High prevalence of a 30-base pair deletion in the Epstein-Barr virus (EBV) latent membrane protein 1 gene and of strain type B EBV in Mexican classical Hodgkin's disease and reactive lymphoid tissue

Distribution of Epstein-Barr Virus LMP1 Variants in Patients with Infectious Mononucleosis and Association with Selected Biochemical and Hematological Parameters

The molecular diversity of Epstein-Barr virus (EBV) is exceptionally complex and based on the characterization of sequences coding for several viral genes. The aim of this study was to analyze the distribution of EBV types 1 and 2 and to characterize LMP1 variants in a cohort of 73 patients with infectious mononucleosis (IM), as well as to investigate a possible association between viral diversity and relevant clinical parameters. Population-based sequencing of EBNA-2 gene showed the presence of EBV type 1 in all IM patients. Analysis of LMP1 gene found a restricted repertoire of LMP1 variants with the predominance of wild-type B95-8, China1, Mediterranean and North Carolina variants with the presence of more than one LMP1 variant in 16.4% of patients. Co-infections with different LMP1 variants were associated with significantly higher levels of C-reactive protein and lower levels of maximal neutrophil counts and minimal platelet count. The results of this study have shown a narrow repertoire of LMP1 variants and an exclusive presence of EBV type 1 in a cohort of IM from Croatia, suggesting a characteristic local molecular pattern of this virus. The clinical importance of distinct immunobiological features of IM patients with LMP1 variant co-infections needs to be investigated further.

Molecular Characterisation of Epstein-Barr Virus in Classical Hodgkin Lymphoma

Hodgkin lymphomas (HLs) are a heterogeneous group of lymphoid neoplasia associated with Epstein-Barr virus (EBV) infection. EBV, considered to be an important etiological co-factor in approximately 1% of human malignancies, can be classified into two genotypes based on EBNA-2, EBNA-3A and EBNA-3C sequences, and into genetic variants based on the sequence variation of the gene coding for the LMP1 protein. Here, we present the results on the distribution of EBV genotypes 1 and 2 as well as LMP1 gene variants in 50 patients with EBV-positive classical HL selected from a cohort of 289 histologically verified cases collected over a 9-year period in a tertiary clinical center in the Southeast of Europe. The population-based sequencing of the EBNA-3C gene showed the exclusive presence of EBV genotype 1 in all cHL samples. The analysis of EBV LMP1 variant distribution showed a predominance of the wild-type strain B95-8 and the Mediterranean subtype with 30 bp deletion. These findings could contribute to the understanding of EBV immunobiology in cHL as well as to the development of a prophylactic and therapeutic vaccine.

EBV and the Pathogenesis of NK/T Cell Lymphoma

Epstein-Barr virus (EBV) is a ubiquitous gamma herpes virus with tropism for B cells. EBV is linked to the pathogenesis of B cell, T cell and NK cell lymphoproliferations, with extranodal NK/T cell lymphoma, nasal type (ENKTCL) being the prototype of an EBV-driven lymphoma. ENKTCL is an aggressive neoplasm, particularly widespread in East Asia and the native population of Latin America, which suggests a strong genetic predisposition. The link between ENKTCL and different populations has been partially explored. EBV genome sequencing analysis recognized two types of strains and identified variants of the latent membrane protein 1 (LMP1), which revealed different oncogenic potential. In general, most ENKTCL patients carry EBV type A with LMP1 wild type, although the LMP1 variant with a 30 base pair deletion is also common, especially in the EBV type B, where it is necessary for oncogenic transformation. Contemporary high-throughput mutational analyses have discovered recurrent gene mutations leading to activation of the JAK-STAT pathway, and mutations in other genes such as BCOR, DDX3X and TP53. The genomic landscape in ENKTCL highlights mechanisms of lymphomagenesis, such as immune response evasion, secondary to alterations in signaling pathways or epigenetics that directly or indirectly interfere with oncogenes or tumor suppressor genes. This overview discusses the most important findings of EBV pathogenesis and genetics in ENKTCL.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Mutational profile and EBV strains of extranodal NK/T-cell lymphoma, nasal type in Latin America

Extranodal NK/T-cell lymphoma (ENKTL) is an Epstein-Barr virus (EBV) associated lymphoma, prevalent in Asia and Latin America. Studies in Asian cohorts have identified some recurrent gene mutations in ENKTL; however, the mutational landscape of ENKTL in Latin America is unknown. In this study, we investigated the mutational profile and EBV strains of 71 ENKTL cases from Latin America (42 from Mexico, 17 from Peru, and 12 from Argentina) and compared it with Asian cohorts. The mutational analysis was performed by next generation sequencing (NGS) using an Ion AmpliSeq™ custom panel covering for the most frequently mutated genes identified in ENKTL. STAT3 was the most frequent mutated gene (16 cases: 23%), followed by MSN (10 cases; 14%), BCOR (9 cases; 13%), DDX3X (6 cases; 8%), TP53 (6 cases; 8%), MGA (3 cases; 4%), JAK3 (2 cases; 3%), and STAT5B (1 case; 1%). Mutations in STAT3, BCOR, and DDX3X were nearly mutually exclusive, suggesting different molecular pathways involved in the pathogenesis of ENKTL; whereas mutations in MGA, MSN, and TP53 were concomitant with other mutations. Most cases (75%) carried Type A EBV without the 30-bp LMP1 gene deletion. The overall survival was significantly associated with serum LDH level, Eastern Cooperative Oncology Group (ECOG) performance status, International Prognostic Index (IPI) score, and therapy (p < 0.05), but not associated with any mutation, EBV strain or deletion in EBV LMP1 gene. In conclusion, mutational analysis of ENKTL from Latin America reveals frequent gene mutations leading to activation of the JAK-STAT pathway (25%), mostly STAT3. Compared to Asian cohorts, BCOR, DDX3X  and TP53 mutations were also identified but with different frequencies. None of these mutations were associated with prognosis.

Epstein-Barr Virus-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

EBV-Positive Lymphoproliferations of B- T- and NK-Cell Derivation in Non-Immunocompromised Hosts

The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.

The Epstein-Barr virus latent membrane protein-1 (LMP1) 30-bp deletion and XhoI-polymorphism in nasopharyngeal carcinoma: a meta-analysis of observational studies

BACKGROUND

Epstein-Barr virus (EBV) is considered to be closely associated with nasopharyngeal carcinoma (NPC), in which EBV-encoded latent membrane protein 1 (LMP1) was found to have an oncogenic role. However, the results published on the LMP1 polymorphism are inconsistent. In the present study, we performed a meta-analysis to determine the frequency of the associations and a more precise association between NPC and EBV LMP1 gene variants (30-bp deletion (del)/XhoI-loss).

