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

Understanding EBV infection and EBV-associated lymphomas in children

The Epstein-Barr virus (EBV) infects over 90 % of the human population, often behaving as a harmless passenger in most hosts. However, since 1997, it has been classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC) due to its causal association with several malignancies. Most studies on EBV primary infection and EBV-associated lymphomas have been performed in adults from developed countries. The complex interplay between age of acquisition and symptomatic versus asymptomatic infection is related to the subsequent risk of EBV-associated cancers or autoimmune diseases. This review discusses some characteristics of EBV infection and EBV-associated lymphomas in children from low- and middle-income regions, with a focus on the local immune response.

Recent advances in CD5+ diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin's lymphoma (NHL), is substantially heterogeneous. Approximately 5-10% of DLBCLs express CD5, which makes CD5+ DLBCL a rare subgroup. Different studies have shown that CD5+ DLBCL patients are often older and female and have higher lactate dehydrogenase levels, an Eastern Cooperative Oncology Group (ECOG) performance status > 1, and higher International Prognostic Index (IPI) scores. Moreover, patients often have advanced stage disease with a high incidence of central nervous system (CNS) relapse and bone marrow involvement. CD5+ DLBCL cells are more likely to express MYC, BCL-2, and MUM-1, less likely to express CD10, and most belong to the activated B-cell-like (ABC) subtype. The potential mechanisms underlying the poor prognosis of CD5+ DLBCL patients may be related to CD5-mediated B-cell receptor (BCR)-dependent and -independent pathways. The efficacy of the traditional rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen is unsatisfactory in CD5+ DLBCL patients. Despite supporting evidence from retrospective studies, it is currently unclear whether dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin plus rituximab (DA-EPOCH-R) can improve outcomes in this population. Several new drugs, such as Bruton tyrosine kinase inhibitors (BTKi), BCL-2 inhibitors, and CXCR4 antagonists, as well as immunotherapy, may help to improve the prognosis of CD5+ DLBCL patients, but additional clinical explorations are needed to determine the optimal therapeutic strategy for this disease.

Tumor Biology Hides Novel Therapeutic Approaches to Diffuse Large B-Cell Lymphoma: A Narrative Review

Diffuse large B-cell lymphoma (DLBCL) is a malignancy of immense biological and clinical heterogeneity. Based on the transcriptomic or genomic approach, several different classification schemes have evolved over the years to subdivide DLBCL into clinically (prognostically) relevant subsets, but each leaves unclassified samples. Herein, we outline the DLBCL tumor biology behind the actual and potential drug targets and address the challenges and drawbacks coupled with their (potential) use. Therapeutic modalities are discussed, including small-molecule inhibitors, naked antibodies, antibody-drug conjugates, chimeric antigen receptors, bispecific antibodies and T-cell engagers, and immune checkpoint inhibitors. Candidate drugs explored in ongoing clinical trials are coupled with diverse toxicity issues and refractoriness to drugs. According to the literature on DLBCL, the promise for new therapeutic targets lies in epigenetic alterations, B-cell receptor and NF-κB pathways. Herein, we present putative targets hiding in lipid pathways, ferroptosis, and the gut microbiome that could be used in addition to immuno-chemotherapy to improve the general health status of DLBCL patients, thus increasing the chance of being cured. It may be time to devote more effort to exploring DLBCL metabolism to discover novel druggable targets. We also performed a bibliometric and knowledge-map analysis of the literature on DLBCL published from 2014-2023.

Enhanced prognostic evaluation of diffuse large B-cell lymphoma: A comprehensive surveillance study incorporating Epstein-Barr virus infection status and immunohistochemical markers

