Overview of EBV-Associated T/NK-Cell Lymphoproliferative Diseases

Advances in classification and treatment of primary cutaneous lymphomas

Primary cutaneous lymphomas (PCLs) are a heterogeneous group of extranodal non-Hodgkin lymphomas, characterized with skin involvement as the primary or predominant manifestation. While early-stage PCLs typically have a favorable prognosis, managing patients with aggressive progression or advaced stages remains a challenge. Recent advancements in molecular biology and sophisticated clinical laboratory tests have significantly improved the classification and management of PCLs, which provide more targeted and effective treatment strategies for patients. This review summarizes the latest classification schemes and therapeutic options for PCLs, with a focus on the latest developments and future directions in the field.

The 'Oma's of the Gammas-Cancerogenesis by γ-Herpesviruses

Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), which are the only members of the gamma(γ) herpesviruses, are oncogenic viruses that significantly contribute to the development of various human cancers, such as Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's lymphoma, Kaposi's sarcoma, and primary effusion lymphoma. Oncogenesis triggered by γ-herpesviruses involves complex interactions between viral genetics, host cellular mechanisms, and immune evasion strategies. At the genetic level, crucial viral oncogenes participate in the disruption of cell signaling, leading to uncontrolled proliferation and inhibition of apoptosis. These viral proteins can modulate several cellular pathways, including the NF-κB and JAK/STAT pathways, which play essential roles in cell survival and inflammation. Epigenetic modifications further contribute to EBV- and KSHV-mediated cancerogenesis. Both EBV and KSHV manipulate host cell DNA methylation, histone modification, and chromatin remodeling, the interplay of which contribute to the elevation of oncogene expression and the silencing of the tumor suppressor genes. Immune factors also play a pivotal role in the development of cancer. The γ-herpesviruses have evolved intricate immune evasion strategies, including the manipulation of the major histocompatibility complex (MHC) and the release of cytokines, allowing infected cells to evade immune detection and destruction. In addition, a compromised immune system, such as in HIV/AIDS patients, significantly increases the risk of cancers associated with EBV and KSHV. This review aims to provide a comprehensive overview of the genetic, epigenetic, and immune mechanisms by which γ-herpesviruses drive cancerogenesis, highlighting key molecular pathways and potential therapeutic targets.

Epstein Barr virus: A cellular hijacker in cancer

Numerous studies have demonstrated the importance of the Epstein-Barr Virus (EBV), which was initially identified in 1964 while studying Burkitt's lymphoma, in the development of a number of cancers, including nasopharyngeal carcinoma, Hodgkin's lymphoma, Burkitt's lymphoma, and EBV-associated gastric carcinoma. Gammaherpesvirus EBV is extremely common; by adulthood, over 90 % of people worldwide have been infected. Usually, the virus causes a permanent latent infection in B cells, epithelial cells, and NK/T cells. It then contributes to oncogenesis by inhibiting apoptosis and promoting unchecked cell proliferation through its latent proteins, which include EBNA-1, LMP1, and LMP2A. Tumor progression further accelerated by EBV's capacity to transition between latent and lytic phases, especially in cases of nasopharyngeal carcinoma. Although our understanding of the molecular underpinnings of EBV has advanced, there are still difficulties in identifying latent infections and creating targeted therapeutics. To tackle EBV-associated malignancies, current research efforts are concentrated on developing vaccines, developing better diagnostic tools, and developing targeted treatments. In order to improve treatment approaches and lower the incidence of EBV-related cancers worldwide, more research into the relationship between EBV and immune evasion and cancer formation is necessary.

Modified SMILE (mSMILE) is active in the treatment of pediatric Epstein-Barr virus-associated natural killer/T-cell lymphoma: a single center experience, case series

Background

The Epstein-Barr virus-associated natural killer (NK) and T-cell lymphoma (EBV + NK/T cell lymphoma) is a severe illness mainly affecting children and young adults, often resulting in a poor prognosis. To date, there is no consensus on an established treatment strategy. This study aims to evaluate the efficacy and safety of the mSMILE (modified steroid, methotrexate, ifosfamide, L-asparaginase, and etoposide) chemotherapy regimen in treating EBV+ NK/T-cell lymphoma and to provide insights into potential treatment outcomes.

Methods

In this study, we conducted a retrospective analysis of the clinical data and treatment outcomes for patients with EBV + NK/T cell lymphoma treated at Children's Hospital of Nanjing Medical University between July 2017 and January 2022. These patients received at least two cycles of the mSMILE chemotherapy, in which a single dose of pegaspargase was substituted for 7 doses of L-asparaginase per cycle.

Results

Eight patients were included in the study: one with extranodal NK/T-cell lymphoma, one with primary nodal NK/T-cell lymphoma, and six with Systemic EBV+ NK/T cell lymphoma of childhood. The results showed that five patients achieved complete remission, two achieved partial remission, and one showed progressive disease, resulting in a complete remission rate of 62.5% and an overall response rate of 87.5%. The 3-year overall survival (OS) and event-free survival (EFS) rates were 87.5% and 75%, respectively. The most common adverse reactions associated with chemotherapy were hematologic toxicities of stages III to IV. Nonhematologic adverse reactions mainly included impaired liver function, infections, and oral mucositis, which were resolved with aggressive anti-infective therapy.

Conclusions

Based on our clinical experience, the mSMILE appears to be a safe and effective treatment option for EBV + NK/T-cell lymphoma, meriting further investigation in late-phase clinical trials.

Analyzing the Impact of the Highest Expressed Epstein-Barr Virus-Encoded microRNAs on the Host Cell Transcriptome

The Epstein-Barr virus (EBV) has a very high prevalence (>90% in adults), establishes a lifelong latency after primary infection, and exerts an oncogenic potential. This dsDNA virus encodes for various molecules, including microRNAs (miRs), which can be detected in the latent and lytic phases with different expression levels and affect, among others, immune evasion and malignant transformation. In this study, the different EBV miRs are quantified in EBV-positive lymphomas, and the impact on the host cell transcriptome of the most abundant EBV miRs will be analyzed using comparative RNA sequencing analyses. The EBV miRs ebv-miR-BART1, -BART4, -BART17, and -BHRF1-1 were most highly expressed, and their selective overexpression in EBV-negative human cells resulted in a large number of statistically significantly down- and up-regulated host cell genes. Functional analyses showed that these dysregulated target genes are involved in important cellular processes, including growth factor pathways such as WNT, EGF, FGF, and PDGF, as well as cellular processes such as apoptosis regulation and inflammation. Individual differences were observed between these four analyzed EBV miRs. In particular, ebv-miR-BHRF1-1 appears to be more important for malignant transformation and immune evasion than the other EBV miRs.

