Leukemic Mantle Cell 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.

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.

Activity and biophysical properties related to clinical evaluation of a first-in-class EHL ROR1xCD3 T Cell Engager.

e14505 Background: NVG-111, a T cell engager (TCE) targeting ROR1 and CD3, is in clinical development for the treatment of Chronic Lymphocytic Leukemia (CLL) and Mantle Cell Leukemia (MCL). This 55KDa molecule consisting of humanised tandem scFvs is administered into patients as a continuous intravenous infusion. The intrinsically short half-life of NVG-111 has its advantages, such as rapid management of CRS by cessation of infusion. Early safety and efficacy clinical data supports the development of an extended half-life (EHL) ROR1xCD3 TCE for ease of administration and convenience for patients, building on the favorable activity and biophysical attributes of NVG-111. A next generation therapy possessing such an EHL has potential to improve patient experience by offering a different drug administration paradigm. Methods: Several formats were designed and evaluated, incorporating different EHL technology solutions by increasing the size and enabling FcRn-mediated recycling. EHL TCEs and non-EHL TCEs were cloned in-format with Fc, HSA, or an HSA binding moiety into a suitable expression vector. The resultant clones were expressed using Expi293 cells and the potency of TCEs were evaluated by co-culture assays using MCL derived JeKo-1 target cells and T cells from healthy donor PBMCs. Cytotoxic responses and T cell activation as determined by CD69 expression were measured by flow cytometry. T cell activation was also assessed by measuring CD3 signalling in a reporter gene assay. Biophysical properties were evaluated by determining the post-purification expression titer, the aggregation profile using analytical SEC, and the impact of stability challenge in formulation buffer and serum on target cell binding and activity. Results: Reformatting NVG-111 into an IgG-like heterodimeric bispecific scFv-Fc resulted in loss of potency, which may be due to a change in geometry of binding and/or poorer target engagement. Activity and expression titer were also deleteriously affected by directly fusing NVG-111 to human serum albumin (HSA), or to an HSA binding moiety. Fusing NVG-111 directly to Fc resulted in maintained potency in cytotoxicity and T cell activation assays, the expression titer of parental NVG-111, and exhibited very low levels of aggregation. Stability studies performed in formulation buffer and in human serum showed that NVG-111-Fc was at least as stable as parent. Furthermore, other studies with this molecular format indicate that the half-life in mice is comparable to a heterodimeric bispecific scFv-Fc. Conclusions: NVG-111 has been successfully engineered into an EHL format that increased the molecular size and has the potential to engage in FcRn-mediated recycling. This format maintains functional activity, is stable, and expresses well with a favorable aggregation profile. Further molecular refinements are being actively evaluated in readiness for IND enabling studies.

Synthesis and biological activity of imidazole group-substituted arylaminopyrimidines (IAAPs) as potent BTK inhibitors against B-cell lymphoma and AML

Bruton’s tyrosine kinase (BTK) is a member of the Tec kinase family and plays a key role in the modulation of the B-cell receptor (BCR)-mediated signaling pathway. Inhibition of BTK has been proven to be an effective therapeutic approach for various hematological malignancies, such as chronic lymphocytic leukemia (CLL), mantle cell leukemia (MCL), diffuse large B-cell lymphoma (DLBCL) and acute myeloid leukemia (AML). Here, a new series of imidazole group-substituted arylaminopyrimidines (IAAPs) were designed and synthesized as potent inhibitors of the enzymatic activity of BTK with a half maximal inhibitory concentration (IC50) ranging from 13.10 to 42.40 nM. In particular, 11a and 11b exhibited stronger antiproliferative activity against AML and B lymphomas cell lines compared with BTK inhibitor ibrutinib and showed low cytotoxicity against normal peripheral blood mononuclear cells (PBMCs). In addition, analysis of the mechanism of action of these compounds revealed that 11a and 11b induced significant apoptosis in AML and B lymphoma cells by arresting the cell cycle at the G1/G0 or G2/M stage and blocked BTK autophosphorylation as well as the ensuing abrogation of pro-survival AKT and ERK signaling. Taken together, these results suggest that 11a and 11b might serve as valuable preclinical candidates for the treatment of AML and B-cell lymphoma.

