Genomic imbalances in AIDS-related lymphomas: relation with tumoral Epstein-Barr virus status

BACKGROUND: The pathologic heterogeneity of AIDS related lymphomas (ARL) reflects several pathogenic mechanisms: chronic antigenic stimulation, Epstein-Barr virus (EBV) infection, and genomic abnormalities. Genetic abnormalities, known to play a major role in lymphomas of non-immunocompromised patients, are not well characterized in ARL. OBJECTIVE: Characterization of the DNA copy number change (CNC) in ARL and comparison of our findings with tumoral EBV and immune status. DESIGN AND METHODS: We have studied by comparative genomic hybridization (CGH), 28 ARL well characterized for histopathologic, clonality and EBV findings. RESULTS: DNA-CNC were detected in 50% of cases. Gains of chromosomal material were much more frequent than losses and involved chromosomes 9p, 11q, 12q, 17q, and 19q recurrently. DNA-CNC tended to be more frequent in EBV-positive lymphomas with latency type II/III than in EBV-positive latency I or EBV-negative lymphomas. Most chromosomal regions affected in HIV-related lymphoma were similar to those already reported in HIV-negative lymphomas. CONCLUSION: This CGH study allowed the identification of non-random chromosomal alterations in ARL. The results suggested an inverse relationship between EBV infection (latency II/III), associated with deep acquired immune suppression, and the number of chromosomal alterations which may be explained by a direct role of viral proteins in lymphomagenesis by activation of signalling pathways without needing several genomic alterations.     

Association of Epstein-Barr virus with human immunodeficiency virus-negative peripheral T-cell lymphomas in Japan

The association of Epstein-Barr virus (EBV) with human immunodeficiency virus-negative T-cell lymphoma was examined in 68 patients using the polymerase chain reaction (PCR) with DNA obtained from formalin-fixed paraffin-embedded tissues and an in situ hybridization technique. EBV-encoded RNA (EBER) was detected in 43 of 68 cases (63%) of peripheral T-cell lymphoma: in 100% (11 of 11 cases) of NK/T-cell lymphomas, 70% (14 of 20 cases) of angioimmunoblastic T-cell lymphomas (AILT) and 49% (18 of 37 cases) of other types of peripheral T-cell lymphoma. A positive band was also detected at high incidence (36 of 65 cases; 55%) in a PCR analysis using primers to detect the Bam HI-W fragment of EBV. In the immunohistochemical analysis using a monoclonal antibody to latent membrane protein 1 (LMP-1) of EBV, one of the EBV-encoded latent gene products, LMP-1, was found to be expressed in 13 of 64 cases (20%), but EBNA-2 was not expressed in all the cases examined (0 of 59 cases; 0%). The 5-yr survival rate was 28% for peripheral T-cell lymphomas overall, 0% for NK/T-cell lymphomas, 38% for AILTs and 28% for other types of peripheral T-cell lymphoma. The difference in the overall survival rate between NK/T-cell lymphoma and non-NK/T-cell lymphoma was significant (P = 0.0498 by Log-rank test). Among peripheral T-cell lymphoma patients overall, the group severely infected with EBV (EBER-ISH ++) had a lower 5-yr survival rate (8%) than the group slightly (EBER-ISH +) or not infected (38%; P = 0.0013).     

Epstein-Barr virus provides a survival factor to Burkitt's lymphomas

Epstein-Barr virus (EBV) has been causally associated with at least five human malignancies. The exact contributions made by EBV to these cancers remain unknown. We demonstrate that one viral protein found in all EBV-associated malignancies, Epstein-Barr nuclear antigen 1 (EBNA-1), is required for survival of one of these cancers, EBV-positive Burkitt's lymphoma. Inhibition of EBNA-1 decreases survival of these tumor cells by inducing apoptosis. Expression of EBNA-1 in uninfected cells also can inhibit apoptosis induced by expression of p53 in the absence of the EBV genome. Our findings demonstrate that EBNA-1 is critical for the continued survival of EBV-associated Burkitt's lymphoma, and, by extension, for the other B cell tumors with which EBV is associated. Efficient inhibitors of EBNA-1's functions would likely prove useful in the therapy of EBV-associated malignancies.     

