Molecular Lesions Of Signalling Pathway Genes In Indolent B-Cell Lymphoproliferations Mimicking Splenic Marginal Zone Lymphoma

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4250-4250 ◽  
Author(s):  
Davide Rossi ◽  
Alessio Bruscaggin ◽  
Sara Monti ◽  
Stefania Cresta ◽  
Rosella Famà ◽  
...  
Keyword(s):  
Lymph Node ◽  
Cell Differentiation ◽  
B Cell ◽  
Plasma Cell ◽  
Marginal Zone ◽  
Lymphoproliferative Disorders ◽  
Marginal Zone Lymphoma ◽  
Splenic Marginal Zone Lymphoma ◽  
Plasma Cell Differentiation ◽  
Monoclonal Component

Abstract Background Almost 60% cases of splenic marginal zone lymphoma (SMZL) cases harbor molecular lesions affecting signalling pathways involved in normal marginal zone (MZ) differentiation, including the NOTCH pathway, the NF-kB pathway, the toll-like receptor (TLR) pathway and the B-cell receptor (BCR) pathway. However, little is known with regard to these lesions in other indolent B-cell lymphoproliferative disorders mimicking SMZL. Methods Candidate gene mutations (NOTCH2, NOTCH1, BIRC3, TNFAIP3, TRAF3, IKBKB, MYD88, CD79A, CD79B, CARD11) were investigated in 60 indolent B-cell lymphoproliferative disorders, including nodal marginal zone lymphoma (NMZL=33), monoclonal B-cell lymphocytosis showing a MZL-like phenotype (MZL-like MBL=16), and variant hairy cell leukemia (vHCL=11). In all cases, tumor representation was >50% in order to allow the detection of clonal lesions. All cases lacked the BRAF V600E mutation as assessed by AS-PCR. Results Overall, the genetics of NMZL and MZL-like MBL was consistent with that of SMZL, suggesting the involvement of a common oncogenic pathway in these disorders. Among NMZL, 51% (17/33) of cases were characterized by mutually exclusive genetic lesions affecting MZ differentiation genes, including NOTCH2 stabilizing mutations in 24% (8/33) of cases, TNFAIP3 disrupting mutations in 12% (4/33), MYD88 activating mutations in 12% (4/33), and NOTCH1, TRAF3 and BIRC3 mutations in 3% (1/33) of cases each. Among MZL-like MBL, 37% (6/16) of cases harbored mutually exclusive lesions of MZ genes, including MYD88 mutations in 25% (4/16) of cases, NOTCH2 mutations in 12% (2/16), and TNFAIP3 and CD79B mutations in 6% (1/16) of cases each. On the contrary, all cases (n=11) of vHCL lacked mutations of NOTCH, NF-kB, TLR or BCR genes, suggesting that none of these signaling pathways plays a relevant role in this disease. Among NMZL, MYD88 mutations were enriched among cases harboring an IgM type monoclonal component (3/4, 75% vs 1/18, 5%, p=.010) and showing cytological clues of plasma cell differentiation of lymph node tumor cells (3/6, 50% vs 0/9; p=.040). NOTCH2 mutations did not correlate with any pathologic feature (i.e. lymph node pattern of infiltration, presence of monocytoid B cells, immunoglobulin gene usage or mutation status). Among MZL-like MBL, neither MYD88 mutations nor NOTCH2 mutations correlated with specific clinico-pathologic features (i.e. presence of an IgM type monoclonal component, intrasinusoidal bone marrow infiltration, plasma cell differentiation). Conclusions These data suggest that: i) SMZL, NMZL and MZL-like MBL share a similar genotype and are all promoted by the same molecular deregulation of MZ differentiation genes; and ii) vHCL stands as a genetically different entity among indolent B-cell lymphoproliferations. These data might help to refine the differential diagnosis of indolent B-cell lymphoproliferations mimicking SMZL. Disclosures: No relevant conflicts of interest to declare.