Discovery of Novel PRMT5 Inhibitors by Virtual Screening and Biological Evaluations.

As an important epigenetics related enzyme, protein arginine methyltransferase 5 (PRMT5) has been confirmed as an anticancer therapeutic target in recent years. Among all the reported PRMT5 inhibitors, two small molecules (GSK-3326595 and JNJ-64619178) are currently being assessed in clinical trial. In this study, 40 PRMT5 inhibitor candidates were purchased from SPECS database supplier according to the pharmacophore and molecular docking based virtual screening results. Alpha linked immunosorbent assay (LISA) methylation assay was performed to test their inhibitory activity against PRMT5. The in vitro enzymatic assay results indicated that four compounds (2, 4, 10 and 37) showed PRMT5 inhibitory activity, while 4 and 10 displayed the most potent activity with IC50 values of 8.1 ± 1.1 and 6.5 ± 0.6 µM, respectively. The inhibitory activity results of 20 extra analogs of 4 further confirmed the potency of this scaffold. As expected, compounds 4 and 10 exhibited moderate anti-proliferative activity against mantle cell lymphoma Jeko-1 and leukemia cell MV4-11. Besides, Western blot assay results showed that 4 could reduce the H4R3me2s level in a dose-dependent manner, indicating that it could inhibit the activity of PRMT5 in cellular context. Detailed interactions between 4 and PRMT5 were characterized by binding mode analysis through molecular docking. The compounds discovered in this study will inspire medicinal chemists to further explore this series of PRMT5 inhibitors.

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.

Pharmacokinetically-targeted dosed everolimus maintenance therapy in lymphoma patients.

Everolimus, an mTOR inhibitor, is active in refractory lymphomas. However, toxicity with flat dosing limits its usage. Speculatively, pharmacokinetically-targeted dosing could improve tolerability. Therefore, we studied serum-trough dosing with rituximab as maintenance after high-dose cyclophosphamide (HDC) consolidation in lymphoma patients. After HDC, everolimus was dosed to serum trough levels (goal 3-15ng/mL), with quarterly rituximab infusions for 1year while maintaining < grade II non-hematologic and < grade III hematologic toxicities. Adult patients in first PR/CR with: mantle cell, transformed, double-hit, or high risk chronic lymphocytic leukemia or in second PR for any relapsed B cell lymphoma were eligible. Prophylaxis was given for encapsulated organisms, HSV and PCP. Serum IgG levels were maintained > 500mg/dL. 49 patients, median age: 59.0years enrolled; MCL (26), CLL (10), transformed lymphoma (7), and other histologies (6). During the life of the study, the most frequent everolimus dosing has been 2.5mg daily or 2.5mg every other day; at these doses, serum levels are within the therapeutic range and non-hematologic toxicity is rare. At a median follow-up of 27.1months, three patients remain on active therapy. Two patients withdrew secondary to potentially-attributable adverse events including a bacterial pneumonia and a viral pneumonia; this low rate of discontinuation compares well to other long-term everolimus trials. While a 58 and 76% EFS at 30months for the entire cohort and MCL cohort, respectively, compares similarly to previously published HDC/rituximab data, longer follow-up is required. Pharmacokinetically-targeted dosing appears to increase everolimus tolerability. This finding may be applicable to other patient populations.

CD5-Negative Mantle Cell Leukemia Shows Frequent 17p Deletion and Marrow Involvement Mimicking Marginal Zone Lymphoma

