority of patients. Cyclin D1 overexpression, which results from t(11; 14)(q13; q32), is the pathogenic hallmark in MCL disease and causing cell cycle disruption. MCL has been categorized based on lymphoid malignancies in the WHO update into two significant subgroups, nodal and leukemic non-nodal MCL; each type has a particular clinical presentation and distinct molecular features. SOX11 is overexpressed in nodal MCL subtype, while the leukemic non-nodal sub-type is associated with SOX11 negativity. MCL has a wide range of differential diagnoses, including other types of low-grade lymphoma, most notably chronic lymphocytic leukaemia (CLL), follicular lymphoma (FL), marginal zone lymphoma (MZL), and lymphoblastic lymphoma (LBL). Therefore, accurate histological biopsy diagnosis is paramount in this rare subtype of NHL. MCL has a distinctive clinical presentation and particular morphological and immunophenotypic features with specific cytogenetic abnormalities. The recent advances in molecular and cytogenetic analysis have improved the accuracy of MCL diagnosis and enhanced disease prognosis. Furthermore, B cell receptor inhibitors have revolutionized MCL treatment. Therefore, an accurate diagnosis of MCL is very important since this may require an aggressive and novel targeted therapy.

Stabilization of β-catenin upon B-cell receptor signaling promotes NF-kB target genes transcription in mantle cell lymphoma.

B-cell receptor (BCR) signaling pathways and interactions with the tumor microenvironment account for mantle cell lymphoma (MCL) cells survival in lymphoid organs. In several MCL cases, the WNT/β-catenin canonical pathway is activated and β-catenin accumulates into the nucleus. As both BCR and β-catenin are important mediators of cell survival and interaction with the microenvironment, we investigated the crosstalk between BCR and WNT/β-catenin signaling and analyzed their impact on cellular homeostasis as well as their targeting by specific inhibitors. β-catenin was detected in all leukemic MCL samples and its level of expression rapidly increased upon BCR stimulation. This stabilization was hampered by the BCR-pathway inhibitor Ibrutinib, supporting β-catenin as an effector of the BCR signaling. In parallel, MCL cells as compared with normal B cells expressed elevated levels of WNT16, a NF-κB target gene. Its expression increased further upon BCR stimulation to participate to the stabilization of β-catenin. Upon BCR stimulation, β-catenin translocated into the nucleus but did not induce a Wnt-like transcriptional response, i.e., TCF/LEF dependent. β-catenin rather participated to the regulation of NF-κB transcriptional targets, such as IL6, IL8, and IL1. Oligo pull down and chromatin immunoprecipitation experiments demonstrated that β-catenin is part of a protein complex that binds the NF-κB DNA consensus sequence, strengthening the idea of an association between the two proteins. An inhibitor targeting β-catenin transcriptional interactions hindered both NF-κB DNA recruitment and induced primary MCL cells apoptosis. Thus, β-catenin likely represents another player through which BCR signaling impacts on MCL cell survival.

Leukemic Non-nodal Mantle Cell Lymphoma: Diagnosis and Treatment.

Mantle cell lymphoma (MCL) encompasses nearly 6% of all the non-Hodgkin lymphomas. It is considered an incurable neoplastic process arising from B cells. The cytogenetic abnormality t(11;14) (q13; q32) leading to cyclin D1 overexpression is the sentinel genetic event and provides an exceptional marker for diagnosis. MCL is generally considered to have an aggressive course as compared with other indolent lymphomas with traditionally reported median survival of 3-5years. According to the 2016 WHO classification, there are two major known variants of MCL: classical which affects the lymph nodes and extra nodal sites and leukemic non-nodal MCL (L-NN-MCL) which characteristically involves the bone marrow, peripheral blood, and the spleen. It is important to distinguish between classical and leukemic non-nodal MCL since the latter variant of MCL follows a rather indolent course with a wait and watch approach in order to avoid overtreatment. However, a subset of patients with L-NN-MCL can transform into a more aggressive course requiring treatment. Current evidence suggests those patients with alteration in TP53 gene do not respond to standard chemotherapy agents and may need targeted therapy. In this review, we describe the characteristics of L-NN-MCL, its diagnosis, and management.