Prevalence and Clinical Significance of the MYD88 (L265P) Somatic Mutation in Patients with Waldenström Macroglobulinemia, IgM-Monoclonal Gammopathy of Undetermined Significance or Other Mature B-Cell Neoplasms.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2667-2667 ◽  
Author(s):  
Marzia Varettoni ◽  
Luca Arcaini ◽  
Silvia Zibellini ◽  
Emanuela Boveri ◽  
Sara Rattotti ◽  
...  
Keyword(s):  
B Cell ◽  
Marginal Zone ◽  
Lymphoproliferative Disorders ◽  
Marginal Zone Lymphoma ◽  
Splenic Marginal Zone Lymphoma ◽  
Specific Pcr ◽  
Allele Specific ◽  
Myd88 L265p Mutation ◽  
Myd88 L265p ◽  
Monoclonal Component

Abstract Abstract 2667 Waldenström Macroglobulinemia (WM) is a B-cell lymphoproliferative disorder characterized by bone marrow infiltration by lymphoplasmacytic lymphoma associated with a monoclonal component of IgM type in the serum. WM is often preceded by an IgM monoclonal gammopathy of undetermined significance (IgM-MGUS). The cumulative probability of progression of IgM-MGUS to WM or to other lymphoproliferative disorders is approximately 1.5% per year. Other mature B-cell neoplasms such as splenic marginal zone lymphoma (SMZL) and B-cell chronic lymphoproliferative disorders (B-CLPD) can carry an IgM monoclonal component and should therefore be considered in differential diagnosis with WM. In a study based on parallel sequencing of the whole genome of lymphoplasmacytic cells and paired normal tissue from WM patients, Treon et al (Blood. 2011;118:Abstract 300) have identified a highly recurrent somatic mutation with oncogenic activity in the myeloid differentiation primary response (MYD88) gene, leading to a change from leucine to proline at position 265 of the aminoacid sequence [MYD88 (L265P)]. Targeted Sanger resequencing showed MYD88 (L265P) in 90% of WM patients, but only in a minority of patients with IgM-MGUS or other mature B-cell neoplasms such as SMZL. We developed an allele-specific PCR for the MYD88 (L265P) mutation, and studied 58 patients with WM, 77 with IgM-MGUS, 84 with splenic marginal zone lymphoma (SMZL) and 52 with B-cell chronic lymphoproliferative disorders (B-CLPD). DNA was obtained from bone marrow cells (n=204) and peripheral blood (n=67). The aims of this study were: i) to assess the prevalence of the mutation in WM, IgM-MGUS, SMZL, and B-CLPD; ii) to analyze the relationship between MYD88 (L265P) mutation and clinical phenotype; iii) to evaluate the impact of the mutation on the risk of progression from IgM-MGUS WM or other lymphoproliferative disorders. The MYD88 (L265P) mutation was detected in 58/58 (100%) patients with WM, either asymptomatic (n=39) or symptomatic (n=18), and in 36/77 (47%) patients with IgM-MGUS. In addition, it was detected in 5/84 (6%) patients with SMZL and in 3/52 (6%) with B-CLPD; of these MYD88 (L265P)-positive subjects, 4 SMZL and 2 B-CLPD patients carried a serum IgM monoclonal component, while the remaining B-CLPD patient carried a double (IgM and IgG) monoclonal component. Compared with IgM-MGUS patients with wild-type MYD88, those carrying MYD88 (L265P) had significantly higher levels of IgM (P<.0001), lower levels of IgG (P=.04) and IgA (P=.04), and higher incidence of Bence-Jones proteinuria at diagnosis (P=.002). During the follow-up, 9 patients with IgM-MGUS progressed to WM (7 cases) or to marginal zone lymphoma (2 cases). Using a case-control approach, the risk of evolution of patients with MYD88 (L265P) was significantly higher as compared to that of patients with wild-type MYD88 sequence (OR 4.7, 95% confidence interval 0.8–48.7, P=.047). In conclusion, the findings of this study indicate that: i) the allele-specific PCR we developed is able to detect the MYD88 (L265P) mutation in all patients with WM and in nearly half the patients with IgM-MGUS, and therefore represents a useful diagnostic tool; ii) MYD88 (L265P) is an uncommon molecular lesion in SMZL and in B-CLPD, but is associated with an IgM monoclonal component in the few positive patients, suggesting that some cases of B-CLPD might be included in the spectrum of WM; iii) in IgM-MGUS, the mutation is associated with greater disease burden and higher risk of disease progression, and therefore represents a useful prognostic marker. Disclosures: No relevant conflicts of interest to declare.

