Epstein-Barr virus infection and risk of lymphoma: immunoblot analysis of antibody responses against EBV-related proteins in a large series of lymphoma subjects and matched controls

Impact of Epstein-Barr virus co-infection on natural acquired Plasmodium vivax antibody response

Background

The simultaneous infection of Plasmodium falciparum and Epstein-Barr virus (EBV) could promote the development of the aggressive endemic Burkitt’s Lymphoma (eBL) in children living in P. falciparum holoendemic areas. While it is well-established that eBL is not related to other human malaria parasites, the impact of EBV infection on the generation of human malaria immunity remains largely unexplored. Considering that this highly prevalent herpesvirus establishes a lifelong persistent infection on B-cells with possible influence on malaria immunity, we hypothesized that EBV co-infection could have impact on the naturally acquired antibody responses to P. vivax, the most widespread human malaria parasite.

Methodology/Principal findings

The study design involved three cross-sectional surveys at six-month intervals (baseline, 6 and 12 months) among long-term P. vivax exposed individuals living in the Amazon rainforest. The approach focused on a group of malaria-exposed individuals whose EBV-DNA (amplification of balf-5 gene) was persistently detected in the peripheral blood (PersVDNA, n = 27), and an age-matched malaria-exposed group whose EBV-DNA could never be detected during the follow-up (NegVDNA, n = 29). During the follow-up period, the serological detection of EBV antibodies to lytic/ latent viral antigens showed that IgG antibodies to viral capsid antigen (VCA-p18) were significantly different between groups (PersVDNA > NegVDNA). A panel of blood-stage P. vivax antigens covering a wide range of immunogenicity confirmed that in general PersVDNA group showed low levels of antibodies as compared with NegVDNA. Interestingly, more significant differences were observed to a novel DBPII immunogen, named DEKnull-2, which has been associated with long-term neutralizing antibody response. Differences between groups were less pronounced with blood-stage antigens (such as MSP1-19) whose levels can fluctuate according to malaria transmission.

Conclusions/Significance

In a proof-of-concept study we provide evidence that a persistent detection of EBV-DNA in peripheral blood of adults in a P. vivax semi-immune population may impact the long-term immune response to major malaria vaccine candidates.

Antibodies as biomarkers for cancer risk: a systematic review

Increasing evidence has linked the humoral immune response with the development of various cancers. Therefore, there is growing interest in investigating the predictive value of antibodies to assess overall and tissue site-specific cancer risk. Given the large amount of antibody types and the broad scope of the search (i.e. cancer risk), the primary aim of this systematic review was to present an overview of the most researched antibodies (i.e. immunoglobulin (Ig) isotypes (IgG, IgM, IgA, and IgE), tumour and self-antigen-reactive antibodies, infection-related antibodies) in relation to overall and site-specific cancer risk. We identified various antibody types that have been associated with the risk of cancer. While no significant associations were found for IgM serum levels, studies found an inconsistent association among IgE, IgA, and IgG serum levels in relation to cancer risk. When evaluating antibodies against infectious agents, most studies reported a positive link with specific cancers known to be associated with the specific agent recognized by serum antibodies (i.e. helicobacter pylori and gastric cancer, hepatitis B virus and hepatocellular carcinoma, and human papillomavirus and cervical cancer). Several reports identified autoantibodies, as single biomarkers (e.g. anti-p53, anti-MUC1, and anti-CA125) but especially in panels of multiple autoantibodies, to have potential as diagnostic biomarkers for specific cancer types. Overall, there is emerging evidence associating certain antibodies to cancer risk, especially immunoglobulin isotypes, tumour-associated antigen-specific, and self-reactive antibodies. Further experimental studies are necessary to assess the efficacy of specific antibodies as markers for the early diagnosis of cancer.

EBV/HHV-6A dUTPases contribute to Myalgic Encephalomyelitis/Chronic-Fatigue-Syndrome pathophysiology by enhancing TFH cell differentiation and extrafollicular activities

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating multisystem illness of unknown etiology for which there is no cure and no diagnostic tests available. Despite increasing evidence implicating EBV and human herpesvirus-6A (HHV-6A) as potential causative infectious agents in a subset of ME/CFS patients, there are few mechanistic studies to address a causal relationship. In this study we examined a large ME/CFS cohort (n=351) and 77 controls and demonstrate a significant increase in activin A and IL-21serum levels, which correlated with seropositivity for antibodies to the EBV and HHV-6 protein deoxyuridine-triphosphate nucleotidohydrolase (dUTPase), but not CXCL13. These cytokines are critical for T follicular helper (TFH) cell differentiation, generation of high-affinity antibodies and long-lived plasma cells. Notably, ME/CFS serum was sufficient to drive TFH cell differentiation via an activin A-dependent mechanism. The lack of simultaneous CXCL13 increase with IL-21 indicates impaired TFH-function in ME/CFS. In vitro studies revealed that virus-dUTPases strongly induced activin A secretion while in vivo, EBV-dUTPase induced the formation of splenic marginal zone B and invariant NKTFH cells. Altogether, our data indicate abnormal germinal center (GC) activity in ME/CFS subjects and highlight a mechanism by which EBV and HHV6-dUTPases may alter GC and extrafollicular Ab responses.

Examination of control asymptomatic cohorts reveals heightened anti-EBV and HHV-6 A/B dUTPase antibodies in the aging populations

Members of the human Herpesviridae are found in high prevalence in the human virome. While these viruses are known to cause numerous disease pathologies in symptomatic individuals little is known concerning the role that these viruses may have in modulating the host immune system in asymptomatic “healthy” individuals, especially during the aging process. Examination of three cohorts of “healthy asymptomatic” individuals (n = 255) for the presence of antibodies against the herpesviruses deoxyuridine triphosphate nucleotidohydrolase (dUTPase) as a marker for lytic/abortive‐lytic replication demonstrated that all cohorts exhibited differential anti‐herpesvirus dUTPase antibodies positivity frequencies ranging from 40.4% to 84% with some individuals in these cohorts expressing antibodies to the dUTPases of multiple herpesviruses (17.2%–56%). Furthermore, our results demonstrate that there was a statistically significant difference in anti‐human herpesvirus 6 A and 6B (HHV‐6 A/B) dUTPase antibodies in Cohort 3 (age = 66.2 ± 15.02 years) versus Cohort 1 (age 46.88 ± 8.61 years), suggesting that reactivation of HHV‐6 A/B is not attenuated by aging. It is well established/documented that herpesvirus dUTPases induce immune dysfunction, as such it is of critical importance that additional studies be performed to determine how these viral proteins alter immune responses in asymptomatic individuals.

