Relationship of Epstein-Barr virus and interleukin 10 promoter polymorphisms with the risk and clinical outcome of childhood Burkitt lymphoma

Worldwide Prevalence of Epstein-Barr Virus in Patients with Burkitt Lymphoma: A Systematic Review and Meta-Analysis

Burkitt lymphoma (BL) is a form of B-cell malignancy that progresses aggressively and is most often seen in children. While Epstein-Barr virus (EBV) is a double-stranded DNA virus that has been linked to a variety of cancers, it can transform B lymphocytes into immortalized cells, as shown in BL. Therefore, the estimated prevalence of EBV in a population may assist in the prediction of whether this population has a high risk of increased BL cases. This systematic review and meta-analysis aimed to estimate the prevalence of Epstein-Barr virus in patients with Burkitt lymphoma. Using the appropriate keywords, four electronic databases were searched. The quality of the included studies was assessed using the Joanna Briggs Institute's critical appraisal tool. The results were reported as percentages with a 95% confidence interval using a random-effects model (CI). PROSPERO was used to register the protocol (CRD42022372293), and 135 studies were included. The prevalence of Epstein-Barr virus in patients with Burkitt lymphoma was 57.5% (95% CI: 51.5 to 63.4, n = 4837). The sensitivity analyses demonstrated consistent results, and 65.2% of studies were of high quality. Egger's test revealed that there was a significant publication bias. EBV was found in a significantly high proportion of BL patients (more than 50% of BL patients). This study recommends EBV testing as an alternative for predictions and the assessment of the clinical disease status of BL.

Investigation of cytokine polymorphisms on viral infections after renal transplantation exhibit association between IFN-γ +874 A > T and CMV manifestations

We investigated the effects of TNF-α, IFN-γ, IL-10 polymorphisms on viral infections (CMV, BKPyV, HHV-6, EBV) after renal transplantation. IFN-γ+874 A > T (lower IFN production) was associated with CMV disease (p = .039) in patients under mycophenolate-based therapy and graft failure (p = .025). This study underscores the role of IFN-γ+874 SNP in CMV infection.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Role of Epstein-Barr Virus in Pathogenesis and Racial Distribution of IgA Nephropathy

IgA nephropathy (IgAN) is the dominant type of primary glomerulonephritis worldwide. However, IgAN rarely affects African Blacks and is uncommon in African Americans. Polymeric IgA1 with galactose-deficient hinge-region glycans is recognized as auto-antigen by glycan-specific antibodies, leading to formation of circulating immune complexes with nephritogenic consequences. Because human B cells infected in vitro with Epstein-Barr virus (EBV) secrete galactose-deficient IgA1, we examined peripheral blood B cells from adult IgAN patients, and relevant controls, for the presence of EBV and their phenotypic markers. We found that IgAN patients had more lymphoblasts/plasmablasts that were surface-positive for IgA, infected with EBV, and displayed increased expression of homing receptors for targeting the upper respiratory tract. Upon polyclonal stimulation, these cells produced more galactose-deficient IgA1 than did cells from healthy controls. Unexpectedly, in healthy African Americans, EBV was detected preferentially in surface IgM- and IgD-positive cells. Importantly, most African Blacks and African Americans acquire EBV within 2 years of birth. At that time, the IgA system is naturally deficient, manifested as low serum IgA levels and few IgA-producing cells. Consequently, EBV infects cells secreting immunoglobulins other than IgA. Our novel data implicate Epstein-Barr virus infected IgA⁺ cells as the source of galactose-deficient IgA1 and basis for expression of relevant homing receptors. Moreover, the temporal sequence of racial-specific differences in Epstein-Barr virus infection as related to the naturally delayed maturation of the IgA system explains the racial disparity in the prevalence of IgAN.

Current Trends and Alternative Scenarios in EBV Research

Epstein-Barr virus (EBV) infection is associated with several distinct hematological and epithelial malignancies, e.g., Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal carcinoma, gastric carcinoma, and others. The association with several malignant tumors of local and worldwide distribution makes EBV one of the most important tumor viruses. Furthermore, because EBV can cause posttransplant lymphoproliferative disease, transplant medicine has to deal with EBV as a major pathogenic virus second only to cytomegalovirus. In this review, we summarize briefly the natural history of EBV infection and outline some of the recent advances in the pathogenesis of the major EBV-associated neoplasms. We present alternative scenarios and discuss them in the light of most recent experimental data. Emerging research areas including EBV-induced patho-epigenetic alterations in host cells and the putative role of exosome-mediated information transfer in disease development are also within the scope of this review. This book contains an in-depth description of a series of modern methodologies used in EBV research. In this introductory chapter, we thoroughly refer to the applications of these methods and demonstrate how they contributed to the understanding of EBV-host cell interactions. The data gathered using recent technological advancements in molecular biology and immunology as well as the application of sophisticated in vitro and in vivo experimental models certainly provided deep and novel insights into the pathogenetic mechanisms of EBV infection and EBV-associated tumorigenesis. Furthermore, the development of adoptive T cell immunotherapy has provided a novel approach to the therapy of viral disease in transplant medicine and hematology.