Deregulated PAX-5 Transcription From a TranslocatedIgH Promoter in Marginal Zone Lymphoma

Blood ◽  
1998 ◽  
Vol 92 (10) ◽  
pp. 3865-3878 ◽  
Author(s):  
Aline M. Morrison ◽  
Ulrich Jäger ◽  
Andreas Chott ◽  
Michael Schebesta ◽  
Oskar A. Haas ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cell ◽  
Marginal Zone ◽  
B Cell Lymphoma ◽  
Marginal Zone Lymphoma ◽  
Chain Gene ◽  
Splenic Marginal Zone Lymphoma ◽  
Derivative Chromosome ◽  
B Cell Differentiation ◽  
Loss Of Function

Abstract The PAX-5 gene codes for the transcription factor BSAP, which is expressed throughout B-cell development. Although loss-of-function mutation in the mouse showed an essential role forPax-5 in early B lymphopoiesis, gain-of-function mutations have implicated the human PAX-5 gene in the control of late B-cell differentiation. PAX-5 (on 9p13) has been involved together with the immunoglobulin heavy-chain (IgH) gene (on 14q32) in the recurring t(9;14)(p13;q32) translocation that is characteristic of small lymphocytic lymphoma with plasmacytoid differentiation. Here we have characterized a complex t(2;9;14)(p12;p13;q32) translocation present in a closely related non-Hodgkin’s lymphoma referred to as splenic marginal zone lymphoma (MZL). In this MZL-1 translocation, the two promoters of PAX-5 were replaced on the derivative chromosome 14 by an immunoglobulin switch Sμ promoter that was linked to the structural PAX-5 gene upstream of its translation initiation codon in exon 1B. Expression analyses confirmed thatPAX-5 transcription was upregulated due to efficient initiation at the Sμ promoter in the malignant B lymphocytes of patient MZL-1. For comparison we have analyzed PAX-5 expression in another B-cell lymphoma, KIS-1, indicating that transcription from the distalPAX-5 promoter was increased in this tumor in agreement with the previously characterized translocation of the immunoglobulin Eμ enhancer adjacent to PAX-5 exon 1A. In both lymphomas, the J-chain gene, which is thought to be under negative control by BSAP, was not expressed, whereas transcription of the putative target genep53 was unaffected by PAX-5 overexpression. Together these data indicate that the t(9;14)(p13;q32) translocation contributes to lymphoma formation as a regulatory mutation that leads to increasedPAX-5 expression in late B-cell differentiation due to promoter replacement or enhancer insertion.

scholarly journals FcγRIIB regulates (auto)antibody responses by limiting marginal zone B cell activation

2021 ◽  
Author(s):  
Ashley N. Barlev ◽  
Susan Malkiel ◽  
Annemarie L. Dorjée ◽  
Jolien Suurmond ◽  
Betty Diamond
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Cell Activation ◽  
Marginal Zone ◽  
Plasma Cells ◽  
B Cell Activation ◽  
Autoantibody Production ◽  
Plasma Cell Differentiation

AbstractFcγRIIB is an inhibitory receptor expressed throughout B cell development. Diminished expression or function is associated with lupus in mice and humans, in particular through an effect on autoantibody production and plasma cell differentiation. Here, we analysed the effect of B cell-intrinsic FcγRIIB expression on B cell activation and plasma cell differentiation.Loss of FcγRIIB on B cells (Fcgr2b cKO mice) led to a spontaneous increase in autoantibody titers. This increase was most striking for IgG3, suggestive of increased extrafollicular responses. Marginal zone (MZ) and IgG3+ B cells had the highest expression of FcγRIIB and the increase in serum IgG3 was linked to increased MZ B cell signaling and activation in the absence of FcγRIIB. Likewise, human circulating MZ-like B cells had the highest expression of FcγRIIB, and their activation was most strongly inhibited by engaging FcγRIIB. Finally, marked increases in IgG3+ plasma cells and B cells were observed during extrafollicular plasma cell responses with both T-dependent and T-independent antigens in Fcgr2b cKO mice. The increased IgG3 response following immunization of Fcgr2b cKO mice was lost in MZ-deficient Notch2/Fcgr2b cKO mice.Thus, we present a model where high FcγRIIB expression in MZ B cells prevents their hyperactivation and ensuing autoimmunity.Graphical abstract

