Exploring the Roles of EBV and HIV in the Development of Head and Neck Lymphomas

1. Introduction

Human viruses were discovered at the beginning of the 20th century. Certain types of viruses are known to be oncogenic or tumor-causing viruses [1].

Viruses can weaken the host immune system. In addition to the inherent ability of some viruses to drive carcinogenesis, immunosuppression itself is a risk factor for cancer [2]. Additionally, researchers have observed that immunosuppression makes patients more susceptible to infections from other tumor-causing viruses [3].

Epstein-Barr virus (EBV) commonly causes infectious mononucleosis, especially in teenagers and young adults. Key symptoms include fatigue, fever, sore throat, swollen lymph nodes, and an enlarged spleen. However, EBV also acts as a carcinogenic virus, primarily affecting the head and neck regions and contributing to 1% of all cancers [4]. Researchers first isolated EBV from Burkitt lymphoma (BL) in 1964, thanks to the work of Epstein and Barr [5]. Emphasizing the significance of implementing routine screening protocols specifically designed for detecting lymphoma in patients with EBV infection.

Monitoring EBV viral load in immunocompromised patients can be beneficial. Clinicians should remain vigilant for the signs and symptoms of lymphoma and evaluate patients accordingly if they present with concerning features[6,7,8].

This review will examine the roles of EBV and Human immunodeficiency virus (HIV) in the pathogenesis of lymphomas in the head and neck region, as well as their impact on prognosis and treatment outcomes.

2. Epstein-Barr

Epstein-Barr virus (EBV), formally known as human herpesvirus 4, infects more than 90% of adults worldwide [9]. It is typically transmitted through saliva but can also spread via semen during sexual contact, organ transplantation, and blood transfusion [10,11]. When infection occurs early in life, it may remain asymptomatic; however, primary infection later in life can present symptoms of infectious mononucleosis [10].

Infectious mononucleosis (IM) warrants consideration for surveillance due to its increased potential for carcinogenesis. A retrospective study assessed the risk of developing neoplasms in 25,582 patients with a history of mononucleosis infection, compared with a control group of the same size. During the follow-up period, newly diagnosed cases of lymphoma were significantly higher in the IM group than in the control group (P < 0.05), along with other types of cancers. Patients with IM exhibited a fivefold higher risk of developing lymphoma compared to healthy controls [12].

Hjalgrim et al. reported that lymphoma often develops within an average of four years after the onset of IM [13]. This timeframe can create the impression of rapid malignancy progression, influenced by several factors. The overlapping symptoms of infectious mononucleosis (IM) and lymphoma—such as fever, cervical lymphadenopathy, and tonsillar enlargement—can result in diagnostic confusion or short-term misdiagnoses. Persistent or worsening symptoms in IM patients often lead to further evaluation, including lymph node biopsies, which may uncover lymphoma [12].

These observations highlight the importance of closely monitoring IM infected patients, particularly those with unresolved or progressing symptoms. Early detection of potential malignancy is essential for timely diagnosis and treatment, ultimately improving patient outcomes.

2.1. Pathophysiology

EBV exhibits a strong tropism for oropharyngeal epithelial cells and B lymphocytes [10]. A remarkable feature of EBV is its ability to immortalize normal resting B lymphocytes in vitro, showcasing its potent transforming potential [14,15]. EBV exists in two types, Type 1 and Type 2. Type 1 is more prevalent worldwide and has a greater capacity for malignant transformation [16]. Entry into human B lymphocytes—the primary reservoir for EBV—is facilitated by the viral glycoprotein gp350/220 binding to the complement receptor 2 (CR2/CD21) and the interaction of the glycoprotein complex gH/gL/gp42 with HLA class II molecules [10,17,18].

After primary infection, EBV adopts one of two infection patterns: latent or lytic. The lytic infection pattern propagates the virus and promotes its spread [19,20], while latent infection allows EBV to persist in the host with minimal impact, effectively evading the immune system. During latency, EBV resides in the circulating B-cell pool of peripheral blood, minimizing viral production. The primary human host cells for EBV include lymphocytes, T lymphocytes, NK cells, epithelial cells, and myocytes [10].

