EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2022 update on diagnosis, risk-stratification, and management

EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2024 update on the diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Epstein Barr virus-positive (EBV+) diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) is an aggressive B-cell lymphoma associated with EBV infection included in the WHO classification of lymphoid neoplasms since 2016. Although historically associated to poor prognosis, outcomes seem to have improved in the era of chemoimmunotherapy.

DIAGNOSIS

The diagnosis is established through meticulous pathological evaluation. Detection of EBV-encoded RNA (EBER) is the standard diagnostic method. The ICC 2022 specifies EBV+ DLBCL, NOS as occurring when >80% of malignant cells express EBER, whereas the WHO-HAEM5 emphasizes that the majority of tumor cells should be EBER positive without setting a defined threshold. The differential diagnosis includes plasmablastic lymphoma, DLBCL associated with chronic inflammation, primary effusion lymphoma, among others.

RISK-STRATIFICATION

The International Prognostic Index (IPI) and the Oyama score can be used for risk-stratification. The Oyama score includes age >70 years and presence of B symptoms. The expression of CD30 and PD-1/PD-L1 are emerging as potential adverse but targetable biomarkers.

MANAGEMENT

Patients with EBV+ DLBCL, NOS, should be staged and managed following similar guidelines than patients with EBV-negative DLBCL. EBV+ DLBCL, NOS, however, might have a worse prognosis than EBV-negative DLBCL in the era of chemoimmunotherapy. Therefore, inclusion of patients in clinical trials when available is recommended. There is an opportunity to study and develop targeted therapy in the management of patients with EBV+ DLBCL, NOS.

Treatment of Epstein-Barr Virus infection in immunocompromised patients

Epstein-Barr Virus (EBV), is a ubiquitous γ-Herpesvirus that infects over 95% of the human population and can establish a life-long infection without causing any clinical symptoms in healthy individuals by residing in memory B-cells. Primary infection occurs in childhood and is mostly asymptomatic, however in some young adults it can result in infectious mononucleosis (IM). In immunocompromised individuals however, EBV infection has been associated with many different malignancies. Since EBV can infect both epithelial and B-cells and very rarely NK cells and T-cells, it is associated with both epithelial cancers like nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC), with lymphomas including Burkitt Lymphoma (BL) or Post-transplant Lymphoproliferative Disorder (PTLD) and rarely with NK/T-cell lymphomas. Currently there are no approved antivirals active in PTLD nor in any other malignancy. Moreover, lytic phase disease almost never requires antiviral treatment. Although many novel therapies against EBV have been described, the management and/or prevention of EBV primary infections or reactivations remains difficult. In this review, we discuss EBV infection, therapies targeting EBV in both lytic and latent state with novel therapeutics developed that show anti-EBV activity as well as EBV-associated malignancies both, epithelial and lymphoproliferative malignancies and emerging therapies targeting the EBV-infected cells.

Update: The molecular spectrum of virus-associated high-grade B-cell non-Hodgkin lymphomas

The vast spectrum of aggressive B-cell non-Hodgkin neoplasms (B-NHL) encompasses several infrequent entities occurring in association with viral infections, posing diagnostic challenges for practitioners. In the emerging era of precision oncology, the molecular characterization of malignancies has acquired paramount significance. The pathophysiological comprehension of specific entities and the identification of targeted therapeutic options have seen rapid development. However, owing to their rarity, not all entities have undergone exhaustive molecular characterization. Considerable heterogeneity exists in the extant body of work, both in terms of employed methodologies and the scale of cases studied. Presently, therapeutic strategies are predominantly derived from observations in diffuse large B-cell lymphoma (DLBCL), the most prevalent subset of aggressive B-NHL. Ongoing investigations into the molecular profiles of these uncommon virus-associated entities are progressively facilitating a clearer distinction from DLBCL, ultimately paving the way towards individualized therapeutic approaches. This review consolidates the current molecular insights into aggressive and virus-associated B-NHL, taking into consideration the recently updated 5th edition of the WHO classification of hematolymphoid tumors (WHO-5HAEM) and the International Consensus Classification (ICC). Additionally, potential therapeutically targetable susceptibilities are highlighted, offering a comprehensive overview of the present scientific landscape in the field.