Introduction: Mantle cell lymphoma is characterized by the t(11;14)(q13;q32) and can usually be recognized by its typical CD5+/CD23- immunophenotype. However, phenotypic variations have been observed and such variants can resemble other types of B-cell neoplasms, including chronic lymphocytic leukemia (CLL/SLL) and marginal zone lymphoma. In particular, the CD5- variant is diagnostically challenging. Some CD5- mantle cell lymphomas have been reported to have an indolent clinical course, while others follow an aggressive course similar to typical mantle cell lymphoma. To our knowledge, CD5- mantle cell leukemia has not been fully characterized. To further our understanding of this disease entity for diagnostic workup and risk assessment, we evaluated clinical, morphologic, immunophenotypic, and genetic features in a cohort of CD5- mantle cell leukemia.Methods: Among 111 cases of mantle cell leukemia identified from our database over a 2-year period, 12 were CD5- with t(11;14) and absolute peripheral lymphocytosis (>5,000/uL). Antigen expression was defined by flow cytometry as positive, dim positive, or negative. Conventional chromosome analysis and FISH were performed on all cases, including probes for 11q22.3 (ATM), 12 (CEP 12), 13q14, 13q34, 17p13 (TP53) and t(11;14) (IGH-CCND1). Other parameters obtained included age, gender, CBC, blood and bone marrow histology, and IgVH mutational status.Results: Of the 12 patients, 7 were female with a median age of 67 years (range: 55-88 years). Patients presented with marked lymphocytosis (mean: 55 K/uL) and mild normocytic anemia (mean: 11.3 g/dL). The average platelet count was within the low normal range (mean: 173 K/uL). Flow cytometric analysis showed that all cases expressed CD19 and surface light chain restriction (10 kappa and 2 lambda), and lacked CD5 and CD10. All except one case expressed CD20. CD23 was negative in 8 cases and dim positive in 4 cases. Thus, the leukemic phenotype was suggestive of a marginal zone lymphoma. Morphologically, the leukemic cells were small to medium sized with round nuclei and scant to moderately abundant cytoplasm. Bone marrow biopsy was performed in 6 of 12 cases. All 6 cases showed marrow involvement (mean: 45%; range: 25-85%) with interstitial and intrasinusoidal distribution patterns. While the marrow histology was suggestive of involvement by marginal zone lymphoma, immunohistochemical testing for cyclin D1 revealed positive nuclear staining in the leukemic cells. FISH for t(11;14) was positive in all 12 cases. In contrast, conventional chromosome analysis detected t(11;14) in only 6 cases (3 blood and 3 marrow samples). Additional cytogenetic abnormalities were detected in 8 (67%) patients. Five (42%) cases showed 17p deletion. Other abnormalities included 13q- (3/12; 25%), 11q- (2/12; 17%), and trisomy 12 (1/12; 8%). IgVH analysis was performed in 2 cases, and both exhibited IgVH hypermutation.Conclusions: CD5- mantle cell leukemia comprised approximately 11% of mantle cell leukemia in our series. In addition to t(11;14), other chromosome abnormalities were identified in the majority of the cases (67%). Deletion of 17p was most frequent, likely representing a more aggressive form in contrast to the previously described indolent form. The leukemic immunophenotype and marrow infiltration features resembled marginal zone lymphoma, indicating the importance of detecting t(11;14) for proper classification and clinical management of the disease. We observed that FISH was much more sensitive in detecting t(11;14) than conventional chromosome analysis. Therefore, performing FISH for t(11;14) and 17p- would be useful for diagnostic workup of mature B-cell leukemia regardless of CD5 positivity. Our limited observation of IgVH hypermutation in CD5- mantle cell leukemia would suggest future studies to investigate this potential relationship for prognostic implications. DisclosuresNo relevant conflicts of interest to declare.

Abstract 1649: Potent anticancer activity of an orally bioavailable small molecule, ON 013100, and its water soluble derivative, briciclib, a clinical-stage eIF4E-targeted agent