Clinical implications of plasma Epstein-Barr virus DNA in early-stage extranodal nasal-type NK/T-cell lymphoma patients receiving primary radiotherapy

The clinical value of plasma Epstein-Barr virus (EBV) DNA has not been evaluated in patients with early-stage extranodal nasal-type NK/T-cell lymphoma (NKTCL) receiving primary radiotherapy. Fifty-eight patients with stage I disease and 11 with stage II disease were recruited. High pretreatment EBV-DNA concentrations were associated with B-symptoms, elevated lactate dehydrogenase levels, and a high International Prognostic Index score. EBV-DNA levels significantly decreased after treatment. The 3-year overall survival (OS) rate was 82.6% for all patients. Stage I or II patients with a pretreatment EBV-DNA level of ≤ 500 copies/mL had 3-year OS and progression-free survival (PFS) rates of 97.1% and 79.0%, respectively, compared with 66.3% (P = .002) and 52.2% (P = .045) in patients with EBV-DNA levels of > 500 copies/mL. The 3-year OS and PFS rates for patients with undetectable EBV-DNA after treatment was significantly higher than patients with detectable EBV-DNA (OS, 92.0% vs 69.8%, P = .031; PFS, 77.5% vs 50.7%, P = .028). Similar results were observed in stage I patients. EBV-DNA levels correlate with tumor load and a poorer prognosis in early-stage NKTCL. The circulating EBV-DNA level could serve both as a valuable biomarker of tumor load for the accurate classification of early-stage NKTCL and as a prognostic factor.     

Treatment of extranodal lymphomas

At least one-quarter of the non-Hodgkin's lymphomas arise primarily at extranodal sites. The rising incidence of non-Hodgkin's lymphomas, observed over recent decades, have mainly affected the primary extranodal entities. Survival rates vary among the specific sites of primary extranodal lymphomas. This is due partly to differences in natural history, related mainly to the histological type but also to differences in management strategy which are related to organ-specific problems. Few controlled studies facilitate therapeutic decisions in this setting. This chapter represents a general overview of the available data.     

Epstein-Barr virus T-cell immunity despite rituximab

Immunosuppression following solid organ transplantation results in impaired T-cell immunity and risk of Epstein-Barr virus (EBV)-positive post-transplant lymphoproliferative disorders (PTLD). The B-cell targeting antibody rituximab has efficacy in PTLD. As B cells are the principle reservoir for EBV, we investigated the effect of rituximab on the persistence of EBV-specific CD8(+) T-cell immunity. To avoid the confounding factor of concurrent immunosuppression to prevent transplant rejection, immunity was analysed in non-transplanted lymphoma patients (i.e. a non-PTLD setting). Cytomegalovirus-specific T-cell immunity was assessed as an internal control. Our data demonstrated that circulating B cells were not critical for maintaining EBV-specific T-cell immunity.     