Incidence of non-Hodgkin’s lymphoma among adults in Sardinia, Italy

The causes of the peculiar time trend in the incidence of non-Hodgkin’s lymphoma (NHL) in most parts of the world and of its geographic distribution are still unknown. We used the data base of 1974–2003 incident cases of hematological malignancies to explore the time trend of NHL incidence in the region of Sardinia, Italy, and we used Bayesian methods to plot the probability of NHL incidence by residential unit on the regional map. In 1974–2003, 4109 NHL cases were diagnosed among resident adults in Sardinia, with an incidence rate of 13.38 x 10⁻⁵ (95% CI 12.97–13.80). NHL incidence showed an upward trend along the study period with an average annual percent change (APC) of 4.94 (95% CI -5.39–16.4), which did not vary by gender or by age-group. Cancer registry data, covering part of the region starting from 1993, suggest that the increasing trend did not persist in the subsequent years. Areas with the highest probability of an excess incidence tended to cluster in the north-eastern part of the region and in two major urban centers, with the low incidence areas located in the south, confirming previous observations. Prevalence of viral infections, environmental and occupational exposures, or socio-economic deprivation would not explain the peculiar geographic distribution we observed. These findings provide convincing arguments for extending the coverage of routine cancer registration over the whole Sardinian population, while prompting further research on the genetic and environmental determinants of NHL in the risk areas.

Quantitative cytokine level of TNF-α, IFN-γ, IL-10, TGF-β and circulating Epstein-Barr virus DNA load in individuals with acute Malaria due to P. falciparum or P. vivax or double infection in a Malaria endemic region in Indonesia

Plasmodium falciparum Malaria and Epstein-Barr Virus (EBV) infection are risk factors in the development of Burkitt’s lymphoma. In Indonesia, 100% of the population is persistently infected with EBV early in life and at risk of developing EBV-linked cancers. Currently, 10.7 million people in Indonesia are living in Malaria-endemic areas. This cross-sectional study was initiated to investigate how acute Malaria dysregulates immune control over latent EBV infection. Using blood and plasma samples of 68 patients with acute Malaria and 27 healthy controls, we measured the level of parasitemia for each plasmodium type (P. falciparum, P. vivax, and mixed) by microscopy and rapid test. The level of 4 regulatory cytokines was determined by quantitative ELISA and the level of circulating EBV genome by real-time PCR targeting the single copy EBNA-1 sequence. All Plasmodium-infected cases had high-level parasitemia (>1000 parasites/ul blood) except for one case. EBV-DNA levels were significantly more elevated in P. falciparum and P. vivax infections (P<0.05) compared to controls. EBV-DNA levels were not related to age, gender, Malaria symptoms, or plasmodium type. TNF-α and IL-10 levels were increased in Malaria cases versus controls, but IFN-γ and TGF- β levels were comparable between the groups. Only TNF-α levels in P. falciparum cases showed a clear correlation with elevated EBV DNA levels (R² = 0.8915). This is the first study addressing the relation between EBV (re)activation and cytokine responses during acute Malaria, revealing a clear correlation between pro-inflammatory cytokine TNF-α and EBV-DNA levels, specifically in P. falciparum cases, suggesting this cytokine to be key in dysregulating EBV homeostasis during acute P. falciparum Malaria.

Pathogenic Role of Epstein-Barr Virus in Lung Cancers

Human oncogenic viruses account for at least 12% of total cancer cases worldwide. Epstein–Barr virus (EBV) is the first identified human oncogenic virus and it alone causes ~200,000 cancer cases and ~1.8% of total cancer-related death annually. Over the past 40 years, increasing lines of evidence have supported a causal link between EBV infection and a subgroup of lung cancers (LCs). In this article, we review the current understanding of the EBV-LC association and the etiological role of EBV in lung carcinogenesis. We also discuss the clinical impact of the knowledge gained from previous research, challenges, and future directions in this field. Given the high clinical relevance of EBV-LC association, there is an urgent need for further investigation on this topic.

Role of Virally Encoded Circular RNAs in the Pathogenicity of Human Oncogenic Viruses

Human oncogenic viruses are a group of important pathogens that etiologically contribute to at least 12% of total cancer cases in the world. As an emerging class of non-linear regulatory RNA molecules, circular RNAs (circRNAs) have gained increasing attention as a crucial player in the regulation of signaling pathways involved in viral infection and oncogenesis. With the assistance of current circRNA enrichment and detection technologies, numerous novel virally-encoded circRNAs (vcircRNAs) have been identified in the human oncogenic viruses, initiating an exciting new era of vcircRNA research. In this review, we discuss the current understanding of the roles of vcircRNAs in the respective viral infection cycles and in virus-associated pathogenesis.

Ubiquitin Modification of the Epstein-Barr Virus Immediate Early Transactivator Zta

The Epstein-Barr virus (EBV) immediate early transactivator Zta plays a key role in regulating the transition from latency to the lytic replication stages of EBV infection. Regulation of Zta is known to be controlled through a number of transcriptional and posttranscriptional events. Here, we show that Zta is targeted for ubiquitin modification and that this can occur in EBV-negative and in EBV-infected cells. Genetic studies show critical roles for both an amino-terminal region of Zta and the basic DNA binding domain of Zta in regulating Zta ubiquitination. Pulse-chase experiments demonstrate that the bulk population of Zta is relatively stable but that at least a subset of ubiquitinated Zta molecules are targeted for degradation in the cell. Mutation of four out of a total of nine lysine residues in Zta largely abrogates its ubiquitination, indicating that these are primary ubiquitination target sites. A Zta mutant carrying mutations at these four lysine residues (lysine 12, lysine 188, lysine 207, and lysine 219) cannot induce latently infected cells to produce and/or release infectious virions. Nevertheless, this mutant can induce early gene expression, suggesting a possible defect at the level of viral replication or later in the lytic cascade. As far as we know, this is the first study that has investigated the targeting of Zta by ubiquitination or its role in Zta function.IMPORTANCE Epstein-Barr virus (EBV) is a ubiquitous human pathogen and associated with various human diseases. EBV undergoes latency and lytic replication stages in its life cycle. The transition into the lytic replication stage, at which virus is produced, is mainly regulated by the viral gene product, Zta. Therefore, the regulation of Zta function becomes a central issue regarding viral biology and pathogenesis. Known modifications of Zta include phosphorylation and sumoylation. Here, we report the role of ubiquitination in regulating Zta function. We found that Zta is subjected to ubiquitination in both EBV-infected and EBV-negative cells. The ubiquitin modification targets 4 lysine residues on Zta, leading to both mono- and polyubiquitination of Zta. Ubiquitination of Zta affects the protein's stability and likely contributes to the progression of viral lytic replication. The function and fate of Zta may be determined by the specific lysine residue being modified.

