Lymphomas occurring specifically in HIV-infected patients: from pathogenesis to pathology

Gallbladder Burkitt's Lymphoma: A Literature Review Including a Case Report in a Child Living with HIV

Malignant lymphoma is an unusual form of gallbladder neoplasm. Almost all these tumors are diffuse large B-cell lymphomas or mucosa-associated lymphoid tissue-type lymphomas. Herein, we present a literature review of gallbladder Burkitt's lymphoma (BL) cases that includes also an unpublished case in an HIV-infected child, observed by our center. The patient (a five-year-old black female child) attended the Federal Hospital of Lagoa, Rio de Janeiro, Brazil, underwent cholecystectomy, and the postoperative pathological analysis of the gallbladder revealed a diagnosis of BL (EBV-positive). Also, HIV serology was performed and returned positive. She was transferred to the Martagão Gesteira Institute of Pediatrics and Childcare for oncological treatment, dying from sepsis and disease progression about 18 months later. The patient did not undergo ART/cART. Previous cases of gallbladder BL were herein described and analyzed to characterize the clinicopathological features and possible similarities. BL can occur in the gallbladder both in the context of HIV infection and in the pediatric population. A biopsy is mandatory in cases with suggestive findings of lymphoma, and an early diagnosis can change the course of the disease. Furthermore, the case highlights the importance of an early initiation of ART/cART in people living with HIV (PLWH), especially in children.

Human herpesvirus reactivation and its potential role in the pathogenesis of post-acute sequelae of SARS-CoV-2 infection

The emergence of SARS-CoV-2 has precipitated a global pandemic with substantial long-term health implications, including the condition known as post-acute sequelae of SARS-CoV-2 infection (PASC), commonly referred to as Long COVID. PASC is marked by persistent symptoms such as fatigue, neurological issues, and autonomic dysfunction that persist for months beyond the acute phase of COVID-19. This review examines the potential role of herpesvirus reactivation, specifically Epstein-Barr virus (EBV) and cytomegalovirus (CMV), in the pathogenesis of PASC. Elevated antibody titers and specific T cell responses suggest recent herpesvirus reactivation in some PASC patients, although viremia is not consistently detected. SARS-CoV-2 exhibits endothelial trophism, directly affecting the vascular endothelium and contributing to microvascular pathologies. These pathologies are significant in PASC, where microvascular dysfunction may underlie various chronic symptoms. Similarly, herpesviruses like CMV also exhibit endothelial trophism, which may exacerbate endothelial damage when reactivated. Evidence suggests that EBV and CMV reactivation could indirectly contribute to the immune dysregulation, immunosenescence, and autoimmune responses observed in PASC. Additionally, EBV may play a role in the genesis of neurological symptoms through creating mitochondrial dysfunction, though direct confirmation remains elusive. The reviewed evidence suggests that while herpesviruses may not play a direct role in the pathogenesis of PASC, their potential indirect effects, especially in the context of endothelial involvement, warrant further investigation.

Long-Term Survival Rates and Treatment Trends of Burkitt Lymphoma in Patients with HIV-A National Cancer Database (NCDB) Study

BACKGROUND

Burkitt lymphoma (BL) accounts for 10-35% of AIDS-defining lymphoma in people with HIV (PWH). Previous research consisting of smaller cohorts has shown decreased survival for HIV-associated BL. This study aims to compare overall mortality in BL patients with and without HIV, while investigating impact of treatment modalities in HIV-associated BL.

METHODS

Using the 2004-2019 NCDB, we identified 4312 patients with stage 3 or 4 BL who had a known HIV status and received either chemotherapy alone or chemotherapy and immunotherapy. Time to death was evaluated using Kaplan-Meier survival estimates. Risk of death was evaluated using an extended multivariable Cox model adjusted for multiple factors and with a Heaviside function for HIV status by time period (0-3 month vs. 3-60 month).

RESULTS

Of the 4312 patients included, 1514 (35%) had HIV. For months 0-3 from time of diagnosis, HIV status was not associated with a statistically significant increase in risk of death (HR = 1.04, 95% CI: 0.86, 1.26, p = 0.6648). From month 3to 60, positive HIV status was associated with a 55% increase in risk of death compared to those without HIV (95% CI: 1.38, 1.75, p < 0.0001). Further, this difference in hazard rates (0-3 vs. 3-60) was statistically significant (HR = 1.49, 95% CI: 1.22-1.82, p < 0.001).

CONCLUSIONS

There is an increased mortality rate from months 3 to 60 in BL patients with HIV compared to patients without HIV. Additionally, risk of death in the first 3 months is significantly decreased by 45% in patients with HIV treated with combination chemotherapy and immunotherapy compared to patients without HIV receiving combination chemotherapy and immunotherapy, providing valuable clinical insight into treatment decision making in the care of HIV-associated BL.

Carcinogenic mechanisms of virus-associated lymphoma

The development of lymphoma is a complex multistep process that integrates numerous experimental findings and clinical data that have not yet yielded a definitive explanation. Studies of oncogenic viruses can help to deepen insight into the pathogenesis of lymphoma, and identifying associations between lymphoma and viruses that are established and unidentified should lead to cellular and pharmacologically targeted antiviral strategies for treating malignant lymphoma. This review focuses on the pathogenesis of lymphomas associated with hepatitis B and C, Epstein-Barr, and human immunodeficiency viruses as well as Kaposi sarcoma-associated herpesvirus to clarify the current status of basic information and recent advances in the development of virus-associated lymphomas.

The Correlation Between 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography Semiquantitative Parameters and the Clinical Features and Pathological Biological Indexes of Gastric Cancer

Objective: This study explored the application value of the maximum standard uptake value (SUVmax) of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) in gastric cancer. Materials and Methods: Data of 164 patients with gastric cancer who had undergone18F-FDG PET/CT before a biopsy were collected, and the correlation of SUVmax with clinical stage, pathological differentiation degree, human epidermal growth factor receptor-2 (HER-2) status, and Ki-67 index of gastric cancer was analyzed. Results: The SUVmax of poorly differentiated adenocarcinoma was significantly higher than that of moderately differentiated adenocarcinoma and signet-ring cell carcinoma (p < 0.01), and SUVmax in the well-differentiated adenocarcinoma group was higher than that in the signet-ring cell carcinoma group (p < 0.01). The SUVmax in the HER-2 negative group was higher than that in the HER-2 positive group (p < 0.01). The SUVmax was higher in the Ki-67 high expression group than in the low expression group (p < 0.01), and there was a significant positive correlation between the two (p < 0.01). Conclusion: 18F-FDG PET/CT SUVmax can, to some extent, predict the degree of differentiation, HER-2 status, and Ki-67 index of gastric cancer patients.

Clinical pathology of primary central nervous system lymphoma in HIV-positive patients-a 41 Chinese patients retrospective study

OBJECTIVES

The purpose of this study was to investigate the clinicopathological characteristics of primary central nervous system lymphoma (PCNSL).

METHODS

We collected 41 PCNSL formalin-fixed, paraffin-embedded (FFPE) samples from human immunodeficiency virus (HIV)-positive patients and performed HE (haematoxylin-eosin) staining, immunohistochemistry (IHC) staining, in situ hybridization, fluorescence in situ hybridization (FISH). Real-time quantitative polymerase chain reaction (RT-qPCR) was performed in 9 cases of FFPE samples. Meanwhile, we analysed the clinical pathological significance of the results.