Clinical epidemiology of Epstein-Barr virus-associated Lymphoproliferative Disorders (EBV-LPDs) in hospitalized children: A six-year multi-institutional study in China

BACKGROUND

Epstein-Barr virus-associated lymphoproliferative disorders (EBV-LPDs) are a group of disorders involving lymphoid tissues or lymphocytes. The epidemiology and economic burden of hospitalized children with EBV-LPDs in China have not been well studied. This study aimed to reveal the epidemic characteristics and disease burden of EBV-LPDs among the Chinese hospitalized children, providing strategies for the prevention and management.

METHODS

This study was based on the FUTang Updating medical REcords (FUTURE) database of China and collected the medical records from 27 tertiary children's hospitals between January 2016 and December 2021 in China, counting five types of EBV-LPDs, namely EBV-positive T-cell lymphoproliferative disease, NK/T cell lymphoma, extranodal NK/T-cell lymphoma (nasal type), systemic EBV-positive T-cell lymphoproliferative disease of childhood and posttransplant lymphoproliferative disorders. We conducted a retrospective syhthesis and analysis of the epidemiological characteristics, expenses, length of stay (LOS), as well as complications among hospitalized children diagnosed with five types of EBV-LPDs and compared parameters using appropriate statistical tests.

RESULTS

The study described 153 children aged 0-18 years hospitalized with EBV-LPDs from 2016 to 2021 in the FUTURE database. The male-to-female ratio was 1.10:1, and more than half of the age distribution was in the 6-12 y group. Among EBV-LPDs cases, EBV+ T-LPD accounted for the largest proportion (65.36%). Complications were presented in 93 children with EBV-LPDs, mainly hemophagocytic lymphohistiocytosis (HLH). The median LOS of NKTL was 26.5 days [interquartile range (IQR) = 3-42], which was the longest among EBV-LPDs. The median hospitalization cost of PTLD was 10 785.74 United States dollars (IQR = 7 329.38-16 531.18), which was the heaviest among EBV-LPDs.

CONCLUSIONS

Compared with the total number of hospitalized children in China during the same period and in the same age group, the proportion of EBV-LPD is very low. EBV-LPD can develop in all age groups, but it is more common in school-age children. Among 5 EBV-LPDs, the disease with the highest proportion is EBV+ T-LPD. The overall disease burden of EBV-LPD was heavy, especially the economic burden. HLH was one of the most common complications, which could directly affect the burden of patients because of prolonged hospitalization. These data are taken from a very large database, illustrating the epidemiological and economic burden of EBV-LPDs hospitalized children in China, which enriched the existing epidemiological and disease burden content of EBV-LPDs.

Analysis of the treatment and prognosis of 266 cases of extranodal natural killer/T-cell lymphoma, nasal type in a single medical center

Objective

To assess the impact of different treatment strategies and risk factors on the prognosis of patients with extranodal NK/T-cell lymphoma, nasal type (ENKTL) in a single medical center.

Methods and analysis

The clinical features of 266 patients with ENKTL were retrospectively analyzed, among whom those in stages I and II received sandwich therapy, while those in stages III and IV underwent chemotherapy plus autologous hematopoietic stem cell transplantation. The Kaplan-Meier curves, univariate and multivariate Cox regression analyses were employed for survival and prognosis analysis. Statistical significance was set at P<0.05.

Results

Following treatment, the post-intervention outcomes demonstrated a complete remission (CR) rate of 71.05% and a partial remission (PR) rate of 3.76%. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 70.4% and 70.9%, respectively. In addition, the PFS for patients in stage I/II was 79.8%, with an OS of 81.1%, whereas for those in stage III/IV, the PFS was 41.7% and the OS was 40.9%. Notably, the achievement of CR immediately after treatment was an independent prognostic factor (P<0.001). Patients in stage I/II depicted a favorable 5-year OS rate, while those in stage III/IV manifested a less favorable prognosis.

Conclusion

Stages of the disease and whether CR was achieved following treatment are important factors determining the survival and prognosis of patients with ENKTL. Further researches focusing on disease onset and mechanisms of drug resistance will contribute to better management of ENKTL.

Report of Two Contrasting Cases of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis: Comparison to Infectious Mononucleosis and Flow Cytometric Analysis of Bone Marrow

Purpose

This study aims to investigate the characteristics of Epstein-Barr virus associated-hemophagocytic lymphohistiocytosis (EBV-HLH) and HLH caused by a severe form of infectious mononucleosis (IM-HLH) compared to IM by EBV, and thus also to assist in early diagnosis and providing appropriate treatment.

Methods

Data for this analysis were collected from patients at the Department of General Medicine, Nara Medical University, between April 1, 2012, and August 1, 2020. EBV infection was diagnosed using clinical presentation and laboratory tests. HLH diagnosis followed the HLH-2004 protocol, supplemented by plasma EBV DNA detection. A range of clinical and laboratory parameters were collected, including age, sex, clinical outcomes, blood cell counts, hemoglobin, platelets, and various serum values. Plasma EBV DNA levels and flow cytometric analysis (FCM) of bone marrow were performed for HLH cases.

Results

Among 1850 hospitalized patients, 14 cases were identified, including 2 HLH cases and 12 IM cases. Comparative analysis revealed distinctive features of HLH, including lower lymphocyte and platelet counts and higher levels of ferritin, soluble interleukin 2 receptor (sIL-2R), and D dimer compared to IM. Notably, one HLH case responded well to corticosteroid monotherapy, while the other case did not, resulting in a fatal outcome. Detection of a cluster of CD5-CD7 lymphocytes in bone marrow is a hallmark of EBV-HLH and useful to distinguish from IM-HLH.