Association of ionizing radiation dose from common medical diagnostic procedures and lymphoma risk in the Epilymph case-control study

Medical diagnostic X-rays are an important source of ionizing radiation (IR) exposure in the general population; however, it is unclear if the resulting low patient doses increase lymphoma risk. We examined the association between lifetime medical diagnostic X-ray dose and lymphoma risk, taking into account potential confounding factors, including medical history. The international Epilymph study (conducted in the Czech-Republic, France, Germany, Ireland, Italy, and Spain) collected self-reported information on common diagnostic X-ray procedures from 2,362 lymphoma cases and 2,465 frequency-matched (age, sex, country) controls. Individual lifetime cumulative bone marrow (BM) dose was estimated using time period-based dose estimates for different procedures and body parts. The association between categories of BM dose and lymphoma risk was examined using unconditional logistic regression models adjusting for matching factors, socioeconomic variables, and the presence of underlying medical conditions (atopic, autoimmune, infectious diseases, osteoarthritis, having had a sick childhood, and family history of lymphoma) as potential confounders of the association. Cumulative BM dose was low (median 2.25 mGy) and was not positively associated with lymphoma risk. Odds ratios (ORs) were consistently less than 1.0 in all dose categories compared to the reference category (less than 1 mGy). Results were similar after adjustment for potential confounding factors, when using different exposure scenarios, and in analyses by lymphoma subtype and by type of control (hospital-, population-based). Overall no increased risk of lymphoma was observed. The reduced ORs may be related to unmeasured confounding or other sources of systematic bias.We found little evidence that chronic medical conditions confound lymphoma risk and medical radiation associations.

Evaluation of the antibody response to the EBV proteome in EBV-associated classical Hodgkin lymphoma

The humoral immune response to Epstein-Barr virus (EBV) in classical Hodgkin lymphoma (cHL) stratified by EBV tumor status is unclear. We examined IgG and IgA antibody responses against 202 protein sequences representing 86 EBV proteins using a microarray and sera from 139 EBV-positive cHL cases, 70 EBV-negative cHL cases and 141 population-based controls frequency matched to EBV-positive cHL cases on sex and age by area (UK, Denmark and Sweden). We leveraged existing data on the proportion of circulating B-cells infected by EBV and levels of serum CCL17, a chemokine secreted by cHL tumor cells, from a subset of the cHL cases in the UK. Total IgG but not IgA response level was significantly different between EBV-positive cHL cases and controls. The distinct serological response included significant elevations in 16 IgG antibodies and 2 IgA antibodies, with odds ratios_{highest vs. lowest tertile > 3} observed for the following EBV proteins: LMP1 (oncogene), BcLF1 (VCAp160, two variants) and BBLF1 (two variants). Our cHL IgG signature correlated with the proportion of circulating EBV-infected B-cells, but not serum CCL17 levels. We observed no differences in the anti-EBV antibody profile between EBV-negative cHL cases and controls. BdRF1(VCAp40)-IgG and BZLF1(Zta)-IgG were identified as the serological markers best able to distinguish EBV-positive from EBV-negative cHL tumors. Our results support the hypothesis that differences in the EBV antibody profile are specific to patients with EBV-positive cHL and are not universally observed as part of a systematically dysregulated immune response present in all cHL cases.

EBV Positive Diffuse Large B Cell Lymphoma and Chronic Lymphocytic Leukemia Patients Exhibit Increased Anti-dUTPase Antibodies

The Epstein-Barr virus (EBV), which is a ubiquitous γ-herpesvirus, establishes a latent infection in more than 90% of the global adult population. EBV-associated malignancies have increased by 14.6% over the last 20 years, and account for approximately 1.5% of all cancers worldwide and 1.8% of all cancer deaths. However, the potential involvement/contribution of lytic proteins to the pathophysiology of EBV-associated cancers is not well understood. We have previously demonstrated that the EBV-deoxyuridine triphosphate nucleotidohydrolase (dUTPase) modulates innate and adaptive immune responses by engaging the Toll-Like Receptor 2 (TLR2), which leads to the modulation of downstream genes involved in oncogenesis, chronic inflammation, and in effector T-cell function. Furthermore, examination of serum samples from diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukemia patients revealed the presence of increased levels of anti-dUTPase antibodies in both cohorts compared to controls with the highest levels (3.67-fold increase) observed in DLBCL female cases and the lowest (2.12-fold increase) in DLBCL males. Using computer-generated algorithms, dUTPase amino acid sequence alignments, and functional studies of BLLF3 mutants, we identified a putative amino acid motif involved with TLR2 interaction. These findings suggest that the EBV-dUTPase: TLR2 interaction is a potential molecular target that could be used for developing novel therapeutics (small molecules/vaccines).

Gene Analysis of Epstein-Barr Virus-Associated Lymphomas in Hu-PBL/SCID Chimeras

Aims and background

The mechanisms of Epstein-Barr virus (EBV)-associated tumor development are incompletely understood. The aim of this study was to investigate the gene expression of EBV-associated lymphomas in hu-PBL/SCID mice.

Methods

Human peripheral blood lymphocytes (hu-PBL) from EBV-seropositive donors were transplanted into severe combined immunodeficiency (SCID) mice. In situ hybridization was used to detect EBV-encoded small RNA-1 (EBER1) in tumor tissues. Mutation of TP53 exons 5–8 in EBV-induced lymphomas was analyzed by PCR-SSCP. Immunohistochemical staining was used to examine EBV gene products and cellular oncoproteins.

Results

Twenty-one of 29 mice developed tumors. EBER1 was positive in the nuclei of almost all tumor cells. Immunohistochemistry showed positive staining of LMP1, EBNA2 and ZEBRA in a small number of tumor cells. Immunohistochemically detectable p53 protein expression was common (85.7%), but TP53 gene mutations were identified in only four cases (19.1%) of EBV-associated lymphomas. Positivity rates of C-myc, Bcl-2 and Bax expression were 100%, 95.2%, and 90.5%, respectively, in the 21 cases of EBV-associated lymphomas.

Conclusions

Our preliminary findings suggest that EBV-associated lymphomas in hu-PBL/SCID chimeras show EBV infection, expression of oncogenic viral genes, and overexpression of cellular oncogenes. TP53 gene mutations are rare but p53 protein is commonly expressed in EBV-associated lymphomas.

Molecular diversity of IgG responses to Epstein-Barr virus proteins in asymptomatic Epstein-Barr virus carriers

The Epstein-Barr virus (EBV) is a ubiquitous pathogen that infects over 90 % of adults. EBV is the primary etiological agent of infectious mononucleosis and is closely associated with nasopharyngeal carcinoma, gastric carcinoma, Hodgkin lymphoma and Burkitt lymphoma. Clinical serological assays for EBV diagnosis only survey a small portion of the viral proteome, which does not represent the total antigenic breadth presented to the immune system during viral infection. In this study, we have generated an expression library containing the majority of EBV ORFs, and have systematically evaluated IgG responses to those EBV proteins in sera from EBV carriers. In addition to confirming previously recognized dominant EBV antigens, this study has identified additional immunodominant antigens, and has revealed a more expansive antigenic profile of the humoral responses to EBV in asymptomatic carriers. This EBV expression library will be deposited in a public repository with the goal of disseminating this new research tool for the application of identifying potential new biomarkers for EBV-associated diseases.