Abstract Introduction: Eukaryotic translation initiation factor 4E (eIF4E) is a master regulator that controls translation of mRNA in mammalian cells. eIF4E is a proto-oncogene that promotes translation of several genes essential for cellular proliferation (cyclin D1, c-Myc, mTOR), survival (Akt, survivin), angiogenesis (VEGF), and metastasis (MMP9). Overexpression of eIF4E has been observed in almost all major groups of cancers and has been shown to induce increased expression of cyclin D1 and c-Myc. Briciclib is a small molecule, water soluble derivative of ON 013100 that binds to eIF4E. An intravenous formulation of briciclib is currently being investigated in a Phase 1 clinical trial. Recent advancements in formulation technology have made feasible a stable, orally bioavailable version of ON 013100, which may allow for more convenient administration. In this study we investigated and compared the anticancer activity of briciclib to ON 013100. We determined the susceptibility of various breast, mantle cell leukemia (MCL), gastric, and esophageal cancer cell lines to treatment with briciclib or ON 013100. In addition, we investigated the effect of briciclib and ON 013100 on expression of markers associated with eIF4E activity (cyclin D1 and c-Myc) and apoptosis (P53 and Cleaved Caspase 3). Methods: MTT cell viability assays, Western blot analysis, and ELISA assays were used to evaluate cellular viability, survival, and protein expression levels. Results: Briciclib and ON 013100 inhibited the proliferation of MCL (JEKO-1 and MINO), breast (MCF7 and MDA-MB-231), gastric (AGS), and esophageal (OE19, OE33, and FLO-1) cancer cell lines at nanomolar concentrations (Briciclib: GI50 = 9.8 - 12.2 nM; ON 013100 GI50 = 6.7 - 11.2 nM). By comparison, briciclib and ON 013100 were relatively non-toxic to normal endothelial cells. Western blot analysis indicated that treatment with briciclib or ON 013100 significantly reduced the expression of cyclin D1 and c-Myc in breast and MCL cancer cell lines within 8 hours and in a dose-dependent manner. These observations were supported by ELISA analysis of cyclin D1 and c-Myc protein levels. Furthermore, treatment with these agents enhanced the expression of P53 and Cleaved Caspase 3 pro-apoptotic proteins in breast and MCL cancer cell lines. Our ongoing tumor xenograft experiments are in agreement with the aforementioned in vitro observations. Conclusions: Our findings suggest that both an orally bioavailable ON 013100, and its water soluble derivative, briciclib, have the same novel mechanism of action involving translation. Our in vitro and in vivo data demonstrate the potential of briciclib in targeting eIF4E for hematopoietic and solid cancers and the possibility for developing an oral version of this promising clinical agent. Citation Format: Neel Jasani, Bina Desai, Justine M. Betzu, Tanmay Dichwalkar, Samhita Bapat, V. J. Rajadhayksha, Benjamin S. Hoffman, Manoj Maniar, Vikas Sehdev. Potent anticancer activity of an orally bioavailable small molecule, ON 013100, and its water soluble derivative, briciclib, a clinical-stage eIF4E-targeted agent. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1649. doi:10.1158/1538-7445.AM2015-1649

Applying Enhancement Filters in the Pre-processing of Images of Lymphoma

Lymphoma is a type of cancer that affects the immune system, and is classified as Hodgkin or non-Hodgkin. It is one of the ten types of cancer that are the most common on earth. Among all malignant neoplasms diagnosed in the world, lymphoma ranges from three to four percent of them. Our work presents a study of some filters devoted to enhancing images of lymphoma at the pre-processing step. Here the enhancement is useful for removing noise from the digital images. We have analysed the noise caused by different sources like room vibration, scraps and defocusing, and in the following classes of lymphoma: follicular, mantle cell and B-cell chronic lymphocytic leukemia. The filters Gaussian, Median and Mean-Shift were applied to different colour models (RGB, Lab and HSV). Afterwards, we performed a quantitative analysis of the images by means of the Structural Similarity Index. This was done in order to evaluate the similarity between the images. In all cases we have obtained a certainty of at least 75%, which rises to 99% if one considers only HSV. Namely, we have concluded that HSV is an important choice of colour model at pre-processing histological images of lymphoma, because in this case the resulting image will get the best enhancement.

Aberrations of MYC are a common event in B-cell prolymphocytic leukemia.

B-cell prolymphocytic leukemia (B-PLL) remains a controversial entity, and its molecular pathogenesis is largely unknown. Patients are older, typically having marked lymphocytosis and splenomegaly in the absence of lymphadenopathy. It is defined as a mature B-cell leukemia with more than 55% circulating prolymphocytes. Leukemic mantle cell lymphoma and chronic lymphocytic leukemia in prolymphocytic transformation must be excluded. Case archives were retrospectively reviewed for B-PLL in patients without a previous diagnosis of chronic lymphocytic leukemia or other B-cell neoplasm. We identified six cases of B-PLL with available cytogenetic data, five of which showed evidence of aberrations in MYC. Three cases showed additional signals for the MYC gene by fluorescence in situ hybridization (FISH), and two cases demonstrated t(8;14)MYC/IGH by karyotyping or FISH. High levels of MYC protein expression were detected in all cases tested with MYC aberrations. These results suggest that deregulation of MYC plays an important role in the pathogenesis of B-PLL and expands the spectrum of B-cell neoplasms associated with aberrations of MYC.

