Epstein-Barr virus is present in neoplastic cytotoxic T cells in extranodal, and predominantly in B cells in nodal T non-Hodgkin lymphomas

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

Nasal-type extranodal natural killer/T-cell lymphoma presenting with a mass on the buttock: A case report

RATIONALE

Nasal-type extranodal natural killer (NK)/T-cell lymphoma is a highly unusual disease with no standard curative managements yet. Our focus is to emphasize a very rare case of nasal-type extranodal NK/T-cell lymphoma with onset of the mass on the buttock successfully operated by combination of surgical excision together with chemotherapy. The management of these unique cases is of great clinical guiding significance.

PATIENT CONCERNS

A 20-year-old woman presented with a 2-month history of continuous and progressive severe pain on her left buttock. Since December 2017, the patient developed nasal congestion, accompanied with mild pain in the left eye, and new subcutaneous nodules on both cheeks.

DIAGNOSIS

Postoperative pathology confirmed the diagnosis of extranodal NK/T cell lymphoma. This is an extremely rare presentation of nasal-type NK/T-cell lymphoma.

INTERVENTIONS

The patient underwent enlarged resection of the tumor on the buttock. After the diagnosis of extranodal NK/T-cell lymphoma was established, the patient received chemotherapy and autologous hematopoietic stem cell transplantation.

OUTCOMES

The patient's symptoms improved significantly after the surgery, and the postoperative period was uneventful at the 1-year follow-up visit. There were no complications associated with the operation and adjuvant therapies during the follow-up period.

LESSONS

Taken together, the lesion's clinical features, imaging results, and pathological characteristics are unique. Extranodal NK/T-cell lymphoma, although rare, should be part of the differential diagnosis when the patient presents with the mass on the buttock. We recommend enlarged excision of the extranodal lymphoma. Combined of surgical excision of the extranodal lymphoma, chemotherapy and autologous hematopoietic stem cell transplantation are good choice for proper treatment.

Epstein- Barr Virus: Clinical and Epidemiological Revisits and Genetic Basis of Oncogenesis

Epstein-Barr virus (EBV) is classified as a member in the order herpesvirales, family herpesviridae, subfamily gammaherpesvirinae and the genus lymphocytovirus. The virus is an exclusively human pathogen and thus also termed as human herpesvirus 4 (HHV4). It was the first oncogenic virus recognized and has been incriminated in the causation of tumors of both lymphatic and epithelial nature. It was reported in some previous studies that 95% of the population worldwide are serologically positive to the virus. Clinically, EBV primary infection is almost silent, persisting as a life-long asymptomatic latent infection in B cells although it may be responsible for a transient clinical syndrome called infectious mononucleosis. Following reactivation of the virus from latency due to immunocompromised status, EBV was found to be associated with several tumors. EBV linked to oncogenesis as detected in lymphoid tumors such as Burkitt's lymphoma (BL), Hodgkin's disease (HD), post-transplant lymphoproliferative disorders (PTLD) and T-cell lymphomas (e.g. Peripheral T-cell lymphomas; PTCL and Anaplastic large cell lymphomas; ALCL). It is also linked to epithelial tumors such as nasopharyngeal carcinoma (NPC), gastric carcinomas and oral hairy leukoplakia (OHL). In vitro, EBV many studies have demonstrated its ability to transform B cells into lymphoblastoid cell lines (LCLs). Despite these malignancies showing different clinical and epidemiological patterns when studied, genetic studies have suggested that these EBV- associated transformations were characterized generally by low level of virus gene expression with only the latent virus proteins (LVPs) upregulated in both tumors and LCLs. In this review, we summarize some clinical and epidemiological features of EBV- associated tumors. We also discuss how EBV latent genes may lead to oncogenesis in the different clinical malignancies