Detection of Epstein-Barr virus in Korean peripheral T-cell lymphoma

One hundred thirty-seven patients with peripheral T-cell lymphomas (PTL) were examined for the presence of Epstein-Barr virus (EBV) using in situ hybridization for EBV-encoded RNA (EBER) and Bam H-fragment, lower strand frame (BHLF) and immunohistochemical stain for latent membrane protein (LMP). EBER was detected in tumor cells in 79 cases (58%); 26/66 PTL, unspecified (39%), 3/4 AILD (75%), 47/51 angiocentric lymphomas (AL) (92%), and 3/13 anaplastic large cell lymphoma (ALCL) (23%) by Revised European-American Lymphoma (REAL) classification. EBER was detected in 17/36 nodal (47%) vs. 62/101 extranodal PTLs (61%); 21/24 nasal, 12/32 Waldeyer's ring, 9/13 gastrointestinal, and 20/32 skin and soft tissue PTL. AL was consistently associated with the highest frequency of EBER among the extranodal PTL: nose (19/20), GI tracts (3/3), skin (14/15), and Waldeyer's ring (11/14). In extranodal lymphomas, coagulative-type zonal necrosis was seen almost exclusively in AL and showed correlation with EBER-positivity (P < 0.01). LMP was detected in 24 among 107 cases tested (22%). No signal for BHLF was detected in 76 cases tested, implying absent or negligible incidence of lytic infection. In conclusion, high incidence of EBV was observed in PTL among Koreans, with predilection for angiocentric lymphomas and extranodal presentation, especially involving nose, skin, and gastrointestinal tract.     

Influence of Epstein-Barr virus infection in adult T-cell leukemia

The involvement of adult T-cell leukemia (ATL) cells in organs such as the skin and lymph nodes is observed in about 50% of cases of ATL. Epstein-Barr virus (EBV) infection has often been observed in the clinical course of ATL. In this study, we established two B-cell lines from peripheral blood of patients with ATL. EBV DNA, proviral DNA for HTLV-1 and Tax mRNA were detected in both lines. As part of the characterization of these cells, an enhanced expression of intercellular adhesion molecule-1 (ICAM-1) (CD54) or ICAM-3 (ICAM-3) (CD50), lymphocyte function-1 (LFA-1) (CD11a/CD18), and Mac-1 (CD11b/CD18) was observed. To investigate the role of the interaction of these viruses, we transfected EBV and/or HTLV-1 into a healthy donor's lymphocytes, an EBV-infected B cell line, Raji, and a HTLV-1 negative T-cell line, Jurkat. Enhanced expression of adhesion molecules was also observed in double transfectants (EBV and HTLV-1). In the clinical course of ATL, LMP-1, EBNA-2, CD50 and CD54 were detected in lymph nodes and skin specimens by immunohistochemical staining. Furthermore, high levels of interleukin-4 (IL-4) were detected in these cell lines and transfectants. The results indicated that coinfection with HTLV-1 and EBV may induce aggressive organ involvement through the enhanced expression of adhesion molecules via IL-4 signaling. A new mechanism of ATL involvement is discussed.     

Presence of simian virus 40 DNA sequences in human lymphomas

Simian virus 40 (SV40)--a potent oncogenic virus--has been associated previously with some types of human tumours, but not with lymphomas. We examined human tumours for the presence of specific SV40 DNA sequences by PCR and Southern blotting. Viral sequences were present in 29 (43%) of 68 non-Hodgkin lymphomas, and in three (9%) of 31 of Hodgkin's lymphomas. Viral sequences were detected at low frequencies (about 5%) in 235 epithelial tumours of adult and paediatric origin, and were absent in 40 control tissues. Our data suggest that SV40 might be a cofactor in the pathogenesis of non-Hodgkin lymphomas.     

Epstein-Barr virus clonality in lymphomas occurring in patients with rheumatoid arthritis

Objective. A causative role for Epstein-Barr virus (EBV) in the development of lymphoma in patients with rheumatoid arthritis (RA) has been proposed. We investigated the molecular features of EBV-positive diffuse large cell lymphomas in 2 patients with RA. Methods. Southern blot analysis for immunoglobulin gene rearrangements, terminal repeat analysis for clonality of the EBV genome, and double-labeling of the lymphoma cells by in situ hybridization and immuno-peroxidase staining were performed. Results. In both cases, double-labeling studies localized the EBV genome to the malignant B cells. Both neoplasms contained clonal immunoglobulin gene rearrangements and clonal EBV genomes. Conclusion. Our data indicate that EBV infection was an early step in the development of these neoplasms. The findings further extend knowledge on the similarity of this subset of lymphomas to posttransplantation lymphomas and emphasize the role of immunosuppression in their genesis.     