METHODS

Eligible articles met the inclusion/exclusion criteria and were identified in the following electronic databases: PubMed, ScienceDirect, and SciELO. Consequently, the data of interest were extracted and plotted in a table to calculate the frequency and odds ratio (OR) of the outcomes of interest (30-bp del-LMP1/XhoI-loss) in patients with NPC. Study quality (Newcastle-Ottawa Scale (NOS)), publication bias, and heterogeneity were assessed.

RESULTS

Thirty-one observational studies were included with a total of 2,846 individuals (NPC, n = 1,855; control, n = 991). The risk of bias in relation to study quality evaluated by NOS was considered low. The pooled estimate of the frequency of 30-bp del-LMP1 and XhoI-loss in patients with NPC was 77% (95% confidence interval (CI): 72 to 82) and 82% (95% CI: 71 to 92), respectively. There was an association between 30-bp del-LMP1 and NPC susceptibility (OR = 2.86, 95% CI: 1.35 to 6.07, P = 0.00). Similarly, there was an association between XhoI-loss and NPC (OR = 8.5, 95% CI: 1.7 to 41, P = 0.00). However, when we analyze the co-existence of the 30-bp del-LMP1 and XhoI-loss in patients with NPC, there was no association (OR = 1.09, 95% CI: 0.06 to 18.79, P = 0.002).

CONCLUSIONS

Our results suggest an association between the 30-bp del-LMP1 and XhoI-loss with NPC susceptibility. However, our data should be interpreted with caution because the sample size was small, and there was heterogeneity between the studies. Thus, future studies are needed with adjusted estimates to simultaneously evaluate multiple factors involved in the development of NPC.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014013496 .

Hodgkin lymphoma incidence in California Hispanics: influence of nativity and tumor Epstein-Barr virus

PURPOSE

For classical Hodgkin lymphoma (HL), migrant studies could elucidate contributions of environmental factors (including Epstein-Barr virus (EBV)) to the lower rates in non-whites. Given the well-described etiologic complexity of HL, this research requires a large, immigrant population, such as California Hispanics.

METHODS

With 1988-2004 California Cancer Registry data (2,595 Hispanic, 8,637 white HL cases) and tumor cell EBV status on a subset (218 Hispanics, 656 whites), we calculated ethnicity- and nativity-specific HL incidence rates simultaneously by age, sex, and histologic subtype, and tumor cell EBV prevalence.

RESULTS

Compared with white rates, Hispanic HL rates were lower overall (70 %) and for nodular sclerosis HL, particularly among young adults (60-65 % for females). However, they were higher among children (200 %) and older adults, and for mixed cellularity HL. Compared with rates in foreign-born Hispanics, rates in US-born Hispanics were higher among young adults (>threefold in females), lower for children and adults over age 70, and consistently intermediate compared with rates in whites. EBV tumor prevalence was 67, 32, and 23 % among foreign-born Hispanics, US-born Hispanics, and whites, respectively, although with variation by age, sex, and histology.

CONCLUSIONS

Findings strongly implicate environmental influences, such as nativity-related sociodemographic differences, on HL occurrence. In addition, lower young adult rates and higher EBV prevalence in US-born Hispanics than in whites raise questions about the duration/extent of environmental change for affecting HL rates and also point to ethnic differences in genetic susceptibility. Lesser variation in mixed cellularity HL rates and greater variation in rates for females across groups suggest less modifiable factors interacting with environmental influences.

Detection of Epstein-Barr virus and genotyping based on EBNA2 protein in Mexican patients with hodgkin lymphoma: a comparative study in children and adults

BACKGROUND

Epstein-Barr virus (EBV) is a member of the Herpesviridae family and is associated with Hodgkin lymphoma (HL). Isolates of EBV are classified according to sequence variation in the latency genes such as Epstein-Barr virus nuclear antigen (EBNA). EBNA2 contains the most divergent locus and is classified into type 1 and type 2 or EBNA2A and EBNA2B, respectively. We compared the frequency of EBV and the distribution of EBNA genotypes in Mexican children and adults with HL.

PATIENTS AND METHODS

Lymph node biopsy specimens from children and adults with HL were embedded in paraffin. EBV was identified by LMP1 amplification and Epstein-Barr-encoded RNA EBER by in situ hybridization (ISH) and genotyped as EBNA2A or EBNA2B using nested polymerase chain reaction (PCR) and specific primers for the detection of subtype.

RESULTS

Sixty-six samples were obtained from 3 hospitals-42 (63%) from children and 24 (37%) from adults with HL. Thirty-two of the 42 samples (76.1%) were positive for EBV in children and 16 of 24 (66.6%) samples were positive in adults (P = .41). In both children and adults, EBV was found more frequently in male patients. Thirty-four of 48 cases could be typed (70.8%). EBNA2A was found in 7/21 (33.3%) children and in 4/13 (30.8%) adults (P = 1.0), and EBNA2B was found in 10/21 (47.6%) children and in 9/13 (69.2%) adults (P = .22). A mix of subtypes was found in 4/21 (19%) children.

CONCLUSION

EBV was found frequently in both children and adults with HL. EBNA2B was the most frequent subtype, and a high frequency of mixed subtypes was found in children.

Comparison between presence of epstein barr virus in nodal and extra nodal diffuse large B cell lymphoma of head and neck, an Iranian experience

Background

Epstein Barr Virus (EBV) is one of the most common viral infections in human population. EBV has a significant role in pathogenesis of Hodgkin's lymphoma, Burkitt's lymphoma and nasopharyngeal carcinoma. The role of EBV in non-Hodgkin’s lymphoma, diffuse large B cell (NHL - DLBL) in the head and neck is controversial.

Objectives

The purpose of this study is to find out the difference between the presence of Epstein Barr virus in nodal and extra nodal lymphoma of head and neck.

Patients and Methods

A total of 30 cases of DLBL in two separate groups were collected from pathology department. The first group was consisted of 15 patients with DLBL of neck lymph node and the other was consisted of 15 patients with extra nodal DLBL of head and neck mainly in palatine tonsil. Both immune-histo-chemical (IHC) study and polymerase chain reaction (PCR) for detection of late membrane antigen (LMP) were performed on formalin fixed paraffin embedded tissue.

Results

All 30 cases were negative for EBV in IHC method. But in PCR method, 10% of patients were positive for LMP gene. There were 2 positive cases in nodal lymphoma and 1 positive case in extra nodal lymphoma group.

Conclusions

Compare with PCR method, it seems that IHC is not a sensitive method for detection of EBV. Overall, the finding of EBV in NHL depends on site, type of lymphoma and the detection method.

