Expression of multidrug resistance 1 gene in B‐cell lymphomas: association with follicular dendritic cells

Aims: Multidrug resistance (MDR) in B‐cell lymphomas still constitutes a major obstacle to the effectiveness of chemotherapy even in the anti‐CD20 antibody therapy era. The aim of this study was to investigate the expression of MDR‐associated molecules in reactive lymphadenopathy (RL), follicular lymphoma (FL), and diffuse large B‐cell lymphoma (DLBCL). Methods and results: The expression of mRNA for ABC‐transporter family genes was determined by real‐time RT‐PCR in lymph nodes from RL, FL, and DLBCL cases. MDR1 exhibited significantly stronger expression in RL, FL, and DLBCL than Raji B‐cell lymphoma cells. RL and FL showed significantly higher expression than DLBCL. Immunohistochemically, MDR1 positive cells were localized in the germinal centers of RL and center of the nodular lesions of FL showing associations with CD21 positive follicular dendritic cells (FDCs). Raji cells were co‐cultured with FDC sarcoma‐derived cells and the expression of MDR1 and drug resistance were analyzed. The co‐culture of Raji cells with FDCs induced strong expression of MDR1 and introduced resistance to doxorubicin‐induced apoptosis. Conclusions: These results suggest that FDCs induce MDR1 expression in reactive as well as neoplastic B‐cells. Inhibition of the interaction of FDCs with B‐cells may provide a novel strategy for treating the chemotherapy resistant fraction.     

Histone deacetylase 1, 2, 6 and acetylated histone H4 in B- and T-cell lymphomas

Aims:  Histone deacetylase (HDAC) inhibitors are novel therapeutics in the treatment of peripheral T-cell lymphoma, unspecified (PTCL) and diffuse large B-cell lymphoma (DLBCL), where, for unknown reasons, T-cell malignancies appear to be more sensitive than B-cell malignancies. The aim was to determine HDAC expression in DLBCL and PTCL which has not previously been investigated.
Methods and results:  The expression of HDAC1, HDAC2, HDAC6 and acetylated histone H4 was examined immunohistochemically in 31 DLBCL and 45 PTCL. All four markers showed high expression in both DLBCL and PTCL compared with normal lymphoid tissue. HDAC1 was more abundantly expressed in PTCL than in DLBCL ( P  = 0.0046), whereas acetylated H4 was more frequent in DLBCL ( P  < 0.0001), the latter suggesting a mechanism for T-cell lymphoma sensitivity to HDAC inhibitors. Moderate to strong HDAC6 expression was significantly correlated with favourable outcome ( P  = 0.016) in DLBCL patients, whereas the opposite effect was observed in PTCL patients ( P  < 0.0001). The other markers did not correlate with survival ( P  > 0.05).
Conclusions:  HDAC1, HDAC2, HDAC6 and acetylated H4 are overexpressed in DLBCL and PTCL relative to normal lymphoid tissue. Furthermore, HDAC6 may be an important prognostic marker associated with favourable outcome in DLBCL and a more aggressive course in PTCL.     

CD5-positive diffuse large B cell lymphoma arising from a CD5-positive follicular lymphoma

Follicular lymphoma (FL) is a neoplasm originating from germinal centre cells, corresponding to 25-40% of non-Hodgkin's lymphomas. Transformation into diffuse large B cell lymphoma (DLBCL) occurs in about one-third of cases. CD5 is expressed in B-chronic lymphoid leukaemia/small lymphocytic lymphoma and mantle cell lymphoma, but can rarely be expressed in conjunction with CD10 in well-documented cases of FL. In this report one case of grade 1 FL is described, which transformed into a DLBCL 6 months after initial diagnosis, with both tumours expressing CD5. In both specimens, neoplastic cells were strongly positive for CD20, CD79a, bcl-2, bcl-6 and CD5 in virtually all cells. CD10 was strongly positive in initial specimens and weakly positive in the DLBCL. Investigation using the PCR confirmed the derivation of the DLBCL from the FL as they presented the same immunoglobulin heavy chain gene rearrangement and the same BCL2-J(H) break point.     