Circulating interleukin-10 levels and human papilloma virus and Epstein-Barr virus-associated cancers: evidence from a Mendelian randomization meta-analysis based on 11,170 subjects

Recent studies have showed interleukin 10 (IL-10) is a critical cytokine that determines antiviral immune response and is related to virus-associated cancers. However, whether genetically elevated circulating IL-10 levels are associated with the risk of human papilloma virus and Epstein–Barr virus-associated cancers (HEACs) is still unclear. Mendelian randomization method was implemented to meta-analyze available observational studies by employing IL-10 three variants (−592C>A, −819C>T, and −1082A>G) as instruments. A total of 24 articles encompassing 11,170 subjects were ultimately eligible for the meta-analysis. Overall, there was a significant association between IL-10 promoter variant −1082A>G and HEACs under allelic and dominant models (both P<0.01). Subgroup analysis by cancer type indicated that the risk estimate of −1082A>G was significant for nasopharyngeal cancer under allelic, homozygous genotypic and dominant models (all P<0.001). Moreover by ethnicity, carriers of −1082G allele had a 74% increased risk for nasopharyngeal cancer in Asians under dominant model (odds ratio [OR] =1.737; 95% confidence interval [CI]: 1.280–2.358; P<0.001). In further Mendelian randomization analysis, the predicted OR for 10 pg/mL increment in IL-10 levels was 1.14 (95% CI: 1.01–16.99) in HEACs. Our findings provided strong evidence for a critical role of genetically elevated circulating IL-10 levels in the development of HEACs, especially in Asian population and for nasopharyngeal cancer.

Proteomics and Transcriptomics of BJAB Cells Expressing the Epstein-Barr Virus Noncoding RNAs EBER1 and EBER2

In Epstein-Barr virus (EBV) latent infection, the EBV-encoded RNAs EBER1 and EBER2 accumulate in the host cell nucleus to ~10⁶ copies. While the expression of EBERs in cell lines is associated with transformation, a mechanistic explanation of their roles in EBV latency remains elusive. To identify EBER-specific gene expression features, we compared the proteome and mRNA transcriptome from BJAB cells (an EBV-negative B lymphoma cell line) stably transfected with an empty plasmid or with one carrying both EBER genes. We identified ~1800 proteins with at least 2 SILAC pair measurements, of which only 8 and 12 were up- and downregulated ≥ 2-fold, respectively. One upregulated protein was PIK3AP1, a B-cell specific protein adapter known to activate the PI3K-AKT signaling pathway, which regulates alternative splicing and translation in addition to its pro-survival effects. In the mRNA-seq data, the mRNA levels for some of the proteins changing in the SILAC data did not change. We instead observed isoform switch events. We validated the most relevant findings with biochemical assays. These corroborated the upregulation of PIK3AP1 and AKT activation in BJAB cells expressing high levels of both EBERs and EBNA1 (a surrogate of Burkitt’s lymphoma EBV latency I) relative to those expressing only EBNA1. The mRNA-seq data in these cells showed multiple upregulated oncogenes whose mRNAs are enriched for 3´-UTR AU-rich elements (AREs), such as ccl3, ccr7, il10, vegfa and zeb1. The CCL3, CCR7, IL10 and VEGFA proteins promote cell proliferation and are associated with EBV-mediated lymphomas. In EBV latency, ZEB1 represses the transcription of ZEBRA, an EBV lytic phase activation factor. We previously found that EBER1 interacts with AUF1 in vivo and proposed stabilization of ARE-containing mRNAs. Thus, the ~10⁶ copies of EBER1 may promote not only cell proliferation due to an increase in the levels of ARE-containing genes like ccl3, ccr7, il10, and vegfa, but also the maintenance of latency, through higher levels of zeb1.