Identifying novel genes and chemicals related to nasopharyngeal cancer in a heterogeneous network

Nasopharyngeal cancer or nasopharyngeal carcinoma (NPC) is the most common cancer originating in the nasopharynx. The factors that induce nasopharyngeal cancer are still not clear. Additional information about the chemicals or genes related to nasopharyngeal cancer will promote a better understanding of the pathogenesis of this cancer and the factors that induce it. Thus, a computational method NPC-RGCP was proposed in this study to identify the possible relevant chemicals and genes based on the presently known chemicals and genes related to nasopharyngeal cancer. To extensively utilize the functional associations between proteins and chemicals, a heterogeneous network was constructed based on interactions of proteins and chemicals. The NPC-RGCP included two stages: the searching stage and the screening stage. The former stage is for finding new possible genes and chemicals in the heterogeneous network, while the latter stage is for screening and removing false discoveries and selecting the core genes and chemicals. As a result, five putative genes, CXCR3, IRF1, CDK1, GSTP1, and CDH2, and seven putative chemicals, iron, propionic acid, dimethyl sulfoxide, isopropanol, erythrose 4-phosphate, β-D-Fructose 6-phosphate, and flavin adenine dinucleotide, were identified by NPC-RGCP. Extensive analyses provided confirmation that the putative genes and chemicals have significant associations with nasopharyngeal cancer.

Identification of IgH gene rearrangement and immunophenotype in an animal model of Epstein-Barr virus-associated lymphomas

Epstein-Barr virus (EBV) is a human oncogenic herpesvirus associated with lymphoma and nasopharyngeal carcinoma. Because the susceptible hosts of EB virus are limited to human and cotton-top tamarins (Saguinus oedipus), there have been no appropriate animal models until the lymphoma model induced by EBV in human peripheral blood lymphocyte (hu-PBL)/SCID chimeric mice was reported. However, it is still controversial whether the EBV-associated lymphoma induced in hu-PBL/SCID mice is a monoclonal tumor. In this study, we transplanted normal human peripheral blood lymphocytes (hu-PBL) from six donors infected with EBV into SCID mice to construct hu-PBL/SCID chimeric mice. The induced tumors were found in the mediastinum or abdominal cavity of SCID mice. Microscopic observation exhibited tumor cells that were large and had a plasmablastic, centroblastic or immunoblastic-like appearance. Immunophenotyping assays showed the induced tumors were LCA-positive, CD20/CD79a-positive (markers of B cells), and CD3/CD45RO-negative (markers of T cells). A human-specific Alu sequence could be amplified by Alu-PCR. This confirmed that induced tumors were B-cell lymphomas originating from the transplanted human lymphocytes rather than mouse cells. EBER in situ hybridization detected positive signals in the nuclei of the tumor cells. Expression of EBV-encoded LMP1, EBNA-1, and EBNA-2 in the tumors was significantly positive. PCR-based capillary electrophoresis analysis of IgH gene rearrangement revealed a monoclonal peak and single amplification product in all six cases of induced tumors. This indicated that EBV can induce monoclonal proliferation of human B lymphocytes and promotes the development of lymphoma. J. Med. Virol. 88:1804-1813, 2016. © 2016 Wiley Periodicals, Inc.

Aberrant Epstein-Barr virus antibody patterns and chronic lymphocytic leukemia in a Spanish multicentric case-control study

Background

Epstein-Barr virus (EBV)-related malignancies harbour distinct serological responses to EBV antigens. We hypothesized that EBV serological patterns can be useful to identify different stages of chronic lymphocytic leukemia.

Methods

Information on 150 cases with chronic lymphocytic leukemia and 157 frequency-matched (by age, sex and region) population-based controls from a Spanish multicentre case-control study was obtained. EBV immunoglobulin G serostatus was evaluated through a peptide-based ELISA and further by immunoblot analysis to EBV early antigens (EA), nuclear antigen (EBNA1), VCA-p18, VCA-p40 and Zebra. Two independent individuals categorized the serological patterns of the western blot analysis. Patients with very high response and diversity in EBV-specific polypeptides, in particular with clear responses to EA-associated proteins, were categorized as having an abnormal reactive pattern (ab_EBV). Adjusted odds ratios (OR) and 95% confidence interval (CI) were estimated using logistic regression models.

Results

Almost all subjects were EBV-IgG positive (>95% of cases and controls) whereas ab_EBV patterns were detected in 23% of cases (N = 34) and 11% of controls (N = 17; OR: 2.44, 95% CI, 1.29 to 4.62; P = 0.006), particularly in intermediate/high risk patients. Although based on small numbers, the association was modified by smoking with a gradual reduction of ab_EBV-related OR for all Rai stages from never smokers to current smokers.

Conclusions

Highly distinct EBV antibody diversity patterns revealed by immunoblot analysis were detected in cases compared to controls, detectable at very early stages of the disease and particularly among non smokers. This study provides further evidence of an abnormal immunological response against EBV in patients with chronic lymphocytic leukemia.

Electronic supplementary material

The online version of this article (doi:10.1186/1750-9378-10-5) contains supplementary material, which is available to authorized users.

Population-based multicase-control study in common tumors in Spain (MCC-Spain): rationale and study design

INTRODUCTION

We present the protocol of a large population-based case-control study of 5 common tumors in Spain (MCC-Spain) that evaluates environmental exposures and genetic factors.

METHODS

Between 2008-2013, 10,106 subjects aged 20-85 were enrolled in 23 hospitals and primary care centres in 12 Spanish provinces including 1,112 cases with a new diagnosis of prostate cancer, 1,738 of breast cancer, 2,140 of colorectal cancer, 459 of gastro-oesophageal cancer, 559 cases with chronic lymphocytic leukaemia and 4,098 population controls frequency matched to cases by age, sex and region of residence. Participation rates ranged from 57% (stomach cancer) to 87% (CLL cases) and from 30% to 77% in controls. Participants completed a face-to-face computerized interview on sociodemographic factors, environmental exposures, occupation, medication, lifestyle, and personal and family medical history. In addition, participants completed a self-administered food-frequency questionnaire and telephone interviews. Blood samples were collected from 76% of participants while saliva samples were collected in CLL cases and participants refusing blood extractions. Clinical information was recorded for cases and paraffin blocks and/or fresh tumor samples are available in most collaborating hospitals. Genotyping was done through an exome array enriched with genetic markers in specific pathways. Multiple analyses are planned to assess the association of environmental, personal and genetic risk factors for each tumor and to identify pleiotropic effects.

DISCUSSION

This study, conducted within the Spanish Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), is a unique initiative to evaluate etiological factors for common cancers and will promote cancer research and prevention in Spain.