A case of diffuse large B‐cell lymphoma transformed from primary duodenal follicular lymphoma

Primary intestinal follicular lymphoma (FL) is a variant of FL characterized by frequent duodenal involvement and a very indolent clinical behavior without therapy. Unlike nodal FL, there have been no reports of histologic transformation (HT) or death attributable to primary intestinal FL. Here, we report the first case of primary duodenal FL showing HT. A Grade 1 FL in the duodenum was incidentally detected in a 73‐year‐old man. A watch‐and‐wait strategy was adopted because the disease was stage IE. Six months later, bone marrow involvement was suspected. The intestinal lesions had not changed during the first year since the initial diagnosis. Sixty‐two months after the initial diagnosis, a biopsy specimen showed diffuse large B‐cell lymphoma (DLBCL). A perforation of the intestine occurred before chemotherapy was started. Partial resection was performed and subsequent chemotherapy was administered. The clone of the initial FL and DLBCL were identical according to PCR analysis, indicating that the primary intestinal FL had transformed into DLBCL. Although HT is rare, it could occur in some patients with primary intestinal FL. Based on this case, it may be necessary to re‐evaluate the clinical watch‐and‐wait strategy for primary intestinal FL in some patients.     

Complexities in the diagnosis of large B-cell lymphomas,classic Hodgkin lymphomas and overlapping peripheral T-cell lymphomas simplified: An evidence-based guide

The diagnosis of a large B-cell lymphoma and classic Hodgkin lymphoma (CHL) is often straightforward. However, in select circumstances, these simple diagnoses can be quite complex. In part, diagnostic difficulty may be due to uncertainty in the evaluation of morphologic and immunophenotypic features along a biologic continuum, or alternatively arise from uncertainty in predicting the behavior and outcomes of patients. Here, we systematically discuss and review areas of diagnostic difficulty in the diagnosis of large B-cell lymphomas (LBCL), classic Hodgkin lymphomas (CHL) and peripheral T-cell lymphomas (PTCL). We provide careful data-driven analyses and evidence-based approaches to help guide pathologists and clinicians. We discuss: 1) marginal zone lymphomas with increased large cells versus diffuse large B-cell lymphoma (DLBCL), 2) chronic lymphocytic leukemia with expanded proliferation centers versus diffuse large B-cell lymphoma (DLBCL), 3) chronic lymphocytic leukemia with Hodgkin/Reed-Sternberg-like cells versus CHL arising from chronic lymphocytic leukemia, 4) complex cases of follicular lymphoma versus DLBCL, 5) PTCL with large B-cell proliferations versus PTCL with LBCL, 6) PTCL with Hodgkin/Reed-Sternberg-like cells versus CHL, and finally 7) blastoid/pleomorphic mantle cell lymphoma versus DLBCL. Our evidence and data driven approach may serve as a useful diagnostic guide.     

Clinicopathological analysis of a composite lymphoma containing both T‐ and B‐cell lymphomas

Composite lymphomas (CLs) have been reported in 1–4.7% of all lymphomas, however, CLs containing both T‐ and B‐cell lymphomas (CTBLs) are very rare. Here, we examined the clinical and pathological features of 29 CTBLs. These CTBLs included 21 patients with angioimmunoblastic T‐cell lymphoma (AITL) and diffuse large B‐cell lymphoma (DLBCL), two with adult T‐cell leukemia/lymphoma and DLBCL, one with AITL and Follicular lymphoma, one with Lennert lymphoma and DLBCL, one with subcutaneous panniculitis‐like T‐cell lymphoma and DLBCL, one with peripheral T‐cell lymphoma (PTCL) and DLBCL, one with cutaneous T‐cell lymphoma and DLBCL, and one with PTCL and chronic lymphocytic leukemia. Eighteen of 27 patients (67%) were shown to be Epstein‐Barr virus (EBV)‐encoded RNA‐positive in their B‐cell lymphoma component. T‐cell and B‐cell clonality were confirmed by flow cytometry, Southern blot analysis, and/or polymerase chain reaction (PCR). Using Southern blot analysis, clonal immunoglobulin heavy chain (IgH) and T‐cell receptor (TCR) rearrangements were detected in 11 of 21 and 15 of 24 cases, respectively. Using PCR analysis, clonal IgH and TCR rearrangements were detected in 7 of 8 and 7 of 7 Southern blot‐negative cases, respectively. Our results suggested that PCR analysis was useful in diagnosing CTBL.     

