Molecular biology of EBV in relationship to AIDS-associated oncogenesis

Epstein-Barr virus (EBV) is a gammaherpesvirus of the Lymphocryptovirus genus, which infects greater than 90% of the world's population. Infection is nonsymptomatic in healthy individuals, but has been associated with a number of lymphoproliferative disorders when accompanied by immunosuppression. Like all herpesviruses, EBV has both latent and lytic replication programs, which allows it to evade immune clearance and persist for the lifetime of the host. Latent infection is characterized by replication of the viral genome as an integral part of the host cell chromosomes, and the absence of production of infectious virus. A further layer of complexity is added in that EBV can establish three distinct latency programs, in each of which a specific set of viral antigens is expressed. In most malignant disorders associated with EBV, the virus replicates using one of these three latency programs. In the most aggressive latency program, only 11 of the hitherto 85 identified open reading frames in the EBV genome are expressed. The other two latency programs express even smaller subsets of this repertoire of latent genes. The onset of the AIDS pandemic and the corresponding increase in individuals with acquired immunodeficiency resulted in a sharp increase in EBV-mediated AIDS-associated malignancies. This has sparked a renewed interest in EBV biology and pathogenesis.

Spontaneous Regression of Diffuse Large B-Cell Lymphoma Harbouring Epstein-Barr Virus: A Case Report and Review of the Literature

We report an elderly patient with diffuse large B cell lymphoma harbouring Epstein-Barr virus that showed spontaneous regressions with subsequent relapses three times. The patient died of aspiration pneumonia without any anti-neoplastic treatment 5 years 10 months after the initial onset of lymph node swelling. In the literature, there are several reports of aggressive non-Hodgkin's lymphoma cases that showed spontaneous regressions without relapse till the last observation. Over half of the cases were the extra-nodal type. The tendency toward regression of swollen lymph nodes detected by clinicians occurs within 2 weeks after biopsy. If the remaining lymph nodes show a tendency to decrease in size after biopsy without any anti-tumor therapies, the patient may develop spontaneous regression.

MR findings of fulminent leukoencephalopathy in EBV-associated hemophagocytic syndrome

Various manifestations of brain involvement for patients with virus-associated hemophagocytic syndrome have been reported. Here, we report on the sequential magnetic resonance (MR) findings of acute demyelination of the entire brain with subsequent brain atrophy in a follow-up study of a 25-month- old boy who was admitted with fever and then diagnosed with infectious mononucleosis and EBV-associated hemophagocytic syndrome. We also review other conditions that should be included in the differential diagnosis of this disease.

Epidemiology and pathologic features of Hodgkin lymphoma

Hodgkin lymphoma (HL) has unique epidemiologic characteristics. The variation in incidence according to age, sex, race, socioeconomic status, and histologic subtype suggests an etiologic heterogeneity for this tumor. Epidemiologic studies have shown that both genetic and environmental factors play a role in the pathogenesis of HL. HL is one of the Epstein-Barr virus-associated lymphomas, but the oncogenetic mechanism of HL remains to be elucidated. Recent advances in molecular biology have revealed the peculiar nature of the nodular lymphocyte predominant subtype, and as a result this disease is separated from classic types of HL in the new World Health Organization classification. Reed-Sternberg (RS) cells and lymphocytic and/or histiocytic (L&H) cells originate from germinal center B-cells. Loss of the B-cell phenotype due to down-regulation of several B-cell-specific transcription factors is characteristic of RS cells in classic HL.

Absence of human herpesvirus-8 and Epstein-Barr virus in inflammatory myofibroblastic tumor with anaplastic large cell lymphoma kinase fusion gene

Inflammatory myofibroblastic tumor (IMT) is clinically and histologically characterized by inflammation. Some populations of IMT have anaplastic large cell lymphoma kinase (ALK) gene rearrangements. Infection with Epstein-Barr virus (EBV) and human herpesvirus-8 (HHV-8) in tumor cells of IMT has been reported; these reports, however, have been limited to ALK-negative IMT. The purpose of the present paper was to evaluate 21 cases of IMT for the presence of EBV and HHV-8. Immunohistochemically, 15 cases were ALK positive and six were negative. Of eight cases analyzed using reverse transcription-polymerase chain reaction, tropomyosin 3 (TPM3)-ALK, TPM4-ALK and clathrin heavy chain-ALK fusion genes were detected in one, two and two cases, respectively. All 21 IMT, irrespective of ALK expression, were negative for EBV by in situ hybridization for EBV-encoded RNA and immunohistochemical stain for latent membrane antigen-1. HHV-8 was also negative in all IMT by PCR for HHV-8 DNA sequence (KS330/233) and immunohistochemical stain for latent nuclear antigen. These results suggest that IMT may be a heterogeneous group in terms of pathogenesis, and EBV and HHV-8 do not play a major role in the pathogenesis of ALK-positive tumor.