Expression and prognostic significance of the PD-1/PD-L1 pathway in AIDS-related non-Hodgkin lymphoma

OBJECTIVE

Immune tolerance and evasion play a critical role in virus-driven malignancies. However, the phenotype and clinical significance of programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, in aggressive acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) remain poorly understood, particularly in the Epstein-Barr virus (EBV)-positive subset.

METHODS

We used in situ hybridization with EBV-encoded RNA (EBER) to assess the EBV status. We performed immunohistochemistry and flow cytometry analysis to evaluate components of the PD-1/PD-L1/L2 pathway in a multi-institutional cohort of 58 patients with AR-NHL and compared EBV-positive and EBV-negative cases.

RESULTS

The prevalence of EBV+ in AR-NHL was 56.9% and was associated with a marked increase in the expression of PD-1/PD-L1/PD-L2 in malignant cells. Patients with AR-NHLs who tested positive for both EBER and PD-1 exhibited lower survival rates compared to those negative for these markers (47.4% vs. 93.8%, p = 0.004). Similarly, patients positive for both EBER and PD-L1 also demonstrated poorer survival (56.5% vs. 93.8%, p = 0.043). Importantly, PD-1 tissue-expression demonstrated independent prognostic significance for overall survival in multivariate analysis and was correlated to elevated levels of LDH (r = 0.313, p = 0.031), increased PD-1+ Tregs (p = 0.006), and robust expression of EBER (r = 0.541, p < 0.001) and PD-L1 (r = 0.354, p = 0.014) expression.

CONCLUSIONS

These data emphasize the importance of PD-1-mediated immune evasion in the complex landscape of immune oncology in AR-NHL co-infected with EBV, and contribute to the diagnostic classification and possible definition of immunotherapeutic strategies for this unique subgroup.

Frequent expression of PD-L1 in BLS-type diffuse large B-cell lymphoma: implications for aggressiveness and immunotherapy

BLS-type diffuse large B-cell lymphoma (DLBCL) denotes an uncommon, aggressive variant of DLBCL presenting initially in bone marrow, liver and spleen without lymphadenopathy or mass lesion. Patients with BLS-type DLBCL present frequently with haemophagocytic syndrome which often leads to early patient demise. Programmed death ligand 1 (PD-L1) plays a negative regulatory role on effector T cells and is an important target of immunotherapy. Assessment of PD-L1 expression in BLS-type DLBCL may carry therapeutic implications and provide mechanistic insights. Standard immunohistochemical analysis for PD-L1 was performed in seven cohorts for this study: (1) DLBCL-not otherwise specified (NOS) (n=201); (2) Epstein-Barr virus (EBV)-positive DLBCL (n=26); (3) thymic (primary mediastinal) DLBCL (n=12); (4) intravascular LBCL (n=3); (5) high-grade B-cell lymphoma, NOS (n=12); (6) BLS-type DLBCL (n=37); and (7) systemic DLBCL involving bone marrow (n=28). We found that PD-L1 was positive in 12.9% of DLBCL-NOS cases, 46.2% of EBV-positive DLBCL, 91.7% of thymic LBCL, none of intravascular LBCL, 8.3% of high-grade B-cell lymphoma-NOS, and 56.8% of BLS-type DLBCL. By comparison, only 14.3% of bone marrow cases involved by systemic DLBCL were positive for PD-L1 (p<0.001). Interestingly, BLS-type DLBCL more frequently showed activated B-cell phenotype (86.5% vs 65.2%, p=0.010), a high Ki-67 proliferative index (97.1% vs 63.3%, p<0.001), MYC overexpression (90.9% vs 56.2%, p=0.023), presence of haemophagocytic syndrome (86.5% vs 4.0%, p<0.001), and poorer overall survival (p<0.001) than DLBCL-NOS. These data suggest that the poor prognosis of BLS-type DLBCL may be explained by both extrinsic tumour microenvironment factors and intrinsic genetic factors of tumour cells, such as PD-L1-associated inactivation of anti-tumour immunity for the former, and MYC pathway activation-related aggressiveness for the latter.

Immune deficiency/dysregulation -associated lymphoproliferative disorders. Revised classification and management

Significant advances in the field of lymphoma have resulted in two recent classification proposals, the International Consensus Classification (ICC) and the 5th edition WHO. A few entities are categorized differently in the ICC compared to the WHO. Nowhere is this more apparent than the immunodeficiency lymphoproliferative disorders. The three previous versions of the WHO classification (3rd, 4th and revised 4th editions) and the ICC focused on four clinical settings in which these lesions arise for primary categorization. In contrast the 2023 WHO 5th edition includes pathologic characteristics including morphology and viral status, in addition to clinical setting, as important information for lesion classification. In addition, the 2023 WHO recognizes a broader number of clinical scenarios in which these lesions arise, including not only traditional types of immune deficiency but also immune dysregulation. With this classification it is hoped that new treatment strategies will be developed leading to better patient outcomes.