An anti-apoptotic role for galectin-3 in diffuse large B-cell lymphomas

Increased resistance to apoptosis promotes lymphomagenesis with aberrant expression of cell survival proteins such as BCL-2 and c-MYC occurring in distinct lymphoma subtypes. Galectin-3 is an anti-apoptotic protein that protects T cells, macrophages, and breast carcinoma cells from death triggered by a variety of agents. We have found high levels of galectin-3 protein expression in a subset of B-cell neoplasms including diffuse large B-cell lymphoma (DLBCL), primary effusion lymphoma (PEL), and multiple myeloma (MM), in both cell lines and patient samples. However, we failed to detect galectin-3 in Burkitt lymphoma (BL), follicular lymphoma (FL), marginal zone lymphoma (MZL), MALT lymphoma or B-small lymphocytic lymphoma (B-SLL) cell lines or patient samples. To determine whether galectin-3 expression protects B cells from apoptosis, galectin-3-negative BL cells were transfected with a galectin-3 expressing plasmid, which resulted in markedly increased resistance to anti-Fas-induced cell death. In contrast, galectin-3-positive PEL cells transfected with an amino-terminal truncated galectin-3 vector showed increased sensitivity to anti-Fas induced apoptosis. During normal B-cell development, galectin-3 expression was lowest in germinal center and plasma B cells, from which DLBCL, PEL, and MM derive, and highest in long-lived na?ve and memory B cells. This pattern of expression suggests that aberrantly increased galectin-3 levels in specific B-cell populations may yield a protective advantage during transformation and/or progression of certain B-cell neoplasms.     

Gene expression profile of serial samples of transformed B-cell lymphomas

Follicular lymphoma (FL) is characterized by a continuous rate of relapse and transformation to a high-grade lymphoma, usually diffuse large B-cell lymphoma (DLBCL), associated with a dismal prognosis and a poor response to conventional chemotherapy. The progression of indolent to aggressive FL is accompanied by the successive accumulation of recurrent chromosomal defects, but the resultant alterations of gene expression are largely unknown. To expand the understanding of the pathogenesis of FL transformation, we initially performed oligonucleotide microarray analyses using Affymetrix HuFL chips on five cases with matched snap-frozen lymph nodes before and after transformation. Expression data were analyzed using the Affymetrix Microarray Suite 4.0 and Genespring 4.0. Thirty-six genes with increased expression and 66 genes with decreased expression associated with transformation were identified and functionally classified. The expression of differentially expressed genes was confirmed by real-time quantitative RT-PCR (QRT-PCR) using a total of seven matched pairs and an additional five FL and five unrelated DLBCL. In addition, selected genes were further analyzed by QRT-PCR or immunohistochemistry using a large, unrelated series of FL (grades 1 to 3) as well as transformed and de novo DLBCL (total of 51 samples). The microarray results correlated with the protein expression data obtained from samples at the time of initial diagnosis and transformation. Furthermore, the expression of 25 candidate genes was evaluated by QRT-PCR with a 78% confirmation rate. Some of the identified genes, such as nucleobindin, interferon regulatory factor 4, and tissue inhibitor of metalloproteinases 1, are already known to be associated with high-grade non-Hodgkin's lymphoma. Novel candidate genes with confirmed increased and decreased expression in transformed DLBCL include ABL2 and NEK2, and PDCD1 and VDUP1, respectively. In summary, this study shows that transformation of FL to DLBCL is associated with a distinct set of differentially expressed genes of potential functional importance.     