Prognostic significance of Epstein-Barr virus in nodal peripheral T-cell lymphoma, unspecified: a Groupe d'Etude des Lymphomes de l'Adulte (GELA) study

Peripheral T-cell lymphomas (PTCLs) are rare and have a dismal prognosis. The most frequent subtype is PTCL, unspecified. Epstein-Barr virus (EBV) has been detected in around 40% of cases, but its prognostic significance is not fully established. Lymph node samples from 110 patients with PTCL, unspecified included in LNH87 and LNH93 trials were available. EBV status was studied by EBV-encoded small RNA in situ hybridization (EBER-ISH). EBER-ISH showed positive cells in 45 (41%) of 110 patients. Pretreatment characteristics were comparable between positive and negative cases, except for male sex (80% versus 60%, respectively, P = .02). Only 50% of patients achieved complete remission with a 5-year event-free survival (EFS) and overall survival (OS) of 21% and 30%, respectively. EBER-ISH positivity was the sole factor linked with worse EFS, with a 5-year probability of 11% for positive patients. In univariate analysis, factors affecting OS were EBER-ISH positivity, high LDH level, and age older than 60 years. In multivariate analysis, EBER-ISH was associated with a worse OS in the elderly population. Time-dependent analysis showed that the negative impact of EBV was essentially seen in the first 2 years following diagnosis. These results warrant further studies regarding pathogenesis and specific treatment approaches for EBV-associated PTCL patients.

Rituximab therapy for Epstein-Barr virus-related chronic hepatitis following living donor kidney transplantation

A patient who underwent living donor kidney transplantation was infected with Epstein-Barr virus (EBV) that resulted in persistent EBV infection and EBV-associated chronic hepatitis, determined by abnormally elevated anti-EBV antibody titers and high frequency of EBV-infected B lymphocytes. Despite decreases in immunosuppressant doses, persistent EBV infection and chronic hepatitis persisted for several years. Therapy using anti-CD20 monoclonal antibody (rituximab) virtually eliminated peripheral B lymphocytes and EBV-encoded small RNA 1 (EBER-1)-positive cells. Moreover, hepatic enzyme levels normalized and histological findings indicated marked improvement in hepatic inflammation. Although peripheral CD20(+) B lymphocyte and EBER-1-positive cell levels began to increase 4 months after the end of therapy, the number of EBER-1-positive cells remained very low, and liver function test results remained within normal ranges. The present case illustrates the significance of early diagnosis, monitoring of viral load, and vigorous management of EBV-related disorders associated with organ transplantation.

Primary lymphoma of the central nervous system: a clinical-pathological and immunohistochemical study of ten autopsy cases

CONTEXT: Primary central nervous system lymphomas (PCNSL) are a rare subgroup of lymphomas generally associated with HIV and EBV. OBJECTIVE: To study ten autopsy cases of PCNSL, to describe the neuropathological findings, to characterize the phenotype of the neoplastic cells, to detect EBV in the lesion and to compare the findings with the clinical and laboratory data of the patients. METHOD: The clinical, histological and immunohistochemical data of ten cases of PCNSL, eight cases from patients with AIDS, identified among 265 autopsies of these patients were analyzed. RESULTS: Seven patients were males and the mean age was 40.9 years. The most frequent symptomatology was focal neurologic deficit (70%). Six patients presented with only one lesion. Histologically, densely cellular and polymorphous neoplasms with angiocentrism were observed, in 90% of cases. An association with other diseases was observed in four cases. Most patients had diffuse large B cell non-Hodgkin’s lymphoma. EBV was detected by immunohistochemistry in only one case. The lack of detection of the virus might have been due to the long time of fixation of the brain which might have inactivate epitopes therefore compromising the testing. CONCLUSION: In the present series, PCNSL presented with focal symptoms, with unifocal or multifocal lesions, with a predominant B-cell CD20 positive phenotype, rarely associated with EBV.