Conclusion

This study underscores the importance of early differentiation among EBV-HLH, IM-HLH, and IM in adults to guide appropriate treatment strategies. While specific laboratory markers help distinguish HLH from IM, a more detailed analysis of FCM is crucial for precise diagnosis of HLH cases and tailored therapeutic interventions.

Epigenetics of Epstein Barr virus - A review

Epstein Barr is the first-in-human oncogenic virus, closely related to numerous lymphoproliferative and malignant diseases, including HL, BL, NPC, and GC. EBV establishes life-long persistence infection portraying a biphasic viral life cycle: latent period and lytic replication. B-cells serve as critical regions for EBV latent genes, wherein viral gene expression is suppressed, promoting viral genome maintenance and immune recognition evasion. Upon its lytic reactivation, viral gene expression induces its replication, progeny production, and transmission. Dysregulations of epigenetic regulation in expressions of TSGs lead to carcinogenesis. Several studies reveal that EBV is associated with aberrant viral DNA and host genome methylation patterns, promoting immune monitoring, recognition evasiveness and host cell persistence. Among other epigenetic modifications, DNA methylation suppresses the majority of viral latent gene promoters, sparing a few, and acts as a prerequisite for activating EBV's lytic cycle, giving rise to viral progeny. It affects the host's epigenome via reprogramming cells to oncogenic, long-lasting phenotypes, as evident in several malignancies. At each phase of its life cycle, EBV exploits cellular mechanisms of epigenetic regulation, implying its unique host-pathogen relationship. This review summarized the DNA methylation's regulatory roles on several EBV-related promoter regions, along with the host genome in pathological conditions, highlights viral genes involved in a latent, lytic and latent-lytic phase of EBV infection. Moreover, it provides diagrammatic insights into methylation-based pathways in EBV.

Chronic active Epstein-Barr virus and hydroa vacciniforme-like lymphoproliferative disorder in a pediatric patient complicated by fatal ruptured cerebral artery aneurysm

Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a rare cutaneous form of chronic active Epstein-Barr virus (CAEBV) that presents with vesicular lesions induced by sun-exposure. Arterial aneurysm is a rare but potentially fatal complication of CAEBV and HV-LPD.

An update on genetic aberrations in T-cell neoplasms

T-cell neoplasms are a highly heterogeneous group of leukaemias and lymphomas that represent 10-15% of all lymphoid neoplasms. Traditionally, our understanding of T-cell leukaemias and lymphomas has lagged behind that of B-cell neoplasms, in part due to their rarity. However, recent advances in our understanding of T-cell differentiation, based on gene expression and mutation profiling and other high throughput methods, have better elucidated the pathogenetic mechanisms of T-cell leukaemias and lymphomas. In this review, we provide an overview of many of the molecular abnormalities that occur in various types of T-cell leukaemia and lymphoma. Much of this knowledge has been used to refine diagnostic criteria that has been included in the fifth edition of the World Health Organization. This knowledge is also being used to improve prognostication and identify novel therapeutic targets, and we expect this progress will continue, eventually resulting in improved outcomes for patients with T-cell leukaemias and lymphomas.

Intravascular NK/T-Cell Lymphoma: What We Know about This Diagnostically Challenging, Aggressive Disease

Intravascular lymphoma is a form of lymphoid malignancy characterized by neoplastic cells growing almost exclusively within the lumina of small- to medium-sized blood vessels. Most cases are of B-cell origin with rare cases of natural killer or T-cell lineage. Extranodal sites are affected, mainly the skin and central nervous system, although any organ may be involved. Intravascular NK/T-cell lymphoma deserves special attention because of its clinicopathologic features and the need for adequate immunophenotyping combined with clonality test for a proper diagnosis. Moreover, intravascular NK/T-cell lymphoma is strongly linked to Epstein-Barr virus (EBV), which is considered to play a role in tumorigenesis and to be responsible for the aggressive behavior of the disease. In this paper, we review the current knowledge on this rare lymphoma and, in particular, the most recent advances about its molecular landscape. The main distinguishing features with other EBV-related entities, such as extranodal NK/T-cell lymphoma, EBV-positive primary nodal T/NK-cell lymphoma, and aggressive NK-cell leukemia, are discussed to help pathologists obtain the correct diagnosis and consequently develop an adequate and prompt therapy response.

Case report: Cellular therapy for hydroa vacciniforme-like lymphoproliferative disorder in pediatric common variable immunodeficiency with chronic active Epstein-Barr virus infection

Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a cutaneous form of chronic active Epstein-Barrvirus (EBV) infection, which can develop into the extremely rare systemic lymphoma. Patients with Inborn errors of immunity (IEI), such as common variable immunodeficiency (CVID), are at higher risk of developing a severe course of infections especially viral and malignancies than the general population. The aim of the study was to present complex diagnostic and therapeutic management of HV-LPD. The clinical diagnosis was confirmed at the histological and molecular level with next generation sequencing. HV-LPD was diagnosed in a patient with CVID and chronic active Epstein–Barr virus (CAEBV) infection. The patient was refractory to CHOP chemotherapy and immunosuppressive treatment in combination with antiviral drugs (prednisone, bortezomib, gancyclovir). The third-party donor EBV-specific cytotoxic T cells (EBV-CTL, tabelecleucel) were used, which stabilised the disease course. Finally, matched unrelated donor hematopoietic cell transplantation (MUD-HCT) was performed followed by another cycle of EBV-CTL.