Distinctive Epstein-Barr virus variants associated with benign and malignant pediatric pathologies: LMP1 sequence characterization and linkage with other viral gene polymorphisms

The ubiquitous Epstein-Barr virus (EBV) is related to the development of lymphoma and is also the etiological agent for infectious mononucleosis (IM). Sequence variations in the gene encoding LMP1 have been deeply studied in different pathologies and geographic regions. Controversial results propose the existence of tumor-related variants, while others argued in favor of a geographical distribution of these variants. Reports assessing EBV variants in IM were performed in adult patients who displayed multiple variant infections. In the present study, LMP1 variants in 15 pediatric patients with IM and 20 pediatric patients with EBV-associated lymphomas from Argentina were analyzed as representatives of benign and malignant infections in children, respectively. A 3-month follow-up study of LMP1 variants in peripheral blood cells and in oral secretions of patients with IM was performed. Moreover, an integrated linkage analysis was performed with variants of EBNA1 and the promoter region of BZLF1. Similar sequence polymorphisms were detected in both pathological conditions, IM and lymphoma, but these differ from those previously described in healthy donors from Argentina and Brazil. The results suggest that certain LMP1 polymorphisms, namely, the 30-bp deletion and high copy number of the 33-bp repeats, are associated with EBV-related pathologies, either benign or malignant, instead of just being tumor related. Additionally, this is the first study to describe the Alaskan variant in EBV-related lymphomas that previously was restricted to nasopharyngeal carcinomas from North America.

Pathobiology of Epstein-Barr virus-driven peripheral T-cell lymphomas

In the present review, the authors described the pathobiological features of Epstein-Barr virus (EBV)-driven T/natural killer cell-derived malignancies. These rare tumors appear to be quite heterogeneous with regard to both clinical and pathologic features. Nonetheless, some elements, especially regarding the possible role of EBV (ie, genomic predisposition, pathogenesis, pattern of latency), are similar, enforcing the concept of a causative role for the virus. In clinical practice, although definitely rare in Western countries, the tumors are not exceptional; thus, they should be taken into account in the differential diagnosis of T-lymphoproliferative disorders, also considering the need for extremely prompt intervention. The prognosis of such tumors is generally poor using current approaches. A better understanding of their molecular pathogenesis may lead to significant therapeutic improvements. For example, the nuclear factor-KB pathway and platelet-derived growth factor receptor inhibition may represent 2 options to be tested in clinical trials.

Epstein-Barr virus-positive diffuse large B-cell lymphomas of the elderly

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) of the elderly has been included in the 2008 WHO classification as a new provisional entity and is defined as blastic, clonal B-cell proliferation associated with EBV occurring in patients over 50 years of age, presumably due to senescence of the immune system. Secondary immunodeficiencies must be excluded. Morphologically, the predominant polymorphic subtype shows a mixed proliferation of large transformed cells, plasma cells, plasmablasts, lymphocytes, and commonly Reed-Sternberg (RS)-like cells, whereas the monomorphic subtype reveals sheets of large cells. An additional characteristic feature is large areas of "geographical" necrosis. EBV+ DLBCL of the elderly is positive for pan-B cell markers and often for CD30. EBV infection detected by Epstein Barr early RNA in situ hybridization should be present in the majority of tumor cells. Most cases express LMP1 and up to 32% EBNA2, the latter a sign of an impaired immune system. The most challenging differential diagnosis is EBV+ classical Hodgkin lymphoma in older patients. Strong, homogeneous expression of B-cell markers, including transcription factors OCT2 and BOB.1, and lack of CD15 support a diagnosis of EBV+ DLBCL. EBV+ DLBCL of the elderly accounts for 8% to 10% of DLBCL in Asian countries, but seems to be uncommon in Western populations, indicating an ethnic or geographic predisposition. Clinically, patients may present with nodal or extranodal involvement. B-symptoms and poor performance status are common, and prognosis is significantly inferior compared with EBV- cases. Whether EBV+DLBCL of the elderly represents a true entity or only a DLBCL variant remains to be determined.

Geographic variation in the prevalence of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly: a comparative analysis of a Mexican and a German population

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma of the elderly was included as a provisional entity in the 2008 WHO lymphoma classification. Most reports of this disease come from Asia and little is known about it in other regions of the world, including Latin America. Therefore, in this study, 305 diffuse large B-cell lymphomas in patients above 50 years were analyzed, 136 from Mexico and 169 from Germany. EBV was detected by Epstein-Barr early RNA (EBER) in situ hybridization. Only cases with EBER+ in the majority of tumor cells were regarded as EBV+ diffuse large B-cell lymphoma. The prevalence of EBV+ diffuse large B-cell lymphoma in Mexican patients was found to be 7% (9 of 136), whereas only 2% (4 of 169) of the German cases were positive. The median age at diagnosis was 66 years in the Mexican cohort, as opposed to 77 years in the German group. The site of presentation was in both groups predominantly nodal in nine cases (70%) and extranodal in four cases (30%). Of the 13 EBV+ cases, 10 (77%) were classified as polymorphic and 3 (23%) as monomorphic type. The polymorphic cases showed a non-germinal center B-cell immunophenotype (CD10- MUM1+). Twelve cases (92%) were LMP1 positive and two (15%) expressed EBNA2. An interesting finding was the high frequency of EBV type B with the LMP1 30 bp deletion found in the Mexican cases (50%). Eight of the 11 evaluable cases were B-cell monoclonal by polymerase chain reaction. In summary, we found a similar prevalence of EBV+ diffuse large B-cell lymphoma of the elderly in a Mexican population compared with what has been reported in Asian countries, and in contrast to the low frequency in Western populations (1-3%). However, compared with the Asian series, the Mexican patients were younger at diagnosis, presented predominantly with nodal disease and rarely expressed EBNA2 protein.

Epstein-Barr virus genotypes in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is associated with Epstein-Barr virus (EBV) infection, but the relationship between the virus and the disease is not clear. As many different types of EBV exist, it is possible that MS is caused by one particular type of EBV. Objectives - The aim of this study was to determine whether MS is associated with a particular genotype of EBV.

MATERIALS AND METHODS

We collected blood from MS patients and controls, amplified and sequenced the latent membrane protein-1 (LMP-1) gene, and compared the groups.

RESULTS

We found a variety of LMP-1 sequences in both MS and controls, with no significant differences between the groups. Conclusion - We conclude that MS is not associated with a particular genotype of EBV.