Multi-modal features-based human-herpesvirus protein-protein interaction prediction by using LightGBM

The identification of human-herpesvirus protein-protein interactions (PPIs) is an essential and important entry point to understand the mechanisms of viral infection, especially in malignant tumor patients with common herpesvirus infection. While natural language processing (NLP)-based embedding techniques have emerged as powerful approaches, the application of multi-modal embedding feature fusion to predict human-herpesvirus PPIs is still limited. Here, we established a multi-modal embedding feature fusion-based LightGBM method to predict human-herpesvirus PPIs. In particular, we applied document and graph embedding approaches to represent sequence, network and function modal features of human and herpesviral proteins. Training our LightGBM models through our compiled non-rigorous and rigorous benchmarking datasets, we obtained significantly better performance compared to individual-modal features. Furthermore, our model outperformed traditional feature encodings-based machine learning methods and state-of-the-art deep learning-based methods using various benchmarking datasets. In a transfer learning step, we show that our model that was trained on human-herpesvirus PPI dataset without cytomegalovirus data can reliably predict human-cytomegalovirus PPIs, indicating that our method can comprehensively capture multi-modal fusion features of protein interactions across various herpesvirus subtypes. The implementation of our method is available at https://github.com/XiaodiYangpku/MultimodalPPI/.

Mcl-1 Protein and Viral Infections: A Narrative Review

MCL-1 is the prosurvival member of the Bcl-2 family. It prevents the induction of mitochondria-dependent apoptosis. The molecular mechanisms dictating the host cell viability gain importance in the context of viral infections. The premature apoptosis of infected cells could interrupt the pathogen replication cycle. On the other hand, cell death following the effective assembly of progeny particles may facilitate virus dissemination. Thus, various viruses can interfere with the apoptosis regulation network to their advantage. Research has shown that viral infections affect the intracellular amount of MCL-1 to modify the apoptotic potential of infected cells, fitting it to the "schedule" of the replication cycle. A growing body of evidence suggests that the virus-dependent deregulation of the MCL-1 level may contribute to several virus-driven diseases. In this work, we have described the role of MCL-1 in infections caused by various viruses. We have also presented a list of promising antiviral agents targeting the MCL-1 protein. The discussed results indicate targeted interventions addressing anti-apoptotic MCL1 as a new therapeutic strategy for cancers as well as other diseases. The investigation of the cellular and molecular mechanisms involved in viral infections engaging MCL1 may contribute to a better understanding of the regulation of cell death and survival balance.

The biology and treatment of Epstein-Barr virus-positive diffuse large B cell lymphoma, NOS

EBV positive Diffuse Large B-cell lymphoma, not otherwise specified (EBV+DLBCL-NOS) referred to DLBCL with expression of EBV encoded RNA in tumor nucleus. EBV+DLBCL-NOS patients present with more advanced clinical stages and frequent extranodal involvement. Although rituximab-containing immunochemotherapy regimens can significantly improve outcomes in patients with EBV+DLBCL, the best first-line treatment needs to be further explored. Due to the relatively low incidence and regional variation of EBV+DLBCL-NOS, knowledge about this particular subtype of lymphoma remains limited. Some signaling pathways was abnormally activated in EBV+DLBCL-NOS, including NF-κB and JAK/STAT pathways) and other signal transduction pathways. In addition, immune processes such as interferon response, antigen-presenting system and immune checkpoint molecule abnormalities were also observed. Currently, chimeric antigen receptor T-cell (CAR-T) therapy, chemotherapy combined with immunotherapy and novel targeted therapeutic drugs are expected to improve the prognosis of EBV+DLBCL-NOS patients, but more studies are needed to confirm this.