Genetic predispositions, such as variations in specific HLA alleles, may significantly affect the likelihood of developing EBV-associated Hodgkin's lymphoma. Certain HLA class I alleles are linked to either an elevated or reduced risk of this condition, highlighting the pivotal role of the host immune response in its development. One study identified an increased risk associated with the HLA-A01 allele (odds ratio [OR] per allele: 2.15; 95% CI: 1.60–2.88), while the HLA-A02 allele was linked to a reduced risk (OR per allele: 0.70; 95% CI: 0.51–0.97). Notably, the observed connection between IM and Hodgkin's lymphoma risk was present in individuals carrying the HLA-A01 allele but not in those with the HLA-A*02 allele [21].

It is not yet clear how IM progresses to lymphoma, but one hypothesis suggests that alterations in immune function following IM weaken immune surveillance against malignant cells. This immune tolerance may diminish the body’s anti-tumor response [22]. Nevertheless, research has shown that even patients with normal or reduced immunity may still progress to lymphoma [23,24].

EBV antigens play crucial roles in promoting cellular growth and contributing to various mechanisms that favor malignancy. These include resistance to apoptosis, reduced responsiveness to differentiation signals, and enhanced cellular invasion [25,26]. The virus encodes six nuclear antigens—EBNA-1, EBNA-2, EBNA-3A, EBNA-3B, EBNA-3C, and EBNA-LP—as well as three latent membrane proteins: LMP-1, LMP-2A, and LMP-2B [22,27]. Each of these proteins performs distinct functions that are critical to EBV’s ability to drive lymphoma pathogenesis (Table 1).

The period following infection, but preceding cell division is referred to as the pre latent phase [28] (Figure 1 and Table 2). During this phase, as lytic mRNA levels decrease, EBNA2 and EBNA-LP accumulate, directly activating the major upstream EBV latency C promoter (Cp) between 48- and 72-hours post-infection [29]. Approximately 84 hours post-infection, non-coding RNAs and mRNAs associated with latency IIb are expressed. The initial four cell divisions after infection occur rapidly, with each cycle lasting 8–12 hours [30]. Cells that subsequently reduce their proliferation rate become immortalized [28].

Full latency III is marked by the expression of all EBNAs and LMPs and is typically observed in immunosuppressed conditions. Survival during latency III relies heavily on elevated NFκB activity, predominantly mediated by LMP1 [31,32]. However, during the initial two weeks following infection, LMP1-induced NFκB activity is low, raising the unresolved question of how these infected cells persist during this phase [28].

Latency IIa is observed in germinal center cells of healthy individuals and in EBV-positive Hodgkin lymphoma [33]. The mechanisms driving the transition to this state remain unclear, though cytokines such as IL-21 are believed to downregulate Cp and EBNA expression [34]. Cells expressing Latency IIa are also considered precursors of EBV-associated Hodgkin lymphomas [28].

The primary reservoir of EBV-infected B cells consists of resting memory cells [35]. In Latency 0, no viral proteins are expressed except during cell division (Latency I). This limited expression allows these cells to evade detection by T cells [28].

Molecular markers also play a crucial role in prognosis. For instance, p53 overexpression, a high Ki67 index, advanced disease stage, T-cell phenotype, and the presence of the del-LMP1 mutation are associated with poor outcomes [22]. These findings highlight the importance of integrating molecular and clinical markers into prognostic models to refine risk stratification and guide treatment decisions.

2.2. Hit and Run Theory

Epigenetic mechanisms, such as DNA methylation, histone modification, and chromatin conformation alterations, play a significant role in tumor development. Altered DNA methylation states are frequently observed in malignancies linked to EBV. Notably, tumor progression in these cases can occur even in the absence of the virus, indicating that EBV's influence on tumorigenesis does not rely on its continuous presence. This phenomenon is described as the “hit and run” mechanism [48,49].