Structural variability of the carboxy-terminus of Epstein-Barr virus encoded latent membrane protein 1 gene in Hodgkin's lymphomas

Epstein-Barr virus (EBV) is implicated in the pathogenesis of several lymphoid and epithelial neoplasms. Latent membrane protein 1 (LMP1) is the major viral oncogene and it is controversial whether tumor LMP1 variants reflect their geographical predominance or are associated with enhanced oncogenic properties. This study aimed to analyze LMP1 molecular variability of 62 EBV+ Hodgkin's lymphomas and 22 non-neoplastic controls from Brazil and Argentina. EBV association was characterized by EBER-ISH, LMP1 immunohistochemistry and PCR assays for EBNA2 and 3C (typing), LMP1 30 bp deletion (del30) and number of 33 bp tandem repeats. LMP1 C-terminal sequencing was performed in 42 cases. EBV1 was the predominant strain in both geographical Hodgkin's lymphoma groups (average 82%). A higher frequency of del30 variant was observed in lymphomas (41/63) than in non-neoplastic controls (6/22) (OR 4.97, CI 95% 1.53-16.79; P = 0.005, chi(2) test). A large number (5-7) of 33 bp repeat units was characteristic of del30 LMP1 variants (P < 0.0001, Fisher's exact test). Sequence analysis showed a similar mutation spectrum to that described worldwide but none of the current classification schemes could be applied completely. A distinct structural pattern was observed in del30 variants, characterized by a large number of 33 bp repeat units and the presence of a 15 bp insertion encoding the JAK3 Box-1a motif (3/15 wt vs. 16/20 del30; P = 0.001, chi(2) test). The results suggest a pathogenic role for LMP1 del30 variants in Hodgkin's lymphoma from South America and point to particular virus-host molecular mechanisms, such as genomic instability in LMP1 carboxy-terminus, leading to enhanced production and selection of these deletion variants.

Association between Epstein-Barr virus and Hodgkin's lymphoma in Belgium: a pathological and virological study

The association between Epstein-Barr virus (EBV) and classical Hodgkin's lymphoma (cHL) varies according to the geographic location. In this work we sought to characterize EBV involvement in a series of 111 cHL cases diagnosed in Belgium. The overall prevalence of EBV infection detected by in situ hybridization in Reed-Sternberg cells was 33%. EBV positivity correlated with older age at diagnosis (>54 years; p = 0.01), mixed cellularity subtype (p = 0.000001), male gender (p = 0.004) and tended to be associated with higher clinical stage (III/IV; p = 0.02). The molecular features of the virus in EBV-positive cHL were studied by comparison with a series of reactive tonsils. A 30-bp deletion within the LMP-1 gene was in 15/28 (53.6%) EBV-positive cHL cases, and in 41.7% of reactive tonsil samples. This variant did not correlate with any clinical or pathological feature. The EBV strain was type A in all cHL and reactive samples.

Pathobiology of Classical Hodgkin Lymphoma

The World Health Organization has acknowledged the malignant nature of classical Hodgkin lymphoma (cHL), which encompasses four histological subtypes. The diagnosis of cHL is based on the detection of malignant Hodgkin and Reed-Sternberg cells (HRSC) confirmed by immunophenotyping and the detection of growth patterns specific to each histological subtype. The pathologic HRSC arise from germinal center or immediate postgerminal cells that lack detectable immunoglobulin/B-cell antigen receptor expression, with a consequent loss of B-cell identity; very few cHL cases are of T-cell origin. To escape apoptosis, which normally occurs in B cells with nonfunctioning antigen receptor machinery, HRSC develop concurrent antiapoptotic mechanisms by activation of nuclear factor-kappaB or are rescued by Epstein-Barr virus infection. HRSC are characterized by a variable and inconstant immunophenotype, with a remarkable loss of lineage-specific cell antigens and expression of antigens of other cell lineages. The master plan of B-cell identity in HRSC is disturbed not only at the immunoglobulin expression level, but also at the transcriptional factor level. HRSC are further characterized by profound cell cycle deregulation with futile replication, multinucleation and poly- and aneuploidy. Here, we review pathobiological aspects of cHL with respect to lymphomagenesis and routine diagnostics.

Epstein-Barr Virus-Associated Smooth Muscle Tumors Are Distinctive Mesenchymal Tumors Reflecting Multiple Infection Events

Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are rare lesions that occur in immunocompromised patients. Because they have not been fully characterized pathologically or at the molecular level, we have studied 29 tumors from 19 patients, the largest series to date. Cases coded as EBV-SMT were identified in 19 patients from consultation files and from the renal transplant database at Singapore General Hospital. EBV-SMT occurred in adults (mean age 39 years; range, 21-57 years) and predominantly affected males (12 male, 7 female). Causes of immunocompromise were renal transplantation (10), AIDS (8), and steroid therapy (1). Tumors were located in soft tissue (5), lung (5), liver (4), and miscellaneous sites (15). In 13 patients (68%), the tumors were multiple. Infection with EBV was confirmed in all cases by in situ hybridization for EBV early RNAs (EBER). EBV-SMT were typically well-differentiated smooth muscle tumors with little atypia and usually a low level of mitotic activity. Unlike classic leiomyosarcomas, they lacked significant pleomorphism but frequently displayed primitive round cell areas and prominent intratumoral T lymphocytes. No consistent relationship between histologic features and clinical outcome was noted. All expressed actin (29 of 29) and less frequently desmin (14 of 26). Multiple tumors in a given patient were clonally distinct as assessed by the long terminal repeat region of the virus, supporting the view that multifocal tumors arise from multiple infection events rather than from metastasis. Strain typing by analysis of the EBNA-3C gene confirmed the presence of EBV type 2. Two of four tumors assessed were positive for a 30-bp deletion in the LMP1 gene. EBV copy number per cell ranged greatly between patients and between tumors from the same patient. Follow-up information was available in 18 of 19 patients (mean, 25 months; range, 1-105 months). Fifteen patients were alive: 11 with disease and 4 without. Three patients died, 1 due to disease. We conclude that EBV-SMT are histologically distinct from classic soft tissue smooth muscle tumors, are not readily evaluated by means of conventional histologic criteria, and in the case of multifocal tumors are the result of multiple infection events rather than metastasis. EBV-2 can transform smooth muscle cells, independent of the presence of the LMP1 deletion associated with greater virulence.

Classical Hodgkin lymphoma arising in the rectum

We report a case of an 81-year-old immunocompetent Mexican man who underwent an abdominal-perineal rectal resection for a mass clinically thought to be carcinoma. Histopathologic diagnosis revealed classical Hodgkin lymphoma, nodular sclerosis type, involving the rectum. The diagnosis was confirmed by immunohistochemical studies that showed that the neoplastic cells were positive for CD15 and CD30 and negative for CD45 (LCA). In situ hybridization for Epstein-Barr virus small-encoded RNA was also positive in the neoplastic cells. Hodgkin lymphoma arising in the rectum of immunocompetent patients is rare, with only 12 cases (including this one) reported in the literature. Of these, the diagnosis was confirmed by immunohistochemical studies in only two cases, and this is the first case assessed and shown to be positive for Epstein-Barr virus.