Thymic lymphoepitheliomalike carcinoma in children: clinicopathologic features and molecular analysis

Thymic lymphoepitheliomalike carcinoma (LELC) in children is extremely rare and we report 2 such cases with molecular analysis of Epstein-Barr virus (EBV) and its encoded latent membrane protein-1 as well as a literature review. Both of our patients were male, presented with a huge anterior mediastinal mass, expired within a year after diagnosis despite treatment. There were altogether 9 cases of thymic LELC in children. Their common clinical features include a male predominance, large tumor size, advanced clinical stage, and poor clinical outcome. All cases were associated with EBV and nearly half developed concurrent hypertrophic osteoarthropathy (HOA). Thymic LELC in children is an aggressive EBV-associated malignant tumor frequently accompanied by HOA. We proposed that EBV might play a role in the development of HOA through the interactions of latent membrane protein-1, vascular endothelial growth factor, and cyclooxygenases-2.

Epstein-Barr virus nuclear antigen 2 inhibits AID expression during EBV-driven B-cell growth

Somatic hypermutation and class-switch recombination in germinal centers critically depend on activation-induced cytidine deaminase (AID). Deregulation of AID may lead to the aberrant activation or persistence of both genetic processes, thus contributing to the pathogenesis of B-cell lymphomas by mistargeted mutagenesis or recombination. The Epstein-Barr virus (EBV) establishes an asymptomatic latent infection in more than 90% of the human population, but it has also been linked to lymphomagenesis. A cooperative relationship of EBV and the germinal center reaction during the establishment of viral persistence has been postulated, but the contribution of EBV latent genes to the respective genetic events remains to be investigated in detail. In the present study, we show that activation of the EBV growth program has a clear inhibitory effect on AID expression, due to a negative effect of the master transcription factor of this program, EBNA2. This mechanism may counterbalance AID induction by the LMP1 protein, in order to prevent deleterious genetic changes during EBV-induced B-cell growth. EBNA2-mediated AID inhibition also provides a molecular explanation for the previously observed differences in somatic hypermutation activity in EBV-associated lymphoproliferative diseases, thus pointing to a crucial mechanism of EBV-mediated regulation of genomic integrity.

Epstein-Barr virus-associated enteritis with multiple ulcers after stem cell transplantation: first histologically confirmed case

The present case involves unique enteritis forming multiple ulcers associated with Epstein-Barr virus (EBV). A 57-year-old man had undergone a reduced intensity allogeneic stem cell transplantation for a relapse of multiple myeloma following sequential autologous peripheral blood stem cell transplantation. The ileum, resected for massive melena, showed multiple irregular ulcers with occasional cobblestone-like appearance. There was inflammation including numerous plasma cells in the ulcer bases and surrounding areas, where many EBV-infected plasma cells were detected by double staining with EBV-encoded small RNA-1 (EBER-1) in situ hybridization and CD79a, while EBV-infected epithelial cells were not noted. The number of EBER-1-positive cells in the ileum (mucosa, 1451 cells/mm(2); submucosa, 465 cells/mm(2)) was much larger than in control samples (malignant lymphoma or leukemia after allogeneic stem cell transplantation, n = 4, range 0-113 cells/mm(2); malignant lymphoma after chemotherapy, n = 14, range 0-0.89 cells/mm(2); colon cancer, n = 12, range 0-3.5 cells/mm(2)). In the mucosa near the ulcers, EBER-1-positive cells often surrounded and involved the glandular epithelium, forming lymphoepithelial-like lesions. The histological findings differ from post-transplant lymphoproliferative disorders or intestinal thrombotic microangiopathy, and this is the first case of EBV-associated enteritis with ulcers characterized by numerous plasma cells and lymphoepithelial-like lesions after stem cell transplantation.

Epstein?Barr virus in CD30+anaplastic large cell lymphoma involving the skin and lymphomatoid papulosis in South Korea

BACKGROUND

Epstein-Barr virus (EBV)-associated cutaneous lymphoproliferative disorders are prevalent in Asia, and less frequent in Western countries.