Treatment Advances in EBV Related Lymphoproliferative Diseases

Epstein Barr virus (EBV) can affect 90% of the human population. It can invade B lymphocytes, T lymphocytes and natural killer cells of the host and remain in the host for life. The long latency and reactivation of EBV can cause malignant transformation, leading to various lymphoproliferative diseases (LPDs), including EBV-related B-cell lymphoproliferative diseases (EBV-B-LPDs) (for example, Burkitt lymphoma (BL), classic Hodgkin's lymphoma (cHL), and posttransplantation and HIV-related lymphoproliferative diseases) and EBV-related T-cell lymphoproliferative diseases (EBV-T/NK-LPDs) (for example, extranodal nasal type natural killer/T-cell lymphoma (ENKTCL), aggressive NK cell leukaemia (ANKL), and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). EBV-LPDs are heterogeneous with different clinical features and prognoses. The treatment of EBV-LPDs is usually similar to that of EBV-negative lymphoma with the same histology and can include chemotherapy, radiotherapy, and hematopoietic stem cell transplant (HSCT). However, problems such as serious toxicity and drug resistance worsen the survival prognosis of patients. EBV expresses a variety of viral and lytic proteins that regulate cell cycle and death processes and promote the survival of tumour cells. Based on these characteristics, a series of treatment strategies for EBV in related malignant tumours have been developed, such as monoclonal antibodies, immune checkpoint inhibitors, cytotoxic T lymphocytes (CTLs) and epigenetic therapy. These new individualized therapies can produce highly specific killing effects on tumour cells, and nontumour cells can be protected from toxicity. This paper will focus on the latest progress in the treatment of EBV-LPDs based on pathological mechanisms.

Four Decades of Prophylactic EBV Vaccine Research: A Systematic Review and Historical Perspective

Background

Epstein-Barr virus (EBV) is the causal agent of infectious mononucleosis and has been associated with various cancers and autoimmune diseases. Despite decades of research efforts to combat this major global health burden, there is no approved prophylactic vaccine against EBV. To facilitate the rational design and assessment of an effective vaccine, we systematically reviewed pre-clinical and clinical prophylactic EBV vaccine studies to determine the antigens, delivery platforms, and animal models used in these studies.

Methods

We searched Cochrane Library, ClinicalTrials.gov, Embase, PubMed, Scopus, Web of Science, WHO’s Global Index Medicus, and Google Scholar from inception to June 20, 2020, for EBV prophylactic vaccine studies focused on humoral immunity.

Results

The search yielded 5,614 unique studies. 36 pre-clinical and 4 clinical studies were included in the analysis after screening against the exclusion criteria. In pre-clinical studies, gp350 was the most commonly used immunogen (33 studies), vaccines were most commonly delivered as monomeric proteins (12 studies), and mice were the most used animal model to test immunogenicity (15 studies). According to an adaptation of the CAMARADES checklist, 4 pre-clinical studies were rated as very high, 5 as high, 13 as moderate quality, 11 as poor, and 3 as very poor. In clinical studies, gp350 was the sole vaccine antigen, delivered in a vaccinia platform (1 study) or as a monomeric protein (3 studies). The present study was registered in PROSPERO (CRD42020198440).

Conclusions

Four major obstacles have prevented the development of an effective prophylactic EBV vaccine: undefined correlates of immune protection, lack of knowledge regarding the ideal EBV antigen(s) for vaccination, lack of an appropriate animal model to test vaccine efficacy, and lack of knowledge regarding the ideal vaccine delivery platform. Our analysis supports a multivalent antigenic approach including two or more of the five main glycoproteins involved in viral entry (gp350, gB, gH/gL, gp42) and a multimeric approach to present these antigens. We anticipate that the application of two underused challenge models, rhesus macaques susceptible to rhesus lymphocryptovirus (an EBV homolog) and common marmosets, will permit the establishment of in vivo correlates of immune protection and attainment of more generalizable data.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=198440, identifier PROSPERO I.D. CRD4202019844.

EBV+ lymphoproliferative diseases: opportunities for leveraging EBV as a therapeutic target

Epstein-Barr virus (EBV) is a ubiquitous human tumor virus, which contributes to the development of lymphoproliferative disease, most notably in patients with impaired immunity. EBV-associated lymphoproliferation is characterized by expression of latent EBV proteins and ranges in severity from a relatively benign proliferative response to aggressive malignant lymphomas. The presence of EBV can also serve as a unique target for directed therapies for the treatment of EBV lymphoproliferative diseases, including T cell-based immune therapies. In this review, we describe the EBV-associated lymphoproliferative diseases and particularly focus on the therapies that target EBV.

EBV associated T- and NK-cell lymphoproliferative diseases: A comprehensive overview of clinical manifestations and novel therapeutic insights

EBV is a ubiquitous virus that infects nearly all people around the world. Most infected people are asymptomatic and do not show serious sequelae, while others may develop Epstein-Barr virus (EBV)-positive T and NK-cell lymphoproliferations characterised by EBV-infected T or NK cells. These disorders are more common in Asian and Latin American people, suggesting genetic predisposition as a contributing factor. The revised WHO classification classifies the lymphoproliferative diseases as: extranodal NK/T-cell lymphoma nasal type (ENKTL), aggressive NK-cell leukemia (ANKL), primary EBV-positive nodal T or NK cell lymphoma (NNKTL), systemic EBV-positive T-cell lymphoproliferative disease of childhood (STCLC), systemic chronic active EBV infection (sys CAEBV), hydroa-vacciniforme (HV) and severe mosquito bite allergy (SMBA). Recent advances in the molecular pathogenesis of these diseases have led to the development of new therapeutic strategies. Due to the infrequency of the diseases and broad clinicopathological overlap, the diagnosis and classification are challenging for both clinicians and pathologists. In this article, we aim to review the recent pathological findings which can be helpful for designing new drugs, clinical presentations and differential diagnoses, and suggested therapeutic interventions to provide a better understanding of these rare disorders.

Estimating the global burden of Epstein-Barr virus-related cancers

BACKGROUND

More than 90% of the adult population globally is chronically infected by the Epstein-Barr virus (EBV). It is well established that EBV is associated with a number of malignancies, and advances in knowledge of EBV-related malignancies are being made every year. Several studies have analysed the global epidemiology and geographic distribution of EBV-related cancers. However, most have only described a single cancer type or subtype in isolation or limited their study to the three or four most common EBV-related cancers. This review will present an overview on the spectrum of cancers linked to EBV based on observations of associations and proportions in the published literature while also using these observations to estimate the incidence and mortality burden of some of these cancers.