Host genetics of Epstein-Barr virus infection, latency and disease

Epstein–Barr virus (EBV) infects 95% of the adult population and is the cause of infectious mononucleosis. It is also associated with 1% of cancers worldwide, such as nasopharyngeal carcinoma, Hodgkin's lymphoma and Burkitt's lymphoma. Human and cancer genetic studies are now major forces determining gene variants associated with many cancers, including nasopharyngeal carcinoma and Hodgkin's lymphoma. Host genetics is also important in infectious disease; however, there have been no large-scale efforts towards understanding the contribution that human genetic variation plays in primary EBV infection and latency. This review covers 25 years of studies into host genetic susceptibility to EBV infection and disease, from candidate gene studies, to the first genome-wide association study of EBV antibody response, and an EBV-status stratified genome-wide association study of Hodgkin's lymphoma. Although many genes are implicated in EBV-related disease, studies are often small, not replicated or followed up in a different disease. Larger, appropriately powered genomic studies to understand the host response to EBV will be needed to move our understanding of the biology of EBV infection beyond the handful of genes currently identified. Fifty years since the discovery of EBV and its identification as a human oncogenic virus, a glimpse of the future is shown by the first whole-genome and whole-exome studies, revealing new human genes at the heart of the host–EBV interaction. © 2014 The Authors. Reviews in Medical Virology published by John Wiley & Sons Ltd.

Interleukin-6 and interleukin-10 gene promoter polymorphisms and risk of endemic Burkitt lymphoma

Overexpression of interleukin-6 (IL-6) and IL-10 in endemic Burkitt lymphoma (eBL) may facilitate tumorigenesis by providing a permissive cytokine milieu. Promoter polymorphisms influence interindividual differences in cytokine production. We hypothesized that children genetically predisposed for elevated cytokine levels may be more susceptible to eBL. Using case-control samples from western Kenya consisting of 117 eBL cases and 88 ethnically matched healthy controls, we tested for the association between eBL risk and IL-10 (rs1800896, rs1800871, and rs1800872) and IL-6 (rs1800795) promoter single nucleotide polymorphisms (SNPs) as well as IL-10 promoter haplotypes. In addition, the association between these variants and Epstein Barr Virus (EBV) load was examined. Results showed that selected IL-10 and IL-6 promoter SNPs and IL-10 promoter haplotypes were not associated with risk eBL or EBV levels in EBV-seropositive children. Findings from this study reveal that common variants within the IL-10 and IL-6 promoters do not independently increase eBL risk in this vulnerable population.

Analysis of interleukin-10 promoter single nucleotide polymorphisms and risk of non-Hodgkin lymphoma in a Malaysian population

We evaluated the association of two IL10 single nucleotide polymorphisms (SNPs) (rs1800896 and rs1800871) with non-Hodgkin lymphoma (NHL) risk in the three major races of the Malaysian population (Malay, Chinese and Indian; 317 cases and 330 controls). Our initial screening demonstrated that rs1800871 but not rs1800896 was significantly associated with increased NHL risk in Malays (pMalay-Rec = 0.007) and Chinese only (pChinese-Rec = 0.039). Subsequent combined analysis of the Malay and Chinese revealed significant association of rs1800871 with all (ALL) NHL subtypes (pMeta-ALL-NHL-Rec = 0.001), ALL B-cell subtypes (pMeta-ALL-B-cell-Rec = 0.003), diffuse large B-cell lymphoma (DLBCL) subtype (pMeta-DLBCL-Rec = 0.002) and ALL T-cell subtypes (pMeta-ALL-T-cell-Rec = 0.031). SNP rs1800896 showed increased risk only in follicular lymphoma (FL) (pMeta-FL-Dom = 0.0004). We also detected a male-specific association of rs1800871 with increased NHL risk (pMeta-Male-ALL-NHL-Rec = 0.006) in the combined analysis. To our knowledge, this is the first report on the association of IL10 promoter SNPs with NHL susceptibility in the three major races of Malaysia.

Improved survival of gastric cancer with tumour Epstein-Barr virus positivity: an international pooled analysis

BACKGROUND AND OBJECTIVE

About 9% of gastric carcinomas have Epstein-Barr virus (EBV) in the tumour cells, but it is unclear whether viral presence influences clinical progression. We therefore examined a large multicentre case series for the association of tumour EBV status with survival after gastric cancer diagnosis, accounting for surgical stage and other prognostic factors.