肠道T细胞淋巴瘤中EB病毒感染的研究

目的 了解我国肠道T细胞淋巴瘤（ITCL）中EB病毒（EBV）潜伏感染的状态，其亚型的感染情况，基因产物表达与EBV阳性细胞的性质。方法采用PCR检测42例ITCL中的不同EBV亚型的核抗原基因（EBNA－3C），并对其扩增产的行DNA序列分析。运用EBER1／2－RNA原位杂交证实EBV潜伏感染，IHC／ISH双重染色技术判断EBV阳性细胞性质。免疫组化检测EBV基因产物（LMP－1，EBNA－2）的表达。结果 42例ITCL中EBV的阳性率为97．6％，以A型EBV感染居多（32／38例，84．2％），B型为2／38例（5．3％），混合型为4／38例（10．5％）。EBNA－3C基因的PCR产物DNA序列中存在个别碱基的缺失和插入.EBER1/2的检出率为85．7％。EBER1／2阳性细胞同时表达CD45RO和TIA－1，且表达CD4，CD8及CD56的肿瘤细胞呈EBER1／2阳性。16／42例ITCL（38．1％）表达LMP－1。ITCL中EBV的潜伏感染模式多为I型（24／42，66．7％），Ⅱ型次之（12／42，33．4％）。结论 在我国，ITCL中存在高水平的EBV潜伏感染，且多为A型EBV感染，感染模式为Ⅰ型和Ⅱ型。部分ITCL可能与鼻NK／T细胞淋巴瘤属于同一疾病谱系。     

Aggressive peripheral T-cell lymphomas containing Epstein-Barr viral DNA: a clinicopathologic and molecular analysis.

The Epstein-Barr virus (EBV) has been shown to be associated with posttransplant lymphoma, Hodgkin's disease, and T-cell lymphoma, in addition to African Burkitt's lymphoma. In a retrospective study of 56 consecutive cases of T-cell lymphoma, EBV DNA was found by Southern blot and in situ DNA hybridization in 10 (20%) of 50 peripheral T-cell lymphomas, but in none of six cases of T-lymphoblastic lymphoma. Peripheral T-cell lymphomas containing EBV DNA could be subclassified into three categories according to histology and immunophenotypic studies: (1) T-cell lymphoma of the helper phenotype, five cases. Two cases had histologic features resembling angioimmunoblastic lymphadenopathy (AILD). (2) T-cell lymphoma of the cytotoxic/suppressor phenotype, four cases. AILD-like features could also be recognized in two cases. Reed-Sternberg-like giant cells were identified in three cases designated Hodgkin-like T-cell lymphoma. (3) Angiocentric T-cell lymphoma or lymphomatoid granulomatosis in one case, initially affecting the skin and nose; no T-cell subset could be defined. Six of the eight EBV DNA-positive patients tested for serum EBV antibodies had elevated titers of IgG antiviral capsid antigen (greater than 640) and/or early antigen (greater than 10). From combined studies of Southern blot hybridization by using EBV termini fragment probe and in situ DNA hybridization, the EBV genomes appeared to be clonotypically proliferated in the neoplastic T cells. The patients in all three groups usually had prolonged fever preceding the diagnosis, hepatosplenomegaly, an aggressive clinical course, and poor response to chemotherapy; nine died with a median survival of only 8 months. We propose that these EBV-associated aggressive T-cell lymphomas, like human T-cell leukemia/lymphoma virus-positive T-cell lymphoma, have characteristic clinicopathologic features and should be treated as a separate disease entity.     