METHOD

We have reviewed the literature on defining features, distribution and outcomes across six cancers with a relatively large EBV-related case burden: Nasopharyngeal carcinoma (NPC), Gastric carcinoma (GC), Hodgkin lymphoma (HL), Burkitt lymphoma (BL), Diffuse large B-cell lymphoma (DLBCL) and Extranodal NK/T-cell lymphoma, Nasal type (ENKTL-NT). We retrieved published region-specific EBV-related case proportions for NPC, GC, HL and BL and performed meta-analyses on pooled region-specific studies of EBV-related case proportions for DLBCL and ENKTL-NT. We match these pooled proportions with their respective regional incidence and mortality numbers retrieved from a publicly available cancer database. Additionally, we also reviewed the literature on several other less common EBV-related cancers to summarize their key characteristics herein.

CONCLUSION

We estimated that EBV-related cases from these six cancers accounted for 239,700-357,900 new cases and 137,900-208,700 deaths in 2020. This review highlights the significant global impact of EBV-related cancers and extends the spectrum of disease that could benefit from an EBV-specific therapeutic.

Aggressive Natural Killer Cell Leukemia in an Adolescent Patient: A Case Report and Literature Review

Aggressive natural killer cell leukemia (ANKL) is a rare malignant tumor, especially uncommon in children. ANKL has very aggressive clinical course and bad prognosis and is usually caused by Epstein-Barr virus infection. ANKL often has clinical manifestations of hemophagocytic lymphohistiocytosis (HLH) and can be easily treated as HLH, which might complicate this aggressive disease. Here we report an ANKL in adolescent whose clinical presentation was highly aggressive and response to L-asparaginase containing chemotherapy was very bad. Early-onset Flow cytometry of peripheral blood and bone marrow help make the diagnosis.

EBV-Driven Lymphoproliferative Disorders and Lymphomas of the Gastrointestinal Tract: A Spectrum of Entities with a Common Denominator (Part 3)

EBV is the first known oncogenic virus involved in the development of several tumors. The majority of the global population are infected with the virus early in life and the virus persists throughout life, in a latent stage, and usually within B lymphocytes. Despite the worldwide diffusion of EBV infection, EBV-associated diseases develop in only in a small subset of individuals often when conditions of immunosuppression disrupt the balance between the infection and host immune system. EBV-driven lymphoid proliferations are either of B-cell or T/NK-cell origin, and range from disorders with an indolent behavior to aggressive lymphomas. In this review, which is divided in three parts, we provide an update of EBV-associated lymphoid disorders developing in the gastrointestinal tract, often representing a challenging diagnostic and therapeutic issue. Our aim is to provide a practical diagnostic approach to clinicians and pathologists who face this complex spectrum of disorders in their daily practice. In this part of the review, the chronic active EBV infection of T-cell and NK-cell type, its systemic form; extranodal NK/T-cell lymphoma, nasal type and post-transplant lymphoproliferative disorders are discussed.

Peripheral blood lymphocyte counts in patients with infectious mononucleosis or chronic active Epstein-Barr virus infection and prognostic risk factors of chronic active Epstein-Barr virus infection

OBJECTIVE

To explore the peripheral blood lymphocyte counts and analyze the prognostic risk factors for the death in patients with chronic active Epstein-Barr virus (CAEBV) infection.

METHODS

Clinical data of 64 patients infected with CAEBV (CAEBV group) and 64 patients with infectious mononucleosis (IM group) in our hospital were retrospectively analyzed. Meanwhile, 64 healthy individuals came for physical examination were enrolled in the control group. The three groups were compared for white blood cell count, lymphocyte count, and levels of peripheral blood NK cells, B cells, CD3⁺, CD4⁺, CD8⁺, CD4⁺CD28⁺, CD8⁺CD28⁺, CD4⁺CD25⁺, DR⁺CD8⁺, CD38⁺CD8⁺, CD4⁺ and CD8⁺ naive T cells and subsets of memory T cells. Patients infected with CAEBV were further divided into a survival subgroup and a death subgroup according to the survival outcome. The data were processed using univariate analysis and multivariate logistic regression analysis.

RESULTS

Compared with the control group, the IM group had higher levels of white blood cell count, lymphocyte count, CD3⁺, CD4⁺, CD8⁺, CD4⁺CD25⁺, DR⁺CD8⁺, CD38⁺CD8⁺, effector-memory CD4⁺CD62L^-CD45RO⁺ and effector-memory CD8⁺CD62L^-CD45RO⁺, but lower levels of NK cells, B cells, CD4⁺CD28⁺, CD8⁺CD28⁺, naive CD4⁺CD62L⁺CD45RA⁺ and naive CD8⁺CD62L⁺CD45RA⁺ (all P<0.05). Compared with the control group, the CAEBV group had lower levels of white blood cell count, lymphocyte count, CD3⁺, CD4⁺, CD8⁺, NK cells, B cells, CD4⁺CD28⁺, CD8⁺CD28⁺, naive CD4⁺CD62L⁺CD45RA⁺ and naive CD8⁺CD62L⁺CD45RA⁺, but higher levels of CD4⁺CD25⁺, DR⁺CD8⁺, CD38⁺CD8⁺, effector-memory CD4⁺CD62L^-CD45RO⁺ and effector-memory CD8⁺CD62L^-CD45RO⁺ (all P<0.05). Univariate analysis and multivariate logistic regression analysis showed that EBV DNA>105 copies/mL, platelet count <50×10¹²/L, albumin <30 g/L and serum ferritin >5000 μg/L were independent risk factors for the death of patients with CAEBV.

CONCLUSION

Patients infected with CAEBV showed imbalance of lymphocyte subsets and immune dysfunction. EBV DNA>105 copies/mL, platelet count <50×10¹²/L, albumin <30 g/L and serum ferritin >5000 μg/L are risk factors of death in patients with CAEBV.