The Epstein-Barr virus and the pathogenesis of lymphoma

Since the discovery in 1964 of the Epstein-Barr virus (EBV) in African Burkitt lymphoma, this virus has been associated with a remarkably diverse range of cancer types. Because EBV persists in the B cells of the asymptomatic host, it can easily be envisaged how it contributes to the development of B-cell lymphomas. However, EBV is also found in other cancers, including T-cell/natural killer cell lymphomas and several epithelial malignancies. Explaining the aetiological role of EBV is challenging, partly because the virus probably contributes differently to each tumour and partly because the available disease models cannot adequately recapitulate the subtle variations in the virus-host balance that exist between the different EBV-associated cancers. A further challenge is to identify the co-factors involved; because most persistently infected individuals will never develop an EBV-associated cancer, the virus cannot be working alone. This article will review what is known about the contribution of EBV to lymphoma development.

Prevalence and characterization of anaplastic large cell lymphoma and its association with Epstein-Barr virus in Pakistani patients

Anaplastic large cell lymphoma (ALCL), CD30+, is a subtype of T-non-Hodgkin's lymphoma (NHL). Its most common form is a classical systemic type that involves multiple nodal and extranodal sites. In this study, morphologic, immunohistologic, and genetic studies were performed on ALCL cases in Pakistani patients. The median age of the patients in this study was 45 years (age range: 5-70 years), with a male to female ratio of 3.4:1. Thirty-seven (37) patients were diagnosed to have Ki-1 (CD30+) ALCL, which constituted 2% of all NHLs and 12.6% of all T-NHLs, over a period of 11 years (January 01, 1992-December 31, 2002). The tumors were of either T- or null-cell type with constant (100%) expression of CD30 (Ki-1). The majority of the cases (89.2%) expressed EMA, whereas 40.5% of the cases expressed either CD45 (LCA), CD45RO (UCHL1), or ALK. The mean age of ALCL patients with null-cell phenotype was 33.8 years as compared to those with T-cell phenotype having a mean age of 36.3 years. Out of the 37 cases diagnosed as ALCL, amplifiable DNA was isolated from 28 cases, which were further assessed for T-cell clonality for T-cell receptor (TCR)-beta, gamma, and immunoglobulin heavy chain (IgH) for the FR2 and FR3 regions. The polymerase chain reaction (PCR) technique demonstrated clonal rearrangement of the TCR beta, gamma, and IgH regions in 15 (53.6%), 11 (39.3%), and 2 (7.1%) ALCL cases, respectively, out of 28 cases. Association of Epstein-Barr virus (EBV) was noted in seven out of 28 cases (25%) of ALCL by PCR, whereas ISH for EBV-encoded nuclear RNA-1 (EBER-1) detected the presence of EBV in two (16.7%) out of 12 cases, where one was T-cell ALCL and the other null-cell ALCL. Immunostaining for LMP-1 could not be performed, because tissue material was not available. In conclusion, our study demonstrated that the prevalence of ALCL in Pakistan is comparable to that reported for some of the Asian communities and by the International Lymphoma Study Group and that EBV could be partly responsible for the pathogenesis of ALCL.

Biology and Treatment of Epstein-Barr Virus–Associated Non-Hodgkin Lymphomas

Epstein-Barr virus (EBV) is associated with several different types of aggressive non-Hodgkin lymphoma (NHL). Individuals with primary or secondary immunodeficiency are susceptible to developing B cell lymphoproliferation due to outgrowth of EBV-infected B cells that express type III latency characterized by expression of all nine latent-cycle EBV antigens. These cells would normally be susceptible to control by EBV-specific T cells, and strategies to restore EBV-specific immune responses may be effective therapeutically. EBV-associated lymphomas occurring in individuals who do not have a known immunodeficiency include NK and T malignancies with cytotoxic phenotypes, sporadic cases of B-NHL and lymphomatoid granulomatosis. These malignancies respond poorly to standard chemoradiotherapy, and immunotherapeutic or pharmacologic strategies targeting EBV are being explored.