RESULTS

Seven patients had diffuse large B-cell lymphoma (DLBCL) with germinal centre B-cell (GCB)-like DLBCL, 32 had activated B-cell (ABC)-like DLBCL, and 2 had Burkitt lymphoma (BL). GCB-like DLBCL patients were older at onset (P = 0.040).A lower CD4⁺ T-cell count and a decrease in cerebrospinal fluid (CSF) glucose content were more frequent in ABC-like DLBCL (P = 0.012, P = 0.006). Overexpression of P53 was more in ABC-like DLBCL (P = 0.041). 73.2 % cases were Epstein-Barr encoding region (EBER) positive, which was more likely in ABC-like DLBCL patients (P = 0.037). EBV DNA were detected in 5/7 EBER-negative DLBCL cases and none (0/2) of the BL cases. All the cases were negative for HHV8 staining. None of the 7 Double expressor lymphoma (DEL) cases had BCL2, BCL6, or c-MYC genetic rearrangements.

CONCLUSIONS

HIV-related PCNSL showed unique clinical pathological significance. None of EBV detected in HIV-related BL and without HHV8 infectious are new sights in our single-center study of Chinese HIV-related PCNSL patients.

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.

Diagnostic approaches and future directions in Burkitt lymphoma and high-grade B-cell lymphoma

Since the 2016 WHO update, progress has been made in understanding the biology of Burkitt lymphoma (BL) and the concept of high-grade B-cell lymphomas (HGBCL) that allows some degree of refinement. The summary presented here reviews in detail the discussions of the Clinical Advisory Committee and expands upon the newly published 2022 International Consensus Classification for lymphoid malignancies (Campo et al. Blood, 2022). BL remains the prototypic HGBCL and diagnostic criteria are largely unchanged. HGBCL with MYC and BCL2 and HGBCL with MYC and BCL6 rearrangements are now separated to reflect biologic and pathologic differences. HGBCL, NOS remains a diagnosis of exclusion that should be used only in rare cases. FISH strategies for diffuse large B-cell lymphoma (DLBCL) and HGBCL are discussed in detail for these diseases. Advances in integrative analysis of mutations, structural abnormalities, copy number, and gene expression signatures allow a more nuanced view of the heterogeneity of DLBCL, NOS as well as definitions of HGBCL and point to where the future may be headed for classification of these diseases.

Ectopic expression of HIV-1 Tat modifies gene expression in cultured B cells: implications for the development of B-cell lymphomas in HIV-1-infected patients

An increased frequency of B-cell lymphomas is observed in human immunodeficiency virus-1 (HIV-1)-infected patients, although HIV-1 does not infect B cells. Development of B-cell lymphomas may be potentially due to the action of the HIV-1 Tat protein, which is actively released from HIV-1-infected cells, on uninfected B cells. The exact mechanism of Tat-induced B-cell lymphomagenesis has not yet been precisely identified. Here, we ectopically expressed either Tat or its TatC22G mutant devoid of transactivation activity in the RPMI 8866 lymphoblastoid B cell line and performed a genome-wide analysis of host gene expression. Stable expression of both Tat and TatC22G led to substantial modifications of the host transcriptome, including pronounced changes in antiviral response and cell cycle pathways. We did not find any strong action of Tat on cell proliferation, but during prolonged culturing, Tat-expressing cells were displaced by non-expressing cells, indicating that Tat expression slightly inhibited cell growth. We also found an increased frequency of chromosome aberrations in cells expressing Tat. Thus, Tat can modify gene expression in cultured B cells, leading to subtle modifications in cellular growth and chromosome instability, which could promote lymphomagenesis over time.

Castleman disease

Castleman disease (CD), a heterogeneous group of disorders that share morphological features, is divided into unicentric CD and multicentric CD (MCD) according to the clinical presentation and disease course. Unicentric CD involves a solitary enlarged lymph node and mild symptoms and excision surgery is often curative. MCD includes a form associated with Kaposi sarcoma herpesvirus (KSHV) (also known as human herpesvirus 8) and a KSHV-negative idiopathic form (iMCD). iMCD can present in association with severe syndromes such as TAFRO (thrombocytopenia, ascites, fever, reticulin fibrosis and organomegaly) or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes). KSHV-MCD often occurs in the setting of HIV infection or another cause of immune deficiency. The interplay between KSHV and HIV elevates the risk for the development of KSHV-induced disorders, including KSHV-MCD, KSHV-lymphoproliferation, KSHV inflammatory cytokine syndrome, primary effusion lymphoma and Kaposi sarcoma. A CD diagnosis requires a multidimensional approach, including clinical presentation and imaging, pathological features, and molecular virology. B cell-directed monoclonal antibody therapy is the standard of care in KSHV-MCD, and anti-IL-6 therapy is the recommended first-line therapy and only treatment of iMCD approved by the US FDA and EMA.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

Epstein Barr Virus: Development of Vaccines and Immune Cell Therapy for EBV-Associated Diseases

Epstein-Barr virus (EBV) is the first human tumor virus discovered and is strongly implicated in the etiology of multiple lymphoid and epithelial cancers. Each year EBV associated cancers account for over 200,000 new cases of cancer and cause 150,000 deaths world-wide. EBV is also the primary cause of infectious mononucleosis, and up to 70% of adolescents and young adults in developed countries suffer from infectious mononucleosis. In addition, EBV has been shown to play a critical role in the pathogenesis of multiple sclerosis. An EBV prophylactic vaccine that induces neutralizing antibodies holds great promise for prevention of EBV associated diseases. EBV envelope proteins including gH/gL, gB and gp350 play key roles in EBV entry and infection of target cells, and neutralizing antibodies elicited by each of these proteins have shown to prevent EBV infection of target cells and markedly decrease EBV titers in the peripheral blood of humanized mice challenged with lethal dose EBV. Recent studies demonstrated that immunization with the combination of gH/gL, gB and/or gp350 induced markedly increased synergistic EBV neutralizing activity compared to immunization with individual proteins. As previous clinical trials focused on gp350 alone were partially successful, the inclusion of gH/gL and gB in a vaccine formulation with gp350 represents a promising approach of EBV prophylactic vaccine development. Therapeutic EBV vaccines have also been tested clinically with encouraging results. Immunization with various vaccine platforms expressing the EBV latent proteins EBNA1, LMP1, and/or LMP2 promoted specific CD4+ and CD8+ cytotoxic responses with anti-tumor activity. The addition of EBV envelope proteins gH/gL, gB and gp350 has the potential to increase the efficacy of a therapeutic EBV vaccine. The immune system plays a critical role in the control of tumors, and immune cell therapy has emerged as a promising treatment of cancers. Adoptive T-cell therapy has been successfully used in the prevention and treatment of post-transplant lymphoproliferative disorder. Chimeric antigen receptor T cell therapy and T cell receptor engineered T cell therapy targeting EBV latent proteins LMP1, LMP2 and/or EBNA1 have been in development, with the goal to increase the specificity and efficacy of treatment of EBV associated cancers.

Epstein-Barr virus-positive diffuse large B-cell lymphoma with human immunodeficiency virus mimicking complicated frontal sinusitis: A case report

BACKGROUND

Primary non-Hodgkin’s lymphoma of the frontal sinus is extremely rare. In addition, Epstein-Barr virus (EBV) has been reported to play a role in the development of human immunodeficiency virus (HIV)-related malignant lymphomas. To the best of our knowledge, there is no report for the HIV-associated, EBV-positive primary diffuse large B-cell lymphoma (DLBCL) in the frontal sinus.

CASE SUMMARY

We present a unique case of HIV-associated, EBV-positive DLBCL in the frontal sinus in a 46-year-old man. Computed tomography of paranasal sinuses revealed dense opacification of the right frontal sinus with combined soft tissue swelling. Based on the clinical and radiological findings, the initial diagnosis was complicated frontal sinusitis, presenting Pott’s puffy tumor. Unexpectedly, HIV testing was positive on preoperative laboratory test, and the frontal sinus lesion was confirmed as EBV-positive DLBCL on biopsy.