Chronic active Epstein-Barr virus infection progresses to aggressive NK cell leukemia with a poor prognosis

Epstein-Barr virus (EBV) associated T/NK-cell lymphoproliferative diseases (EBV-T/NK-LPDs) are a cluster of diseases that include chronic active EBV infection (CAEBV) and aggressive NK cell leukemia (ANKL). The pathogenesis of EBV-T/NK-LPDs is largely unclear and the treatment is difficult and in most cases a hematopoietic stem cell transplantation is needed. Hemophagocytic lymphohistiocytosis (HLH) is known to affect the prognosis of patients with EBV-T/NK-LPDs. This study reports a case of a 20-year-old male patient with repeated infectious mononucleosis (IM)-like symptoms such as high fever, splenomegaly, lymphadenopathy for more than two years. The patient had a high EBV-DNA load (NK cells were the main target cells). He was first diagnosed as CAEBV. However, the disease gradually progressed and the patient developed with high ferritin, phagocytosis and monoclonal NK cells in bone marrow, pancytopenia, increased cytokines, and elevated expression of Ki-67. Also, his NK cells had abnormal immunophenotypes and impaired function. The patient had a typical clinical course of progression from CAEBV to ANKL, accompanied by HLH complications and a poor prognosis. Herein, the detailed diagnostic and differential diagnostic process of EBV infection was shown in this report.

Molecular Properties and Therapeutic Targeting of the EBV-Encoded Receptor BILF1

The γ-herpesvirus Epstein-Barr Virus (EBV) establishes lifelong infections in approximately 90% of adults worldwide. Up to 1,000,000 people yearly are estimated to suffer from health conditions attributed to the infection with this virus, such as nasopharyngeal and gastric carcinomas as well as several forms of B, T and NK cell lymphoma. To date, no EBV-specific therapeutic option has reached the market, greatly reducing the survival prognoses of affected patients. Similar to other herpesviruses, EBV encodes for a G protein-coupled receptor (GPCR), BILF1, affecting a multitude of cellular signaling pathways. BILF1 has been identified to promote immune evasion and tumorigenesis, effectively ensuring a life-long persistence of EBV in, and driving detrimental health conditions to its host. This review summarizes the epidemiology of EBV-associated malignancies, their current standard-of-care, EBV-specific therapeutics in development, GPCRs and their druggability, and most importantly consolidates the findings of over 15 years of research on BILF1 in the context of EBV-specific drug development. Taken together, BILF1 constitutes a promising target for the development of novel EBV-specific therapeutics.

The Role of Immunotherapy to Overcome Resistance in Viral-Associated Head and Neck Cancer

A subset of head and neck cancers arising in the oropharynx and the nasopharynx are associated with human papillomavirus or Epstein-Barr virus. Unfortunately, limited treatment options exist once patients develop recurrent or metastatic disease in these cancers. Interest has risen in utilizing novel strategies including combination immune checkpoint inhibitors, vaccines, and adoptive cellular therapy, to improve treatment response and outcomes. Several ongoing studies are investigating the potential to overcome resistance to standard of care chemoradiation therapy with monotherapy or combination immunotherapy strategies in these viral-associated head and neck cancers.

Fatal Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis with virus-infected T cells after pediatric multivisceral transplantation: A proof-of-concept case report

BACKGROUND

EBV-associated HLH driven by EBV-infected CD8⁺ T cells is a rare complication after pediatric solid organ transplantation. The etiology and disease spectrum of post-transplant EBV-HLH are poorly understood, and making a precise diagnosis and providing optimal treatment remain a challenge.

METHODS/CASE DESCRIPTION/RESULTS

We report a 2-year-old multivisceral transplant recipient who developed fever and cytopenia with a persistent high EBV-load state. Repeated tissue examinations and CT scans could not identify a localized mass, which is the key to the diagnosis of PTLD as per the WHO classification. Hence, EBV-HLH was diagnosed by clinical manifestations as well as characterization of EBV-infected cells, pathological examination on cell block of pleural effusion and clonality analysis. This EBV-HLH did not respond to intensive chemotherapy, resulted in the recipient's death, acting similarly to hematological malignancy.

CONCLUSIONS

Characterization of EBV-infected cells in peripheral blood should be considered when persistent high EBV loads develop with symptoms consistent with PTLD, but no evidence of localized mass, and the tissue diagnosis is unavailable after pediatric solid organ transplantation.

Article Topic/Title: Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome. Part II: Prognosis and Management

Primary cutaneous T-cell lymphomas (CTCLs) other than Mycosis Fungoides (MF) and Sézary syndrome (SS) encompass a heterogenous group of non-Hodgkin lymphomas with variable clinical course, prognoses, and management. With morphologic and histologic overlap among the CTCL subtypes and other T-cell lymphomas with cutaneous manifestations, thorough evaluation with clinicopathologic correlation and exclusion of systemic involvement are essential prior to initiating therapy. Staging and treatment recommendations vary depending on the subtype, clinical behavior, and treatment response. Generally, for subtypes where staging is recommended, Ann Arbor or TNM staging specific to CTCL other than MF or SS are used. For many subtypes, there is no standard treatment to date. Available recommended treatments range widely from no active or minimal intervention with skin-directed therapy to aggressive systemic therapies including multiagent chemotherapy with consideration for hematopoietic stem cell transplant. Emerging targeted therapies, such as brentuximab, a chimeric antibody targeting CD30, show promise in altering the disease course of non-MF/SS CTCLs.

Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome - Part I: Clinical and histologic features and diagnosis

Primary cutaneous T-cell lymphomas (CTCLs) are defined as lymphomas with a T-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation. CTCLs other than Mycosis Fungoides (MF) and Sézary syndrome (SS) account for approximately one-third of CTCLs and encompass a heterogenous group of non-Hodgkin lymphomas ranging from indolent lymphoproliferative disorders to aggressive malignancies with a poor prognosis. The spectrum of CTCLs continues to broaden as new provisional entities are classified. Given the morphologic and histologic overlap among CTCLs and other diagnoses, a thorough clinical history, physical evaluation, and clinicopathologic correlation are essential in the workup and diagnosis of these rare entities. This article will summarize the epidemiologic, clinical, pathologic, and diagnostic features of CTCLs other than MF and SS.