Nasal NK/T cell lymphoma in Taiwan: a clinicopathologic study of 22 cases, with analysis of histologic subtypes, Epstein-Barr virus LMP-1 gene association, and treatment modalities

Nasal NK/T cell lymphoma is a distinctive type of extranodal lymphoma with an unique immunophenotype and a strong association with Epstein-Barr virus (EBV). It is one of the common extranodal lymphomas in Taiwan. We studied 22 cases of nasal NK/T cell lymphoma to characterize their clinicopathologic features and to explore the possible differences between histologic subtypes and their clinical behavior as well as the prevalence of 30-base pair (bp) deleted latent membrane protein-1 (LMP-1) gene of the EBV. They consisted of 5 cases of small cell type (SC), 6 cases of medium-sized cell type (MC), 6 cases of large cell type (LC), and 5 cases of pleomorphic cell type (PC). Twelve patients were men and 10 were women (1.2 to 1), and their ages ranged from 34 to 75 years with a median age of 55.5 years. The median ages of the LC type and PC type were older than the other 2 types. No other clinical features differed significantly among the 4 subtypes. Nasal obstruction was the most common initial presenting symptom. All but 1 case had stage IE disease at the time of diagnosis. Five cases developed extranasal involvement and skin was the most common site. No bone marrow involvement was detected. The majority of patients received local radiotherapy and chemotherapy. Local irradiation was more effective than chemotherapy alone. We achieved an overall survival of 63.6% at 5 years as estimated by the Kaplan-Meier analysis, which was better than other series. All cases displayed an immunophenotypic profile of CD3(epsilon)+, CD20-, CD56+, and TIA-1+ except that 1 case was CD3(epsilon)-. Fourteen of 22 cases (64%) expressed LMP-1. Nine cases of various cell types (41%) were also CD30+. Among the 4 histologic subtypes, the SC type differed from the other types by the absence of angiodestruction and necrosis, although angioinvasive growth was seen in 2 of them. Pseudoepitheliomatous hyperplasia was seen in only 3 cases of the SC type, and all 5 cases of the SC type were CD30-. No statistical difference in survival was found among the 4 histologic subtypes or between CD30+ and CD30- cases. All 22 cases were positive for EBV by polymerase chain reaction and Epstein-Barr virus early RNA (EBER) in-situ hybridization. A high prevalence rate of 86% (19/22) of the 30-base pair (bp) deleted LMP-1 gene was found, but 81.5% (22/27) of the EBV-positive control reactive lymphoid tissues also had the 30-bp deleted LMP-1 gene. Therefore, the high prevalence of the 30-bp deleted LMP-1 gene found in NK/T cell lymphoma could be due to the high prevalence of the deleted variant in this geographic region. However, it remains possible that the high prevalence of the deleted LMP-1 gene contributed to the increased incidence of EBV-associated nasal NK/T cell lymphoma in Taiwan.

Prevalence of LMP-1 gene in tonsils and non-neoplastic nasopharynxes by nest-polymerase chain reaction in Taiwan

BACKGROUND

The purpose of this study was to investigate the frequency of Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1) in tonsils and non-neoplastic nasopharynxes in Taiwan.

METHODS

Nest-polymerase chain reaction (nest-PCR) was used to examine the presence of LMP-1 gene in lymphoid hyperplasia from non-neoplastic tonsillar and nasopharyngeal tissues and in tonsillar cancers.

RESULTS

In 152 cases, 64 biopsy tissues were obtained from lymphoid hyperplasia of nasopharynxes, 57 from tonsillectomy of non-neoplastic tonsils, and 31 from tonsillar cancers. LMP-1 was detected in 43.4% of the study group. Nineteen (29.7%) and 29 (50.9%) lymphoid hyperplasias from normal nasopharynxes and tonsils, respectively, and 18 (58.1%) biopsies from tonsillar cancers had positive LMP-1. The 30-base pair (bp) deleted variant was detected in 89.5% and 82.8% of normal nasopharynxes and tonsils, respectively, and in 66.7% of biopsies from tonsillar cancers (p =.198).

CONCLUSION

This study found that the 30-bp variant was the predominant type of LMP-1 from a healthy population in Taiwan.

Epstein-barr virus (EBV) in healthy carriers: Distribution of genotypes and 30 bp deletion in latent membrane protein-1 (LMP-1) oncogene

There are two types of Epstein Barr virus (EBV): EBV-1 and EBV-2, distinguished by genomic polymorphism in the genes encoding the nuclear antigens (EBNA-2, -3A, -3B, -3C). Latent membrane protein 1 (LMP-1) is an EBV protein with known oncogenic properties. Different variants had been described; among them, a 30 base pair (bp) deletion (del-LMP-1) had been reported in benign and malignant pathologies, but there is little information about its frequency in healthy populations. The aim of this study was to determine the distribution of the EBV genotypes and the 30 bp deletion frequency, in EBV healthy carriers from Argentina. Analysis of EBNA-3C and LMP-1 genes were done by polymerase chain reaction (PCR) followed by Southern blot hybridization on DNA of peripheral blood mononuclear cells (PBMCs) from blood bank donors. EBV-1 was present in 75.9% of samples, EBV-2 in 14.6%, and co-infections with both types in 6.5%. The deleted LMP-1 variant was found in 7.4% of analyzed samples, corresponding 3.2% to deleted variant alone and 4.2% to co-infections with non-deleted form. The non-deleted variant was found in 64.6% whereas in the remaining 28%, no PCR product was detected. These results showed that EBV-1 was the more prevalent type in healthy carriers of Argentina, similar to reports from others countries. A predominance of the non-deleted LMP-1 variant was observed. The presence of co-infections with both types and variants demonstrated that healthy individuals may also harbor multiple EBV infections.

Comparative analysis of NK/T-cell lymphoma and peripheral T-cell lymphoma in Korea: Clinicopathological correlations and analysis of EBV strain type and 30-bp deletion variant LMP1

Natural killer/T-cell lymphoma (NKTL) and peripheral T-cell lymphomas (PTCL) are prevalent in the Asian population and exhibit a high association with the Epstein-Barr virus (EBV). Moreover, differentiation of these two groups is often difficult and problematic. We investigated 35 cases of NKTL (22 nasal cases and 13 extranasal cases) and 30 cases of PTCL in terms of their clinical features, immunohistology, EBV positivity, EBV strain-type polymorphism and latent membrane protein 1 (LMP1) deletion variant distribution. Eighteen cases (82%) of nasal NKTL and seven (54%) of extranasal NKTL showed EBV positivity by EBV in situ hybridization. Fifteen cases (50%) of PTCL revealed EBV positivity. EBV strain type A was predominant in NKTL (18:5), and EBV strain types A and B were distributed evenly in PTCL (6:6). EBV-positive patients had significantly shorter survival than EBV-negative patients (P < 0.05), and EBV positivity correlated with advanced clinical stage (P < 0.05). Patients harboring type A EBV showed slightly poorer prognoses than those having type B, though it was not obviously statistically different (P = 0.07). The LMP1 deletion variant was prevalent in both NKTL (three wild-type LMP1, 15 deletion variants) and PTCL (three wild-type LMP1, eight deletion variants, two coexistent forms) patients, but did not have prognostic impact. Our results indicate that EBV acts as a negative prognostic factor in NKTL and PTCL, and that the intrinsic properties of a specific viral strain might influence the clinical behavior of these diseases.