Etiological factors in primary hepatic B-cell lymphoma

Sixty-four cases of malignant lymphoma involving the liver were examined. Of these, 20 cases were histologically confirmed to be primary hepatic B-cell lymphoma. Twelve of these 20 cases were diffuse large B-cell lymphoma (DLBCL) and eight cases were mucosa-associated lymphoid tissue (MALT) lymphoma. Of the 12 cases of DLBCL, six were immunohistologically positive for CD10 and/or Bcl6 (indicating a germinal center phenotype), six were positive for Bcl2, and five were positive for CD25. Eight of the 12 DLBCL cases (66.7%) and two of the eight MALT lymphoma cases (25%) had serum anti-hepatitis C virus (HCV) antibodies and HCV RNA. The incidence of HCV infection was significantly higher in the hepatic DLBCL cases than in systemic intravascular large B-cell cases with liver involvement (one of 11 cases, 9.1%) and T/NK-cell lymphoma cases (one of 19 cases, 5.3%) (p?相似文献   

Diagnostic and prognostic significance of gene expression profiling in lymphomas

Gene expression profiling is a powerful tool to uncover complex molecular networks in cancer and, specifically, in malignant lymphomas. Within diffuse large B-cell lymphomas (DLBCL), two major molecular subtypes, the activated B-cell-like (ABC) and the germinal center B-cell-like (GCB) DLBCL, can be defined. Compared to GCB DLBCL, ABC DLBCL shows a vast difference in gene expression and constitutively expresses NFkappaB and its target genes. In retrospective analyses, the molecular phenotype of ABC DLBCL is associated with inferior survival. Gene expression profiling furthermore allows the molecular separation of Burkitt lymphoma (BL) from DLBCL and reveals a Burkitt-specific signature which is also expressed by a subset of tumors that are currently classified as DLBCL. Whether patients with a DLBCL displaying a Burkitt-specific gene expression signature may benefit from alternative therapeutic approaches will have to be determined in future prospective clinical trials. In follicular lymphoma (FL), two outcome-related signatures, termed Immune response 1 (IR1) and Immune response 2 (IR2), have been identified by gene expression profiling, indicating a significant role of the microenvironment in tumor development and progression. IR1, composed of genes mostly expressed by T-cells, was found to be associated with a more favorable clinical course, and IR2, enriched for genes expressed by macrophages and follicular dendritic cells, was found to be associated with an inferior clinical course. In mantle cell lymphoma (MCL), a gene expression-based proliferation signature of 20 different genes was identified that is able to predict survival of MCL patients in a linear fashion. Future efforts will have to be directed towards the translation of relevant molecular diagnostic and prognostic markers derived from the wealth of gene expression data into clinical tests and towards the development of novel, targeted therapies.     

Differential response to H. pylori eradication therapy of co-existing diffuse large B-cell lymphoma and MALT lymphoma of stomach-significance of tumour cell clonality and BCL10 expression

We recently reported that low-grade mucosa-associated lymphoid tissue lymphoma (MALToma) and diffuse large B-cell lymphoma (DLBCL) with MALToma (DLBCL[MALT]) of stomach are equally responsive to H. pylori eradication therapy (HPET) and that H. pylori-independent status is closely associated with nuclear translocation of BCL10. However, co-existing MALToma and DLBCL components of gastric DLBCL(MALT) may respond differentially to HPET and the underlying mechanism remains unclear. Tumour tissue samples from 18 patients with microdissectable co-existing MALToma and DLBCL cells were studied. The clonality of lymphoma cells was examined by polymerase chain reaction-based amplification of the CDR3 region of the IgH gene and confirmed by DNA sequence analysis. BCL10 expression was determined by immunohistochemistry. Differential response of co-existing MALToma and DLBCL to HPET was defined as complete eradication of one component while the other component remained. Five (27.8%) of the 18 patients showed different IgH gene rearrangements in the two components and three (60%) of these five patients had differential response of MALToma and DLBCL to HPET. By contrast, 13 patients showed identical IgH gene rearrangements and only one (8%) of them had differential response of the two components to HPET (p = 0.044). Further, all four patients with differential response of MALToma and DLBCL to HPET showed nuclear expression of BCL10 in the H. pylori-independent component and cytoplasmic expression of BCL10 in the H. pylori-dependent component while the expression patterns of BCL10 were identical in both of these components in the 14 patients who had similar tumour response to HPET. We conclude that different clonality is a common reason for the differential response of co-existing MALToma and DLBCL of gastric DLBCL(MALT) to HPET and that immunohistochemical examination of BCL10 expression may help to identify the co-existence of these components.     