CONCLUSION

Through this article, we suggest that EBV-positive DLBCL should be considered as possible diagnosis for patients with nonspecific space-occupying lesion of the paranasal sinuses. We also highlight an importance of clinical suspicion in diagnosing HIV infection because HIV serology is not routinely tested in patients with paranasal sinus problem.

Unraveling the Mystery of Gray Zone Lymphoma in Human Immunodeficiency Virus-Seropositive Patients: Two Cases

Gray zone lymphoma (GZL) is an uncommon neoplasm with intermediate features of both classic Hodgkin lymphoma (cHL) and diffuse large B-cell lymphoma (DLBCL). It was identified in the World Health Organization (WHO) classification as its own neoplasm in 2008. Patients infected with human immunodeficiency virus (HIV) have been rarely diagnosed with this type of lymphoma and treatment strategies for this subset of patients is not well described. Here we present two cases of patients with HIV that were diagnosed with GZL in a single community-based institution. A 68-year-old male with HIV/acquired immunodeficiency syndrome (AIDS) on highly active antiretroviral therapy (HAART) presented with 6-month history of dyspnea and weight loss. Computed tomography (CT) of the chest revealed multiple lung and mediastinal lesions, the largest measuring 9.4 × 5.5 cm lesion in the right perihilar region. Lymph node biopsy revealed abnormal lymphocytes with immunohistochemistry (IHC) positive for cluster of differentiation 30 (CD30), CD20 and Epstein-Barr virus (EBV), consistent with a diagnosis of GZL. The patient received dose-adjusted etoposide, doxorubicin, vincristine, cyclophosphamide, prednisone, and rituximab (DA-EPOCH-R) and attained a complete response. He since completed maintenance rituximab therapy and remains disease-free at 33 months. A 40-year-old female with HIV/AIDS on HAART presented with high-grade fever, dyspnea, and weight loss. CT imaging revealed multiple lung lesions, hepatosplenomegaly and diffuse lymphadenopathy in the chest and abdomen. Lymph node and bone marrow biopsy revealed cells positive for CD20, CD30, and EBV within atypical lymphoid cells. With this, a diagnosis of GZL was made and she was treated with DA-EPOCH-R. She attained a complete response and was on maintenance rituximab therapy. At 9 months she relapsed, she has now received a bone marrow transplant. GZL is a rarely described neoplasm within the HIV population. Here we describe two HIV patients diagnosed with GZL that were successfully treated at our institution. DA-EPOCH-R was able to induce durable remission with limited side effects and it represents a viable strategy for treating patients in this population. Further studies need to be performed to better characterize this lymphoma, especially in HIV patients. Treatment strategies for this select group of patients also need to be better defined.

Real-time intracranial pressure monitoring during high-dose methotrexate treatment for primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin lymphoma with exclusive central nervous system (CNS) and/or ocular involvement. Increased intracranial pressure (ICP) from cerebral edema can commonly presents secondary to the mass effect of PCNSL. Methotrexate-based induction chemotherapy is the gold standard for treatment, however, several neurotoxic complications have been associated with high-dose methotrexate (HD-MTX) treatment. Tumor lysis and other biochemical disruptions following administration of HD-MTX are postulated to increase cerebral edema and ICP in predisposed patients, therefore, in the setting of ring-enhancing lesions with significant mass effect, monitoring of ICP to prevent cerebral herniation may be necessary.

PRESENTATION OF CASE

We present the case of a patient with diffuse cerebral edema secondary to PCNSL, who was treated with methotrexate-based induction chemotherapy and underwent real-time ICP monitoring to allow for early recognition, and management with aggressive medical therapy to prevent worsening cerebral edema and potential fatal herniation.

DISCUSSION AND CONCLUSIONS

Treatment of patients with high tumor burden PCNSL can prove to be challenging, particularly at the time of initiation of methotrexate based induction chemotherapy in the setting of impending cerebral herniation, as in the case presented. Close monitoring of the patient's ICP proved advantageous in rapidly recognizing, and successfully treating elevations in ICP that could have worsened mass effect and lead to fatal herniation.

HIV-associated Burkitt lymphoma

Burkitt lymphoma is a rare and aggressive non-Hodgkin lymphoma with three classifications: endemic, sporadic, and immunodeficiency-related. High-intensity chemotherapeutic regimens have considerably improved overall survival for patients with Burkitt lymphoma. In this Review of HIV-associated Burkitt lymphoma, we summarise expert opinion and provide general recommendations for the treatment of Burkitt lymphoma in patients with HIV on the basis of retrospective and prospective studies, taking into consideration immune status, CD4 cell counts, the presence of systemic disease, and the risk of CNS involvement or relapse. We also discuss the role of rituximab and antiretroviral therapy. We highlight the reasons behind the possible different mechanisms of lymphomagenesis in HIV-associated Burkitt lymphoma and endemic Burkitt lymphoma, which indicate that HIV might have either a direct or indirect oncogenic role in Burkitt lymphoma. We discuss the possible mechanisms by which HIV and HIV proteins could directly contribute to lymphomagenesis. Identifying these mechanisms might lead to the development of therapies that have fewer toxic effects than high-intensity chemotherapeutic regimens.

Epstein Barr Virus Associated Lymphomas and Epithelia Cancers in Humans

Epstein Barr virus (EBV) is a cosmopolitan oncogenic virus, infecting about 90% of the world's population and it is associated to tumors originating from both epithelia and hematopoietic cells. Transmission of the virus is mainly through oral secretions; however, transmission through organ transplantation and blood transfusion has been reported. In order to evade immune recognition, EBV establishes latent infection in B lymphocytes where it expresses limited sets of proteins called EBV transcription programs (ETPs), including six nuclear antigens (EBNAs), three latent membrane proteins (LMP), and untranslated RNA called EBV encoded RNA (EBER), shown to efficiently transform B cells into lymphoblastic cells. These programs undergo different patterns of expression which determine the occurrence of distinct types of latency in the pathogenesis of a particular tumor. Hematopoietic cell derived tumors include but not limited to Burkitt's lymphoma, Hodgkin lymphoma, post-transplant lymphoproliferative disorders, and natural killer (NK)/T cell lymphoma. EBV undergoes lytic infection in epithelia cells for amplification of the viral particle for transmission where it expresses lytic stage genes. However, for reasons yet to be unveiled, EBV switches from the expression of lytic stage genes to the expression of ETPs in epithelia cells. The expression of the ETPs lead to the transformation of epithelia cells into permanently proliferating cells, resulting in epithelia cell derived malignancies such as nasopharyngeal cancer, gastric cancer, and breast cancer. In this review, we have summarized the current updates on EBV associated epithelial and B cell-derived malignancies, and the role of EBV latency gene products in the pathogenesis of the cancers, and have suggested areas for future studies when considering therapeutic measures.

Epstein-Barr virus-associated B-cell lymphoproliferative disorders and lymphomas: a review

In this review, we focus on B-cell lymphoproliferative disorders (LPDs) and lymphomas associated with Epstein-Barr virus (EBV). In some of these diseases-such as EBV-positive diffuse large B-cell lymphoma (DLBCL), not otherwise specified-virus detection is required for the diagnosis, while in others its detection is not necessary for diagnosis. EBV infection has three main latency patterns (types III, II, and I). Different latency patterns are found in different LPD types and are related to the host immune system status. For each of the LPDs/lymphomas, we discuss the clinical presentation, epidemiology, pathology, immunophenotype, and genetic or molecular basis. We provide data for a better understanding of the relationships among the discussed diseases and other information that can be useful in differential diagnosis. Not included in this review are classic Hodgkin lymphoma and some specific variants of DLBCL, as these entities are discussed in separate reviews in this issue.