Non-neoplastic B-cell predominant lymphoid proliferations at the organs exposed to external environment mimicking lymphoma: A potential diagnostic pitfall

Background: Typically, lymphatic tissue proliferative lesions include either benign lesions or lymphoma. However, not all lymphatic lesions can currently be accurately classified into one category, particularly in mucosal areas that are in contact with the external environment.Aims: To explore the morphology, immunophenotype, and molecular changes of Non-neoplastic B-cell predominant lymphoid proliferations (NBPLP) in pathological areas that are exposed to external surroundings which mimicked lymphoma.Methods and Results: 18 cases of Atypical lymphoid hyperplasia (AtLP)  were retrieved in this study. The biopsy samples were mucosal samples obtained from areas exposed to external surroundings, including intestines, urethra, cervix, tonsils, and tongue. Microscopically, there is a different level of B cell hyperplasia accompanied by morphological atypia. We categorized the morphology into 4 groups: type A (7/18), type B (3/18), type C (3/18), type D (5/18). Part of the AtLP was found positive for BCR gene rearrangement (6/15), and TCR gene rearrangement (1/4). The follow-up period ranged from 14.2 to 70 months. No evidence of lymphoma was found. Therefore, we diagnosed all of the presented cases as NBPLP. We illustrated the key differential points and provided valuable diagnostic experience on each subtype.Conclusions: Areas exposed to the external environment are commonly exposed to antigen and easily present with AtLP of NBPLP, accompanying with positive IGH rearrangement. Therefore, a comprehensive evaluation of macroscopic, morphology, immunophenotype, and molecular diagnostics is required to prevent the overdiagnosis of lymphoma.

Primary hepatic lymphoma a case report and literature review

RATIONALE

Primary hepatic lymphoma is a rare extranodal non-Hodgkin lymphoma that is primarily localized in the liver. It predominantly affects elderly males and presents with nonspecific laboratory findings, imaging results, and clinical symptoms, making diagnosis challenging. Histopathological examination serves as the gold standard for diagnosis, and treatment options include chemotherapy or surgical intervention combined with chemotherapy.

PATIENT CONCERNS

A 50-year-old male patient came to our hospital for treatment after finding a mass in his liver.

DIAGNOSES

Laboratory tests and clinical symptoms lack specificity for primary hepatic lymphoma, and imaging findings can be difficult to differentiate. Pathology is the gold standard.

OUTCOMES

The patient was dead.

CONCLUSION

A definitive diagnosis primarily relies on histopathological examination, and surgical resection combined with chemotherapy yields better treatment outcomes.

Composite Lymphoma with Follicular Lymphoma Transformation to Clonally Related Epstein-Barr Virus (EBV) Positive Diffuse Large B-Cell Lymphoma and EBV-PositiveClassic Hodgkin Lymphoma

While the Epstein-Barr virus (EBV) is known to drive de novo lymphomagenesis, it may rarely contribute to transformation of indolent lymphoma as well. Some EBV-related lymphomas represent a diagnostic challenge with important prognostic and therapeutic implications. We describe a case of follicular lymphoma (FL) transformation to both EBV + diffuse large B-cell lymphoma (DLBCL) and EBV + classic Hodgkin lymphoma (cHL), the latter of which was only identified retrospectively after selective outgrowth during DLBCL therapy. Finally, we describe successful salvage therapy with brentuximab vedotin plus nivolumab. This is the first known case of composite lymphoma with FL, EBV + DLBCL, and EBV + cHL within a single lymph node. The disease course highlights the importance of careful morphologic examination and comprehensive immunophenotypic characterization of EBV + lymphomas to ensure proper clinical care and underscores the potential for novel therapies currently under investigation. This trial is registered with NCT01671813.

Beta2-microglobulin is a valuable marker and identifies a poor-prognosis subgroup among intermediate-risk patients with diffuse large B cell lymphoma

Prognosis of diffuse large B cell lymphoma (DLBCL) can be predicted by various factors. The most widely used tool for prediction is the international prognostic index (IPI). β2-microglobulin is a tumor marker commonly used in hematological malignancies. β2-microglobulin is well correlated with outcome of DLBCL. It has been used as an adjunctive tool in some scoring systems for prognostication of DLBCL. In this study, we collected data of patients with diagnosis of DLBCL between 2015 and 2019 in our institute. For each patient, IPI was calculated according to published literature. At diagnosis, serum levels of β2-microglobulin were measured in the clinical laboratory and the results were retrieved from medical records. A total of 516 patients (269 male and 247 female) were enrolled for retrospective analysis. The median age was 64 (range 22-96). The median follow-up period was 32.2 months. The median level of β2-microglobulin was 2319 μg/L (normal range < 2366 μg/L in the clinical laboratory). Level of β2-microglobulin was significantly different between survivors and patients who succumbed to the disease. β2-microglobulin level was correlated with tumor stage, extranodal involvement, B symptoms and IPI, suggesting that it may be a good surrogate marker for disease severity and outcome prediction. We selected the intermediate-risk patients for further analysis. Patients with intermediate-risk IPI and high β2-microglobulin levels have overall survival comparable to patients with high-risk IPI, suggesting an important role of β2-microglobulin in subdivision of DLBCL patients. In conclusion, β2-microglobulin levels correlated with outcome of DLBCL. It may be used independently as a prognostic factor. Subdivision of patients with intermediate-risk IPI may identify a group of high-risk patients, which can be helpful in refining plans of treatment and follow-up.

