Epstein-Barr Virus: Clinical Diagnostics

Multiple cross displacement amplification combined with nanoparticle-based lateral flow biosensor for rapid and sensitive detection of Epstein-Barr virus

Introduction

Epstein-Barr virus (EBV) is a highly dangerous virus that is globally prevalent and closely linked to the development of nasopharyngeal cancer (NPC). Plasma EBV DNA analysis is an effective strategy for early detection, prognostication and monitoring of treatment response of NPC.

Methods

Here, we present a novel molecular diagnostic technique termed EBV-MCDA-LFB, which integrates multiple cross displacement amplification (MCDA) with nanoparticle-based lateral flow (LFB) to enable simple, rapid and specific detection of EBV. In the EBV-MCDA-LFB system, a set of 10 primers was designed for rapidly amplifying the highly conserved tandem repeat BamHI-W region of the EBV genome. Subsequently, the LFB facilitate direct assay reading, eliminating the use of extra instruments and reagents.

Results

The outcomes showed that the 65°C within 40 minutes was the optimal reaction setting for the EBV-MCDA system. The sensitivity of EBV-MCDA-LFB assay reached 7 copies per reaction when using EBV recombinant plasmid, and it showed 100% specificity without any cross-reactivity with other pathogens. The feasibility of the EBV-MCDA-LFB method for EBV detection was successfully validated by 49 clinical plasma samples. The complete detection process, consisting of rapid template extraction (15 minutes), MCDA reaction (65°C for 40 minutes), and LFB result reading (2 minutes), can be finalized within a 60-minutes duration.

Discussion

EBV-MCDA-LFB assay designed here is a fast, extremely sensitive and specific technique for detecting EBV in field and at the point-of-care (PoC), which is especially beneficial for countries and regions with a high prevalence of the disease and limited economic resources.

Risk factors for multiple sclerosis in the context of Epstein-Barr virus infection

Compelling evidence indicates that Epstein Barr virus (EBV) infection is a prerequisite for multiple sclerosis (MS). The disease may arise from a complex interplay between latent EBV infection, genetic predisposition, and various environmental and lifestyle factors that negatively affect immune control of the infection. Evidence of gene-environment interactions and epigenetic modifications triggered by environmental factors in genetically susceptible individuals supports this view. This review gives a short introduction to EBV and host immunity and discusses evidence indicating EBV as a prerequisite for MS. The role of genetic and environmental risk factors, and their interactions, in MS pathogenesis is reviewed and put in the context of EBV infection. Finally, possible preventive measures are discussed based on the findings presented.

Treatment Options for Epstein-Barr Virus-Related Disorders of the Central Nervous System

Epstein-Barr virus (EBV), a causative agent for several types of lymphomas and mucosal cancers, is a human lymphotropic herpesvirus with the capacity to establish lifelong latent infection. More than 90% of the human population worldwide is infected. The primary infection is usually asymptomatic in childhood, whereas infectious mononucleosis (IM) is common when the infection occurs in adolescence. Primary EBV infection, with or without IM, or reactivation of latent infection in immunocompromised individuals have been associated with a wide range of neurologic conditions, such as encephalitis, meningitis, acute disseminated encephalomyelitis, and cerebellitis. EBV is also involved in malignant lymphomas in the brain. An increasing number of reports on EBV-related disorders of the central nervous system (CNS) including the convincing association with multiple sclerosis (MS) have put in focus EBV-related conditions beyond its established link to malignancies. In this review, we present the clinical manifestations of EBV-related CNS-disorders, put them in the context of known EBV biology and focus on available treatment options and future therapeutic approaches.

Identification of ADA as a Biomarker for Atypical Epstein Barr Virus Infection in Children

OBJECTIVE

This study aims to explore the ability of adenosine deaminase (ADA) to discriminate atypical Epstein Barr virus (EBV) infection in children from acute febrile illness.

METHODS

All children admitted to the Children's Hospital of Soochow University between 2018 and 2019, who were acute febrile patients and subjected to the plasma EBV-DNA polymerase chain reaction (PCR) and indirect immunofluorescence (IIF) assay for EBV-specific antibodies assays. The diagnostic value of each detection index was compared by the area under the ROC curve.