The “hit and run” process begins when EBV infects a B lymphocyte, delivering the necessary instructions for the cell’s growth and survival, effectively making the cell oncogenic. This initial stage is termed the “hit.” Under normal circumstances, the immune system, when functioning effectively, identifies these infected B lymphocytes through the viral antigens displayed on their surfaces and eliminates them [49].

However, EBV has evolved strategies to evade immune detection by inducing epigenetic changes in the host lymphocytes. These changes silence the expression of viral antigens on the cell surface, marking the “run” phase of the mechanism. By doing so, EBV prevents immune recognition and eradication of the infected cells. These epigenetic modifications become heritable, enabling the oncogenic characteristics of the cells to persist even after the virus is no longer present in the host [49].

This "hit and run" mechanism highlights the intricate role of epigenetics in EBV-associated malignancies and provides a framework for understanding how viral infections can have lasting oncogenic effects.

3. HIV

HIV-infected individuals are at significantly higher risk of developing malignancies compared to the general population, with lymphoma being the second most frequent HIV-associated neoplasm [50]. This increased risk underscores the profound impact of HIV on immune function and its interaction with oncogenic viruses such as EBV [50,51]. Notably, plasmablastic lymphoma, a rare and aggressive subtype, nearly always occurs in HIV-positive patients [50]

Most lymphomas in HIV-infected patients are B-cell-derived, with immunoblastic large cell lymphomas and diffuse large B-cell lymphomas (DLBCL) being the most common non-Hodgkin lymphomas (NHLs). These lymphomas typically arise in the setting of moderate to severe immunodeficiency, particularly when CD4+ T-cell counts fall below 100 cells/mm³, and they are often associated with EBV [50,51]. The risk of developing NHL in HIV-infected individuals is starkly elevated, with a 1000-fold increase for Burkitt lymphoma [52,53] and a 400-fold increase for other aggressive lymphoma [54] compared to the general population [52,53].

Persistent immune activation and inflammation play a crucial role in the development of HIV-associated lymphomas. HIV infection triggers ongoing immune activation, partially driven by microbial translocation. This process results in sustained B-cell activation, which can lead to DNA alterations, including oncogene mutations and chromosomal translocations [55]. Such chronic stimulation also disrupts the normal functioning of the B-cell receptor (BCR) signaling pathway, thereby facilitating the progression of lymphoma [56].

In addition to its role in immune suppression, HIV may exert direct oncogenic effects. Certain HIV proteins, such as specific variants of the p17 protein, have demonstrated B-cell clonogenic activity, potentially contributing to lymphoma development [57]. Furthermore, the tumor microenvironment in HIV-associated lymphomas, marked by cytokine imbalances and the presence of reactive inflammatory cells, significantly supports the growth and progression of these malignancies [58].

In the head and neck region, sinonasal lymphoid neoplasms represent less than 1 % of all cancers [59,60], but extranodal lymphomas in general account for 25% of lymphomas in this area. Infectious agents, including EBV, HIV-1, and other pathogens such as Helicobacter pylori and Human T-cell lymphotropic virus-1 (HTLV-1) [54], are implicated in these malignancies. A retrospective study examining 243 cases of head and neck DLBCL revealed that Waldeyer’s ring was the most common site of origin, accounting for 63.7% of cases. The tonsils were most frequently involved (28.8%), followed by the oral cavity (16.04%), salivary glands (8.64%), and the nasal cavity (3.7%). Less frequently affected sites included the larynx/hypopharynx (2.05%) and the mandible (1.23%) [61].

HIV positivity significantly affected survival and increased the risk of death in patients with head and neck lymphomas [51], though no direct correlation was observed between HIV status and the anatomical distribution of tumors. Among these cases, nasopharyngeal and gingival lymphomas had the highest proportion of HIV-positive patients, with 20.8% and 40% positivity rates, respectively [61].