T-cell Posttransplant Lymphoproliferative Disorder Occurring in a Pediatric Solid-organ Transplant Patient

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication seen in transplant patients as a consequence of immunosuppressant therapy. Most cases are of B-cell origin and are commonly associated with Epstein-Barr virus (EBV) infection. T-cell PTLDs are rare and only 13 pediatric T-cell PTLDs with clinicopathologic correlation have been reported previously. We present the histologic, immunophenotypic, and molecular features of a monomorphic PTLD (T-cell lymphoma) identified in a pediatric patient following orthotopic liver transplantation. The lymphoma was identified in the ileum, rectum, and mesenteric lymph nodes. In situ hybridization revealed numerous EBER-1-positive tumor cells. A current review of the literature is also discussed. Of the 14 cases of pediatric T-cell PTLD reported in the literature, only 3 (21.4%) are described as being EBV positive. Most of the reported PTLDs are monoclonal, with 9 of 11 cases (82%) showing a clonal T-cell population by gene rearrangement studies. T-cell PTLD cases appear to have a poor prognosis (11 of 14 patients died of the disease), although patients with involvement of specific anatomic sites may have a better outcome.

ALK-negative anaplastic large-cell lymphoma demonstrates similar poor prognosis to peripheral T-cell lymphoma, unspecified

AIMS

Anaplastic large cell lymphoma (ALCL) is classically considered a clinicopathological entity separate from other nodal mature T-cell lymphomas (TCL). Recently, the anaplastic lymphoma kinase (ALK) protein was shown to identify a subgroup of nodal ALCL with an excellent prognosis, whereas ALK-negative ALCLs are more heterogeneous. The aim of this study was to investigate the clinicopathological parameters in relation to clinical behaviour of ALK-negative ALCL compared with other nodal mature TCL, i.e. peripheral TCL, unspecified (PTCL-NOS) and angioimmunoblastic lymphoma (AILT).

METHODS AND RESULTS

Clinicopathological data of ALK-positive (n = 28) and ALK-negative (n = 46) ALCL; PTCL-NOS (n = 47); and AILT (n = 12) were analysed for their prognostic significance. While ALK-positive ALCL shows favourable clinical features and a good prognosis, ALK-negative ALCL, PTCL-NOS and AILT are all associated with high age groups, advanced disease stage, and poor prognosis (<45% 5-year survival). In multivariate analysis of overall survival time, performed in the combined group of ALK-negative nodal mature T-cell lymphomas, only age and the International Prognostic Index (IPI) remained independent prognostic parameters, while lymphoma subtype (ALCL versus PTCL-NOS versus AILT) gave no additional information.

CONCLUSIONS

The distinction between ALK-negative ALCL and PTCL-NOS or AILT is of limited clinical relevance as they show comparable poor prognosis. In these lymphoma subtypes, only age and the IPI are of significant prognostic value.

Absence of Epstein-Barr virus in anaplastic large cell lymphoma: a study of 64 cases classified according to World Health Organization criteria

The frequency of Epstein-Barr virus (EBV) in anaplastic large cell lymphoma (ALCL) has been controversial. The interpretation of previous studies is complicated by the use of nonuniform EBV detection methods and the inclusion of cases of CD30-positive diffuse large B-cell lymphoma and so-called "ALCL, Hodgkin-like," as defined in the Revised European-American Lymphoma classification scheme. In the current World Health Organization (WHO) classification system, both of these tumors are excluded from the ALCL category. Also, recently developed antibodies (eg, the antibody specific for PAX-5/B-cell-specific activator protein [BSAP]) provide new, sensitive tools for identifying neoplasms of B-cell lineage that can morphologically resemble ALCL. In this study we evaluated 64 cases of ALCL of T- or null-cell lineage, defined according to the WHO classification system, for the presence of EBV. All tumors were negative for B-cell antigens, including PAX-5/BSAP and CD20 or CD79a. The study group included 27 (42%) anaplastic lymphoma kinase (ALK)-positive (18 T-cell and 9 null-cell) and 37 (58%) ALK-negative (30 T-cell and 7 null-cell) tumors analyzed by in situ hybridization for EBV-encoded RNA (EBER) or immunohistochemistry for EBV-latent membrane protein type 1. All 64 cases were negative for EBV. We conclude, based on the current definition of ALCL in the WHO classification, there is no role for EBV in ALCL arising in Western patients. We suggest that published reports of EBV in a small proportion of ALCL cases in Western patients can be explained by the inclusion of tumors no longer considered to be in the current classification of ALCL, such as CD30-positive anaplastic tumors of B-cell origin.