Multiple remissions of extracavitary primary effusion lymphoma treated with a single cycle of liposomal doxorubicin in a patient infected with HIV

Primary effusion lymphoma (pel) is a rare human herpesvirus 8 (hhv8)-related large B cell lymphoma with plasmablastic, immunoblastic, or anaplastic features that often carries a poor prognosis. This lymphoma occurs mainly in patients with hiv infection, most often with Epstein-Barr virus (ebv) co-infection, and usually presents as body cavity effusions or, less commonly, as extracavitary lesions without effusion (ec-pel). Chemotherapeutic treatment options are limited and require concurrent antiretroviral therapy (art). Here, we report the case of an adult patient with hiv infection and chronic hepatitis E virus (hev) co-infection who had low CD4 T cell recovery after years of art. The patient then developed a cutaneous ec-pel which rapidly regressed after 1 cycle of liposomal doxorubicin (ld) for his Kaposi sarcoma (ks) before treatment with chop chemotherapy. He had previously received numerous cycles of ld for cutaneous ks over 2 years. Because of the patient's low CD4 T cell count, hev co-infection, and earlier unexpected remission of ec-pel before chop, the patient opted for a single trial of ld before other options. Surprisingly, he experienced a complete remission lasting 18 months. Subsequently, his ec-pel relapsed twice at 31 and at 41 months after the initial diagnosis. Upon recurrence, a similar single cycle of ld was given, which again induced remission. The patient today is in complete remission after a total of 4 ld infusions over 54 months. This patient represents a unique case of hiv-with-hhv8-related, ebv-negative ec-pel with chronic hev coinfection, in which rapid remission was achieved after a single cycle of ld, suggesting an antiviral response in addition to the chemotherapeutic effect.

Loss of T-Cell Multifunctionality and TCR-Vβ Repertoire Against Epstein-Barr Virus Is Associated With Worse Prognosis and Clinical Parameters in HIV+ Patients

Epstein-Barr virus (EBV) is an oncogenic virus associated with the development of aggressive and poor-prognosis B-cell lymphomas in patients infected with human immunodeficiency virus (HIV⁺ patients). The most important risk factors for these malignancies include immune dysfunction, chronic immune activation, and loss of T-cell receptor (TCR) repertoire. The combination of all these factors can favor the reactivation of EBV, malignant cell transformation, and clinical progression toward B-cell lymphomas. The overarching aim of this study was to evaluate the frequency, phenotype, functionality, and distribution of TCR clonotypes for EBV-specific T-cell subpopulations in HIV⁺ patients at different clinical stages and for HIV⁺ patients with B-cell lymphoma, as well as to establish their association with clinical variables of prognostic value. Factors were studied in 56 HIV⁺ patients at different clinical stages and in six HIV+ subjects with diagnosed B-cell lymphoma. We found a significant decrease in all subpopulations of EBV-specific CD4⁺ T cells from HIV⁺ patients at stage 3 and with B-cell lymphoma. EBV-specific effector CD8⁺ T cells, particularly effector memory cells, were also reduced in HIV⁺ patients with B-cell lymphoma. Interestingly, these cells were unable to produce IFN-γ and lacked multifunctionality in HIV+ patients. The TCR-Vβ repertoire, which is key for protection against EBV in healthy individuals, was less diverse in HIV⁺ patients due to a lower frequency of TCR-Vβ2⁺, Vβ4⁺, Vβ7.1⁺, Vβ9⁺, Vβ13.6⁺, Vβ14⁺, Vβ17⁺, Vβ22⁺ CD4⁺, Vβ14⁺, and Vβ17⁺ CD8⁺ T cells. HIV⁺ patients with positive plasma EBV loads (EBV⁺HIV⁺) had a noteworthy decrease in the levels of both TNF-α⁺ and multifunctional TNF-α⁺/IL-2⁺ and TNF-α⁺/IFN-γ⁺ CD8⁺ T cells. Altogether, our findings demonstrate that HIV⁺ patients have significant alterations in the immune response to EBV (poor-quality immunity) that can favor viral reactivation, escalating the risk for developing EBV-associated B-cell lymphomas.

Identification of amino acid residues critical for the B cell growth-promoting activity of HIV-1 matrix protein p17 variants

BACKGROUND

HIV-1 matrix protein p17 variants (vp17s) detected in HIV-1-infected patients with non-Hodgkin's lymphoma (HIV-NHL) display, differently from the wild-type protein (refp17), B cell growth-promoting activity. Biophysical analysis revealed that vp17s are destabilized as compared to refp17, motivating us to explore structure-function relationships.

METHODS

We used: biophysical techniques (circular dichroism (CD), nuclear magnetic resonance (NMR) and thermal/GuHCL denaturation) to study protein conformation and stability; Surface plasmon resonance (SPR) to study interactions; Western blot to investigate signaling pathways; and Colony Formation and Soft Agar assays to study B cell proliferation and clonogenicity.

RESULTS

By forcing the formation of a disulfide bridge between Cys residues at positions 57 and 87 we obtained a destabilized p17 capable of promoting B cell proliferation. This finding prompted us to dissect refp17 to identify the functional epitope. A synthetic peptide (F1) spanning from amino acid (aa) 2 to 21 was found to activate Akt and promote B cell proliferation and clonogenicity. Three positively charged aa (Arg15, Lys18 and Arg20) proved critical for sustaining the proliferative activity of both F1 and HIV-NHL-derived vp17s. Lack of any interaction of F1 with the known refp17 receptors suggests an alternate one involved in cell proliferation.

CONCLUSIONS

The molecular reasons for the proliferative activity of vp17s, compared to refp17, relies on the exposure of a functional epitope capable of activating Akt.

GENERAL SIGNIFICANCE

Our findings pave the way for identifying the receptor(s) responsible for B cell proliferation and offer new opportunities to identify novel treatment strategies in combating HIV-related NHL.

CK1α and IRF4 are essential and independent effectors of immunomodulatory drugs in primary effusion lymphoma

Primary effusion lymphoma (PEL) is an aggressive cancer with few treatment options. The immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide have recently been shown to kill PEL cell lines, and lenalidomide is in clinical trials against PEL. IMiDs bind to the CRL4^CRBN E3 ubiquitin ligase complex, leading to the acquisition of the Ikaros family zinc finger proteins 1 and 3 (IKZF1 and IKZF3), casein kinase 1 α (CK1α), and zinc finger protein 91 (ZFP91) as neosubstrates. IMiDs are effective against multiple myeloma because of degradation of IKZF1 and IKZF3 and the consequent loss of interferon regulatory factor 4 (IRF4) and MYC expression. Lenalidomide is also effective in chromosome 5q deletion-associated myelodysplastic syndrome as a result of degradation of CK1α. An essential IKZF1-IRF4-MYC axis has recently been proposed to underlie the toxicity of IMiDs in PEL. Here, we further investigate IMiD effectors in PEL cell lines, based on genome-wide CRISPR/Cas9 screens for essential human genes. These screens and extensive validation experiments show that, of the 4 neosubstrates, only CK1α is essential for the survival of PEL cell lines. In contrast, IKZF1 and IKZF3 are dispensable, individually or in combination. IRF4 was critical in all 8 PEL cell lines tested, and surprisingly, IMiDs triggered downregulation of IRF4 expression independently of both IKZF1 and IKZF3. Reexpression of CK1α and/or IRF4 partially rescued PEL cell lines from IMiD-mediated toxicity. In conclusion, IMiD toxicity in PEL cell lines is independent of IKZF1 and IKZF3 but proceeds through degradation of the neosubstrate CK1α and downregulation of IRF4.