Distinct clonal origin in two cases of Hodgkin's lymphoma variant of Richter's syndrome associated With EBV infection

Occurrence of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL), clinically referred to as Richter's syndrome, occasionally manifests as a lymphoproliferation resembling Hodgkin's lymphoma (HL) and often containing the Epstein-Barr virus (EBV). Only a limited number of HL variants have been subject to informative analysis regarding their clonal relationship to the CLL, with evidence of a same clonal origin in some cases and of clonally unrelated neoplasms in other cases. In this paper, we performed a detailed pathologic, virologic, and molecular analysis of two cases of Richter's syndrome with HL features. The first case occurred in a 65-year-old man with a 5-year history of CLL as a mediastinal and supraclavicular mass histologically diagnosed as lymphocyte depleted HL with no background CLL. The second case occurred in a 78-year-old woman with a 4-year history of CLL as an inguinal mass with a composite histologic appearance comprising areas of CLL, areas of CLL with Hodgkin Reed-Sternberg cells, and areas of HL. Both patients had received fludarabine therapy. The HRS cells were CD20-/CD30+/CD15-/J-chain- in case no. 1 and CD20+/-/CD30+/CD15-/J-chain- in case no. 2. In both cases, the Hodgkin's Reed-Sternberg cells (HRS) were positive for type A EBV, and a 30-bp deletion of the LMP-1 gene was detected in case no. 2. Using microdissection and polymerase chain reaction amplification of the immunoglobulin heavy chain gene (IgH) complementarity determining region III of each cell type, we demonstrated a distinct clonal origin for the CLL cells and the HRS in both cases. These cases bring support to the hypothesis that EBV+ HL in CLL patients occurs as unrelated secondary neoplasms most likely as the result of the immune depression associated with CLL and also raise the question of a possible causal role of fludarabine.

EBV-associated neoplasms: alternative pathogenetic pathways

We propose that there are two main classes of Epstein-Barr virus (EBV) associated lymphomas: primarily malignant Burkitt's Lymphoma (BL) and Hodgkin's Disease (HD), on one hand, and primarily benign lymphoproliferations, e.g., post-transplant lymphoproliferative disease (PTLD) on the other hand. PTLD may start as a benign lymphoproliferation which becomes malignant if out of T cell control for too long. Our discovery of a binding site for the oncoprotein c-Myc at a central position of the EBV genome favours a distinction of pathogenetic pathways or scenarios for the proposed lymphoma classes. In the first scenario nuclear maintenance of the EBV genome and activation of viral anti-apoptotic functions with the help of c-Myc are indispensable for the origin of malignant tumours (BL, HD) from the germinal centre B-cell. In the second scenario expression of the main viral transforming protein EBNA2 is essential for immortalisation and non-malignant morphological transformation of any (germinal centre derived or non-germinal centre) B-cell in the absence of T cell control. Although EBNA2 expression is permissible, under specific circumstances, in malignant B-cells, it is not required for oncogenesis.

Longer failure-free survival interval of Epstein-Barr virus-associated classical Hodgkin's lymphoma: a single-institution study

We analyzed Epstein-Barr virus association in classical Hodgkin's lymphoma from a single center in Austria with special emphasis on the latent membrane protein1 gene configuration and clinical outcome. All 119 (65 male, 54 female) patients were treated from 1974 to 1999 in the Division of Hematology and Oncology at the Department of Internal Medicine, University of Innsbruck, Austria. The mean follow-up time was 122 months (range, 3-333 mo). Epstein-Barr virus was examined by latent membrane protein1 immunohistochemistry and by in situ hybridization for Epstein-Barr virus-encoded early ribonuclein acid transcripts. For assessment of the Epstein-Barr virus subtype (A/B) and latent membrane protein1 gene configuration, the polymerase chain reaction was employed. Fifty-four reactive tonsils were used as the control population. These results as well as clinical parameters such as age, gender, tumor stage, risk factors, and B symptoms were correlated with failure-free and overall survival. Latent membrane protein1 was detected in 31/119 (26%) classical Hodgkin's lymphoma, and Epstein-Barr virus subtyping was successful in 19 of the 31 virus-infected classical Hodgkin's lymphoma cases, as well as in 28 of 54 reactive tonsils. Subtype A was observed in all classical Hodgkin's lymphoma patients and in 26/28 (93%) tonsils. The 30-base pair latent membrane protein1 gene deletion was found in only 4/31 (13%) Epstein-Barr virus-associated classical Hodgkin's lymphoma as well as in 20/54 (37%) reactive tonsils. Patients with Epstein-Barr virus-associated classical Hodgkin's lymphoma showed a significantly longer mean time to first relapse of 99 months, as compared with 49 months for the Epstein-Barr virus-negative cases (P <.02), and were more frequent in those aged >45 years (P <.04). Epstein-Barr virus-associated classical Hodgkin's lymphoma were predominantly of the mixed-cellularity subtype and occurred more frequently in male patients, in patients with Stage III and IV, and in patients with B symptoms as well as risk factors. However, overall survival did not correlate with Epstein-Barr virus association. The 30-base pair latent membrane protein1 gene deletion had no influence on overall survival and failure-free survival time. Although the number of patients with this specific mutation was low, it further shows that an increased oncogenic potential of the latent membrane protein1 deletion variant is unlikely. This large single-center study demonstrates a low prevalence of Epstein-Barr virus positivity in classical Hodgkin's lymphoma in western Europe. In accordance with results of similar studies, the presence of Epstein-Barr virus has a beneficial effect on the length of failure-free survival despite the higher frequency of risk factors such as higher tumor stage or advanced age.