METHODS

We combined individual-level data on 4599 gastric cancer patients diagnosed between 1976 and 2010 from 13 studies in Asia (n=8), Europe (n=3), and Latin America (n=2). EBV positivity of tumours was assessed by in situ hybridisation. Mortality HRs for EBV positivity were estimated by Cox regression models stratified by study, adjusted for distributions of sex (71% male), age (mean 58 years), stage (52% tumour-node-metastasis stages III or IV), tumour histology (49% poorly differentiated, 57% Lauren intestinal-type), anatomic subsite (70% non-cardia) and year of diagnosis. Variations by study and continent were assessed using study-specific HRs for EBV positivity.

RESULTS

During median 3.0 years follow-up, 49% of patients died. Stage was strongly predictive of mortality, with unadjusted HRs (vs stage I) of 3.1 for stage II, 8.1 for stage III and 13.2 for stage IV. Tumour EBV positivity was 8.2% overall and inversely associated with stage (adjusted OR: 0.79 per unit change). Adjusted for stage and other confounders, EBV positivity was associated with lower mortality (HR, 0.72; 95% CI 0.61 to 0.86), with low heterogeneity among the study populations (p=0.2). The association did not significantly vary across patient or tumour characteristics. There was no significant variation among the three continent-specific HRs (p=0.4).

CONCLUSIONS

Our findings suggest that tumour EBV positivity is an additional prognostic indicator in gastric cancer. Further studies are warranted to identify the mechanisms underlying this protective association.

Burkitt's lymphoma of the jaws in the Amazon region of Brazil

Objectives: To describe the clinicopathologic and immunohistochemical features of Burkitt’s lymphoma of the jaws in 7 patients of Northern Brazil. Study Design: Clinical data concerning gender, age, affected site, clinical presentation, symptomatology and follow-up were collected from the clinical files. Histopathology was complemented with a broad immunohistochemical panel and in situ hybridization for Epstein-Barr virus (EBV). Results: Most of the patients were infants and 5 out of 7 were males. The mandible was affected in 5 cases and all patients also presented abdominal involvement. All cases were positive for CD45, CD20, CD79a, CD10, Bcl-6 and EBV. Ki-67 proliferative index was approximately 100%. Six patients were treated with R-CHOP (Rituximab + Cyclophosphamide, Doxorubicin, Vincristine and Prednisolone) chemotherapy, and 2 of these died of the disease. One young adult patient refused treatment and died 3 months after initial diagnosis. Conclusions: Burkitt’s lymphoma of the jaws diagnosed in the Amazon region of Brazil present similar clinicopathologic features to those described in endemic areas of Africa, including EBV positivity.

Key words:Burkitt’s lymphoma, EBV, Brazil, Amazon region.

Herpesviruses and the microbiome

The focus of this article will be to examine the role of common herpesviruses as a component of the microbiome of atopic patients and to review clinical observations suggesting that atopic patients might be predisposed to more severe and atypical herpes-related illness because their immune response is biased toward a TH2 cytokine profile. Human populations are infected with 8 herpesviruses, including herpes simplex virus HSV1 and HSV2 (also termed HHV1 and HHV2), varicella zoster virus (VZV or HHV3), EBV (HHV4), cytomegalovirus (HHV5), HHV6, HHV7, and Kaposi sarcoma-associated herpesvirus (termed KSV or HHV8). Herpesviruses are highly adapted to lifelong infection of their human hosts and thus can be considered a component of the human "microbiome" in addition to their role in illness triggered by primary infection. HSV1 and HSV2 infection and reactivation can present with more severe cutaneous symptoms termed eczema herpeticum in the atopic population, similar to the more severe eczema vaccinatum, and drug reaction with eosinophilia and systemic symptoms syndrome (DRESS) is associated with reactivation of HSV6 and possibly other herpesviruses in both atopic and nonatopic patients. In this review evidence is reviewed that primary infection with herpesviruses may have an atypical presentation in the atopic patient and conversely that childhood infection might alter the atopic phenotype. Reactivation of latent herpesviruses can directly alter host cytokine profiles through viral expression of cytokine-like proteins, such as IL-10 (EBV) or IL-6 (cytomegalovirus and HHV8), viral encoded and secreted siRNA and microRNAs, and modulation of expression of host transcription pathways, such as nuclear factor κB. Physicians caring for allergic and atopic populations should be aware of common and uncommon presentations of herpes-related disease in atopic patients to provide accurate diagnosis and avoid unnecessary laboratory testing or incorrect diagnosis of other conditions, such as drug allergy or autoimmune disease. Antiviral therapy and vaccines should be administered promptly when indicated clinically.