Multiple, Independent T Cell Lymphomas Arising in an Experimentally FIV-Infected Cat during the Terminal Stage of Infection

Our laboratory has serially reported on the virologic and immunopathologic features of a cohort of experimental feline immunodeficiency virus (FIV)-infected cats for more than eight years. At 8.09 years post infection (PI), one of these animals entered the terminal stage of infection, characterized by undulating hyperthermia, progressive anorexia, weight loss, and pancytopenia; the animal was not responsive to therapeutic interventions, necessitating euthanasia six weeks later (8.20 years PI). Subsequent analyses indicated that neoplastic lymphocytes infiltrated multiple cervical lymph nodes and a band-like region of the mucosal lamina propria within a segment of the intestine. Immunohistochemistry and T cell clonality testing determined that the nodal and intestinal lesions were independently arising from CD3 T cell lymphomas. In-situ RNA hybridization studies indicated that diffuse neoplastic lymphocytes from the cervical lymph node contained abundant viral nucleic acid, while viral nucleic acid was not detectable in lymphocytes from the intestinal lymphoma lesion. The proviral long terminal repeat (LTR) was amplified and sequenced from multiple anatomic sites, and a common clone containing a single nucleotide polymorphism was determined to be defective in response to phorbol myristate acetate (PMA)-mediated promoter activation in a reporter gene assay. This assay revealed a previously unidentified PMA response element within the FIV U3 region 3’ to the TATA box. The possible implications of these results on FIV-lymphoma pathogenesis are discussed.

Extra-telomeric functions of telomerase in the pathogenesis of Epstein-Barr virus-driven B-cell malignancies and potential therapeutic implications

The Epstein-Barr virus (EBV) is a ubiquitous human γ-herpesvirus causally linked to a broad spectrum of both lymphoid and epithelial malignancies. In order to maintain its persistence in host cells and promote tumorigenesis, EBV must restrict its lytic cycle, which would ultimately lead to cell death, selectively express latent viral proteins, and establish an unlimited proliferative potential. The latter step depends on the maintenance of telomere length provided by telomerase. The viral oncoprotein LMP-1 activates TERT, the catalytic component of telomerase. In addition to its canonical role in stabilizing telomeres, TERT may promote EBV-driven tumorigenesis through extra-telomeric functions. TERT contributes toward preserving EBV latency; in fact, through the NOTCH2/BATF pathway, TERT negatively affects the expression of BZLF1, the master regulator of the EBV lytic cycle. In contrast, TERT inhibition triggers a complete EBV lytic cycle, leading to the death of EBV-infected cells. Interestingly, short-term TERT inhibition causes cell cycle arrest and apoptosis, partly by inducing telomere-independent activation of the ATM/ATR/TP53 pathway. Importantly, TERT inhibition also sensitizes EBV-positive tumor cells to antiviral therapy and enhances the pro-apoptotic effects of chemotherapeutic agents. We provide here an overview on how the extra-telomeric functions of TERT contribute to EBV-driven tumorigenesis. We also discuss the potential therapeutic approach of TERT inhibition in EBV-driven malignancies.

Richter transformation driven by Epstein-Barr virus reactivation during therapy-related immunosuppression in chronic lymphocytic leukaemia

The increased risk of Richter transformation (RT) in patients with chronic lymphocytic leukaemia (CLL) due to Epstein-Barr virus (EBV) reactivation during immunosuppressive therapy with fludarabine other targeted agents remains controversial. Among 31 RT cases classified as diffuse large B-cell lymphoma (DLBCL), seven (23%) showed EBV expression. In contrast to EBV^- tumours, EBV⁺ DLBCLs derived predominantly from IGVH-hypermutated CLL, and they also showed CLL-unrelated IGVH sequences more frequently. Intriguingly, despite having different cellular origins, clonally related and unrelated EBV⁺ DLBCLs shared a previous history of immunosuppressive chemo-immunotherapy, a non-germinal centre DLBCL phenotype, EBV latency programme type II or III, and very short survival. These data suggested that EBV reactivation during therapy-related immunosuppression can transform either CLL cells or non-tumoural B lymphocytes into EBV⁺ DLBCL. To investigate this hypothesis, xenogeneic transplantation of blood cells from 31 patients with CLL and monoclonal B-cell lymphocytosis (MBL) was performed in Rag2^-/- IL2γc^-/- mice. Remarkably, the recipients' impaired immunosurveillance favoured the spontaneous outgrowth of EBV⁺ B-cell clones from 95% of CLL and 64% of MBL patients samples, but not from healthy donors. Eventually, these cells generated monoclonal tumours (mostly CLL-unrelated but also CLL-related), recapitulating the principal features of EBV⁺ DLBCL in patients. Accordingly, clonally related and unrelated EBV⁺ DLBCL xenografts showed indistinguishable cellular, virological and molecular features, and synergistically responded to combined inhibition of EBV replication with ganciclovir and B-cell receptor signalling with ibrutinib in vivo. Our study underscores the risk of RT driven by EBV in CLL patients receiving immunosuppressive therapies, and provides the scientific rationale for testing ganciclovir and ibrutinib in EBV⁺ DLBCL. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Survival and predictors of death in people with HIV-associated lymphoma compared to those with a diagnosis of lymphoma in general population

OBJECTIVES

to compare overall survival in HIV-associated lymphoma (HIV-L) and lymphoma raising in HIV-negative population (nHIV-L) and to identify predictors of increased risk of death.

METHODS

All HIV+ patients with HIV-associated lymphoma (Hodgkin lymphoma, HL; non-Hodgkin Lymphoma, NHL) observed between 1.2000 and 12.2013 in the ICONA Foundation Study cohort or in three collaborating centres, and, as control group, nHIV-L individuals followed in one of the four collaborating centres over the same time period, were included. Survival estimates were calculated by use of Kaplan-Meier (KM) and multivariable Cox regression models.

RESULTS

1,331 pts were included (465 HIV-L, 866 nHIV-L): 909 (68%) NHL, 422 (32%) HL. 3 years-cumulative probability (95% confidence interval, CI) of death was higher in HIV-L compared to nHIV-L in NHL (38% (33-44) vs. 22% (19-26); p<0.001), and HL (22% [15-29] vs. 10% (6-13), p<0.001). Among HL, HIV was associated with an increased risk of death (hazard ratio [HR] = 2.37 [95% CI: 1.24-4.55], p = 0.009) independently of calendar year, age, gender, type of chemotherapy and stage; in NHL, HIV was no longer an independent predictor of death after controlling for rituximab use and IPI (HR = 1.26 (0.97-1.63), p = 0.08).

CONCLUSIONS

Our analysis shows a reduced overall survival in HIV+ patients diagnosed with lymphoma compared to HIV-negative controls. Whereas in HIV people with HL, the increased risk of death was confirmed even after adjustment for main confounders, the association between HIV status and survival in NHL appears to be somewhat attenuated after controlling for more aggressive presentation and lower frequency of rituximab use in HIV-+ people.