Epstein-Barr Virus-Specific Humoral Immune Responses in Health and Disease

Epstein-Barr virus (EBV) is widely distributed in the world and associated with a still increasing number of acute, chronic, malignant and autoimmune disease syndromes. Humoral immune responses to EBV have been studied for diagnostic, pathogenic and protective (vaccine) purposes. These studies use a range of methodologies, from cell-based immunofluorescence testing to antibody-diversity analysis using immunoblot and epitope analysis using recombinant or synthetic peptide-scanning. First, the individual EBV antigen complexes (VCA , MA, EA(D), EA(R) and EBNA) are defined at cellular and molecular levels, providing a historic overview. The characteristic antibody responses to these complexes in health and disease are described, and differences are highlighted by clinical examples. Options for EBV vaccination are briefly addressed. For a selected number of immunodominant proteins, in particular EBNA1, the interaction with human antibodies is further detailed at the epitope level, revealing interesting insights for structure, function and immunological aspects, not considered previously. Humoral immune responses against EBV-encoded tumour antigens LMP1, LMP2 and BARF1 are addressed, which provide novel options for targeted immunotherapy. Finally, some considerations on EBV-linked autoimmune diseases are given, and mechanisms of antigen mimicry are briefly discussed. Further analysis of humoral immune responses against EBV in health and disease in carefully selected patient cohorts will open new options for understanding pathogenesis of individual EBV-linked diseases and developing targeted diagnostic and therapeutic approaches.

Epstein-Barr virus antibodies and the risk of associated malignancies: review of the literature

Epstein-Barr virus (EBV), a ubiquitous herpes virus that infects 90% of humans by adulthood, is linked to the development of various cancers, including nasopharyngeal carcinoma, gastric cancer, Burkitt lymphoma, non-Hodgkin lymphoma (NHL), and Hodgkin lymphoma. We reviewed the literature published since 1980 regarding an association between antibodies against EBV proteins and the risk of EBV-associated malignancies. Immunoglobulin A antibody levels that are elevated before diagnosis have consistently been associated with the risk of nasopharyngeal carcinoma, and patients with Hodgkin lymphoma have significantly higher immunoglobulin G antibody levels than disease-free controls. However, the link between the immune response to EBV and other EBV-associated malignancies was less clear. Although evidence of an association between the risk of Burkitt lymphoma and immunoglobulin G antibodies was consistent for available studies, the sample sizes were limited. Evidence for a link between antibodies against EBV and risk of either gastric cancer or NHL was inconsistent. Future investigations should account for tumor EBV status because only 7%-10% of gastric tumors and select NHL subtypes are related to EBV infection. Comparing differences in the associations between the humoral immune response to EBV and disease risk across cancers may help elucidate how this ubiquitous virus contributes to distinct tumors globally.

Therapeutic implications of Epstein-Barr virus infection for the treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is highly endemic in certain regions including the People’s Republic of China and Southeast Asia. Its etiology is unique and multifactorial, involving genetic background, epigenetic, and environment factors, including Epstein–Barr virus (EBV) infection. The presence of EBV in all tumor cells, aberrant pattern of antibodies against EBV antigens in patient sera, and elevated viral DNA in patient circulation as well as nasopharyngeal site underline the role of EBV during NPC development. In NPC tumors, EBV expresses latency type II, where three EBV-encoded proteins, Epstein–Barr nuclear antigen 1, latent membrane protein 1 and 2 (LMP1, 2), are expressed along with BamH1-A rightward reading frame 1, Epstein–Barr virus-encoded small nuclear RNAs, and BamH1-A rightward transcripts. Among all encoded proteins, LMP1 plays a central role in the propagation of NPC. Standard treatment of NPC consists of radiotherapy with or without chemotherapy for early stage, concurrent chemoradiotherapy in locally advanced tumors, and palliative systemic chemotherapy in metastatic disease. However, this standard care has limitations, allowing recurrences and disease progression in a certain proportion of cases. Although the pathophysiological link and molecular process of EBV-induced oncogenesis are not fully understood, therapeutic approaches targeting the virus may increase the cure rate and add clinical benefit. The promising results of early phase clinical trials on EBV-specific immunotherapy, epigenetic therapy, and treatment with viral lytic induction offer new options for treating NPC.

Epstein-Barr virus and risk of non-Hodgkin lymphoma in the cancer prevention study-II and a meta-analysis of serologic studies

Epstein-Barr virus (EBV) causes rare, malignant lymphomas. The role of EBV in other non-Hodgkin lymphomas (NHLs) remains unclear, but mildly reduced immune function could lead to reactivation of EBV and subsequent NHL. We examined the association between prospectively-collected plasma EBV antibodies and NHL risk in the Cancer Prevention Study-II (CPS-II) Nutrition Cohort and conducted a meta-analysis of our and published results. The CPS-II study included 225 NHL cases and 2:1 matched controls. No associations were observed between EBV serostatus or antibody levels and risk of NHL overall. However, when including only the three most common types of NHL (diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma), high compared to low early antigen (EA-D) diffuse and BZLF1-encoded replication activator antibodies were associated with approximately 60% higher risk of NHL. Odds ratios (ORs) for EBV nuclear antigen-1 and viral capsid antigen (VCA)-p18 were elevated but not statistically significant. In the meta-analysis, both EA (summary OR = 1.52, 95% confidence interval (CI): 1.16-2.00) and VCA (summary OR = 1.20, 95% CI: 1.00-1.44) were positively associated with NHL risk. These results suggest EBV may be associated with a wider spectrum of NHL subtypes, but further study is needed to confirm and fully understand these associations.

Epstein-Barr virus viral load and serology in childhood non-Hodgkin's lymphoma and chronic inflammatory conditions in Uganda: implications for disease risk and characteristics

Epstein-Barr virus (EBV) has been linked to malignancies and chronic inflammatory conditions. In this study, EBV detection was compared in children with non-Hodgkin's lymphoma and children with chronic inflammatory conditions, using samples and data from a case-control study carried out at the Mulago National Referral Hospital between 2004 and 2008. EBV viral load was measured in saliva, whole blood and white blood cells by real-time PCR. Serological values for IgG-VCA, EBNA1, and EAd-IgG were compared in non-Hodgkin's lymphoma and chronic inflammatory conditions; and in Burkitt's lymphoma and other subtypes of non-Hodgkin's lymphoma. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated. Of the 127 children included (87 males and 40 females; median age 7 years, range 2-17), 96 had non-Hodgkin's lymphoma (46 Burkitt's lymphoma and 50 other non-Hodgkin's lymphoma), 31 had chronic inflammatory conditions, and only 10% were HIV-positive. The most common clinical presentations for all disease categories considered were fever, night sweats, and weight loss. EBV viral load in whole blood was elevated in Burkitt's lymphoma compared to other non-Hodgkin's lymphoma (OR 6.67, 95% CI 1.32, 33.69; P-value = 0.04), but EBV viral loads in saliva and white blood cells were not different in any of the disease categories considered. A significant difference in EAd-IgG was observed when non-Hodgkin's lymphoma was compared with chronic inflammatory conditions (OR 0.19, 95% CI 0.07, 0.51; P-value = 0.001). When compared to chronic inflammatory conditions, EBV viral load was elevated in Burkitt's lymphoma, and EA IgG was higher in non-Hodgkin's lymphoma. This study supports an association between virological and serological markers of EBV and childhood non-Hodgkin's lymphoma, irrespective of subtype, in Uganda.