Management of mantle cell leukemia with cardiac involvement leading to cardiogenic shock

Mantle cell lymphoma is an aggressive subtype of B cell non-Hodgkin lymphoma. It can progress to leukemic phase but frank leukemic picture at initial presentation is not common. Leukemic phase indicates advance stage of the disease and generally associated with extensive extra-nodal involvement. Pericardial invasion has been reported, however we could not find a report of myocardial infiltration by this disease since the appraisal of the term "mantle cell lymphoma" in 1992. Here we report a case of cardiac involvement by mantle cell leukemia leading to cardiogenic shock which complicates the treatment decisions.

Anti-CCR7 therapy exerts a potent anti-tumor activity in a xenograft model of human mantle cell lymphoma

BackgroundThe chemokine receptor CCR7 mediates lymphoid dissemination of many cancers, including lymphomas and epithelial carcinomas, thus representing an attractive therapeutic target. Previous results have highlighted the potential of the anti-CCR7 monoclonal antibodies to inhibit migration in transwell assays. The present study aimed to evaluate the in vivo therapeutic efficacy of an anti-CCR7 antibody in a xenografted human mantle cell lymphoma model.MethodsNOD/SCID mice were either subcutaneously or intravenously inoculated with Granta-519 cells, a human cell line derived from a leukemic mantle cell lymphoma. The anti-CCR7 mAb treatment (3 × 200 μg) was started on day 2 or 7 to target lymphoma cells in either a peri-implantation or a post-implantation stage, respectively.ResultsThe anti-CCR7 therapy significantly delayed the tumor appearance and also reduced the volumes of tumors in the subcutaneous model. Moreover, an increased number of apoptotic tumor cells was detected in mice treated with the anti-CCR7 mAb compared to the untreated animals. In addition, significantly reduced number of Granta-519 cells migrated from subcutaneous tumors to distant lymphoid organs, such as bone marrow and spleen in the anti-CCR7 treated mice. In the intravenous models, the anti-CCR7 mAb drastically increased survival of the mice. Accordingly, dissemination and infiltration of tumor cells in lymphoid and non-lymphoid organs, including lungs and central nervous system, was almost abrogated.ConclusionsThe anti-CCR7 mAb exerts a potent anti-tumor activity and might represent an interesting therapeutic alternative to conventional therapies.

MicroRNA Expression Profiles Identify Subtypes of Mantle Cell Lymphoma with Different Clinicobiological Characteristics

microRNAs (miRNA) are posttranscriptional gene regulators that may be useful as diagnostic and/or prognostic biomarkers. We aim to study the expression profiles of a high number of miRNAs and their relationship with clinicopathologic and biologic relevant features in leukemic mantle cell lymphomas (MCL). Expression profiling of 664 miRNAs was investigated using a high-throughput quantitative real-time PCR platform in 30 leukemic MCLs. Statistical and bioinformatic analyses were conducted to define miRNAs associated with different clinicopathologic parameters. Gene expression profiling was investigated by microarrays in 16 matching cases to study the potential genes and pathways targeted by selected miRNAs. The prognostic value of miR-34a was investigated in 2 independent series of 29 leukemic and 50 nodal MCLs. Robust consensus clustering defined 2 main MCL subgroups with significant differences in the immunoglobulin (IGHV) mutational status, SOX11 expression, genomic complexity, and nodal clinical presentation. Supervised analyses of IGHV and SOX11 categories identified 17 and 22 miRNAs differentially expressed, respectively. Enriched targets of these miRNAs corresponded to relevant pathways in MCL pathogenesis such as DNA stress response, CD40 signaling, and chromatin modification. In addition, we found 7 miRNAs showing prognostic significance independently of IGHV status and SOX11 expression. Among them, miR-34a was also associated with poor prognosis in 2 independent series of leukemic and nodal MCL, and in cooperation with high expression of the MYC oncogene. We have identified miRNAs and target pathways related to clinical and biologic variants of leukemic MCL, and validated miR-34a as a prognostic marker in MCL.