The Immune Response to Epstein Barr Virus and Implications for Posttransplant Lymphoproliferative Disorder

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication in organ transplant recipients and is most often associated with the Epstein Barr virus (EBV). EBV is a common gammaherpes virus with tropism for B lymphocytes and infection in immunocompetent individuals is typically asymptomatic and benign. However, infection in immunocompromised or immunosuppressed individuals can result in malignant B cell lymphoproliferations, such as PTLD. EBV+ PTLD can arise after primary EBV infection, or because of reactivation of a prior infection, and represents a leading malignancy in the transplant population. The incidence of EBV+ PTLD is variable depending on the organ transplanted and whether the recipient has preexisting immunity to EBV but can be as high as 20%. It is generally accepted that impaired immune function due to immunosuppression is a primary cause of EBV+ PTLD. In this overview, we review the EBV life cycle and discuss our current understanding of the immune response to EBV in healthy, immunocompetent individuals, in transplant recipients, and in PTLD patients. We review the strategies that EBV uses to subvert and evade host immunity and discuss the implications for the development of EBV+ PTLD.

Hepatitis C virus positive diffuse large B-cell lymphomas have distinct molecular features and lack BCL2 translocations

Background:

The clinical presentation of patients with hepatitis C virus (HCV)-positive diffuse large B-cell lymphoma (DLBCL) is different from their HCV-negative counterparts, but the underlying molecular and pathological characteristics are largely under investigated. The virus has a role in lymphomagenesis, as witnessed by the curative potential of antiviral therapy in HCV-related low-grade B-cell lymphomas.

Methods:

We performed a case-control study including 44 HCV-positive cases of de novo DLBCL, comparing them with 132 HCV-negative patients as controls (ratio 3 to 1). Cases and controls were matched for age, lactate dehydrogenase level and international prognostic index at presentation. Patients were studied by gene expression profiling for cell-of-origin determination and to perform differential expression analysis between groups, fluorescence in-situ hybridisation and immunohistochemistry for MYC, BCL2 and BCL6, TP53 mutations, and diagnostic specimens reviewed to exclude transformation from low-grade lymphoma.

Results:

Compared to the HCV-negative controls, patients with HCV-positive de novo DLBCL had differential expression of genes that regulate innate immune response and modulate apoptotic pathways, have higher proliferative index, and lack BCL2 translocations.

Conclusions:

HCV-positive DLBCL have distinct molecular and pathological features compared to the HCV-negative counterparts.

Molecular epidemiological study of gammaherpesvirus in domestic cats in Japan

Gammaherpesviruses (GHVs) are members of an emerging subfamily of the family Herpesviridae. A recent study identified a novel GHV in domestic cats (Felis catus GHV1, FcaGHV1), and epidemiological surveys have found that FcaGHV1 is distributed worldwide. In this study, we investigated the prevalence of GHVs in domestic cats in Japan with a molecular epidemiological survey. Blood samples were collected from 1,738 domestic cats and GHV-derived DNA was detected with PCR in 1.3% (23/1,738) of the Japanese domestic cats. The FcaGHV1 detected in this study was very similar to FcaGHV1 detected in a domestic cat in North America. Older age (>5 years old) and Feline immunodeficiency virus infection were identified as risk factors for GHV infection.

Epstein-Barr virus associated lymphomas in people with HIV

PURPOSE OF REVIEW

The present review summarizes the association of the different histotypes of Epstein-Barr virus (EBV)-associated lymphomas with known genetic lesions and/or oncogenic viruses. A more comprehensive understanding of the complex interplay existing between genetic abnormalities of tumor cells and the viral contribution to the development of EBV-associated lymphomas is pivotal for the development of more effective treatments.

RECENT FINDINGS

Recent evidence indicates that HIV may contribute to lymphomagenesis by acting directly on B lymphocytes as a critical microenvironmental factor. The pathogenesis of EBV-associated lymphomas in patients with HIV infection is considered the result of the concerted action of different factors, mainly including impaired immune surveillance, genetic alterations, and concomitant viral infection (EBV and HIV).

SUMMARY

Immunodeficiency states usually increase susceptibility to cancer as a result of reduced immune surveillance and enhanced chances for virus-driven oncogenesis. Lymphoma remains the most frequent neoplastic cause of death among patients infected with HIV. Several of the HIV-associated lymphomas are related to EBV infection. EBV-associated lymphomas in patients infected with HIV are heterogeneous, not only pathologically but also in terms of pathogenetic pathways and cellular derivation.

Fever and generalised lymphadenopathy in an HIV-positive patient: a diagnostic challenge

Fever and generalised lymphadenopathy is a common presentation of a variety of diseases and a thorough investigation is often necessary for appropriate diagnosis.We present a 53-year-old male patient admitted with fever, weight loss of 15 kg in 3 months and abdominal discomfort. Examination was only remarkable for axillary and inguinal lymphadenopathy. Blood tests showed normocytic normochromic anaemia, cholestasis and a previously unknown HIV-1 infection with lymphocyte CD4 +count of 239 cells/mm³ and viral load 3.172.370 copies/mL. A body CT scan showed multiple axillary, mediastinal, lumbar, aortic, iliac and pelvic lymphadenopathy as well as hepatosplenomegaly. An excisional biopsy of the left axillary lymphadenopathy was performed and histology ultimately revealed multicentric Castleman's disease associated with Human Herpes Virus-8. After initiation of antiretroviral therapy, rituximab was given and progressive clinical improvement occurred.

Pathological Mandibular Fracture Associated With Diffuse Large B-Cell Lymphoma in HIV-Positive Patient

This article describes the occurrence of diffuse large B-cell lymphoma in a 39-year-old human immunodeficiency virus-positive patient. The patient sought medical care complaining of increased volume in the right mandibular angle and imaging tests showed an extensive radiolucency with undefined boundaries compromising the mandibular border. After the incisional biopsy, the patient had a pathological fracture in the region, which was properly treated in a second surgical procedure using a 2.4-mm reconstruction plate. Immunohistochemical analysis revealed positive marking for CD3, CD79a, Ki67, and Epstein-Barr virus-encoded RNA. The treatment consisted of concurrent antiretroviral therapy with chemotherapy with rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone. Examinations of images (2 years postoperatively) revealed complete bone repair and absence of injury recurrence. This work is important because it describes an unusual location of diffuse large B-cell lymphoma and shows the importance of diagnosis and treatment of the injury at an early stage in order to promote the prognosis and survival of patients.

Multiple viral infections in primary effusion lymphoma: a model of viral cooperation in lymphomagenesis

INTRODUCTION

Primary effusion lymphoma (PEL) is a rare B-cell lymphoid neoplasm mainly associated with HIV infection, presenting as pleural, peritoneal, and pericardial effusions. A defining property of PEL is its consistent association with Kaposi sarcoma associated herpesvirus (KSHV) infection, and, in most cases, Epstein Barr virus (EBV) co-infection. On these grounds, a review of the literature related to viral cooperation and lymphomagenesis can help to understand the complex interplay between KSHV and EBV in PEL pathogenesis. Areas covered: In this review, the authors highlight clinical, pathologic, genetic and proteomic features of PEL, in the context of viral cooperation in PEL lymphomagenesis. Expert commentary: Tumour cells are characterized by the overexpression of genes that are involved in inflammation and invasion. Coherently, PEL secretomes are enriched in proteins probably responsible for the particular tropism (cell adhesion and migration) of PEL cells. The development of PEL in HIV+ patients is multifactorial and involves a complex interplay among co-infection with oncogenic viruses (EBV and KSHV), inflammatory factors, and environmental conditions.