NK/T-cell non-Hodgkin lymphoma: Case report and review of the literature

Natural killer (NK)/T-cell lymphomas represent a rare type of lymphoid malignancy with mostly extranodal involvement, having NK cell or (rare) T cell lineage, classified by the World Health Organization into several subtypes which can involve the head and neck region, with the most frequent one being the nasal type. This article presents the case of a 31-year-old patient who presented at the Emergency Unit of Saint Andrew Emergency Clinical Hospital of Galati suffering from mycosis fungoides-like cutaneous lesions, associated with partial left eyelid ptosis of unknown etiology, as well as a poor health status with fever and respiratory failure. The final diagnosis was NK/T-cell non-Hodgkin lymphoma, possibly nasal type with medium sized T cells. The complexity of the rare diagnosis, associated with the unusual rapid patient evolution towards exitus 3 months after diagnosis, the intra-orbital metastatic involvement and the absence of a standardized treatment are case peculiarities, some of which are consistent with current literature data.

Comparison of Systemic EBV-positive T-Cell and NK-Cell Lymphoproliferative Diseases of Childhood Based on Classification Evolution: New Classification, Old Problems

Systemic Epstein-Barr virus-positive T-cell and natural killer (NK)-cell lymphoproliferative diseases of childhood are a group of lethal diseases mostly affecting children and young adults. The Ohshima Grading System and the 2017 World Health Organization (WHO) classification have been used for classifying this spectrum, but these systems have not been validated externally and compared. Therefore, we examined 36 cases of systemic Epstein-Barr virus-positive T-cell and NK-cell lymphoproliferative diseases of childhood with long-term follow-up, from Southwest China, to systematically summarize the clinicopathologic features and to validate and compare the Ohshima Grading System and the 2017 WHO classification in discrimination ability, predictive accuracy, concordance indices, and explained variation. Clinically, our cohort showed severe manifestations and poor prognoses. Morphologically, the hematopoietic and lymphoid specimens showed proliferation of small-sized to medium-sized bland-looking lymphocytes that might mask disease severity, whereas other extranodal lesions showed a disorganized to obliterated architecture infiltrated by medium-sized to large-sized, subtle to obvious atypical cells, which may mimic extranodal NK/T-cell lymphoma. Immunophenotypically, our cases mainly originate from CD8 αβ T cells. Therefore, clinical and pathologic features should be equally considered to avoid missed diagnosis or misdiagnosis. In addition, the 2017 WHO classification shows a flexible grasp of pathologic features, thus classifying some cases (polymorphic and monoclonal cases with fulminant course) more reasonably; thereby, it showed statistically improved results compared with the Ohshima Grading System. However, underestimating the risk of some polyclonal cases and imprecisely discriminating monoclonal cases at diagnosis are common dilemmas in both systems. Therefore, the construction of a comprehensive grading algorithm for improved prognostic value and precise diagnosis requires additional studies.

The interplay between EBV and KSHV viral products and NF-κB pathway in oncogenesis

Among the DNA tumor viruses Epstein-Barr virus (EBV) and Kaposi sarcoma herpesvirus (KSHV), account for a considerable percentage of virus-associated cancers. Deregulation of transcription factors signaling pathways is one of the most significant oncogenic characteristics of EBV and KSHV. NF-κB is a transcription factor that play a remarkable role in oncogenesis because of its function as a master regulator of a spectrum of genes involved in physiological and pathophysiological process. Constitutive activation of NF-κB is a frequent and well-described event in many human malignancies. Compelling evidence represent EBV and KSHV are capable of targeting different components of NF-κB cascade. Here, we summarized recent findings to clarify the precise relationship between dysregulation of NF-κB and EBV and KSHV-related malignancies. This essay also emphasizes on contribution of various viral products in developing cancer through alteration of NF-κB signaling pathway.

T-cell neoplasms in the spleen

Hematopoietic neoplasms involving the spleen are uncommon, but T cell neoplasms involving the spleen are extremely rare. The rarity of splenic involvement by T cell neoplasms has resulted in a limited body of literature describing their splenic characteristics. As a result, our purpose in this review article is to provide and summarize some of the characteristics seen by different T cell neoplasms that may involve the spleen.

Long-term outcomes of upfront concurrent chemoradiotherapy followed by P-GDP regimen in newly diagnosed early stage extranodal nasal-type NK/T cell lymphoma: A prospective single-center phase II study

The optimal treatment strategy of newly diagnosed stage I/II, extranodal nasal-type natural killer/T cell lymphoma (NKTCL) remains unclear. This prospective phase II trial was conducted to explore the short-term and the long-term efficacy and safety of upfront concurrent chemoradiotherapy (CCRT) followed by pegaspargase, gemcitabine, dexamethasone, cisplatin (P-GDP) regimen in patients newly diagnosed with early stage NKTCL.Thirty patients newly diagnosed with stage I/II NKTCL were enrolled from January 2013 to December 2016, and treated as the following strategy: upfront CCRT with cisplatin weekly (25 mg/m) for 5 weeks, followed by 3 cycles of P-GDP regimen chemotherapy (pegaspargase 2500IU/m capped at 3750IU, intramuscular on day 4, gemcitabine 850 mg/m intravenous on days 1 and 8; dexamethasone 40 mg/day intravenous on days 1 to 4; and cisplatin 20 mg/m intravenous on days 1-3) 3 weeks after the completion of CCRT. The objective response rate (ORR) and the complete response (CR) rate were the primary endpoints, and the secondary endpoints were the overall survival (OS), progression-free survival (PFS), and the adverse event (AE).The median follow-up period was 51.5 months (range, 5-78months). The ORR was 93.3% (28/30) and all these 28 patients attained CR at the end of the treatment. Two patients suffered from lymphoma associated hemophagocytic syndrome (LAHS) during the period of consolidation chemotherapy and died within 2 months. The 5-year OS was 93.3%, and the 5-year PFS was 89.4%Mucositis was the most common grades 3/4 nonhematologic AEs (10%, 3/30) of CCRT. During the P-GDP chemotherapy, vomiting (6.7%, 2/30), neutropenia (43.3%, 13/30) and thrombocytopenia (23.3%, 7/30) were the major grades 3/4 toxicities during chemotherapy. No treatment-related deaths occurred.The upfront CCRT followed by P-GDP regimen chemotherapy is an effective and well-tolerated first-line treatment strategy for patients diagnosed with early stage NKTCL. Further investigation of larger sample size is warranted.