Epstein-Barr virus and oncogenesis: from latent genes to tumours

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus associated with the development of both lymphoid and epithelial tumours. As a common virus infection, EBV appears to have evolved to exploit the process of B cell development to persist as a life-long asymptomatic infection. However, the virus can contribute to oncogenesis as evidenced by its frequent detection in certain tumours, namely Burkitt's lymphoma (BL), post-transplant B cell lymphomas, Hodgkin's disease (HD) and nasopharyngeal carcinoma (NPC), and by its unique ability to efficiently transform resting B cells in vitro into permanently growing lymphoblastoid cell lines (LCLs). These transforming effects are associated with the restricted expression of EBV genes such that only a subset of so-called latent virus proteins are expressed in virus infected tumours and in LCLs. Distinct forms of EBV latency are manifest in the different tumours and these appear to be a vestige of the pattern of latent gene expression used by the virus during the establishment of persistent infection within the B cell pool. This review summarises our current knowledge of EBV latent gene function and how this relates to the role of the virus in the aetiology of different tumours.

ALK-negative systemic anaplastic large cell lymphoma: differential diagnostic and prognostic aspects--a review

Anaplastic large cell lymphoma (ALCL) can be divided into two major groups. The first is a spectrum of CD30+ T-cell lymphoproliferative disorders including primary cutaneous ALCL and lymphomatoid papulosis, usually affecting older patients but characterized by an excellent prognosis. The second is systemic nodal ALCL, which on the basis of genetic and immunophenotypic features combined with clinical parameters can be divided into two subgroups: anaplastic lymphoma kinase (ALK)-positive and ALK-negative systemic ALCL. ALK expression, usually the result of a t(2;5) translocation, correlates with the expression of other markers such as EMA and a cytotoxic phenotype, and is strongly related to younger age groups, lower international prognostic index (IPI) risk groups, and a good prognosis. ALK-negative ALCL, however, shows a more heterogeneous immunophenotype and clinical behaviour, and prognostic parameters are needed to determine treatment strategies in individual patients. Besides clinical parameters included in the IPI, recent studies have pointed out several biological prognosticators of potential value, such as the percentage of tumour-infiltrating activated cytotoxic T-lymphocytes. The expression of proteins involved in the execution or regulation of apoptosis, such as activated caspase 3, Bcl-2, and PI9, was also found to be strongly related to clinical outcome. These studies indicate that inhibition of the apoptosis cascade in particular is an important mechanism that can explain the poor clinical outcome in therapy refractory ALCL. Functional studies are required to investigate whether disruption of one or more of the apoptosis pathways is the major factor in the fatal outcome of the disease and whether apoptosis resistance based on inhibition of one pathway can be overcome by activating another pathway that is still intact.

Pathogenic roles for Epstein-Barr virus (EBV) gene products in EBV-associated proliferative disorders

Epstein-Barr virus (EBV) is associated with a still growing spectrum of clinical disorders, ranging from acute and chronic inflammatory diseases to lymphoid and epithelial malignancies. Based on a combination of in vitro and in vivo findings, EBV is thought to contribute in the pathogenesis of these diseases. The different EBV gene expression patterns in the various disorders, suggest different EBV-mediated pathogenic mechanisms. In the following pages, an overview of the biology of EBV-infection is given and functional aspects of EBV-proteins are discussed and their putative role in the various EBV-associated disorders is described. EBV gene expression patterns and possible pathogenic mechanisms are discussed. In addition, expression of the cellular genes upregulated by EBV in vitro is discussed, and a comparison with the in vivo situation is made.