Investigation of epstein-barr virus as a potential cause of B-cell non-Hodgkin lymphoma in a prospective cohort

BACKGROUND

We hypothesized that poor control of Epstein-Barr virus (EBV) infection, leading to reactivation of the virus, increases the risk of non-Hodgkin lymphoma (NHL) in the general population of primarily immunocompetent persons.

METHODS

We conducted a case-control study nested within the Women's Health Initiative Observational Study cohort in which we measured antibodies to EBV antigens [immunoglobulin G (IgG) to viral capsid antigen (VCA), nuclear antigen (EBNA1), and early antigen-diffuse (EA-D)] and EBV DNA load in prediagnostic samples of 491 B-cell NHL cases and 491 controls.

RESULTS

We found no association with established EBV infection, based on seropositivity for VCA. Seropositivity for EBNA1 was associated with decreased risk of B-cell NHL, overall [OR = 0.5; 95% confidence interval (CI), 0.3-0.8] and for each of the histologic subtypes examined. Increased risk of chronic lymphocytic leukemia (CLL) and related subtypes was observed with higher levels of EBV DNA and antibody to EA-D, both markers reflective of reactivation. These associations were strongest for cases with the shortest time interval between blood draw and diagnosis.

CONCLUSIONS

In balance, these results do not provide strong evidence of EBV playing a causal role in B-cell NHL in general population women. The associations we observed may reflect increased risk of NHL with underlying immune impairment or could be due to reverse causation.

IMPACT

Further characterization of the subtype-specific association with CLL is warranted. Exclusion of cases with preclinical disease markers (such as monoclonal B-lymphocytosis for CLL) may help rule out reverse causation in future studies.

Epstein-Barr virus and human herpesvirus 6 detection in a non-Hodgkin's diffuse large B-cell lymphoma cohort by using RNA sequencing

Comprehensive virome analysis of RNA sequence (RNA-seq) data sets from 118 non-Hodgkin's B-cell lymphomas revealed a small subset that is positive for Epstein-Barr virus (EBV) or human herpesvirus 6B (HHV-6B), with one coinfection. EBV transcriptome analysis revealed expression of the latency genes RPMS1, LMP1, and LMP2, with one sample additionally showing a high level of early lytic expression and another sample showing a high level of EBNA2 expression. HHV-6B transcriptome analysis revealed that the majority of genes were transcribed.

Self-reported history of infections and the risk of non-Hodgkin lymphoma: an InterLymph pooled analysis

We performed a pooled analysis of data on self-reported history of infections in relation to the risk of non-Hodgkin lymphoma (NHL) from 17 case-control studies that included 12,585 cases and 15,416 controls aged 16-96 years at recruitment. Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were estimated in two-stage random-effect or joint fixed-effect models, adjusting for age, sex and study centre. Data from the 2 years before diagnosis (or date of interview for controls) were excluded. A self-reported history of infectious mononucleosis was associated with an excess risk of NHL (OR = 1.26, 95% CI = 1.01-1.57 based on data from 16 studies); study-specific results indicate significant (I(2) = 51%, p = 0.01) heterogeneity. A self-reported history of measles or whooping cough was associated with an approximate 15% reduction in risk. History of other infection was not associated with NHL. We find little clear evidence of an association between NHL risk and infection although the limitations of data based on self-reported medical history (particularly of childhood illness reported by older people) are well recognized.

Antibodies against lytic and latent Kaposi's sarcoma-associated herpes virus antigens and lymphoma in the European EpiLymph case-control study

Background:

Kaposi's sarcoma-associated herpes virus is associated with primary effusion lymphoma and multicentric Castleman's disease.

Methods:

Seropositivity to lytic and latent Kaposi's sarcoma herpes virus (KSHV) antigens were examined in 2083 lymphomas and 2013 controls from six European countries.

Results:

Antibodies against KSHV latent and lytic antigens were detectable in 4.5% and 3.4% of controls, respectively, and 3.6% of cases (P>0.05). The KSHV seropositivity was associated with splenic marginal zone lymphoma (SMZL) (odds ratio (OR)=4.11, 95% confidence interval (CI)=1.57–10.83) and multiple myeloma (OR=0.31, 95% CI=0.11–0.85).

Conclusion:

The KSHV is unlikely to contribute importantly to lymphomagenesis among immunocompetent subjects. However, the observed association with SMZL may underline a chronic antigen mechanism in its aetiology.

Epstein-Barr virus in the multiple sclerosis brain: a controversial issue--report on a focused workshop held in the Centre for Brain Research of the Medical University of Vienna, Austria

Recent epidemiological and immunological studies provide evidence for an association between Epstein-Barr virus infection and multiple sclerosis, suggesting a role of Epstein-Barr virus infection in disease induction and pathogenesis. A key question in this context is whether Epstein-Barr virus-infected B lymphocytes are present within the central nervous system and the lesions of patients with multiple sclerosis. Previous studies on this topic provided highly controversial results, showing Epstein-Barr virus reactivity in B cells in the vast majority of multiple sclerosis cases and lesions, or only exceptional Epstein-Barr virus-positive B cells in rare cases. In an attempt to explain the reasons for these divergent results, a workshop was organized under the umbrella of the European Union FP6 NeuroproMiSe project, the outcome of which is presented here. This report summarizes the current knowledge of Epstein-Barr virus biology and shows that Epstein-Barr virus infection is highly complex. There are still major controversies, how to unequivocally identify Epstein-Barr virus infection in pathological tissues, particularly in situations other than Epstein-Barr virus-driven lymphomas or acute Epstein-Barr virus infections. It further highlights that unequivocal proof of Epstein-Barr virus infection in multiple sclerosis lesions is still lacking, due to issues related to the sensitivity and specificity of the detection methods.

Household contact with pets and birds and risk of lymphoma

BACKGROUND

Contact with household pets has been suggested to be inversely associated with lymphoma risk.

METHODS

We tested the hypothesis in a case-control study of lymphoma in the Sardinia region of Italy. Cases were 326 patients, first diagnosed with lymphoma in 1999-2003. Controls were 464 population controls, frequency matched to cases by age, gender, and area of residence. In person interviews included self-reported household contact with pets and birds, type of pet(s), and age at starting contact.

RESULTS

Frequent contact with birds was inversely associated with lymphoma, and particularly B-cell non-Hodgkin lymphoma (odds ratio [OR] = 0.6, 95% confidence interval [95% CI]: 0.4, 0.9). Contact with chickens accounted for this inverse association, which was strongest for first contact occurring at age ≤8 years (OR = 0.4, 95% CI: 0.2, 1.0). No association was observed when first contact occurred at age 9 or older. Contact with any pets was inversely associated with risk of diffuse large B-cell lymphoma (OR = 0.4, 95% CI: 0.2, 1.0), but not other lymphoma subtypes.