Animal Models for Gammaherpesvirus Infections: Recent Development in the Analysis of Virus-Induced Pathogenesis

Epstein–Barr virus (EBV) is involved in the pathogenesis of various lymphomas and carcinomas, whereas Kaposi’s sarcoma-associated herpesvirus (KSHV) participates in the pathogenesis of endothelial sarcoma and lymphomas. EBV and KSHV are responsible for 120,000 and 44,000 annual new cases of cancer, respectively. Despite this clinical importance, no chemotherapies or vaccines have been developed for virus-specific treatment and prevention of these viruses. Humans are the only natural host for both EBV and KSHV, and only a limited species of laboratory animals are susceptible to their experimental infection; this strict host tropism has hampered the development of their animal models and thereby impeded the study of therapeutic and prophylactic strategies. To overcome this difficulty, three main approaches have been used to develop animal models for human gammaherpesvirus infections. The first is experimental infection of laboratory animals with EBV or KSHV. New-world non-human primates (NHPs) and rabbits have been mainly used in this approach. The second is experimental infection of laboratory animals with their own inherent gammaherpesviruses. NHPs and mice have been mainly used here. The third, a recent trend, employs experimental infection of EBV or KSHV or both to immunodeficient mice reconstituted with human immune system components (humanized mice). This review will discuss how these three approaches have been used to reproduce human clinical conditions associated with gammaherpesviruses and to analyze the mechanisms of their pathogenesis.

Central nervous system vasculitis from Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorder in children: A case report

BACKGROUND

Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders (EBV-T/NK-LPD) is a group of rare disorders resulting from EBV-infected T/NK-cells. It manifests as a broad spectrum of clinical symptoms according to immunologic status and viral load of an infected patient. Here, we report a boy who developed central nervous system (CNS) vasculitis and myelopathy as possible neurologic manifestations of EBV-T/NK-LPD.

CASE REPORT

A 16-year-old boy came to our hospital with a necrotic skin lesion on his right shoulder. He suffered from local skin reactions with high fevers after mosquito bites since he was 10 years old. During the evaluation of his skin lesion, he suddenly developed left facial palsy. Brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) showed acute infarctions of the pons and middle cerebellar peduncle and irregularities of both anterior inferior cerebellar arteries. Serologic testing showed an elevation of total Ig E levels, anti-VCA IgG levels, and anti-EA IgG titers. EBV DNA copy numbers of the whole blood and cerebrospinal fluid (CSF) were elevated. Biopsy of the right shoulder skin showed extranodal NK/T-cell lymphoma. According to clinical features and laboratory findings, he was diagnosed with EBV-T/NK-LPD. He was treated with chemotherapy and hematopoietic stem cell transplantation but developed recurrent infarctions during treatment.

CONCLUSION

This case showed the diagnostic challenge of neurologic manifestations of EBV-T/NK-LPD. EBV-T/NK-LPD-associated CNS vasculitis needs to be considered as a differential diagnosis of CNS vasculitis, when it is accompanied by the typical clinical spectrum of EBV-T/NK-LPD such as severe mosquito bite allergy, extranodal NK/T-cell lymphoma.

Recurrent GNAQ mutation encoding T96S in natural killer/T cell lymphoma

Natural killer/T cell lymphoma (NKTCL) is a rare and aggressive malignancy with a higher prevalence in Asia and South America. However, the molecular genetic mechanisms underlying NKTCL remain unclear. Here, we identify somatic mutations of GNAQ (encoding the T96S alteration of Gαq protein) in 8.7% (11/127) of NKTCL patients, through whole-exome/targeted deep sequencing. Using conditional knockout mice (Ncr1-Cre-Gnaqfl/fl), we demonstrate that Gαq deficiency leads to enhanced NK cell survival. We also find that Gαq suppresses tumor growth of NKTCL via inhibition of the AKT and MAPK signaling pathways. Moreover, the Gαq T96S mutant may act in a dominant negative manner to promote tumor growth in NKTCL. Clinically, patients with GNAQ T96S mutations have inferior survival. Taken together, we identify recurrent somatic GNAQ T96S mutations that may contribute to the pathogenesis of NKTCL. Our work thus has implications for refining our understanding of the genetic mechanisms of NKTCL and for the development of therapies.

The Global Landscape of EBV-Associated Tumors

Epstein-Barr virus (EBV), a gamma-1 herpesvirus, is carried as a life-long asymptomatic infection by the great majority of individuals in all human populations. Yet this seemingly innocent virus is aetiologically linked to two pre-malignant lymphoproliferative diseases (LPDs) and up to nine distinct human tumors; collectively these have a huge global impact, being responsible for some 200,000 new cases of cancer arising worldwide each year. EBV replicates in oral epithelium but persists as a latent infection within the B cell system and several of its diseases are indeed of B cell origin; these include B-LPD of the immunocompromised, Hodgkin Lymphoma (HL), Burkitt Lymphoma (BL), Diffuse Large B cell Lymphoma (DLBCL) and two rarer tumors associated with profound immune impairment, plasmablastic lymphoma (PBL) and primary effusion lymphoma (PEL). Surprisingly, the virus is also linked to tumors arising in other cellular niches which, rather than being essential reservoirs of virus persistence in vivo, appear to represent rare cul-de-sacs of latent infection. These non-B cell tumors include LPDs and malignant lymphomas of T or NK cells, nasopharyngeal carcinoma (NPC) and gastric carcinoma of epithelial origin, and leiomyosarcoma, a rare smooth muscle cell tumor of the immunocompromised. Here we describe the main characteristics of these tumors, their distinct epidemiologies, histological features and degrees of EBV association, then consider how their different patterns of EBV latency may reflect the alternative latency programmes through which the virus first colonizes and then persists in immunocompetent host. For each tumor, we discuss current understanding of EBV's role in the oncogenic process, the identity (where known) of host genetic and environmental factors predisposing tumor development, and the recent evidence from cancer genomics identifying somatic changes that either complement or in some cases replace the contribution of the virus. Thereafter we look for possible connections between the pathogenesis of these apparently different malignancies and point to new research areas where insights may be gained.