AIM

To elucidate the possible association of EBV with CD30+ anaplastic large cell lymphoma (ALCL) involving the skin and lymphomatoid papulosis (LyP) in South Korea.

METHODS

In situ hybridization for EBV-encoded small RNA (EBER) and immunohistochemistry including viral latent membrane protein-1 (LMP-1) were performed on formalin-fixed, paraffin-embedded skin specimens of 26 cases of LyP and 16 cases of CD30+ ALCL involving the skin which were selected from six university hospital medical centers in South Korea.

RESULTS

In situ hybridization studies showed positivity of the neoplastic cells for EBER in two of 16 cases of CD30+ ALCL and in none of the cases of LyP. One EBER-positive case was cutaneous CD30+ ALCL with concurrent lymph node involvement. The other was CD30+ ALCL involving the skin and other organs, including lymph nodes, bone, lung, and spleen. Immunostaining for LMP-1 was also positive only for the two cases of EBER-positive CD30+ ALCL.

CONCLUSION

LyP and primary cutaneous CD30+ ALCL are very rarely associated with EBV in South Korea.

Chronic Epstein-Barr virus-related hepatitis in immunocompetent patients

AIM: To investigate reactivated Epstein-Barr virus (EBV) infection as a cause for chronic hepatitis.

METHODS: Patients with occasionally established elevated serum aminotransferases were studied. HIV, HBV and HCV-infections were excluded as well as any other immunosuppressive factors, metabolic or toxic disorders. EBV viral capsid antigen (VCA) IgG and IgM, EA-R and EA-D IgG and Epstein-Barr nuclear antigen (EBNA) were measured using IFA kits. Immunophenotyping of whole blood was performed by multicolor flow cytometry. CD8⁺ T cell responses to EBV and PHA were determined according to the intracellular expression of IFN-γ.

RESULTS: The mean alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (GGTP) values exceeded twice the upper normal limit, AST/ALT ratio < 1. Serology tests showed reactivated EBV infection in all patients. Absolute number and percentages of T, B and NK cells were within the reference ranges. Fine subset analysis, in comparison to EBV⁺ healthy carriers, revealed a significant decrease of naive T cells (P < 0.001), accompanied by increased percentage of CD45RA^- (P < 0.0001), and terminally differentiated CD28^-CD27^-CD8⁺ T cells (P < 0.01). Moderately elevated numbers of CD38 molecules on CD8⁺ T cells (P < 0.05) proposed a low viral burden. A significantly increased percentage of CD8⁺ T cells expressing IFN-γ in response to EBV and PHA stimulation was registered in patients, as compared to controls (P < 0.05). Liver biopsy specimens from 5 patients revealed nonspecific features of low-grade hepatitis.

CONCLUSION: Chronic hepatitis might be a manifestation of chronic EBV infection in the lack of detectable immune deficiency; the expansion of CD28^-CD27^- and increase of functional EBV-specific CD8⁺ T cells being the only surrogate markers of viral activity.

Association between the Epstein-Barr virus and Hodgkin's lymphoma in the North-Eastern part of Hungary: effects on therapy and survival

This retrospective study included 109 patients with Hodgkin's lymphoma (HL; 45 females, 64 males). In 47 of the 109 HL patients (43%), immunohistochemical analysis of their formalin-fixed, paraffin-embedded histologic samples revealed Epstein-Barr virus (EBV) by latent membrane protein (LMP) 1. The highest virus association (50%) was found with the mixed cellularity histologic subtype, especially in patients aged 11-20 and >50 years. Virus positivity in nodular sclerosis was 35% (negative cases accumulated in patients aged 15-30 years). Regarding clinical stages, histologic subtypes, general symptoms, treatments employed and response to treatment, the EBV-positive group was not significantly different from the virus-negative group. During the mean follow-up time of 83 months (9-300 months), the overall or event-free survival of EBV-negative patients was more favorable than that of EBV-positive patients, although the difference was not significant (p = 0.16 and p = 0.24, respectively). EBV infection may be involved in the pathogenesis of HL in our Hungarian study cohort, but it does not significantly affect clinical symptoms, therapeutic results or complete and event-free survival of HL patients.