Human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) related lymphomas, pathology view point

The contribution of Epstein Barr virus (EBV) and Kaposi sarcoma herpes virus (KSHV) to the development of specific types of malignant lymphomas occurring in the human immunodeficiency virus (HIV) setting has been extensively studied since the beginning of the HIV epidemic 35 years ago. The introduction of highly active antiretroviral therapies (HAART) in 1996 has changed dramatically the incidence of HIV-related malignancies. Nevertheless, malignant lymphomas continue to be the major group of malignances observed in HIV infected individuals, and the most common cause of cancer related-deaths. Common features of the predominant B-cell lymphomas in the HIV⁺ setting are the frequent plasmacytoid morphology of the neoplastic cells, advanced stage, aggressive disease and frequent extranodal involvement. In this article, we review the evolving concepts and definitions of the various EBV-associated lymphomas in HIV⁺ patients, including diffuse large B-cell lymphoma, Burkitt lymphoma, classical Hodgkin lymphoma, plasmablastic lymphoma and primary effusion lymphoma. The current knowledge regarding the pathogenesis of these malignancies, the interplay between HIV and EBV co-infection in the development of certain HIV related lymphomas, and the emerging paradigm that suggests that HIV may play a direct role in lymphomagenesis are explored as well.

Head and neck lymphomas: A 20-year review in an Oral Pathology Unit, Johannesburg, South Africa, a country with the highest global incidence of HIV/AIDS

OBJECTIVES

Non-Hodgkin lymphoma occurs with increasing frequency in HIV/AIDS. As South Africa has the highest incidence of HIV/AIDS worldwide, an epidemiologic study of this nature provides insight into head and neck lymphomas in a defined South African population. This retrospective review evaluated frequency and clinico-pathologic characteristics of patients diagnosed with head and neck lymphoma at the Oral Pathology Department, University of Witwatersrand between 1993 and 2012.

MATERIALS AND METHODS

Histopathology reports of patients with head and neck lymphomas (n=504) were reviewed. Demographic (age, gender), clinical (site and size of tumour), laboratory and histological parameters were recorded.

RESULTS

There were 504 patients with head and neck lymphomas. The mean age was 40.4years. The male:female ratio was 1.1:1. The cervical lymph node was the most common anatomic site (115 cases) and the maxilla (60 cases) the most common extranodal site. Plasmablastic lymphoma (159 cases) was the most common histologic subtype, seen more frequently as a result of its strong association with HIV/AIDS. The most common Hodgkin's lymphoma was the nodular sclerosing variant (21 cases). Of the head and neck lymphomas in patients with a known HIV status, 56% had plasmablastic lymphoma, 43.9% diffuse large B cell lymphoma and 25% Burkitt lymphoma.

CONCLUSION

There is an increase in head and neck lymphoma frequency, contrary to that found in Western countries. The high HIV prevalence in certain lymphomas provides strong indication of the role of HIV/AIDS in pathogenesis of lymphomas. This study serves as a baseline for future studies, especially in South Africa.

Role of Feline Immunodeficiency Virus in Lymphomagenesis--Going Alone or Colluding?

Feline immunodeficiency virus (FIV) is a naturally occurring lentivirus of domestic and nondomestic feline species. Infection in domestic cats leads to immune dysfunction via mechanisms similar to those caused by human immunodeficiency virus (HIV) and, as such, is a valuable natural animal model for acquired immunodeficiency syndrome (AIDS) in humans. An association between FIV and an increased incidence of neoplasia has long been recognized, with frequencies of up to 20% in FIV-positive cats recorded in some studies. This is similar to the rate of neoplasia seen in HIV-positive individuals, and in both species neoplasia typically requires several years to arise. The most frequently reported type of neoplasia associated with FIV infection is lymphoma. Here we review the possible mechanisms involved in FIV lymphomagenesis, including the possible involvement of coinfections, notably those with gamma-herpesviruses.

Current Progress in EBV-Associated B-Cell Lymphomas

Epstein-Barr virus (EBV) was the first human tumor virus discovered more than 50 years ago. EBV-associated lymphomagenesis is still a significant viral-associated disease as it involves a diverse range of pathologies, especially B-cell lymphomas. Recent development of high-throughput next-generation sequencing technologies and in vivo mouse models have significantly promoted our understanding of the fundamental molecular mechanisms which drive these cancers and allowed for the development of therapeutic intervention strategies. This review will highlight the current advances in EBV-associated B-cell lymphomas, focusing on transcriptional regulation, chromosome aberrations, in vivo studies of EBV-mediated lymphomagenesis, as well as the treatment strategies to target viral-associated lymphomas.

B-cell Lymphoproliferative Disorders Associated with Primary and Acquired Immunodeficiency

The diagnosis of lymphoproliferative disorders associated with immunodeficiency can be challenging because many of these conditions have overlapping clinical and pathologic features and share similarities with their counterparts in the immunocompetent setting. There are subtle but important differences between these conditions that are important to recognize for prognostic and therapeutic purposes. This article provides a clinicopathologic update on how understanding of these B-cell lymphoproliferations in immunodeficiency has evolved over the past decade.

Risk of lymphoid neoplasms in a Swedish population-based cohort of 337,437 patients undergoing appendectomy

OBJECTIVE

Appendectomy remains one of the most common surgical procedures, but possible long-term consequences for health and disease are incompletely investigated. The appendix forms part of the secondary lymphoid system and appendectomy has been associated with increased risks of hematolymphoproliferative malignancies in some studies.

MATERIALS AND METHODS

We examined the risk of lymphoid neoplasms in a large cohort of 337,437 appendectomised patients <60 years of age in Sweden 1975-2009. We estimated relative risks of non-Hodgkin lymphoma (NHL) and major subtypes, Hodgkin lymphoma (HL), chronic lymphocytic leukaemia (CLL), myeloma, and acute lymphoblastic leukaemia (ALL) versus the general population using standardised incidence ratios (SIRs) with 95% confidence intervals (CIs).

RESULTS

There was no increased risk of NHL (SIR = 0.97, 95%CI 0.88-1.06), major NHL subtypes, CLL (SIR = 0.87, 95%CI 0.70-1.06), myeloma (SIR = 1.14, 95%CI 0.96-1.33) or ALL (SIR = 1.10, 95%CI 0.80-1.47) following appendectomy. An increased risk of HL was observed among patients diagnosed with appendicitis (SIR = 1.29, 95%CI 1.07-1.54, p=0.007), especially individuals aged <20 years at surgery (SIR = 1.43, 95%CI 1.11-1.82), and for the nodular sclerosis subtype of HL (SIR = 1.55, 95%CI 1.01-2.27). A marginally increased risk of myeloma was noted among men, but the association was limited to the first few years of follow-up.

CONCLUSION

Appendectomy is not associated with any notable increase in risk of lymphoid neoplasms. A small increased risk of HL following appendicitis (rather than appendectomy per se) could reflect a true association, or shared susceptibility to infection/inflammation among individuals prone to develop HL. The association observed for myeloma may be explained by chance or surveillance bias.

Determining protein biomarkers for DLBCL using FFPE tissues from HIV negative and HIV positive patients

DLBCL is the most common lymphoma subtype occurring in older populations as well as in younger HIV infected patients. The current treatment options for DLBCL are effective for most patients yet the relapse rate is high. While many biomarkers for DLBCL exist, they are not in clinical use due to low sensitivity and specificity. In addition, these biomarkers have not been studied in the HIV context. Therefore, the identification of new biomarkers for HIV negative and HIV positive DLBCL, may lead to a better understanding of the disease pathology and better therapeutic design. Protein biomarkers for DLBCL were determined using MALDI imaging mass spectrometry (IMS) and characterised using LC-MS. The expression of one of the biomarkers, heat shock protein (Hsp) 70, was confirmed on a separate cohort of samples using immunohistochemistry. The biomarkers identified in the study consisted of four protein clusters including glycolytic enzymes, ribosomal proteins, histones and collagen. These proteins could differentiate between control and tumour tissue, and the DLBCL immunohistochemical subtypes in both cohorts. The majority (41/52) of samples in the confirmation cohort were negative for Hsp70 expression. The HIV positive DLBCL cases had a higher percentage of cases expressing Hsp70 than their HIV negative counterparts. The non-GC subtype also frequently overexpressed Hsp70, confirming MALDI IMS data. The expression of Hsp70 did not correlate with survival in both the HIV negative and HIV positive cohort. This study identified potential biomarkers for HIV negative and HIV positive DLBCL from FFPE tissue sections. These may be used as diagnostic and prognostic markers complementary to current clinical management programmes for DLBCL.