T-Cell Clonal Expansion and Activation Associated with Durable Clinical Response to Dual BTK and CDK4/6 Inhibitor Therapy in Mantle Cell Lymphoma

T-Cell Clonal Expansion and Activation Associated with Durable Clinical Response to Dual BTK and CDK4/6 Inhibitor Therapy in Mantle Cell Lymphoma

Subtype Distribution, Clinical Features, and Survival in B-cell Chronic Lymphoproliferative Disorders in China: A Review of 1592 Cases

BackgroundB-cell chronic lymphoproliferative disorders (B-CLPDs) are characterized by the sustained accumulation of monoclonal B cells. Limited studies have systematically described the clinical features and outcomes of the whole patient group, especially in Eastern populations. Patients and MethodsA total of 1592 patients with newly diagnosed B-CLPD were enrolled. Chronic lymphocytic leukemia (CLL) accounted for 39%, and Waldenström macroglobulinemia (WM), leukemic marginal zone lymphoma, follicular lymphoma (FL), and mantle cell lymphoma (MCL) constituted 13%, 13%, 9%, and 8% of cases, respectively. ResultsThe median age at diagnosis was 58 years, and the male/female ratio was 1.8:1. The 17p and 11q deletions were most common in MCL (36% and 17%, respectively), and 13q deletion and trisomy 12 were most frequent in CLL (35% and 21%, respectively). Patients with leukemic MCL had significantly worse survival than that of patients with other disease entities, with a 3-year overall survival (OS) of 58%, followed by 68.2% for WM/lymphoplasmacytic lymphoma. Those with CLL, leukemic marginal zone lymphoma, and FL had relatively favorable outcomes, with a 5-year OS > 80%. The survival of patients with B-CLPDs has improved over time with the emergence of novel drugs (3-year OS improvement from 82.1% to 92.2%). The improvement in survival mainly resulted from improvement among patients with MCL, WM/lymphoplasmacytic lymphoma, and FL. On multivariate analysis, only hemoglobin, lactate dehydrogenase, and 17p deletion were independently associated with survival (hazard ratio, 1.6, 2.0, and 3.1, respectively). ConclusionsComprehensive analysis of the clinical characteristics, immunophenotypic profiles, and cytogenetic features can be helpful in the differential diagnosis, especially for patients without a non–bone marrow biopsy specimen available. Universal prognostic factors could help with the early detection of high-risk patients and stratification for risk-adapted therapy.

Mantle cell lymphoma pathology update in the 2016 WHO classification

Mantle cell lymphoma (MCL) is an aggressive mature B-cell neoplasm genetically characterized by the presence of the t(11;14)(q13;q32) that leads to the constitutive overexpression of cyclin D1. The pathological and biological spectrum of this neoplasm has been expanded in recent years. This improvement in the knowledge of the disease has provided a better understanding of the diverse clinical evolution of the patients. The characterization of cyclin D1-negative MCL has led to the identification of cyclin D2 and D3 translocations as alternative mechanisms in this variant. Two major biological and clinical subtypes of the disease have been recognized, conventional and leukemic non-nodal MCL (nnMCL). MCL derives from CD5+ mature B-cells that have bypassed or experienced the germinal center microenvironment, retain a naive or memory-like epigenetic signature and carry a variable load of somatic mutations in the IGHV region; from truly unmutated to highly mutated, respectively. These two subtypes of tumors also differ in their genomic alterations, and clinical behavior, the conventional MCL (cMCL) being more aggressive than the leukemic nnMCL. This review will focus on the new aspects of the pathology of MCL in the updated 2016 WHO classification and its relevance for the clinical practice.

CSF1R and BTK Inhibitions As Novel Strategies to Disrupt the Dialogue between Mantle Cell Lymphoma and Macrophages