Antiretroviral therapy (ART) in addition to restoring immune function, which is crucial for preventing oncogenesis, has shown efficacy in reducing EBV viral loads. This provides the additional benefit of lowering the risk of EBV oral transmission [25,62]. However, despite ART, HIV-infected patients remain more susceptible to EBV-associated malignancies than the general population [63].

HIV-associated lymphomas are a prominent and aggressive complication of HIV infection, and they are often linked to EBV co-infection. The interaction between these pathogens amplifies the oncogenic potential, underscoring the critical need for effective HIV management and lymphoma surveillance in this vulnerable population.

4. Prevention

Given the significant role of EBV in the pathogenesis of various neoplasms, the concept of developing a vaccine against EBV has gained traction. One promising target for such a vaccine is the glycoprotein gp350/220. This protein is abundantly expressed on the plasma membranes of lytically infected cells and constitutes the predominant protein on the virus's outer coat. It plays a critical role in EBV's infection mechanism by binding to the CD21 receptor on B cells, initiating the infection process. Furthermore, the majority of human EBV-neutralizing antibodies are directed against gр350/220, making it an optimal candidate for a subunit vaccine. Research efforts are currently focused on this glycoprotein as the basis for potential immunization strategies [64,65].

In parallel, the principles of active surveillance programs employed for other oncogenic viruses, such as those targeting oncoviruses, could be extended to EBV-associated conditions. Such measures might include routine HIV screening, as well as ensuring efficient and widespread access to antiretroviral therapies. These efforts not only reduce HIV-associated immunosuppression but may also decrease EBV loads and mitigate its oncogenic potential.

5. Diagnostic Approach

Lymphoma presents with a variety of clinical manifestations that can differ based on the subtype and stage of the disease. For Hodgkin lymphoma, the most common presentation is painless lymphadenopathy, often in the cervical region. Systemic symptoms, known as B-symptoms, such as fever, night sweats, and unexplained weight loss, are also common and tend to occur in more advanced stages [66].The Lugano classification system is used for staging, which incorporates these symptoms and imaging findings to guide treatment decisions [67].

Non-Hodgkin lymphoma (NHL), which encompasses a variety of subtypes, can manifest in different ways. Typical presentations include enlargement of peripheral lymph nodes and involvement of extranodal sites, such as the gastrointestinal tract or skin. B-symptoms are also seen in NHL, especially in more aggressive forms [66]. In pediatric and adolescent cases, B-cell lymphomas frequently present with swollen lymph nodes in the neck or periphery, abdominal masses, and systemic symptoms like fever and weight loss [68]

Certain subtypes of NHL can exhibit distinct clinical presentations. For example, lymphomas associated with AIDS often involve systemic effects and may include primary central nervous system lymphoma or primary effusion lymphoma [69]. Follicular lymphoma, a frequently encountered indolent subtype of NHL, usually presents with enlarged lymph nodes and may be associated with constitutional symptoms or blood cell deficiencies [70]. Oral lymphomas, though rarer, may present as painful, ulcerative lesions that are frequently linked to bone destruction, especially in high-grade subtypes [71].

The main task of otorhinolaryngologists and maxillofacial surgeons is diagnosis and follow-up in order to determine recurrences. Neck nodes require thorough examination as they can serve as the initial indication of cancer in the head and neck region. In HIV-positive individuals, the neck is the most common site for lymphoma development, accounting for 50% of cases. These lymphomas often develop in younger patients and may be the first sign that prompts suspicion of HIV infection [72]. Therefore, the diagnostic workup for head and neck lymphomas should routinely include HIV testing. On average, lymphoma develops approximately 1.5 years after an HIV diagnosis [73].

Enlarged neck nodes also warrant endoscopic examination to rule out cavum lymphoma, particularly in HIV-infected patients. Cavum lymphomas often present initially as isolated neck node enlargement [101] and include subtypes such as Burkitt lymphoma, immunoblastic lymphoma, and DLBCL [50].