皮下脂膜炎性T细胞淋巴瘤临床病理分析

目的分析皮下脂膜炎性Ｔ细胞淋巴瘤的病理形态和生物学行为特点,并对其分类命名作一探讨。方法用ＨＥ和免疫组化ＡＢＣ方法对４例原发并定位于皮下脂肪组织中的Ｔ细胞淋巴瘤进行临床病理学和免疫组织化学观察。结果４例病人均表现１～３ｃｍ的皮下结节,伴高热,临床经过凶猛,短期死亡。组织学上以肿瘤细胞（ＣＤ４５ＲＯ阳性）浸润脂肪小叶之间及大量豆袋细胞（ｂｅａｎｂａｇｃｅｌ,ＣＤ６８阳性）为特征。结论皮下脂膜炎性Ｔ细胞淋巴瘤是一种恶性度很高的外周Ｔ细胞淋巴瘤。     

Epstein-Barr virus-associated lymphoproliferative disorder presenting with classical Hodgkin lymphoma and developing as peripheral T-cell lymphoma 9 years later: a case report of composite lymphoma

We describe a patient who was diagnosed with classical Hodgkin lymphoma (CHL) at 67-years-old and peripheral T-cell lymphoma, not otherwise specified (PTCL) at 76-years-old, and died 5 months later. Both tumors showed prominent epithelioid cell reaction admixed with neoplastic cells. Hodgkin and Reed-Sternberg cells in the swollen lymph node were positive for CD30 and EBV-encoded RNA (EBER). PTCL cells in the skin tumor were positive for cytoplasmic CD3ε, CD4 and EBER. A rearrangement band of the T-cell receptor gene was detected in the skin tumor. This case is the first documented EBV-associated composite lymphoma composed of CHL and PTCL. The patient may show the possibility that both EBV infection and/or immunodeficiency induce the development of CHL and PTCL.     

根据WHO新分类对493例非霍奇金淋巴瘤的临床病理分析

目的探讨非霍奇金淋巴瘤(NHL)的临床病理特点,评价世界卫生组织(WHO)2001淋巴瘤新分类标准的实用性.方法复查1992-2003年500例既往经病理诊断为NHL的病例,观察其形态学、免疫学及临床特点,按WHO新分类标准进行重新定性和分类,对其中156例有随访的病例进行生存率分析.结果 500例中,493例NHL,其中B细胞肿瘤69.0%,T和NK细胞肿瘤29.8%;前六位最常见类型为弥漫大B细胞淋巴瘤(DLBCL)、滤泡性淋巴瘤(FL)、非特殊型周围T细胞淋巴瘤(PT-un)、T淋巴母细胞淋巴瘤(T-LBL)、MALT型结外边缘区B细胞淋巴瘤(MALT)及B-小淋巴细胞性淋巴瘤(B-SLL);青少年中最常见为LBL、DLBCL及Burkitt淋巴瘤.在本组病例中,LBL在所有患者尤其是青少年患者中的比例均明显高于国外报道,FL的比例明显高于国内报道.不同类型NHL的生存情况在总体上差异有统计学意义(P<0.001),其中边缘区B细胞淋巴瘤(MZL)与SLL的预后最佳,LBL与PT-un的预后最差,DLBCL与FL介于前两组之间.按WHO推荐的两种方法划分的FL不同级别之间,生存情况差异无统计学意义(P>0.05).结论淋巴瘤WHO2001新分类实用性强、便于掌握,各亚型的形态学、免疫学指标可靠,结合临床能较好应用于淋巴瘤的诊断和预后.但是,建议国内同行对FL的判断及分级标准进一步审定.     

Efficacy of rituximab plus chemotherapy in follicular lymphoma depends on Ki-67 expression

Rituximab is widely used for the treatment of B-cell non-Hodgkin's lymphoma (NHL), and encouraging results have been obtained. However, some CD20-positive NHL show minimal response to rituximab, indicating that the treatment effect depends on the presence or absence of an unidentified factor. We analyzed the relationship between the effect of rituximab plus chemotherapy and expression of Ki-67, p53 and bcl-2 and several clinical variables in cases of B-NHL, particularly follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). Forty-four patients were included in the present study, and the overall treatment response rate was 68%. Twelve of 30 patients (40%) achieved a complete response, five (16%) reached an unconfirmed complete response and 13 (43%) achieved a partial response. A high serum lactate dehydrogenase level and International Prognostic Index of high or high intermediate risk were associated with a decreased response in the case of FL. Immunohistochemical assays were performed in 18 FL patients (55%) and 15 DLBCL patients (45%). Significant correlation was found between an inferior response to treatment and high Ki-67 expression in the cases of FL (P = 0.006). p53 and bcl-2 expression did not correlate significantly with the response rate. The cell cycle appears to be an important factor in the efficacy of rituximab treatment. Ki-67 expression might be a predictor of efficacy of rituximab plus chemotherapy.     