Targeted therapy with nanatinostat and valganciclovir in recurrent EBV-positive lymphoid malignancies: a phase 1b/2 study

Lymphomas are not infrequently associated with the Epstein-Barr virus (EBV), and EBV positivity is linked to worse outcomes in several subtypes. Nanatinostat is a class-I selective oral histone deacetylase inhibitor that induces the expression of lytic EBV BGLF4 protein kinase in EBV+ tumor cells, activating ganciclovir via phosphorylation, resulting in tumor cell apoptosis. This phase 1b/2 study investigated the combination of nanatinostat with valganciclovir in patients aged ≥18 years with EBV+ lymphomas relapsed/refractory to ≥1 prior systemic therapy with no viable curative treatment options. In the phase 1b part, 25 patients were enrolled into 5 dose escalation cohorts to determine the recommended phase 2 dose (RP2D) for phase 2 expansion. Phase 2 patients (n = 30) received RP2D (nanatinostat 20 mg daily, 4 days per week with valganciclovir 900 mg orally daily) for 28-day cycles. The primary end points were safety, RP2D determination (phase 1b), and overall response rate (ORR; phase 2). Overall, 55 patients were enrolled (B-non-Hodgkin lymphoma [B-NHL], [n = 10]; angioimmunoblastic T-cell lymphoma-NHL, [n = 21]; classical Hodgkin lymphoma, [n = 11]; and immunodeficiency-associated lymphoproliferative disorders, [n = 13]). The ORR was 40% in 43 evaluable patients (complete response rate [CRR], 19% [n = 8]) with a median duration of response of 10.4 months. For angioimmunoblastic T-cell lymphoma-NHL (n = 15; all refractory to the last prior therapy), the ORR/CRR ratio was 60%/27%. The most common adverse events were nausea (38% any grade) and cytopenia (grade 3/4 neutropenia [29%], thrombocytopenia [20%], and anemia [20%]). This novel oral regimen provided encouraging efficacy across several EBV+ lymphoma subtypes and warrants further evaluation; a confirmatory phase 2 study (NCT05011058) is underway. This phase 1b/2 study is registered at www.clinicaltrials.gov as #NCT03397706.

Could Immune Checkpoint Disorders and EBV Reactivation Be Connected in the Development of Hematological Malignancies in Immunodeficient Patients?

Primary immunodeficiencies (PIDs) and secondary immunodeficiencies (SIDs) are characterized by compromised immune function, rendering individuals susceptible to infections and potentially influencing cancer development. Epstein-Barr virus (EBV), a widespread herpesvirus, has been linked to cancer, particularly in those with weakened immune systems. This study aims to compare selected immune parameters, focusing on immune checkpoint molecules (PD-1/PD-L1, CTLA-4/CD86, CD200R/CD200), and EBV reactivation in patients with chronic lymphocytic leukemia (CLL, a representative of SIDs) and common variable immunodeficiency (CVID, a representative of PIDs). We performed a correlation analysis involving patients diagnosed with CLL, CVID, and a healthy control group. EBV reactivation was assessed using specific antibody serology and viral load quantification. Peripheral blood morphology, biochemistry, and immunophenotyping were performed, with emphasis on T and B lymphocytes expressing immune checkpoints and their serum concentrations. Our findings revealed elevated EBV reactivation markers in both CLL and CVID patients compared with healthy controls, indicating increased viral activity in immunodeficient individuals. Furthermore, immune checkpoint expression analysis demonstrated significantly altered percentages of T and B lymphocytes expressing PD-1/PD-L1, CTLA-4/CD86, and CD200R/CD200 in CLL and CVID patients. This suggests a potential interplay between immune checkpoint dysregulation and EBV reactivation in the context of immunodeficiency. In conclusion, our study underscores the intricate relationship between immune dysfunction, EBV reactivation, and immune checkpoint modulation in the context of immunodeficiency-associated cancers. The altered expression of immune checkpoints, along with heightened EBV reactivation, suggests a potential mechanism for immune evasion and tumor progression. These findings provide insights into the complex interactions that contribute to cancer development in immunocompromised individuals, shedding light on potential therapeutic targets for improved management and treatment outcomes. Further investigations are warranted to elucidate the underlying mechanisms and to explore potential interventions to mitigate cancer risk in these patient populations.