Biopsy of deep-seated head and neck lesions under intraoral ultrasound guidance

Although transcutaneous ultrasound combined with fine-needle aspiration is often used as initial modality for evaluating superficial neck masses, its role in management of deep-seated neck masses is limited. Intraoral ultrasound and guided biopsy helps in obtaining tissue from deep-seated neck masses for an accurate histologic diagnosis, providing useful information in treatment planning. This article discusses the role of intraoral ultrasound and presents 3 cases in which biopsy of deep-seated neck masses under intraoral ultrasound guidance helped in diagnosis and management.

KSHV/HHV8-associated primary cutaneous plasmablastic lymphoma in a patient with Castleman's disease and Kaposi's sarcoma

We report a unique case of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV)/human herpesvirus (HHV)8-associated lymphoma in a 56-year-old man with a history of acquired immune deficiency syndrome, Castleman's disease, KS, and idiopathic thrombocytopenic purpura. Three months following the diagnosis of KS affecting a left cervical lymph node and Castleman's disease with bone marrow involvement, he presented with a subcutaneous, tender lesion on his left arm. A skin biopsy demonstrated a superficial and deep, interstitial-nodular infiltrate of severely atypical lymphoid cells showing plasmacytoid features, numerous mitotic figures, and frequent individual apoptotic tumor cells. The morphologic features were those of plasmablastic lymphoma (PBL). Immunohistochemical study showed that the lymphoma cells strongly expressed CD45, CD30, and KSHV/HHV8 latency-associated nuclear antigen. KSHV/HHV8 was also detected in the biopsy sections of the patient's KS and Castleman's disease. Epstein-Barr virus in situ hybridization was diffusely positive. In situ hybridization demonstrated kappa-light chain restriction. Although KSHV/HHV8 has been individually associated with KS, Castleman's disease, and PBL, this appears to be the first reported case in which all three entities were present simultaneously in one person, suggesting a critical role of KSHV/HHV8 as a common denominator in the pathogenesis of these diseases.

Epstein-Barr virus associated lymphoepithelial carcinoma of the parotid gland; a clinicopathological report of three cases

Lymphoepithelial carcinoma is a relatively uncommon malignant tumor of the salivary gland demonstrating malignant epithelial cells with dense lymphoid stroma. The authors report three cases of lymphoepithelial carcinoma associated with Epstein-Barr virus of the right parotid gland with clinically presenting as painless, gradual enlargement of the preauricular mass. The histopathologic examination of the parotid gland is characterized by malignant epithelial cells with dense lymphoid stroma. Immunohistochemical stains show positive reactivity to cytokeratin and p53 in malignant epithelial cells. In situ hybridization of the Epstein-Barr virus-encoded Ribonucleic acid shows positivity in malignant epithelial cells. Clinical and pathologic features with relevant literatures are discussed. These are the first reported cases of primary parotid lymphoepithelial carcinoma associated with Epstein-Barr virus infection in Thailand and Southeast Asia.

Human papillomavirus and Epstein-Barr virus infection, p53 expression, and cellular proliferation in laryngeal carcinoma

Laryngeal carcinomas are aggressive neoplasms with controversial association with the human papillomavirus (HPV) and Epstein-Barr virus (EBV). So far, the impairment of p53 protein function and its impact on cellular proliferation has not been studied adequately in these tumors. In this work, molecular biologic techniques were used to assess the frequency of HPV and EBV in 110 squamous cell carcinomas of the larynx. In addition, accumulation of p53 and Ki-67 cell proliferation antigen expression in malignant cells was assessed by immunohistochemical analysis. High-grade HPV was found in 37.3% of cases, and none had demonstrable EBV infection. Accumulation of p53 was found in 78.2% of the cases, and it was related to a high Ki-67 labeling index and higher histologic grade. The results demonstrate association of HPV with more than one third of laryngeal carcinomas studied, mainly glottic tumors. Tumors with increased cell proliferation were more frequently high grade, with p53 accumulation and lymph node metastasis.