[Plasmablastic lymphoma]

Plasmablastic lymphoma (PBL) is a rare and aggressive subtype of non-Hodgkin lymphoma that commonly occurs in human immunodeficiency virus (HIV)-positive individuals, and affects oral sites. Occasionally, it has been described in HIV-negative patients and involving non-oral sites. Pathologically, PBL is a high-grade B-cell lymphoma that displays the immunophenotype of a terminally differentiated B-lymphocyte with loss of B-cell markers (CD20) and expression of plasma-cell antigens. Epstein-Barr virus infection and MYC rearrangements are frequently observed. Treatment of PBL is challenging because of the lack of established treatment and poor outcomes, with median survival times shorter than one year. In this review, we discuss the clinical and epidemiologic spectrum of PBL as well as its distinct pathological features. Finally, we summarize the currently available approaches for the treatment of patients with PBL.

Viral-associated malignancies in Africa: are viruses 'infectious traces' or 'dominant drivers'?

Since the discovery of Epstein-Barr virus (EBV) the first human virus associated with cancer in 1964, the number of human malignancies associated with viruses has grown. A review of cancer incidence reveals substantial variation in the incidence of such cancers around the world. In some parts of Africa, the majority of cancers are caused by infectious agents. However, there remain huge challenges in measuring the burden of cancer, especially in sub-Saharan Africa. Despite this limitation, it is clear that viral-associated malignancies are key drivers of cancer incidence rates in Africa. Prevention is available through vaccination for some but development of vaccines for others remains an important the goal.

Trends in primary central nervous system lymphoma incidence and survival in the U.S

It is suspected that primary central nervous system lymphoma (PCNSL) rates are increasing among immunocompetent people. We estimated PCNSL trends in incidence and survival among immunocompetent persons by excluding cases among human immunodeficiency virus (HIV)-infected persons and transplant recipients. PCNSL data were derived from 10 Surveillance, Epidemiology and End Results (SEER) cancer registries (1992-2011). HIV-infected cases had reported HIV infection or death due to HIV. Transplant recipient cases were estimated from the Transplant Cancer Match Study. We estimated PCNSL trends overall and among immunocompetent individuals, and survival by HIV status. A total of 4158 PCNSLs were diagnosed (36% HIV-infected; 0·9% transplant recipients). HIV prevalence in PCNSL cases declined from 64·1% (1992-1996) to 12·7% (2007-2011), while the prevalence of transplant recipients remained low. General population PCNSL rates were strongly influenced by immunosuppressed cases, particularly in 20-39 year-old men. Among immunocompetent people, PCNSL rates in men and women aged 65+ years increased significantly (1·7% and 1·6%/year), but remained stable in other age groups. Five-year survival was poor, particularly among HIV-infected cases (9·0%). Among HIV-uninfected cases, 5-year survival increased from 19·1% (1992-1994) to 30·1% (2004-2006). In summary, PCNSL rates have increased among immunocompetent elderly adults, but not in younger individuals. Survival remains poor for both HIV-infected and HIV-uninfected PCNSL patients.

Clinicopathologic characteristics of HIV/AIDS-related plasmablastic lymphoma

Plasmablastic lymphoma is a rare and aggressive B cell lymphoma that is considered to be strongly associated with HIV infection. This article explores the histological morphology and immunohistochemical characteristics of HIV/AIDS-related plasmablastic lymphoma with the goal of improving the diagnosis and treatment of this rare tumor. According to criteria of the World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues (2008), six plasmablastic lymphoma cases admitted to the Shanghai Public Health Clinical Center were comprehensively analyzed with conventional hematoxylin-eosin staining, immunohistochemical staining and in situ hybridization. The morphological features of six tumors were consistent with PBL. Immunohistochemical staining showed that all six cases were negative for CD19, CD20, and CD79a, and positive for OCT-2, BOB-1, VS38c, and melanoma ubiquitous mutated 1. The Ki67 proliferation index was higher than 90% in all six cases. In situ hybridization indicated that four cases were EBER-positive. In addition, three cases had C-MYC translocation rearrangement. Our results showed that the immunophenotypes of PBL vary, which makes PBL diagnosis difficult. Therefore, morphological characteristics, immunophenotypic markers, and clinical data should be used in combination to enable an accurate diagnosis, especially in the presence of immunophenotypic variation, as this approach will facilitate timely treatment.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.

PD-1/CTLA-4 Blockade Inhibits Epstein-Barr Virus-Induced Lymphoma Growth in a Cord Blood Humanized-Mouse Model

Epstein-Barr virus (EBV) infection causes B cell lymphomas in humanized mouse models and contributes to a variety of different types of human lymphomas. T cells directed against viral antigens play a critical role in controlling EBV infection, and EBV-positive lymphomas are particularly common in immunocompromised hosts. We previously showed that EBV induces B cell lymphomas with high frequency in a cord blood-humanized mouse model in which EBV-infected human cord blood is injected intraperitoneally into NOD/LtSz-scid/IL2Rγ^null (NSG) mice. Since our former studies showed that it is possible for T cells to control the tumors in another NSG mouse model engrafted with both human fetal CD34+ cells and human thymus and liver, here we investigated whether monoclonal antibodies that block the T cell inhibitory receptors, PD-1 and CTLA-4, enhance the ability of cord blood T cells to control the outgrowth of EBV-induced lymphomas in the cord-blood humanized mouse model. We demonstrate that EBV-infected lymphoma cells in this model express both the PD-L1 and PD-L2 inhibitory ligands for the PD-1 receptor, and that T cells express the PD-1 and CTLA-4 receptors. Furthermore, we show that the combination of CTLA-4 and PD-1 blockade strikingly reduces the size of lymphomas induced by a lytic EBV strain (M81) in this model, and that this anti-tumor effect requires T cells. PD-1/CTLA-4 blockade markedly increases EBV-specific T cell responses, and is associated with enhanced tumor infiltration by CD4+ and CD8+ T cells. In addition, PD-1/CTLA-4 blockade decreases the number of both latently, and lytically, EBV-infected B cells. These results indicate that PD-1/CTLA-4 blockade enhances the ability of cord blood T cells to control outgrowth of EBV-induced lymphomas, and suggest that PD-1/CTLA-4 blockade might be useful for treating certain EBV-induced diseases in humans.

EBV is a human herpesvirus that remains in the host for life, but is normally well controlled by the host immune response. Nevertheless, EBV causes lymphomas in certain individuals, particularly when T cell function is impaired. Antibodies against two different inhibitory receptors on T cells, PD-1 and CTLA-4, have been recently shown to improve T cell cytotoxic function against a subset of non-virally associated tumors. Here we have used an EBV-infected cord blood-humanized mouse model to show that EBV-infected lymphomas express both the PD-L1 and PD-L2 inhibitory ligands for PD-1. Importantly, we find that the combination of PD-1 and CTLA-4 blockade decreases the growth of EBV-induced lymphomas in this model, and demonstrate that this anti-tumor effect requires T cells and enhances their responses to EBV. Our results suggest that PD-1/CTLA-4 blockade might be useful for treating certain EBV-associated diseases in humans.