High-throughput tissue microarray analysis of G1-cyclin alterations in classical Hodgkin's lymphoma indicates overexpression of cyclin E1

Deregulation of G1-cyclins (CCN) plays a key role in the pathogenesis of many human malignancies, including non-Hodgkin's lymphomas (NHLs). In contrast to NHL, little is known about phenotypic and genotypic changes in the regulation of the cell cycle in classical Hodgkin's lymphoma (cHL). To facilitate analysis of aberrant gene expression in cHL, a lymphoma tissue microarray (TMA) containing 752 cores of 330 different cHL samples was constructed. Direct comparison of Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) expression in Hodgkin's and Reed-Sternberg (HRS) cells on conventional full sections with the corresponding duplicate/triplicate tumour cores on the TMA showed a concordance of 100%, indicating that cHL-TMA is a reliable and representative method for evaluating gene expression profiles in situ. Using TMA technology, protein expression and gene amplification of different G1-CCNs in cHL were analysed. Among the G1-CCNs analysed, cyclin E (CCNE) was expressed in 212/253 cases (84%). In most of the individual tumours, over 75% of the HRS cells stained positive for CCNE, suggesting that CCNE is overexpressed in cHL. This overexpression was not due to CCNE gene amplification, as judged by fluorescence in situ hybridization, and did not correlate with EBV infection, as assessed by the expression of LMP-1. Thus, the overexpression of CCNE could be caused by profound changes in HRS cell-cycle regulation that could contribute to the malignant phenotype.

High frequency of a 30-bp deletion of Epstein-Barr virus latent membrane protein 1 gene in primary HIV non-Hodgkin's brain lymphomas

A characteristic 30-base pair (bp) deletion (del) in the 3' end of the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) gene, coding for the C-terminal NF-kappa B activation domain, has been identified in various lymphoproliferative disorders and nasopharyngeal carcinomas. In the single report to date of human immunodeficiency virus primary brain lymphomas (HIV-PBLs), del-LMP1 was noted in seven cases out of nine. The present study was designed to identify this deletion in a series of 31 diffuse large B-cell HIV-PBLs, with the aim of determining its possible oncogenic action. The presence of EBV was confirmed by EBER mRNA in situ hybridization. After genomic extraction from frozen tissue, two 20-base oligonucleotide primers flanking the site of the 30-bp deletion were used. DNA sequencing of the polymerase chain reaction (PCR) products confirmed an identical segment spanning 30-bp and 69-bp, frequently associated with mutational hotspots in 19 cases (61%). A role for del-LMP1 in the oncogenic potential of EBV in systemic proliferations is a matter of debate. Its high incidence suggests that the oncogenic mechanism of LMP1 in the brain might differ significantly from that in systemic lymphoid proliferations, and might be enhanced by HIV infection.

Epstein-Barr virus-associated peripheral T-cell and NK-cell proliferative disease/lymphoma: clinicopathologic, serologic, and molecular analysis

Peripheral T-cell proliferative disease/lymphoma is a group of diseases which exhibits heterogeneity in clinical manifestations, pathological findings and outcomes. They are highly associated with the Epstein-Barr virus (EBV) infection. It is likely that EBV plays an important role in the tumorigenesis. From January 1997 through April 2000, we identified 100 patients. One hundred healthy age- and sex- matched controls were selected. Serologic tests for the EBV infection and the study of EBV genomes in circulating non-T cells (CD3- cells), T cells (CD3+ cells), and T-cell subsets (CD4+ and CD8+ cells) were performed. The main features were prolonged fever, weight loss, hepatosplenomegaly, lymphadenopathy, multiorgan involvement, anemia, and high serum alkaline phosphatase and lactate dehydrogenase. Fifty-one patients had an aggressive course and died; median survival was 21 months. Chemotherapy was not effective in improving survival. Anti-viral capsid antigen-IgG and anti-early antigen-IgG were significantly elevated, whereas there was no significant difference in anti-EBV nuclear antigen. EBV internal repeat-1 region (IR-1) in the peripheral blood CD3+ cells was detected in 65% of the patients but in none of the controls. For the CD3- cells, EBV IR-1 was detected in 88% of the patients and 50% of the controls. Among twenty-five patients whose CD3+ cells were positive for EBV IR-1, 6 (24%) showed EBV IR-1 in only CD4+ cells, 6 (24%) in only CD8+ cells, and 13 (52%) in both CD4+ and CD8+ cells. The 30-bp deletion variant of the EBV latent membrane protein-1 gene was significantly higher in the patients than in the controls. These data support the chronic infective process. The EBV which is dormant in non-T cells may infect T cells and contribute to the pathogenesis of disease in a select group of patients.

Hepatosplenic gammadelta-T-cell lymphoma with leukemic course after renal transplantation

Hepatosplenic gammadelta-T-cell lymphoma (HSTCL) is a rare extranodal T-cell non-Hodgkin's lymphoma (T-NHL) with only 46 well-documented cases in medical literature. Notably, a relatively high number of these case reports (15%) describe the occurrence of HSTCL after solid organ transplantation. We describe the case of a 45-year-old man who developed a leukemic HSTCL 5 years after renal transplantation and continous immunosuppression with cyclosporine A and prednisolone. After a rapid clinical course, the patient died and autopsy was performed. The malignant lymphocytes showed a natural killer-like gammadelta-T-cell phenotype (CD2(+), CD3(+), CD7(+), TCR gammadelta(+), CD56(+), TIA-1(+), CD4(-), CD8(-), and TCR alphabeta(-)) and infiltrated the sinusoids of liver and the red pulp of the spleen. Cytogenetically, an isochromosome 7q, trisomy 8, Y-loss, and a translocation t(1;4) was detectable. This case shows the difficulties of recognizing HSTCL early in the clinical course and underlines that all types of T-NHL, nodal as well as extranodal, have to be considered in the differential diagnosis of posttransplantation lymphoproliferative disorders. Moreover, HSTCL seems to occur as a specific late complication of solid organ transplantation.

Epstein-Barr virus-associated extranodal NK/T-cell lymphoma, nasal type of the hypopharynx, in a renal allograft recipient: case report and review of literature

Posttransplant lymphoproliferative disorders (PTLPDs) are predominantly B-cell lymphoproliferations, whereas a T-cell origin is rarely observed. In contrast to B-cell PTLPD, T-cell PTLPDs show an inconsistent association with Epstein-Barr virus (EBV). Until now, only 13 cases of EBV-associated T-cell PTLPDs have been reported. We describe a case of an EBV-associated T-cell PTLPD in a renal allograft recipient 2 years after transplantation. Histologic examination showed medium- to large-sized lymphoid cells with an angiocentric growth pattern and necrosis. The atypical cells showed a CD2+, CD3epsilon+, CD7+, CD43+, CD45R0+, CD56+, and CD4-, CD5-, CD8- betaF1- phenotype with expression of the latent membrane protein (LMP)-1 of EBV. In addition, EBV-specific RNAs (EBER 1/2) were identified by in situ hybridization. Molecular analysis of the T-cell receptor (TCR) gamma chain by polymerase chain reaction (PCR) showed a polyclonal pattern. The morphologic, immunohistochemical, and molecular findings were consistent with a diagnosis of an EBV-associated extranodal natural killer (NK)/T-cell non-Hodgkin lymphoma (NHL) of nasal type. To our knowledge, this is the first reported case of this rare entity in the posttransplant setting.