CD11b Is Useful in the Diagnosis of Chronic Lymphocytic Leukemia/Prolymphocytic Leukemia, Mixed Chronic Lymphocytic Leukemia, and Prolymphocytic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4806-4806
Author(s):  
William Fricke
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Marginal Zone ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoproliferative Disorders ◽  
Marginal Zone Lymphoma ◽  
Lymphocytic Leukemia ◽  
Splenic Marginal Zone Lymphoma ◽  
Prolymphocytic Leukemia

Abstract CD11b is well known as an integrin, Mac-1, is often complexed with CD18, and is found on monocytes, granulocytes, and natural killer cells. It also serves as a receptor for iC3b. However, its occurrence in B cell chronic lymphoproliferative disorders is not generally recognized and has not been fully evaluated. To address this issue, a series of B cell leukemias and lymphomas referred for primary diagnosis was evaluated for the presence of CD11b. The purpose was to determine the frequency of its expression on these tumors and to evaluate its diagnostic value. Consecutive cases referred for flow cytometry as possible lymphoproliferative disease were analyzed. Included were bone marrow, peripheral blood, and lymph nodes. All cases were diagnosed according to the WHO classification based on immunophenotypic, morphologic, and clinical findings. The morphologic criteria of Melo (1986) and Bennett (1989) were used for classification of chronic lymphocytic leukemia (CLL), CLL/prolymphocytic leukemia (CLL/PLL), mixed CLL, and PLL. Cases identified as not related to chronic lymphocytic leukemia or prolymphocytic leukemia were recorded but not further analyzed. Similarly, lymph node and spleen-based tumors were excluded from the final analysis. CD11b was present on cells from 32 of 123 cases, including occasional follicular lymphoma, (5/35); mantle cell lymphoma, (1/8); diffuse large B cell lymphoma, (3/9); hairy cell leukemia, (3/5); multiple myeloma, (1/2); lymphoplasmacytic lymphoma, (2/2); nodal marginal zone lymphoma, 0/1); and splenic marginal zone lymphoma, (1/1). However, it was most consistently expressed on CLL that contained increased numbers of prolymphocytes or large cells and on PLL. A total of 16 such cases were found. Morphologic assessment showed them to include 8 CLL/PLL, 3 mixed CLL, 4 PLL, and 1 typical CLL. The typical CLL case included both large cells and prolymphocytes but did not have more than 10% PLs. Five of the 16 cases (31%) were negative for CD5, CD23, and CD38 but were positive for FMC-7. In contrast, the other 11 cases were all CD5(+) and CD23(+); 3/11 were positive for CD38; and 5/11 were positive for FMC-7. Forty-five CLLs also were identified during the study, of which 27 had sufficient data for comparison. Twenty-six of the 27 CLLs were morphologically typical. The remaining case was mixed CLL. All of the CLLs were CD11b(−), CD5(+) and CD23(+); 15/43 were CD38(+), and 6/43 were FMC-7(+). The findings show that CD11b is expressed on chronic B cell lymphoproliferative disorders. In particular, it is expressed on almost all CLL cases that contain large cells or prolymphocytes and on PLL. Inclusion of CD11b in routine screening panels of possible chronic B cell leukemiaa will improve diagnosis of these disorders.

Deregulated PAX-5 Transcription From a TranslocatedIgH Promoter in Marginal Zone Lymphoma

Blood ◽  
1998 ◽  
Vol 92 (10) ◽  
pp. 3865-3878 ◽  
Author(s):  
Aline M. Morrison ◽  
Ulrich Jäger ◽  
Andreas Chott ◽  
Michael Schebesta ◽  
Oskar A. Haas ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cell ◽  
Marginal Zone ◽  
B Cell Lymphoma ◽  
Marginal Zone Lymphoma ◽  
Chain Gene ◽  
Splenic Marginal Zone Lymphoma ◽  
Derivative Chromosome ◽  
B Cell Differentiation ◽  
Loss Of Function