Pathology results are critical, and an excisional lymph node biopsy is the preferred method for obtaining a definitive diagnosis of lymphoma. This approach provides adequate tissue sampling for histopathological and immunophenotypic analyses. When an excisional biopsy is not feasible, a core-needle biopsy may be considered [74,75], although it may not provide as comprehensive a sample. Ultrasound-guided core needle biopsy (US-CNB) is a minimally invasive alternative to surgical excision biopsy, offering high diagnostic accuracy, with sensitivity and specificity often exceeding 90% for both Hodgkin and non-Hodgkin lymphomas [76,77,78]. However, US-CNB may have limitations in certain scenarios, such as the subclassification of low-grade lymphomas and Hodgkin lymphoma, where histological architecture is crucial for an accurate diagnosis [79]. In such cases, if the US-CNB results are inconclusive or if there is strong clinical suspicion of malignancy despite a benign biopsy result, a follow-up excisional biopsy may be necessary to confirm the diagnosis [80].

Extranodal lesions require deep biopsies close to healthy tissue to avoid necrotic tissue. open biopsy of neck masses, paranasal sinus lesions, and excision of affected glands or tonsils. may also be used depending on the tumor's location. Immunohistochemical staining is necessary for accurate diagnosis [50].

Half of extranodal lymphomas in the head and neck occur in the Waldeyer ring. Common symptoms include dysphagia and sore throat [50,81]. The decision to excise asymmetrical tonsils should be guided by clinical context and risk factors. Rapid unilateral tonsil enlargement, rather than asymmetry alone, is significantly associated with malignancy [82].

Oral lymphomas may present as swelling, pain, or ulcers in the gingiva, palate, or tongue [50,83]. In HIV-positive patients, plasmablastic lymphoma is the most common subtype in this location [84,85], followed by B-cell lymphomas with high proportions of plasmablastic cells [50].Parotid gland lymphomas present as unilateral enlargement with or without facial paresis, with subtypes including marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT), follicular lymphoma, and DLBCL [50]. Laryngeal lymphoma, typically located in the supraglottic region, often manifests as dysphagia, hoarseness, and dyspnea [50].

The presence of elevated EBV antibody titers often precedes the onset of tumors such as Burkitt and Hodgkin’s lymphoma by several years [86]. IgG antibodies to EBNA begin to appear 6 to 12 weeks after the onset of symptoms and persist throughout life.In situ hybridization for EBV-encoded small RNA (EBER) is considered the most sensitive method for detecting EBV-infected cells [19,87], with EBV-specific antibodies being the diagnostic gold standard for infectious mononucleosis [88]. However, some EBER-negative samples may still contain EBV, resulting in a sensitivity of approximately 67.8%for this marker [48,89,90]. Novel molecular biology techniques, such as microRNA-based markers, are under investigation but require further validation

HL tends to arise in the jugular chain, whereas NHL is more commonly found in retropharyngeal, parotid, occipital, or submandibular nodes. Extranodal lymphomas in the Waldeyer ring often involve gastrointestinal sites, making barium studies essential for staging [91]

Key prognostic factors include neutropenia, lymphopenia, anemia, elevated serum alkaline phosphatase, and calcium levels, which may indicate bone infiltration. Bone marrow involvement is more frequent in immunodeficiency and advanced stages, warranting biopsies in patients with B symptoms, cytopenias, or bulky disease. PET imaging is the gold standard for staging aggressive lymphomas and HL [50]. Additionally CD4 count particularly in HIV patients or specific lymphoma subtypes provides important prognostic information.

The Lugano classification system is widely used to stage both Hodgkin and non-Hodgkin lymphomas. It combines clinical assessments, imaging results, and the presence of B-symptoms to establish the disease stage, which is essential for determining the appropriate treatment. The modified Ann Arbor staging system is also utilized, especially for Hodgkin lymphoma, where the suffixes A and B indicate the absence or presence of B-symptoms, respectively [67,75].

6. General Treatment Approaches for Lymphomas

Treatment for lymphomas broadly depends on the type of lymphoma, its stage, and the patient’s overall health [50,92]. Below is an overview of treatments across various lymphoma subtypes.