Rare primary extranodal lymphomas: diffuse large B-cell lymphomas of the genital tract

Primary non-Hodgkin’s lymphoma (NHL) of the genital tract is a rare entity. Etiology and pathogenesis of these NHLs are unknown, although there might be a possible association between chronic inflammation and lymphomas. The most common histological subtype is the diffuse large B-cell lymphoma. We report two cases of uterine lymphoma and one case of prostate lymphoma in this paper. The symptoms and the differential diagnosis are also discussed. Because of the low incidence, there is no widely accepted consensus on its treatment. We demonstrate that the rituximab and CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone; R-CHOP) chemoimmunotherapy is a good and tolerable treatment option in all cases. The two young patients are disease-free nowadays; the older patient with poor prognostic histological-type lymphoma relapsed in a short time and died after second relapse. A multicenter analysis is necessary to evaluate the long-term results of chemoimmunotherapy in these rare extranodal lymphoma entities.     

Establishment of human T-cell leukemia virus type I T-cell lymphomas in severe combined immunodeficient mice

Human T-cell leukemia virus type I (HTLV-I) is recognized as the etiologic agent of adult T-cell leukemia (ATL), a disease endemic in certain regions of southeastern Japan, Africa, and the Caribbean basin. Although HTLV-I can immortalize T lymphocytes in culture, factors leading to tumor progression after HTLV-I infection remain elusive. Previous attempts to propagate the ATL tumor cells in animals have been unsuccessful. Severe combined immunodeficient (SCID) mice have previously been used to support the survival of human lymphoid cell populations when inoculated with human peripheral blood lymphocytes (PBL). SCID mice were injected intraperitoneally with PBL from patients diagnosed with ATL, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), or from asymptomatic HTLV-I-seropositive patients. Many of these mice become persistently infected with HTLV-I. Furthermore, after human reconstitution was established in these mice, HTLV-I-infected cells displayed a proliferative advantage over uninfected human cells. Lymphoblastic lymphomas of human origin developed in animals injected with PBL from two ATL patients. The tumor cells represented outgrowth of the original ATL leukemic clone in that they had monoclonal or oligoclonal integrations of the HTLV-I provirus identical to the leukemic clone and predominantly expressed the cell surface markers, CD4 and CD25. In contrast, cell lines derived by HTLV immortalization of T cells in vitro did not persist or form tumors when inoculated into SCID mice, indicating differences between in vitro immortalized cells and ATL leukemic cells. This system represents the first small animal model to study HTLV-I tumorigenesis in vivo.     

Frequent latent Epstein-Barr virus infection of neoplastic T cells and bystander B cells in human immunodeficiency virus-negative European peripheral pleomorphic T-cell lymphomas

We investigated 81 cases of peripheral pleomorphic T-cell lymphoma (PMTCL) occurring in human immunodeficiency virus-negative Europeans for the presence of Epstein-Barr virus (EBV)-DNA through polymerase chain reaction (PCR) for the presence of EBV-encoded small nuclear RNAs (EBER) and immediate early mRNAs (Bam H-fragment, lower strand frame [BHLF]) by in situ hybridization (ISH) and for EBV-encoded latent membrane protein (LMP) and nuclear antigen 2 (EBNA2) by immunohistology (IH). EBER-ISH, which could be applied on all cases, showed an overall incidence of EBV-infected cells in 38 of 81 cases (47%) of PMTCL. These data could be confirmed by PCR, which produced congruent results in the cases with amplifiable DNA. By EBER-ISH, the virus was located in the tumor cells in 30 of the 38 EBV-positive cases, with the proportion of the infected cells ranging from 1% to 100%. In 18 of these cases and in the 8 cases without EBV-infected tumor cells, the virus was, respectively, either additionally or exclusively detectable in occasional nonmalignant lymphoid bystander cells. An LMP expression was observed in several of the EBER-expressing tumor cells in 18 cases, whereas EBNA2 was detectable only in one case, which also displayed signs of viral replication. Some nonmalignant EBV-infected B immunoblasts also expressed LMP in several cases. Primary cutaneous and enteropathy-associated PMTCL displayed less frequent EBV infection when compared with other extranodal or nodal manifestations.