The PAX-5 gene codes for the transcription factor BSAP, which is expressed throughout B-cell development. Although loss-of-function mutation in the mouse showed an essential role forPax-5 in early B lymphopoiesis, gain-of-function mutations have implicated the human PAX-5 gene in the control of late B-cell differentiation. PAX-5 (on 9p13) has been involved together with the immunoglobulin heavy-chain (IgH) gene (on 14q32) in the recurring t(9;14)(p13;q32) translocation that is characteristic of small lymphocytic lymphoma with plasmacytoid differentiation. Here we have characterized a complex t(2;9;14)(p12;p13;q32) translocation present in a closely related non-Hodgkin’s lymphoma referred to as splenic marginal zone lymphoma (MZL). In this MZL-1 translocation, the two promoters of PAX-5 were replaced on the derivative chromosome 14 by an immunoglobulin switch Sμ promoter that was linked to the structural PAX-5 gene upstream of its translation initiation codon in exon 1B. Expression analyses confirmed thatPAX-5 transcription was upregulated due to efficient initiation at the Sμ promoter in the malignant B lymphocytes of patient MZL-1. For comparison we have analyzed PAX-5 expression in another B-cell lymphoma, KIS-1, indicating that transcription from the distalPAX-5 promoter was increased in this tumor in agreement with the previously characterized translocation of the immunoglobulin Eμ enhancer adjacent to PAX-5 exon 1A. In both lymphomas, the J-chain gene, which is thought to be under negative control by BSAP, was not expressed, whereas transcription of the putative target genep53 was unaffected by PAX-5 overexpression. Together these data indicate that the t(9;14)(p13;q32) translocation contributes to lymphoma formation as a regulatory mutation that leads to increasedPAX-5 expression in late B-cell differentiation due to promoter replacement or enhancer insertion.

Nodal marginal zone B-cell lymphoma showing prominent plasma cell differentiation in the pleural effusion: A case report

2012 ◽  
Vol 42 (2) ◽  
pp. 189-191
Author(s):  
Masaru Kojima ◽  
Yoshimasa Nakazato ◽  
Show Shiino ◽  
Yuko Kaneko ◽  
Kaoru Hirabayashi ◽  
...  
Keyword(s):  
Case Report ◽  
Cell Differentiation ◽  
Pleural Effusion ◽  
B Cell ◽  
Plasma Cell ◽  
Marginal Zone ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Plasma Cell Differentiation

scholarly journals Down-regulation of BLIMP1α by the EBV oncogene, LMP-1, disrupts the plasma cell differentiation program and prevents viral replication in B cells: implications for the pathogenesis of EBV-associated B-cell lymphomas

Blood ◽  
2011 ◽  
Vol 117 (22) ◽  
pp. 5907-5917 ◽  
Author(s):  
Katerina Vrzalikova ◽  
Martina Vockerodt ◽  
Sarah Leonard ◽  
Andrew Bell ◽  
Wenbin Wei ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Virus Replication ◽  
Plasma Cell ◽  
Germinal Center ◽  
Lytic Cycle ◽  
Transformed Cells ◽  
Down Regulation ◽  
Plasma Cell Differentiation

AbstractAn important pathogenic event in Epstein-Barr virus (EBV)-associated lymphomas is the suppression of virus replication, which would otherwise lead to cell death. Because virus replication in B cells is intimately linked to their differentiation toward plasma cells, we asked whether the physiologic signals that drive normal B-cell differentiation are absent in EBV-transformed cells. We focused on BLIMP1α, a transcription factor that is required for plasma cell differentiation and that is inactivated in diffuse large B-cell lymphomas. We show that BLIMP1α expression is down-regulated after EBV infection of primary germinal center B cells and that the EBV oncogene, latent membrane protein-1 (LMP-1), is alone capable of inducing this down-regulation in these cells. Furthermore, the down-regulation of BLIMP1α by LMP-1 was accompanied by a partial disruption of the BLIMP1α transcriptional program, including the aberrant induction of MYC, the repression of which is required for terminal differentiation. Finally, we show that the ectopic expression of BLIMP1α in EBV-transformed cells can induce the viral lytic cycle. Our results suggest that LMP-1 expression in progenitor germinal center B cells could contribute to the pathogenesis of EBV-associated lymphomas by down-regulating BLIMP1α, in turn preventing plasma cell differentiation and induction of the viral lytic cycle.

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