For diffuse large B-cell lymphoma (DLBCL), combination chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) is the standard approach, with the addition of rituximab for CD20-positive cases and in whom the CD4 cell count is > 50 cells/μl, has been suggested [93,94]. Dose-adjusted EPOCH (etoposide, vincristine, doxorubicin, prednisone, and cyclophosphamide) plus rituximab is often preferred for cases with high proliferation rates (Ki 67 > 80%) or plasmablastic histology [95,96], considering prophylactic for opportunistic infections and in patients with affectation of paranasal sinuses, epidural space, or bone marrow are involved, or if disease involvement includes more than two extranodal sites lumbar puncture should be done as part of workup [50].

In Burkitt lymphoma, highly aggressive regimens like CODOX-M/IVAC (cyclophosphamide, vincristine, doxorubicin, methotrexate alternating with ifosfamide, etoposide, and cytarabine)[97,98,99], Hyper CVAD(cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with high-dose methotrexate and cytarabine) [100,101,102], or CDE (cyclophosphamide, doxorubicin, etoposide) plus rituximab [103,104] for most patients with AID related BL are used. Intrathecal chemotherapy is crucial due to the high risk of CNS involvement [50]. Plasmablastic lymphoma is treated similarly to Burkitt lymphoma [50].

Hodgkin lymphoma is typically managed with ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) as the standard chemotherapy regimen, or BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) followed by field radiation therapy [105]

For NK-/T-cell lymphomas, combined chemotherapy and radiotherapy are preferred for localized disease due to the high systemic relapse rate. Regimens like SMILE (dexamethasone, methotrexate, ifosfamide, L-asparaginase, etoposide) [106,107,108,109], GELOX (gemcitabine, L-asparaginase, oxaliplatin), or VIPD (etoposide, ifosfamide, cisplatin, dexamethasone) are commonly employed. Radiotherapy doses of at least 50 Gy are necessary to minimize in-field failure rates [110].

Relapsed lymphoma is associated with a poor prognosis, with a median survival of less than one year in most cases. For patients with relapsed non-Hodgkin lymphoma (NHL) of B-cell origin, a second-line treatment option is the ESHAP regimen, which includes etoposide, methylprednisolone, cytarabine, and cisplatin. In certain cases, especially with advancements in HIV control and immune reconstitution, autologous stem cell transplantation may be considered as a viable therapeutic option. This approach offers a chance for extended remission or potential cure in select patients, depending on their overall health, response to salvage therapy, and lymphoma characteristics [50].

Targeted Therapies for EBV-Associated Lymphomas

The association of EBV with lymphomas has spurred research into therapies that target EBV-specific mechanisms to improve outcomes for affected patients. Despite progress, challenges such as the lack of suitable animal models limit the development of effective treatments, as EBV exclusively infects humans [111]. Nonetheless, promising strategies are emerging, focusing on pathways and molecules crucial to EBV-driven oncogenesis.

One avenue of targeted therapy involves exploiting the interplay between EBV and apoptosis-related proteins. EBNA3C, an EBV nuclear antigen, disrupts Bcl-6 activity, leading to the derepression of Bcl-2 expression, a key event in lymphomagenesis [112]. While ABT-199, a Bcl-2-selective inhibitor, has shown efficacy in some tumors [113], it has proven ineffective in EBV-immortalized cells [114], the efficacy in early infection EBV it must be defined.

Conversely, the EBV-encoded Bcl-2 homolog, BHRF1, blocks apoptosis by binding the Bcl-2-related protein Bim [115]. An inhibitor specifically designed to target BHRF1 has demonstrated significant efficacy, suppressing tumor growth and prolonging survival in a mouse model of EBV-positive B-cell lymphoma [116].