Dynamic changes in circulating EBV-DNA load during treatment have prognostic values in EBV+ DLBCL-NOS: a Chinese cohort study

EBV-positive diffuse large B-cell lymphoma, not otherwise specified (EBV+ DLBCL-NOS), is an EBV-positive clonal B-cell lymphoid proliferation and circulating EBV-DNA is a great indicator for prognosis among EBV associated disease. In this retrospective study, we report 66 EBV+ DLBCL cases among 2137 DLBCL-NOS cases diagnosed from 2013 to 2021 (prevalence of 6.0%). After a median follow-up of 27 months, progression-free survival (PFS) and overall survival (OS) at 2 years were 39.5% ± 6.2% and 53.6% ± 6.4%, respectively. Multivariate analysis showed that only the biomarker of the positivity of post treatment EBV-DNA had a borderline correlation with shorter PFS and OS (PFS: P = 0.053; OS: P = 0.065). Patients were divided into three subgroups according to dynamic changes of EBV-DNA status: EBV-DNA persistently negative group, EBV-DNA persistently positive group, and EBV-DNA transformed from positive to negative group; among the three groups, patients of the persistently positive group had worst PFS and OS (P = 0.0527 and P = 0.0139, respectively). Decline in EBV copies correlated significantly with treatment response as well. In conclusion, circulating EBV-DNA level played a vital role in prognostic and monitoring marker for EBV+ DLBCL-NOS.

Diffuse large B-cell lymphoma in large intestine presenting as multiple polypoid lesions

A solitary large ulcerated mass is the common morphological feature of diffuse large B-cell lymphoma (DLBCL) in the large intestine under endoscopy. Here we report a 54-year-old man with DLBCL presenting with multiple polypoid lesions in the large intestine, which is an uncommon morphological form of DLBCL.

Epstein‒Barr virus-associated cellular immunotherapy

Epstein‒Barr virus (EBV) is a human herpes virus that is saliva-transmissible and universally asymptomatic. It has been confirmed that more than 90% of the population is latently infected with EBV for life. EBV can cause a variety of related cancers, such as nasopharyngeal carcinoma, diffuse large B-cell lymphoma, and Burkitt lymphoma. Currently, many clinical studies have demonstrated that EBV-specific cytotoxic T lymphocytes and other cell therapies can be safely and effectively transfused to prevent and treat some diseases caused by EBV. This review will mainly focus on discussing EBV-specific cytotoxic T lymphocytes and will touch on therapeutic EBV vaccines and chimeric antigen receptor T-cell therapy briefly.

EBV and Lymphomagenesis

The clinical significance of Epstein–Barr virus (EBV) cannot be understated. Not only does it infect approximately 90% of the world’s population, but it is also associated with numerous pathologies. Diseases linked to this virus include hematologic malignancies such as diffuse large B-cell lymphoma, Hodgkin lymphoma, Burkitt lymphoma, primary CNS lymphoma, and NK/T-cell lymphoma, epithelial malignancies such as nasopharyngeal carcinoma and gastric cancer, autoimmune diseases such as multiple sclerosis, Graves’ disease, and lupus. While treatment for these disease states is ever evolving, much work remains to more fully elucidate the relationship between EBV, its associated disease states, and their treatments. This paper begins with an overview of EBV latency and latency-associated proteins. It will then review EBV’s contributions to select hematologic malignancies with a focus on the contribution of latent proteins as well as their associated management.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

Epstein-Barr Virus History and Pathogenesis

Epstein-Barr virus (EBV) is the first identified human oncogenic virus that can establish asymptomatic life-long persistence. It is associated with a large spectrum of diseases, including benign diseases, a number of lymphoid malignancies, and epithelial cancers. EBV can also transform quiescent B lymphocytes into lymphoblastoid cell lines (LCLs) in vitro. Although EBV molecular biology and EBV-related diseases have been continuously investigated for nearly 60 years, the mechanism of viral-mediated transformation, as well as the precise role of EBV in promoting these diseases, remain a major challenge yet to be completely explored. This review will highlight the history of EBV and current advances in EBV-associated diseases, focusing on how this virus provides a paradigm for exploiting the many insights identified through interplay between EBV and its host during oncogenesis, and other related non-malignant disorders.