Peripheral T-cell lymphoma with extensive dendritic cell network mimicking follicular dendritic cell tumor: a case report with pathologic, immunophenotypic, and molecular findings

Peripheral T-cell lymphoma (PTCL) with a nodular pattern of growth is uncommon and may be misdiagnosed initially as a B-cell lymphoma or reactive process. We report a case of a rapidly growing PTCL with a distinctly nodular pattern in an axillary lymph node from an 89-year-old man. Immunohistochemical stains for CD21, CD23, and CD35 highlighted an extensive dendritic cell network that imparted the nodular appearance and, in addition, was associated intimately with the neoplastic cells. The neoplastic cells otherwise had an immunophenotype similar to previously reported cases of PTCL with a nodular pattern and germinal center origin (CD3+, CD4+, CD5+, bcl-6+, CD31+, subset CD10+, subset CXCL13+, and subset CD79a+). Molecular studies confirm a clonal T-cell receptor g gene rearrangement. This case emphasizes unusual morphologic features in a PTCL that may be mistaken for follicular lymphoma or a tumor of follicular dendritic cell origin.

Composite recurrent hodgkin lymphoma and diffuse large B-cell lymphoma: one clone, two faces

We describe a composite lymphoma with recurrent Hodgkin lymphoma and diffuse large B-cell lymphoma components manifesting as a single, perforated small intestinal tumor in a 56-year-old man with a history of classical Hodgkin lymphoma and recent relapse in the bone marrow. The resected mass had 2 morphologically and immunophenotypically distinct components; 1 showed a pleomorphic cellular infiltrate with fibrosis and contained numerous, large Hodgkin/Reed-Sternberg-like cells and variants. The tumor cells were CD30+ and focally positive for CD15 but CD20-, CD79a-, and PAX-5-. In situ hybridization for Epstein-Barr virus (EBV) was strongly positive in the large pleomorphic tumor cells. The adjacent component displayed sheets of relatively uniform, large lymphoid cells with typical morphologic features of diffuse large cell lymphoma. The tumor cells showed uniform expression of tested B-cell antigens, absence of CD30 or CD15, and complete absence of EBV-encoded RNA. Separate molecular studies with immunoglobulin heavy and k light chain gene rearrangements clearly demonstrated an identical rearrangement pattern, indicating derivation from the same clone, which was confirmed by direct DNA sequencing analysis. Such distinctly different morphology, immunophenotype, and EBV status in different components within a clonally related single tumor mass is striking.

Detection of Epstein-Barr virus in lower gastrointestinal tract lymphomas: a study in Malaysian patients

BACKGROUND

Many studies in the literature have shown that Epstein-Barr virus (EBV) is associated with several human lymphoid and epithelial malignancies. However, the prevalence of EBV in non-Hodgkin lymphoma (NHL) of the lower gastrointestinal (GI) tract has not been fully elucidated.

AIM

The aim of this study was to determine the presence and distribution of EBV in formalin-fixed paraffin-embedded tissue samples obtained from 18 Malaysian patients diagnosed with NHL of the lower GI tract.

METHODS

The GI tract lymphoma tissue samples analyzed for the presence of EBV were divided into the following groups: NHL of the small intestine (seven cases); NHL of the ileocecum (ten cases); and NHL of the rectum (one case). The presence of EBV-encoded RNA (EBER) in all of the above tissue samples was tested for using conventional in situ hybridization technology.

RESULTS

Two of 18 cases (11.1%) of NHL of the lower GI tract demonstrated positive signals for EBV/EBER. In the first positive case, EBV/EBER signals were located in lymphoma cells in the serosa layer of the small intestine. In the second EBV/EBER-positive case, EBV/EBER signals were detected in diffuse B-cell lymphoma of the ileocecum.

CONCLUSION

These findings demonstrate a rare association between EBV and lower GI tract lymphomas in this group of Malaysian patients.

Concomitant Epstein-Barr virus-negative large B-cell lymphoma (Richter syndrome) and Epstein-Barr virus- positive B-cell lymphoproliferation after treatment with fludarabine and cyclophosphamide in a patient with B-cell chronic lymphocytic leukemia

We report the case of a patient treated with a combination of fludarabine and cyclophosphamide after suffering from B-cell chronic lymphocytic leukemia for 10 years. Three months after treatment, the patient presented with an unusual association, not previously reported in the literature: Richter syndrome (monotypic Epstein-Barr virus- negative large B-cell lymphoma) with the proliferation of Epstein-Barr virus-positive B cells secreting a polytypic immunoglobulin A. The Epstein-Barr virus-positive lymphoproliferation can be accounted for by the type of immunosuppression induced by the treatment.