CONCLUSION

Our results support the hypothesis that early-life exposure to pets, birds and particularly with chickens might be associated with a reduced risk of lymphoma.

Single nucleotide polymorphisms of matrix metalloproteinase 9 (MMP9) and tumor protein 73 (TP73) interact with Epstein-Barr virus in chronic lymphocytic leukemia: results from the European case-control study EpiLymph

Using EpiLymph case-control data, we found that chronic lymphocytic leukemia patients were more likely to have abnormal reactive serological patterns to Epstein Barr virus than controls. Here, we aimed to assess whether this association is modified by genetic variants. We examined 1,305 Single Nucleotide Polymorphisms from 300 selected genes related to various pathways in 240 cases and 513 controls from five European centers. In a recessive model, patients positive to aberrant antibody pattern and homozygous for rare genotypes in rs8113877T>G or rs17576A>G of the MMP9 gene were at highest risk of chronic lymphocytic leukemia. In a dominant model, TP73 showed the highest risk in patients positive to aberrant antibody pattern and homozygous for the wild-type genotype in rs1885859G>C or rs3765701A>T. All interactions were additive and no main effect was observed. The strong interactions observed may be indicative of a specific pathway in cancer genesis. Confirmation of these results is warranted.

A prospective study of Epstein-Barr virus antibodies and risk of non-Hodgkin lymphoma

Severe immunosuppression is an established risk factor for non-Hodgkin lymphoma (NHL), but an association with subclinical immune dysfunction is unclear. We conducted a case-control study nested in the Physicians' Health Study and the Nurses' Health Study cohorts to determine whether patterns of antibody response to Epstein-Barr virus (EBV) were associated with NHL risk. We measured antibody titers against viral capsid antigen, early antigen, and Epstein-Barr nuclear antigen (EBNA-1 and EBNA-2) in blood samples collected before diagnosis from 340 cases and 662 matched controls. Using conditional logistic regression, we estimated rate ratios (RRs) and 95% confidence intervals (CIs) for elevated versus normal titers and the ratio of anti-EBNA-1 to anti-EBNA-2 titers (≤ 1.0 vs > 1.0). We found no association between EBV serostatus, elevated titers, or an EBNA-1/EBNA-2 ratio ≤ 1.0 and NHL risk overall. For chronic lymphocytic leukemia/small lymphocytic lymphoma, suggestive associations were noted for elevated anti-EBNA-2 (RR, 1.74; 95% CI, 0.99-3.05), anti-viral capsid antigen (RR, 1.58; 95% CI, 0.79-3.14), and EBNA-1/EBNA-2 ratio ≤ 1.0 (RR, 1.52; 95% CI, 0.91-2.55). There was no evidence of heterogeneity by subtype. Overall, we found no evidence that EBV antibody profile predicts NHL risk in immunocompetent persons, with the possible exception of chronic lymphocytic leukemia/small lymphocytic lymphoma.

No evidence for intrathecal IgG synthesis to Epstein Barr virus nuclear antigen-1 in multiple sclerosis

BACKGROUND

Recent studies suggest an intrathecal IgG response against Epstein Barr virus (EBV) in multiple sclerosis (MS), implicating a pathogenic role for the virus in MS.

OBJECTIVES

To determine the spectrum of anti-EBV antibodies and B-cell epitopes within EBV nuclear antigen-1 (EBNA-1). Furthermore, to determine whether EBNA-1-specific IgG is produced intrathecally.

STUDY DESIGN

Immunoblot analysis was used to study the anti-EBV IgG response in serum and cerebral spinal fluid (CSF) in MS and controls. EBNA-1 B-cell epitopes were identified by immunoscreening of 12 residue long peptides, with 11 residue overlap, spanning EBNA-1. Thirteen peptides containing all immunoreactive regions were constructed and used in paired serum and CSF of MS patients (n=17) and controls (n=18). Subsequently, reactivity to the identified immunodominant peptide was analysed in a large cohort of serum and CSF of MS patients (n=114) and disease controls (n=62).

RESULTS

No difference was observed in the overall anti-EBV antibody diversity, but EBNA-1 reactivity was increased in MS patients versus controls for immunoblot and ELISA (p<0.0001). Epitope analysis on EBNA-1 revealed one immunodominant region covering residues 394-451: EBNA-1(394-451). Anti-EBNA-1(394-451) IgG levels in serum and CSF were significantly higher in MS patients compared to controls. However, normalization for total IgG content of paired serum and CSF samples abrogated this disease association.

CONCLUSIONS

MS patients have normal overall anti-EBV antibody responses with increased reactivity to EBNA-1(394-451). No evidence was found for intrathecal EBNA-1-specific IgG synthesis in MS.

Epstein-Barr virus positive diffuse large B-cell lymphoma of the elderly

Epstein-Barr virus positive diffuse large B-cell lymphoma (EBV+ DLBCL) of the elderly is a rare B-cell lymphoproliferative disorder (B-LPD) that occurs in patients > 50 years with no known history of immunodeficiency or lymphoma. Patients present with moderate to severe clinical B-symptoms. These lesions show complete effacement of normal tissue/nodal architecture by large atypical lymphoid cells/immunoblasts and Hodgkin/Reed-Sternberg-like giant cells with variable amounts of inflammatory cells in the background. The ratio of neoplastic to inflammatory cells, degree of mitoses and necrosis can be quite variable; hence EBV+ DLBCL of the elderly was historically divided into low grade polymorphic and high grade monomorphic types. Further studies have shown both types to be different points in the spectrum of disease, and are all high grade lymphomas. The neoplastic large lymphoid cells show expression of CD20/CD79a and PAX-5, with variable expression of CD30, LMP-1 and EBNA-2, but CD15, CD10 and BCL6 are generally negative. Neoplastic cells show EBER positivity and high Ki-67 expression. Differential diagnoses include EBV+ B-LPD, classical Hodgkin lymphoma and EBV-DLBCL. EBV+ DLBCL of the elderly is highly aggressive with a median survival of 2 years. These patients are less responsive to standard chemotherapy compared with other B-LPD.