Virological Markers in Epstein–Barr Virus-Associated Diseases

Epstein–Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world’s population. After primary infection—responsible for infectious mononucleosis in young adults—the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma. Recent reports also suggest a link between EBV infection and multiple sclerosis. In the absence of vaccines, research efforts have focused on virological markers applicable in clinical practice for the management of patients with EBV-associated diseases. Nasopharyngeal carcinoma is an EBV-associated malignancy for which serological and molecular markers are widely used in clinical practice. Measuring blood EBV DNA load is additionally, useful for preventing lymphoproliferative disorders in transplant patients, with this marker also being explored in various other EBV-associated lymphomas. New technologies based on next-generation sequencing offer the opportunity to explore other biomarkers such as the EBV DNA methylome, strain diversity, or viral miRNA. Here, we review the clinical utility of different virological markers in EBV-associated diseases. Indeed, evaluating existing or new markers in EBV-associated malignancies or immune-mediated inflammatory diseases triggered by EBV infection continues to be a challenge.

Epstein-Barr Virus and the Pathogenesis of Diffuse Large B-Cell Lymphoma

Epstein-Barr virus (EBV), defined as a group I carcinogen by the World Health Organization (WHO), is present in the tumour cells of patients with different forms of B-cell lymphoma, including Burkitt lymphoma, Hodgkin lymphoma, post-transplant lymphoproliferative disorders, and, most recently, diffuse large B-cell lymphoma (DLBCL). Understanding how EBV contributes to the development of these different types of B-cell lymphoma has not only provided fundamental insights into the underlying mechanisms of viral oncogenesis, but has also highlighted potential new therapeutic opportunities. In this review, we describe the effects of EBV infection in normal B-cells and we address the germinal centre model of infection and how this can lead to lymphoma in some instances. We then explore the recent reclassification of EBV+ DLBCL as an established entity in the WHO fifth edition and ICC 2022 classifications, emphasising the unique nature of this entity. To that end, we also explore the unique genetic background of this entity and briefly discuss the potential role of the tumour microenvironment in lymphomagenesis and disease progression. Despite the recent progress in elucidating the mechanisms of this malignancy, much work remains to be done to improve patient stratification, treatment strategies, and outcomes.

EBV dUTPase: A Novel Modulator of Inflammation and the Tumor Microenvironment in EBV-Associated Malignancies

There is increasing evidence that put into question the classical dogma that the Epstein-Barr virus (EBV) exists in cells as either a lytic virus in which new progeny is produced or in a latent state in which no progeny is produced. Notably, a third state has now been described, known as the abortive-lytic phase, which is characterized by the expression of some immediate early (IE) and early (E) genes, but no new virus progeny is produced. While the function of these IE and E gene products is not well understood, several recent studies support the concept they may contribute to tumor promotion by altering the tumor microenvironment (TME). The mechanisms by which these viral gene products may contribute to tumorigenesis remain unclear; however, it has been proposed that some of them promote cellular growth, immune evasion, and/or inhibit apoptosis. One of these EBV early gene products is the deoxyuridine triphosphate nucleotidohydrolase (dUTPase) encoded by BLLF3, which not only contributes to the establishment of latency through the production of activin A and IL-21, but it may also alter the TME, thus promoting oncogenesis.

Epstein-Barr virus: Biology and clinical disease

Epstein-Barr virus (EBV) is a ubiquitous, oncogenic virus that is associated with a number of different human malignancies as well as autoimmune disorders. The expression of EBV viral proteins and non-coding RNAs contribute to EBV-mediated disease pathologies. The virus establishes life-long latency in the human host and is adept at evading host innate and adaptive immune responses. In this review, we discuss the life cycle of EBV, the various functions of EBV-encoded proteins and RNAs, the ability of the virus to activate and evade immune responses, as well as the neoplastic and autoimmune diseases that are associated with EBV infection in the human population.