Complete Remission After Treatment With Single-Agent Ofatumumab in a Patient With High-Risk Leukemic Mantle-Cell Lymphoma

Complete Remission After Treatment With Single-Agent Ofatumumab in a Patient With High-Risk Leukemic Mantle-Cell Lymphoma

Immunophenotype analysis of leukemic mantle cell lymphoma

Mantle cell lymphoma (MCL) is a kind of mature B-cell neoplasms with significantly poor prognosis and is usually misdiagnosed. With the development of flow cytometry and cytogenetic technique, most patients were at leukemic phase when diagnosed. This study was purposed to investigate the immunophenotypes of MCL, the immunophenotype information of 22 leukemic MCL patients was analyzed retrospectively. All the patients were conformed t(11;14) translocation by fluorescence in situ hybridization. Immunophenotypes were detected by a four-color flow cytometry including CD3, CD4, CD5, CD8, CD10, CD19, CD20, CD22, CD23, CD25, CD38, CD103, CD148, CD200, FMC7, ZAP-70, κ, λ. The results showed that CD19, CD5, CD20 and monoclonal sIg expressed in all 22 patients with CD20 high expression; CD22 expressed weakly in 17 patients; CD23 expressed in 6 patients including 2 cases highly expressed; FMC7 expressed in 12 patients. 5 patients were 4-point score and 17 patients had a score less than 4 according to CLL scoring system. CD148 and CD200 were detected in 18 patients, in which CD200 expressed negatively in 11 patients, CD200 expressed weakly in 7 patients with median fluorescence intensity (MFI) 25.8 (6.6 - 254.26); CD148 expressed positively in all 18 patients with median MFI: 337 (73.4 - 1341.9). It is concluded that the atypical immunophenotype is common in leukemia MCL, thereby the diagnosis of MCL needs comprehensively analyze with morphocytology, immunophenotype and cytogenetic, CD200 and CD148 as new bio-markers can differentiate MCL from chronic B cell lymphoproliferative disease.

Targeting early B-cell receptor signaling induces apoptosis in leukemic mantle cell lymphoma

BackgroundWe previously showed that B-cell receptor (BCR) signaling pathways are important for in vitro survival of mantle cell lymphoma (MCL) cells. To further identify early BCR-activated signaling pathways involved in MCL cell survival, we focused our study on BCR-proximal kinases such as LYN whose dysregulations could contribute to the aggressive course of MCL.MethodsPrimary MCL cells were isolated from 14 leukemic patients. Early BCR-induced genes were identified by qRT-PCR array. The basal and BCR-induced phosphorylation of LYN and JNK were evaluated by immunoblottting. Cell survival signals were evaluated by apoptosis using flow cytometry.ResultsWe showed that LYN was constitutively phosphorylated in MCL cell lines and in 9/10 leukemic MCL cases. Treatment with dasatinib or with a specific inhibitor of Src kinases such as PP2 suppressed constitutive LYN activation and increased in vitro spontaneous apoptosis of primary MCL cells. BCR engagement resulted in an increase of LYN phosphorylation leading to activation of c-JUN NH2-terminal kinase (JNK) and over-expression of the early growth response gene-1 (EGR-1). Inhibition of JNK with SP600125 induced apoptosis and reduced level of basal and BCR-induced expression of EGR-1. Furthermore, decreasing EGR1 expression by siRNA reduced BCR-induced cell survival. Treatment with PP2 or with dasatinib suppressed BCR-induced LYN and JNK phosphorylation as well as EGR-1 upregulation and is associated with a decrease of cell survival in all cases analysed.ConclusionsThis study highlights the importance of BCR signaling in MCL cell survival and points out to the efficiency of kinase inhibitors in suppressing proximal BCR signaling events and in inducing apoptosis.