A malignant lymphoma with histological features and immunophenotypic profile intermediate between EBV-positive diffuse large B-cell lymphoma and EBV-positive classical Hodgkin lymphoma in a 67-year-old female: a "gray zone" lymphoma associated with Epstein-Barr virus in the elderly

Epstein-Barr virus (EBV) can be associated with both classical Hodgkin lymphoma (cHL) and non-Hodgkin lymphoma of the B-cell type, particularly in immunodeficient patients or elderly individuals. While polymorphic variants of EBV-positive large B-cell lymphoma (EBV+ DLBCL) frequently resemble cHL in morphology, and thereby may cause diagnostic difficulty, a true gray zone lymphoma with overlapping morphological and immunophenotypical features of EBV+ DLBCL and EBV+ cHL has not been reported in the literature. We describe a unique case of an EBV+ malignant lymphoma of B-cell origin with hybrid features of EBV+ DLBCL and EBV+ cHL in a 67-year-old female without an identifiable etiology for immunodeficiency. The biopsy of an enlarged lymph node showed a polymorphic infiltrate containing Reed-Sternberg-like pleomorphic large cells, which were positive for CD30 and CD15. Although CD20 was negative and PAX5 and CD45 were down-regulated, the pleomorphic large cells expressed multiple other B-cell antigens which are characteristically absent in cHL. EBV-encoded RNA hybridization (EBER) studies demonstrated nuclear reactivity in the large cells as well as in the smaller bystander cells. A clonal rearrangement of the immunoglobulin heavy chain gene was also detected by PCR. Although the results of the EBV and genotypic studies suggest this case may be an example of EBV+ DLBCL of the elderly instead of EBV+ cHL, the immunophenotype is strikingly ambiguous. Thus, this case may represent an interface between EBV+ DLBCL and EBV+ cHL.     

Coexpression of Bcl-6 and CD10 in diffuse large B-cell lymphomas: significance of Bcl-6 expression patterns in identifying germinal center B-cell lymphoma

Most follicular lymphomas (FLs) transform to diffuse lymphoma eventually, comprising a significant proportion of diffuse large B-cell lymphoma (DLBCL). Judging by bcl-2 rearrangement (bcl-2R), one third of DLBCLs are believed to be of FL derivation in the Western population. However, bcl-2R is not specific and is not detectable in every case of FL. In East Asia, FL is uncommon but DLBCL is not. The proportion of tumors of FL origin in DLBCL is not known in this region. The coexpression of Bcl-6 and CD10 proteins, a reliable marker to identify germinal center (GC) B-cell lymphoma including FL, was analyzed in primary nodal DLBCLs (n = 104) diagnosed at major hospitals in Seoul during a recent 2-year period, along with well-defined cases (n = 17) of nodal FL as controls. Bcl-2 protein expression (n = 77) was also studied along with bcl-2R (n = 64), by polymerase chain reaction. Formalin-fixed archival specimens were used in all these assays. The Bcl-6/CD10 coexpression was observed in 35 DLBCLs (34%) and 14 FLs (82%), and most of them showed a pattern of Bcl-6 expression similar to that of the GC. Bcl-2 expression or bcl-2R did not correlate with Bcl-6/CD10 coexpression. Histologically, compartmentalizing sclerosis was associated with a high rate of the coexpression (8 of 10). In conclusion, to detect GC B-cell lymphoma in routine biopsy specimens, a pattern of Bcl-6 staining similar to the GC must be identified. Bcl-6+/CD10+ GC B-cell lymphomas thus defined comprised one third of primary nodal DLBCLs in Korea. The incidence rate is similar to that in the West. The reasons for the discrepancy between the incidence of GC B-cell lymphoma and the paucity of the follicular pattern in East Asian subjects warrant further studies.