Antisense oligodeoxynucleotides to latent membrane protein 1 induce growth inhibition, apoptosis and Bcl-2 suppression in Epstein-Barr virus (EBV)-transformed B-lymphoblastoid cells, but not in EBV-positive natural killer cell lymphoma cells

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP-1) is essential for immortalization of B cells by EBV, protects the infected cells from apoptotic cell death and induces Bcl-2 expression. Suppression of LMP-1 expression by antisense oligodeoxynucleotides (AS-oligo) to LMP-1 inhibits proliferation, promotes apoptosis and suppresses Bcl-2 expression in EBV-transformed B cells. However, the function of LMP-1 expression in EBV-positive natural killer (NK) cell lymphoma cells has not been reported previously. We examined the function of LMP-1 in two EBV-positive NK cell lymphoma cell lines (NK-YS and YT) through suppressing LMP-1 expression by AS-oligo to LMP-1. The AS-oligo to LMP-1 suppressed LMP-1 mRNA and protein expression in two EBV-positive NK cell lymphoma cell lines, as well as in an EBV-transformed B-cell line (CMG-1). Proliferation was inhibited, apoptosis was induced and Bcl-2 expression was suppressed in CMG-1 cells, but none of these events were observed in NK-YS or YT cells. These results suggest that proliferation, inhibition of apoptosis and Bcl-2 expression in EBV-positive NK cell lymphoma cells are not directly regulated by LMP-1 as in EBV-transformed B-cell lines, but are probably mediated through other signal transducing systems.

Epstein--Barr virus gene polymorphisms in Chinese Hodgkin's disease cases and healthy donors: identification of three distinct virus variants

Epstein--Barr virus (EBV) is associated with several malignancies. Specific EBV gene variants, e.g. the BamHI f configuration, a C-terminal region 30 bp deletion in the latent membrane protein-1 (LMP1) gene (del-LMP) and the loss of an XhoI site in LMP1 (XhoI-loss), are found in Chinese cases of nasopharyngeal carcinoma (NPC), suggesting that EBV sequence variation may be involved in oncogenesis. In order to understand better the epidemiology of these EBV variants, they were studied in virus isolates from EBV-positive Chinese cases of Hodgkin's disease (HD; n=71) and donor throat washings from healthy CHINESE: Sequencing was performed of 15 representative EBV isolates, including the first analysis of the LMP1 promoter in Asian wild-type EBV isolates. The following observations were made. (i) Three EBV LMP1 variants were identified, designated Chinese groups (CG) 1--3. In both EBV-associated HD and in healthy Chinese, CG1-like viruses showing del-LMP1 and XhoI-loss were predominant. (ii) CG1viruses were distinct from European and African variants, suggesting that this profile is useful for epidemiological studies. (iii) Specific patterns of mutations were present in the LMP1 promoter in both CG1 and CG2. (iv) The BamHI f variant was not found in Chinese HD, in contrast to Chinese NPC and European HD. This study confirms that EBV isolates in Chinese HD and other tumours differ from those reported in Western cases. However, this reflects the predominant virus strain present in the healthy Chinese population, suggesting that these are geographically restricted polymorphisms rather than tumour-specific strains.

Association of Burkitt's lymphoma with the Epstein-Barr virus in two developing countries

The clinical presentation of Burkitt's lymphoma (BL) and it's association with the Epstein-Barr virus (EBV) varies in different geographic areas, BL in developing countries being "intermediate" between the sporadic and endemic types, both in it's clinical presentation and it's association with EBV, which varies from 25-80%. In this study we have analysed the clinical features, EBV association, subtype and prevalence of the deleted variant of the Latent Membrane Protein-1 (LMP-1) of EBV in forty-two cases from two developing countries- India (n = 25) and Argentina (n = 17). In both countries the abdomen was the site most commonly involved while jaw involvement was rare. EBV was detected by in-situ hybridization using the EBER-1 RNA probe. 47% of cases from Argentina and 80% of cases from India were EBER positive. EBV typing using EBNA-3C primers showed a predominance of Type A in both countries (India-13/16 and Argentina-(7/8)). The 30bp deletion of the LMP-1 gene was detected in all evaluated cases from Argentina while the wild type of the gene was seen in all the evaluable Indian cases. Our study highlights the similarities and differences in the clinical presentation and EBV association of BL in two developing countries and also indicates that the subtype of EBV and prevalence of the LMP-1 deletion may reflect the predominant subtype in a particular population.

Epstein-Barr virus-associated multicentric leiomyosarcoma in an adult patient after heart transplantation: case report and review of the literature

Epstein-Barr virus (EBV)-associated smooth muscle tumors following solid organ transplantation are extremely rare, with only 12 cases reported in the literature thus far. The exact pathogenetic role of EBV infection in the oncogenesis of these soft tissue tumors in immunodeficient patients and the biologic behavior of such tumors is still unclear. We report a 26-year-old man in whom multiple smooth muscle tumors developed 36 to 51 months after heart transplantation. All tumors, two synchronous liver nodules, two subsequently occurring paravertebral tumors, and a single tumor in a vein at the left ankle were surgically resected. The tumor tissue was processed for routine histology and immunohistochemical (IHC) stains. Additionally, competitive polymerase-chain-reaction (PCR), reverse-transcriptase PCR (RT-PCR), as well as in situ hybridization (ISH) were used for EBV particle quantification and gene transcription analysis. The histologic features and immunohistochemical profiles were consistent with leiomyosarcoma in all tumor nodules. EBV infection was detected in >95% of tumor cell nuclei by EBER 1/2 ISH. Competitive PCR revealed 3105 EBV particles per milligram of tumor tissue. The EBV gene expression pattern analyzed by RT-PCR and IHC corresponded to the latency type III with specific expression of EBNA1, EBNA2, LMP1, and LMP2A genes. Under continuous antiviral therapy (famcyclovir) the patient currently shows no evidence of disease. Our data indicate that EBV infection plays a causal role in the development of smooth muscle tumors following organ transplantation. A latency type III, identical to EBV-associated posttransplant lymphoproliferative disorders, was identified and suggests a common pathogenetic mechanism in the development of these histogenetically distinct neoplasms. The fact that the patient currently shows no evidence of disease may be the result of the continuous administration of antiviral therapy because the soft tissue recurrences of the leiomyosarcoma occurred while the patient was not receiving antiviral prophylaxis.