Emerging biologic subsets and new prognostic markers are significantly important for aggressive diffuse large B-cell lymphoma (DLBCL). Nevertheless, the high cost of testing limits the availability of these tests in most hospitals, thus making prognostic judgment based on basic immunohistochemical testing, whole blood Epstein-Barr virus DNA (WBEBV) surveillance and clinical features advantageous for hospitals and patients with poor medical conditions. We included 647 DLBCL patients treated in our hospital from January 2009 to March 2023. Non-germinal center B-cell like, Ki-67, and International Prognostic Index (IPI) scores were related to cMYC/B-cell lymphoma 2 (Bcl-2)-double expression. Age, Epstein-Barr virus-encoded small RNA (EBER) positivity, and IPI scores were associated with mortality. The cutoffs for differential overall survival (OS) of age, WBEBV, Bcl-2, and cMYC were 57 years, 1514 copies/mL (baseline), 5.89 × 104 copies/mL (treatment), 40%, and 55%, respectively. EBER positivity was significantly associated with a worse OS. Patients with newly defined DE (Bcl-2 ≥ 40 and cMYC > 55) had a worse prognosis than controls (p = 0.04). We found that cMYC with an optimal cutoff of 47.5 could effectively predict high-grade DLBCL with an area under the curve of 0.912, and the specificity and sensitivity were 70.7% and 100%, respectively. Our study provides valuable insights into the prognostic factors and biomarker cutoffs that influence OS in DLBCL patients, which may guide clinicians in tailoring treatment strategies and improving patient outcomes.

Epstein-Barr virus-related lymphoproliferative disorders of the skin

Epstein Barr Virus (EBV) is associated both solid (nasopharyngeal carcinoma, non-nasopharyngeal lymphoepithelioma-like carcinoma, gastric carcinoma, leiomyosarcoma) and hematolymphoid malignancies, some of the latter, however, spanning over a spectrum ranging from reactive and self-limiting to severe and life-threatening conditions. This review will focus on the disorder most commonly involving the skin, namely: EBV-positive mucocutaneous ulcer; lymphomatoid granulomatosis; EBV-positive diffuse large B cell lymphoma; plasmablastic lymphoma; post-transplant lymphoproliferative disorder; extranodal NK/T cell lymphoma, nasal type; angoimmunoblastic T cell lymphoma; severe mosquito bite allergy; hydroa vacciniformelike lymphoproliferative disorder. Given the uncommon occurrence of all these infiltrates in the skin, multidisciplinary approach, as well as referral to tertiary care centers are always advisable.

A Mouse Model to Study the Pathogenesis of γ-herpesviral Infections in Germinal Center B Cells

CD30-positive germinal center (GC)-derived B cell lymphomas are frequently linked to Epstein-Barr Virus (EBV) infection. However, a suitable animal model for the investigation of the interplay between γ-herpesvirus and host cells in B cell pathogenesis is currently lacking. Here, we present a novel in vivo model enabling the analysis of genetically modified viruses in combination with genetically modified GC B cells. As a murine γ-herpesvirus, we used MHV-68 closely mirroring the biology of EBV. Our key finding was that Cre-mediated recombination can be successfully induced by an MHV-68 infection in GC B cells from Cγ1-Cre mice allowing for deletion or activation of loxP-flanked cellular genes. The implementation of PrimeFlow RNA assay for MHV-68 demonstrated the enrichment of MHV-68 in GC and isotype-switched B cells. As illustrations of virus and cellular modifications, we inserted the EBV gene LMP2A into the MHV-68 genome and induced constitutively active CD30-signaling in GC B cells through MHV-68 infections, respectively. While the LMP2A-expressing MHV-68 behaved similarly to wildtype MHV-68, virally induced constitutively active CD30-signaling in GC B cells led to the expansion of a pre-plasmablastic population. The findings underscore the potential of our novel tools to address crucial questions about the interaction between herpesviral infections and deregulated cellular gene-expression in future studies.

Non-Response of Epstein-Barr Virus-Associated Breast Cancer after Primary Chemotherapy: Report of Two Cases

Based on epidemiological evidence and molecular findings, a possible association of Epstein-Barr virus (EBV) with the carcinogenesis of breast cancer has been described. However, the frequency of EBV in breast cancer and the role of EBV regarding tumor progression or therapeutic results is largely unexplored. Here, we report on two cases of advanced, lymph node-positive invasive breast cancer of no special type (NST), histologically showing no clinical or histological evidence of tumor regression as an equivalent of a lack of response to primary systemic therapy. Both tumors were considered to be EBV-associated due to their positivity in EBV-encoded RNA (EBER) in situ hybridization (ISH) and their immunoreactivity against EBV Epstein-Barr nuclear antigen 1 (EBNA1). We hypothesize that the unusual non-response to chemotherapy in these cases of breast cancer classified as triple-negative and HER2-positive may be linked to the EBV co-infection of tumor cells. Therefore, EBV tumor testing should be considered in patients with breast cancer presenting with resistance to chemotherapy. This hypothesis may provide a new aspect in the context of EBV-associated mechanisms of tumor progression.