ALK-positive anaplastic large T-cell lymphoma preceded by Epstein-Barr virus infection complicated by development of an aorto-esophageal fistula

We report an unusual case of aggressive ALK-positive anaplastic large cell lymphoma with widespread mediastinal involvement immediately preceded by an acute Epstein-Barr virus (EBV) infection. Following initiation of chemotherapy and radiological evidence of significant tumor regression, the patient suffered a fatal massive upper gastrointestinal hemorrhage from an aorto-esophageal fistula. The relevant literature relating to EBV in the pathogenesis of ALK-lymphomas and literature relating to aorto-enteric fistula (AEF) in mediastinal lymphoma is reviewed.

Activity of the EBNA1 promoter associated with lytic replication (Fp) in Epstein-Barr virus associated disorders

BACKGROUND/AIMS

In Epstein-Barr virus (EBV) positive cell lines that are stably infected, three different promoters are known to direct the transcription of EBV nuclear antigen 1 (EBNA1). These are located in the BamHI-C, BamHI-Q, and BamHI-F regions of the viral genome (Cp, Qp, and Fp, respectively). Fp is activated upon induction of the viral lytic cycle. The aim of this study was to investigate the activity of Fp in EBV associated diseases.

METHODS

Using reverse transcriptase polymerase chain reaction, a qualitative analysis of EBNA1 promoter usage in various EBV associated diseases was performed.

RESULTS

Fp driven transcription was detected in the context of primary infection and/or lytic replication; at least a portion of the Fp driven transcripts encoded EBNA1. Qp driven EBNA1 transcripts were detected in most samples across the range of disorders tested. Cp driven EBNA1 transcripts were detected in the context of immune suppression and in samples containing EBV positive (non-neoplastic) lymphoid cells.

CONCLUSIONS

These results confirm the previously proposed "housekeeping" function of the Qp promoter.

Percentage of activated cytotoxic T-lymphocytes in anaplastic large cell lymphoma and Hodgkin's disease: an independent biological prognostic marker

Recently, we demonstrated that the presence of high percentages of activated cytotoxic T-lymphocytes (CTLs) in biopsy specimens of both Hodgkin's disease (HD) and ALK negative anaplastic large cell lymphoma (ALCL) is associated with a poor prognosis. To test whether this biological prognostic factor is more important in predicting clinical outcome than histological diagnosis or clinical factors, we compared the prognostic value of these parameters in an expanded group of classical HD and ALK negative ALCL. Tumor biopsies of classical HD (n = 83) and ALK negative systemic nodal ALCL (n = 43) were investigated for the presence of activated CTLs by immunohistochemistry, using a monoclonal antibody directed against granzyme B. Percentages of activated CTLs were quantified using Q-PRODIT, and their prognostic value was compared to that of histological diagnosis and clinical parameters, including age and stage. Both in classical HD and ALK negative ALCL, a high percentage of activated CTLs (ie > or = 15%) identified a group of patients with poor overall and progression-free survival time, even when adjusted for stage. In multivariate analysis, percentage of activated CTLs remained a strong independent prognostic marker, and was more sensitive than histological diagnosis or clinical factors in predicting overall survival time. We conclude that a high percentage of activated CTLs in the reactive infiltrate of ALK negative ALCL and classical HD is a strong indicator for an unfavorable clinical outcome, regardless of histological diagnosis or clinical parameters. As such, this biological parameter may be an especially helpful tool to determine therapeutic strategies in cases in which the differentiation between ALK negative ALCL and HD remains difficult.