The aggressive clinical behavior of mantle cell lymphoma (MCL) and its short-term response to treatments highlight a need for novel options. The microenvironment strongly controls MCL cell survival, proliferation and chemoresistance, nevertheless little is known regarding the interactions that occur in the tumor niches. Here, we studied the interplay between primary MCL cells (n=55) and macrophages and identified mechanism-based targeted strategies to disrupt this dialogue.Using ex vivo co-cultures of peripheral blood MCL cells and monocytes (healthy donors), we showed that monocytes greatly improved MCL cell survival, whereas MCL cells poorly survived when cultured alone (co-culture, 85.9%; alone, 6.5%; D7; n=17; p<0.001). We also demonstrated that monocytes supported the proliferation of conventional (n=7) and blastoid (n=4), but not leukemic non-nodal MCL subtypes (n=5) (p<0.05).During co-culture, primary MCL cells polarized monocytes into MCL-associated-macrophages (MϕMCL). To define the nature of MϕMCL, we studied their phenotype and function with 12 markers differentially expressed in M1 and M2 macrophages (CD14, CD68, CD163, CD11b, CD86, HLA-DR, CD16, CD23, IL10, IL6, IGF1, BAFF). The analysis showed that even though MϕMCL distinctly clustered from both M1 and M2, they shared more similarities with M2 (CD163high, CD11blow, IL10+, IGF1+).To determine how MCL cells polarized monocytes into CD163high MϕMCL, we analyzed the expression of known M2-polarizing factors and observed that CSF1 and IL10 were overexpressed in MCL cells compared to normal B cells (GEP, p<0.01). CSF1 and IL-10 were detected at the protein level in co-culture (ELISA), and CSF1, but not IL-10, neutralization significantly blocked MϕMCL polarization ex vivo. Previous studies reported modulations of the MCL secretome upon BTK inhibition. Here, we demonstrated that both CSF1 and IL-10 were inhibited upon ibrutinib treatment (0.5 µM) in sensitive MCL cells, whereas no modulation was observed in ibrutinib-resistant cells. Reduction of the CSF1 level by ibrutinib consequently inhibited M2-like polarization and resulted in the inhibition of MϕMCL-dependent tumoral survival (n=8/14) and proliferation (n=4/4). Nevertheless, 6 MCL samples cocultured with MϕMCL appeared resistant to ibrutinib. To test whether targeting the CSF1R could bypass this resistance, we treated MCL/MϕMCL coculture with the inhibitor GW2580. We showed that CSF1R inhibition efficiently reduced the viability of ibrutinib-resistant MCL cells. Moreover, the combination in low concentrations of ibrutinib/GW2580 (125nM) induced a supra-additive effect in ibrutinib-sensitive samples.In vivo, we showed higher levels of CSF1 and IL-10 in the plasma of MCL patients (n=28) compared to match-aged HD (p<0.01). We also showed that CD163 was overexpressed at the surface of circulating monocytes in MCL compared to HD (n=32; p < 0.05), which was consistent with the CD163-inducing properties of CSF1 and IL-10. Taking advantage of a local clinical trial (NCT02558816), we evaluated modulations of CSF1 and IL-10 plasma concentrations as well as CD163 expression on monocytes from 8 patients treated with ibrutinib. We observed a reduction of CSF1 and IL-10 as well as inhibition of CD163 expression in 7/8 patients after 8 days (D8) of treatment (median CD163+ reduction, - 58%). We performed longitudinal follow-up of 4 patients treated with ibrutinib, 3 were characterized by a dramatic reduction in CD163 at D8 and achieved a durable complete response. In contrast, 1 patient who displayed an increase in CD163 at D8, progressed upon treatment.In conclusion, through secretion of IL-10 and CSF1, MCL cells polarized monocytes into M2-like macrophages (MϕMCL), which in turn support tumor survival and proliferation. Ibrutinib counteracts the MCL/MϕMCL dialogue through inhibition of CSF1 production and, consequently, impairs the MϕMCL-dependent expansion of ibrutinib-sensitive MCL cells. Of note, our in vivo retrospective analysis highlights that CSF1, IL-10 and CD163 modulations might be early markers of ibrutinib response. A larger cohort of MCL patients treated with ibrutinib is now necessary to confirm the strength of this soluble and cellular signature. Lastly, targeting the CSF1R is an alternative to disrupt the MCL/MϕMCL pro-tumoral dialogue, especially for ibrutinib-refractory patients for which no therapeutic alternative is available. DisclosuresMoreau:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Le Gouill:Roche: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria.

SOX11, a key oncogenic factor in mantle cell lymphoma.

SOX11 has emerged as a key transcription factor in the pathogenesis of mantle cell lymphoma (MCL) whereas it is not expressed in normal B cells or virtually in any other mature B-cell neoplasm. This review will examine the role of SOX11 as a biomarker in MCL, the new information on its transcriptional targets, and the mechanisms regulating its expression in MCL. SOX11 is highly expressed in conventional MCL, including cyclin D1-negative cases, but it is not expressed in the indolent leukemic nonnodal MCL subtype. These two MCL subtypes also differ in their cell-of-origin, IGHV mutational status and genomic instability. SOX11 promotes tumor growth of MCL cells in vivo and regulates a broad transcriptional program that includes B-cell differentiation pathways and tumor-microenvironment interactions, among others. The mechanisms upregulating SOX11 in MCL are not well understood but are mediated in part by the three-dimensional reconfiguration of the DNA, bringing together a distant enhancer region and the SOX11 promoter. SOX11 is a relevant element in the pathogenesis of MCL and has been instrumental to identify two distinct clinicobiological subtypes of this tumor. Further studies should clarify the mechanisms mediating its oncogenic potential and leading to its intriguing expression in these tumors.