Zidovudine (AZT), a nucleoside analog, has been investigated for its potential to trigger EBV lytic gene expression, resulting in the apoptosis of EBV-infected cells. Regimens that include AZT, often combined with other agents like hydroxyurea that induce lytic activity, have demonstrated effectiveness in treating EBV-positive lymphomas, such as primary central nervous system lymphoma (PCNSL) in patients with AIDS [117,118,119].

Proteasome inhibition has also emerged as a therapeutic strategy. The FDA-approved proteasome inhibitor ixazomib has shown promise in EBV-positive lymphoma cells by inducing apoptosis and cell cycle arrest [120]. Similarly, targeting spleen tyrosine kinase (SYK), a critical component of the B-cell receptor (BCR) signaling pathway, has proven effective. TAK-659, a novel SYK inhibitor, induces cell death and inhibits tumor development in EBV-associated lymphomas in vivo [121,122], showcasing the potential of signaling pathway inhibitors in treating these malignancies.

Various stimuli, including histone deacetylase (HDAC) inhibitors [123], 12-O-tetradecanoylphorbol-13-acetate (TPA) [124], sodium butyrate [125,126], and anti-immunoglobulin [127,128], can switch EBV-infected cells from latent to lytic infection. This approach allows for the selective targeting of infected cells. A clinical trial demonstrated the efficacy of combining arginine butyrate with ganciclovir [129]. Arginine butyrate induced the lytic cycle, activating the EBV thymidine kinase (EBV-TK), which rendered infected cells susceptible to ganciclovir, a nucleoside antiviral agent that inhibits viral replication [129,130]. However, another study revealed that the EBV protein kinase BGLF4, rather than EBV-TK, mediated the ganciclovir response [131].

Monoclonal antibodies targeting specific pathways and genes involved in EBV lymphoma pathogenesis are under investigation. Among the most promising approaches are HDAC inhibitors, which are currently undergoing clinical trials [132,133].

TCR-like monoclonal antibodies mimic T-cell receptors and specifically target EBV-transformed B lymphoblastoid cells by binding to EBV peptides displayed on HLA molecules. For example, antibodies such as E1, L1, and L2 recognize peptides like EBNA1, LMP1, and LMP2A presented by HLA-A*0201. Studies have demonstrated their ability to reduce tumor burden and induce apoptosis in EBV-transformed cells, highlighting their potential as therapeutic tools for EBV-associated lymphomas [134,135].

Monoclonal antibodies targeting the EBV glycoprotein 42 (gp42), such as mAb A10 and 4C12, have been developed to block the interaction between gp42 and HLA class II molecules. This disruption prevents the fusion of the virus with B cells. Among these, mAb A10 has shown strong neutralizing effects and has demonstrated the ability to protect against EBV infection and lymphoma development in humanized mouse models [136].

Monoclonal antibodies targeting the gH/gL glycoprotein complex of EBV have been identified as effective in neutralizing the virus by blocking the fusion of the viral membrane with host cells. Research has revealed several antigenic sites on the gH/gL complex that are susceptible to neutralization, paving the way for the development of therapeutic antibodies to combat EBV-related diseases [137,138].

A bispecific antibody targeting the viral envelope protein gp350 and CD89 on immune cells has been developed to promote phagocytosis and clearance of EBV-infected cells. Preclinical studies have shown its effectiveness in lowering viral load and preventing tumor development in EBV-related hematological disorders [139].

The ongoing research into targeted therapies offers hope for more effective and tailored treatments for EBV-associated lymphomas. Continued efforts to refine these approaches and address existing gaps will be pivotal in advancing patient care.

The fundamental problem about developing any therapeutic option against EBV is the lack of well defined animal models for studies due to EBV only infects humans

7. Prognosis

The prognosis of lymphomas, particularly those associated with Epstein-Barr Virus (EBV), depends on various factors, including the type of lymphoma, patient characteristics, and EBV's influence on the disease's biology. The International Prognostic Index (IPI) remains a cornerstone for assessing prognosis in aggressive lymphomas. It categorizes patients into low-, intermediate-, and high-risk groups based on baseline characteristics such as age, Eastern Cooperative Oncology Group (ECOG) performance status, lactate dehydrogenase (LDH) levels, Ann Arbor stage, and extranodal involvement [140]. In HIV patients, who frequently experience extranodal involvement, the prognosis is often poor [141].