Two-step Epstein-Barr virus immunoglobulin A enzyme-linked immunosorbent assay system for serological screening and confirmation of nasopharyngeal carcinoma

Undifferentiated nasopharyngeal carcinoma (NPC; WHO type III) is 100% associated with Epstein-Barr virus (EBV) infection and the fourth most prevalent cancer in Indonesian males. Therapy failure is high, since most patients come to the hospital at an advanced stage of disease. Screening for early-stage NPC is needed. Here, a simple and economical two-step enzyme-linked immunosorbent assay (ELISA) system is proposed for diagnosing NPC in high-risk populations, employing the peptide-based immunoglobulin A (IgA) EBNA1 plus viral capsid antigen p18 ELISA as an initial screening test and the IgA early antigen (EA) ELISA using a different set of EBV antigens as a confirmation test. A total of 151 NPC patients and 199 regional healthy EBV carriers were used to evaluate the two-step ELISA approach. Routinely, EBV IgG immunoblotting is used as a standard confirmation test. The sensitivity and specificity for diagnosing NPC by the two-step ELISA approach increased from 85.4% to 96.7% and 90.1% to 98%, respectively, with positive predictive values and negative predictive values increasing from 78.7 and 93.9% to 97.3 and 97.5%, respectively, relative to the immunoblotting confirmation system. On discrepant samples, additional testing was done by EBV DNA load quantification in blood. Results showed that 5/11 discrepant NPC samples with an elevated IgA EA ELISA also had elevated an EBV DNA load in the circulation (range, 3,200 to 25,820 copies/ml). Therefore, the IgA EA ELISA is proposed as a confirmation test in first-line NPC serological screening studies. This two-step EBV ELISA system provides a standardized approach for NPC screening and may be used in combination with dried blood sampling in future field studies for identification of early-stage NPC in high-risk regions.

Laboratory assays for Epstein-Barr virus-related disease

Epstein-Barr virus (EBV) infects various cell types in a wide spectrum of benign and malignant diseases. Laboratory tests for EBV have improved and are increasingly used in diagnosis, prognosis, prediction, and prevention of diseases ranging from infectious mononucleosis to selected subtypes of lymphoma, sarcoma, and carcinoma. Indeed, the presence of EBV is among the most effective tumor markers supporting clinical management of cancer patients. In biopsies, localization of EBER transcripts by in situ hybridization remains the gold standard for identifying latent infection. Other RNA- and protein-based assays detect lytic viral replication and can distinguish carcinoma-derived from lymphocyte-derived EBV in saliva or nasopharyngeal brushings. Analysis of blood using EBV viral load and serology reflects disease status and risk of progression. This review summarizes prior research in the context of basic virologic principles to provide a rational strategy for applying and interpreting EBV tests in various clinical settings. Such assays have been incorporated into standard clinical practice in selected settings such as diagnosis of primary infection and management of patients with immune dysfunction or nasopharyngeal carcinoma. As novel therapies are developed that target virus-infected cells or overcome the adverse effects of infection, laboratory testing becomes even more critical for determining when intervention is appropriate and the extent to which it has succeeded.

Malignant lymphomas (ML) and HIV infection in Tanzania

Background

HIV infection is reported to be associated with some malignant lymphomas (ML) so called AIDS-related lymphomas (ARL), with an aggressive behavior and poor prognosis. The ML frequency, pathogenicity, clinical patterns and possible association with AIDS in Tanzania, are not well documented impeding the development of preventive and therapeutic strategies.

Methods

Sections of 176 archival formalin-fixed paraffin-embedded biopsies of ML patients at Muhimbili National Hospital (MNH)/Muhimbili University of Health and Allied Sciences (MUHAS), Tanzania from 1996–2001 were stained for hematoxylin and eosin and selected (70) cases for expression of pan-leucocytic (CD45), B-cell (CD20), T-cell (CD3), Hodgkin/RS cell (CD30), histiocyte (CD68) and proliferation (Ki-67) antigen markers. Corresponding clinical records were also evaluated. Available sera from 38 ML patients were screened (ELISA) for HIV antibodies.

Results

The proportion of ML out of all diagnosed tumors at MNH during the 6 year period was 4.2% (176/4200) comprising 77.84% non-Hodgkin (NHL) including 19.32% Burkitt's (BL) and 22.16% Hodgkin's disease (HD). The ML tumors frequency increased from 0.42% (1997) to 0.70% (2001) and 23.7% of tested sera from these patients were HIV positive. The mean age for all ML was 30, age-range 3–91 and peak age was 1–20 years. The male:female ratio was 1.8:1. Supra-diaphragmatic presentation was commonest and histological sub-types were mostly aggressive B-cell lymphomas however, no clear cases of primary effusion lymphoma (PEL) and primary central nervous system lymphoma (PCNSL) were diagnosed.

Conclusion

Malignant lymphomas apparently, increased significantly among diagnosed tumors at MNH between 1996 and 2001, predominantly among the young, HIV infected and AIDS patients. The frequent aggressive clinical and histological presentation as well as the dominant B-immunophenotype and the HIV serology indicate a pathogenic association with AIDS. Therefore, routine HIV screening of all malignant lymphoma patients at MNH is necessary to enable comprehensive ARL diagnosis and formulation of preventive and therapeutic protocols.

Evaluation of commercial EBV RecombLine assay for diagnosis of nasopharyngeal carcinoma

BACKGROUND

In recent years a number of Epstein-Barr virus (EBV) proteins were defined as being immunodominant for either IgM, IgG or IgA immune responses, yielding promising markers for diagnostic serology. Specific reactivity patterns to these proteins have been described for infectious mononucleosis (IM), nasopharyngeal carcinoma (NPC), various types of lymphoma, and healthy EBV carriers.

OBJECTIVES

To compare the NPC-related diagnostic value of EBV RecombLine test (Mikrogen, Germany) with a standardized immunoblot assay [Fachiroh J, Schouten T, Hariwiyanto B, Paramita DK, Harijadi A, Haryana SM, et al. Molecular diversity of Epstein-Barr virus IgG and IgA antibody responses in nasopharyngeal carcinoma: a comparison of Indonesian, Chinese, and European subjects. J Infect Dis 2004;190:53-62] and to define the diagnostic value of individual EBV marker proteins in a population with high incidence of NPC.

RESULT

Sera from Indonesian NPC patients taken at primary diagnosis (n=108) were analyzed for IgG and IgA reactivity and compared with regional healthy blood donors (n=62), non-NPC patient controls (n=10) and IM patients (n=10). Most NPC patients and controls showed strong IgG reactivity to VCA-p18, -p23, and EBNA1, limiting their diagnostic use. Few (<20%) healthy donors and patient controls showed IgG reactivity to EA proteins p47/54 and p138, yielding combined sensitivity/specificity and PPV/NPV values of 92.6%/98.3% and 99.0%/88.1%, for diagnosing NPC. NPC sera showed significantly more EBV reactive IgA antibody (>80% positive) than controls (<10% positive), although being less broadly reactive and significantly less strong compared to IgG. For IgA best results were observed for RecombLine EBNA1 with sensitivity/specificity and PPV/NPV values of 92%/89% and 93.4%/85.9%, respectively.

CONCLUSION

In high incidence NPC regions with low incidence IM yet high prevalence of EBV infection, both RecombLine IgG and IgA tests provide a useful alternative to the more complex cell-extract based immunoblot assay as confirmation test for NPC diagnosis in particular when using EA and EBNA1 as discriminators in IgG and IgA testing, respectively.