Leukemic mantle cell lymphoma and chronic lymphocytic leukemia: a rare composite lymphoma and literature review

Composite lymphomas are rare entities that either represent a collision of two separate lymphomas, or one lymphoma that expresses two distinct phenotypes. Mantle cell lymphoma has been reported in some composite lymphomas, but when combined with chronic lymphocytic leukemia, it can be difficult to recognize because of the phenotypic overlap of these two entities. We report a case of a 75-year-old male with a slowly progressing lymphocytosis, but who was otherwise asymptomatic. Flow cytometry revealed two different populations, one showing bright Lambda positivity and CD5(+), while the other was positive for both lambda and kappa and was CD5(+). Subsequently, cytogenetics revealed two different populations, one with a trisomy 12 and the other with a t(11;14). Additionally, immunohistochemistry on a bone marrow biopsy showed SOX-11 to be negative and cyclin D1 to be positive on scattered lymphocytes. This was consistent with a composite lymphoma of leukemic mantle cell lymphoma and chronic lymphocytic lymphoma.

Role of SOX11 and Genetic Events Cooperating with Cyclin D1 in Mantle Cell Lymphoma.

Mantle cell lymphoma (MCL) is an aggressive lymphoid neoplasm, incurable with current therapies. The t(11;14)(q13;q32) involving cyclin D1 is considered the first oncogenic hit found in virtually all MCLs. However, additional secondary genomic alterations are essential for complete transformation. MCLs are genetically very unstable with several genetic alterations associated with its high proliferative behavior involving several oncogenic pathways. Furthermore, SOX11 is overexpressed in the majority of conventional MCLs (cMCL), including cyclin D1-negative cases, but absent in non-nodal leukemic MCL with indolent clinical behavior (nnMCL). Recent data have revealed the potential oncogenic role of SOX11 in MCL biology, highlighting its implication in tumor aggressiveness and progression. This review addresses the implication of SOX11 overexpression and frequent genetic lesions, cooperating with cyclin D1 underlying the pathogenesis of this aggressive disease.

Reproducibility of SOX-11 detection in decalcified bone marrow tissue in mantle cell lymphoma patients

Mantle cell lymphoma (MCL) usually harbors the t(11;14)(q13;q32) with overexpression of CCND1 mRNA and transcription of the cyclin D1 nuclear protein. Regardless of CCND1 status, most MCLs also express the SOX11 nuclear protein, which is thus helpful in the diagnosis of the rare CCND1-negative MCLs. Recently, SOX11 has been reported to be often negative in MCLs clinically resembling marginal zone lymphoma and recently defined as "leukemic non-nodal" MCL in the incoming revision of the WHO classification of lymphoid tumors, for which the bone marrow biopsy is commonly the first diagnostic approach. Due to the less aggressive clinical behavior of the latter MCLs, the reliable determination of the SOX11 antigen in decalcified tissue is mandatory. To this end, since little data are available in the literature, four commercially available anti-SOX11 antibodies (two polyclonal and two monoclonal) were tested on 21 positive staging bone marrow (BM) biopsies from cyclin D1/SOX11-positive MCL patients (17 fixed in B5, 4 in 10% buffered formalin) and on 9 positive BM biopsies from leukemic non-nodal MCL patients. The results were compared for specificity, sensitivity, staining strength and degree of an additional staining on myeloid precursors, also evaluating possible impact of the different fixatives used. Non-mantle cell lymphomas were also tested to address specificity. All reagents showed high sensitivity but the monoclonal code CMC38221001 provided the highest specificity and the lowest degree of non-lymphoid staining on myeloid cells. Formalin fixation generally improved the performance of most antibodies when compared to B5 fixation.

Autoimmune haemolytic anaemia in mantle cell lymphoma : an insidious complication associated with leukemic disease

Autoimmune haemolytic anaemia in mantle cell lymphoma : an insidious complication associated with leukemic disease