Research suggests that localized malignant lymphomas in the head and neck region, particularly diffuse large B-cell lymphoma (DLBCL), have demonstrated better prognosis with contemporary treatment strategies. One study reported a 5-year overall survival rate of 83% for patients with localized lymphomas in this area, reflecting significant progress compared to historical data [142].

For head and neck DLBCL, treatment with R-CHOP chemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) followed by radiotherapy has shown high rates of local control and survival. This approach has been associated with a 5-year overall survival rate of 61% and a relapse-free survival rate of 72% [143]. Radiotherapy after chemotherapy has further improved local control, achieving a final local control rate of 94% [143].

Extranodal non-Hodgkin lymphoma of the head and neck has a 5-year overall survival rate of 63.2%, with factors such as ECOG performance status, Ann Arbor stage, and IPI risk stratification being significant predictors of survival [144]. Additionally, ill-defined tumor margins on imaging have been associated with poorer clinical outcomes [145].

HIV-positive individuals face a 20- to 60-fold increased risk of developing lymphoma , with B-cell lymphomas being predominant [146,147]. In these cases, EBV is integrated into the neoplastic cells in 40% to 60% of systemic lymphomas and nearly all primary central nervous system lymphomas [148,149].

In ENKTL, a review of 153 cases revealed no association between EBV status and prognosis, although EBV-positive patients exhibited a higher propensity for metastasis [150]. Conversely, a systematic review and meta-analysis highlighted that EBV positivity correlates with poorer overall survival (OS) and disease-specific survival (DSS) in Hodgkin lymphoma (HL). Specifically, EBV-positive HL patients had a hazard ratio (HR) of 1.443 for OS and 2.312 for DSS compared to EBV-negative patients. However, age plays a significant role. Among children and adolescents, EBV positivity was linked to favorable OS outcomes, though this trend reversed in older adults, where EBV positivity was associated with significantly poorer OS (HR=1.905) and DSS [151].

The Chelsea and Westminster cohort study of 111 patients treated for AIDS-related NHL identified critical prognostic factors, including age, tumor stage, LDH levels, ECOG status, and the number of extranodal sites. Additionally, a CD4 count below 100 x 10 6 cells/L was a strong predictor of mortality. While survival has improved in the combined antiretroviral therapy (cART) era, prognostic scores in the highest quartile showed a sevenfold increased risk of death compared to the lowest quartile. Nonetheless, the study's limited sample size and variability in treatment regimens warrant further investigation [152].

Patients with higher CD4 counts tend to have better survival rates, as effective HIV management with cART can mitigate some of the adverse effects of immunosuppression on lymphoma prognosis. Therefore, maintaining a higher CD4 count through effective antiretroviral therapy is crucial for improving the prognosis of lymphoma in HIV-infected patients [153,154].

8. Conclusions

The roles of EBV and HIV in the development of various lymphomas are crucial and underscores the complexity of their pathogenesis. EBV’s ability to manipulate cellular pathways emphasizes the importance of targeted therapies that address both viral and host factors driving lymphoma formation. Advances in diagnostic methods, including molecular and immunohistochemical tools, have enhanced the detection of EBV-associated lymphomas. The progression from EBV infection to lymphoma remains poorly understood, particularly in immunosuppressed populations and in older patients, where the risk is elevated. Prognosis varies based on clinical, biological, and molecular markers and age. While significant therapeutic progress has been achieved, especially with the introduction of ART, challenges persist in managing relapsed and refractory lymphomas. Continued research into novel therapies, such as inhibitors targeting specific EBV-related pathways and personalized treatment approaches, is vital. Bridging the gaps in understanding EBV's role in lymphoma development and addressing the absence of effective animal models are essential steps toward improving the management and outcomes of EBV-associated lymphomas.