Morphological spectrum of leukemic mantle cell lymphoma

Leukemic involvement in mantle cell lymphoma (MCL) is common, and can be secondary to nodal or extranodal disease or can be de-novo. There is paucity of literature that describes the morphological spectrum. This study was aimed at studying the morphological spectrum of leukemic MCL and to correlate the morphology with other features. Twenty six such cases diagnosed over a period of four years were studied. Peripheral blood and bone marrow aspiration smears stained with Wrights stain were examined by three hematopathologists. Immunophenotyping was done using multicolor flow cytometry. Fluorescence in situ hybridization (FISH) done in 12 cases showed t(11;14)(q13:q32). Six cases had de-novo leukemic involvement; while 20 cases had secondary involvement. Morphologically, the cells were small (less than twice the size of red blood cell) or large. Small cell morphology in turn showed irregular nuclear border (n=13) or round nuclear contour (n=6). Large cells had blastic morphology (n=5) or had central prominent nucleoli resembling prolymhphocytes (n=2). Twenty cases showed characteristic immunophenotype of CD5+/CD19+/CD20+/FMC7+/CD10-/CD23- and light chain restrictions. Three cases expressed CD23 and two cases were negative for FMC7. Five out of 12 cases, where FISH was done, showed cytogenetic abnormalities in addition to t(11;14)(q13;q32). Morphological spectrum of leukemic MCL ranges from small cells resembling chronic lymphocytic leukemia (CLL) or follicular lymphoma (FL) to large cell mimicking prolymphocytic leukemia (PLL) or acute leukemia. Large cell morphology was associated with more frequent additional cytogenetic abnormality as well as a poorer outcome.

Case Report: Blastic Mantle Cell Leukemia

The patient, who was being followed up for Mantle Cell Lymphoma, was diagnosed with Mast Cell Leukemia 2 years after receiving R-CHOP treatment. The results of flow cytometry, which was performed upon determining leucocytosis and detecting blasts in the peripheral smear following the patient’s presentation due to his poor general condition, was consistent with Mantle Cell Leukemia. This case is being presented since there are a very limited number of previously published cases on this topic.

Indolent mantle cell leukemia: a clinicopathological variant characterized by isolated lymphocytosis, interstitial bone marrow involvement, kappa light chain restriction, and good prognosis

Cases of mantle cell lymphoma with indolent behavior have been reported, but are poorly identified by current clinical risk models. Early studies found peripheral blood involvement to be an adverse prognostic factor; however, cases of a seemingly indolent variant of mantle cell lymphoma, characterized by peripheral blood involvement and minimal nodal disease, have been incompletely described, particularly with regard to bone marrow findings. We report a series of leukemic phase mantle cell lymphomas with a non-progressive or slowly progressive course. Cases presenting with mantle cell lymphoma limited to the peripheral blood/bone marrow from 2000-2010 were identified. Diagnoses were established by morphology, flow cytometric analysis and requisite evidence of IGH-CCND1@ by fluorescence in-situ hybridization or t(11;14)(q13;q32) by cytogenetics. Patients with lymphadenopathy, splenomegaly and gastrointestinal symptomatology were excluded. Patients (n=8, median age 60.5 years) were asymptomatic with mild lymphocytosis (8.7×10(9)/L; range, 4.5-14.2×10(9)/L) and cytology typical of mantle cell lymphoma. Flow cytometric analysis showed that all expressed CD5, CD19, CD20, variable CD23, and a striking kappa immunoglobulin light chain restriction (7/8 cases). Bone marrow biopsy at diagnosis showed interstitial single or small lymphoid aggregates with similar patterns of CD20 and cyclin D1 immunostaining which were not readily discernable by hematoxylin and eosin stain. SOX11 was negative (4/5) or only weakly expressed (1/5). The median follow-up was 27 months (range, 5-109 months) and all patients, but one, are alive with no clinical evidence of disease. The prevalence of indolent mantle cell lymphoma presenting only with lymphocytosis, among all mantle cell lymphomas diagnosed during the same period, was 3%. Leukemic mantle cell lymphoma limited to blood and bone marrow is an indolent variant characterized by mild-moderate lymphocytosis, interstitial low-level bone marrow involvement, simple karyotype, kappa light chain expression, cyclin D1 expression with lack of SOX11, and slow or absent clinical progression. Some cases may represent a mantle cell lymphoma counterpart to chronic lymphocytic leukemia - phenotype monoclonal B-cell lymphocytosis. Recognition of this variant could inform treatment decisions and possibly avoid unnecessary treatment.