RESULTS

In children with atypical Epstein Barr virus infection, the sensitivity, specificity, positive predictive value, negative predictive value and Youden index were 62.87%, 100.00%,100.00%, 61.73% and 0.63 for EBV-DNA PCR assay, 80.84%, 100.00%, 100.00%, 75.76% and 0.81 for VCA-IgG avidity and 89.22%, 87.00%, 91.98%, 82.86% and 0.76 for ADA. VCA-IgG avidity (AUC=0.904, P<0.01) and ADA (AUC=0.881, P<0.01) assays had the great diagnostic efficiency. In addition, the sensitivity, specificity and AUC were 92.75%,91.43% and 0.921(95%CI: 0.856-0.985) for ADA in the course≤3 days group, respectively.

CONCLUSIONS

ADA has a good diagnostic value in the early stage of atypical EBV infection, and is not affected by primary EBV infection and reactivation. SCHLüSSELWöRTER: Adenosine deaminase, Epstein -Barr virus, Biomarker, children.

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.

Is There an Association between Concurrent Epstein-Barr Virus Infection and Sudden Hearing Loss?-A Case-Control Study in an East Asian Population

Viral infection serves as the crucial etiology for the development of sudden sensorineural hearing loss (SSNHL). We aimed to investigate whether there is an association between concurrent Epstein-Barr virus (EBV) infection and SSNHL in an East Asian population. Patients who were older than 18 years of age and met the criteria of sudden hearing loss without an identifiable etiology were enrolled from July 2021 until June 2022, followed by the serological testing of IgA antibody responses against EBV-specific early antigen (EA) and viral capsid antigen (VCA) with an indirect hemagglutination assay (IHA) and real-time quantitative polymerase chain reaction (qPCR) of EBV DNA in serum before the treatment was initiated. After the treatment for SSNHL, post-treatment audiometry was performed to record the treatment response and degree of recovery. Among the 29 patients included during enrollment, 3 (10.3%) had a positive qPCR result for EBV. In addition, a trend of poor recovery of hearing thresholds was noted for those patients with a higher viral PCR titer. This is the first study to use real-time PCR to detect possible concurrent EBV infection in SSNHL. Our study demonstrated that approximately one-tenth of the enrolled SSNHL patients had evidence of concurrent EBV infection, as reflected by the positive qPCR test results, and a negative trend between hearing gain and the viral DNA PCR level was found within the affected cohort after steroid therapy. These findings indicate a possible role for EBV infection in East Asian patients with SSNHL. Further larger-scale research is needed to better understand the potential role and underlying mechanism of viral infection in the etiology of SSNHL.

High Predictive Value of the Soluble ZEBRA Antigen (Epstein-Barr Virus Trans-Activator Zta) in Transplant Patients with PTLD

The ZEBRA (Z EBV replication activator) protein is the major transcription factor of EBV, expressed upon EBV lytic cycle activation. An increasing body of studies have highlighted the critical role of EBV lytic infection as a risk factor for lymphoproliferative disorders, such as post-transplant lymphoproliferative disease (PTLD). We studied 108 transplanted patients (17 PTLD and 91 controls), retrospectively selected from different hospitals in France and in the Netherlands. The majority of PTLD were EBV-positive diffuse large B-cell lymphomas, five patients experienced atypical PTLD forms (EBV-negative lymphomas, Hodgkin’s lymphomas, and T-cell lymphomas). Fourteen patients among the seventeen who developed a pathologically confirmed PTLD were sZEBRA positive (soluble ZEBRA, plasma level above 20 ng/mL, measured by an ELISA test). The specificity and positive predictive value (PPV) of the sZEBRA detection in plasma were 98% and 85%, respectively. Considering a positivity threshold of 20 ng/mL, the sensitivity of the sZEBRA was 82.35% and the specificity was 94.51%. The mean of the sZEBRA values in the PTLD cases were significantly higher than in the controls (p < 0.0001). The relevance of the lytic cycle and, particularly, the role of ZEBRA in lymphomagenesis is a new paradigm pertaining to the prevention and treatment strategies for PTLD. Given the high-specificity and the predictive values of this test, it now appears relevant to investigate the lytic EBV infection in transplanted patients as a prognostic biomarker.

Detection of low-load Epstein-Barr virus in blood samples by enriched recombinase aided amplification assay

Epstein-Barr virus (EBV), a common human γ-herpesvirus, infects more than 90% of adults worldwide. The purpose of this study was to establish a novel EBV detection method by combining the recombinase aided amplification (RAA) assay with an initial enrichment step that utilizes magnetic beads coated with a recombinant human mannan-binding lectin (rhMBL, M1 protein). An M1 protein–protein A magnetic bead complex (M1 beads) was prepared and used to achieve separation and enrichment of EBV from blood. After nucleic acid extraction, DNA was amplified by RAA. Using 388 whole blood samples and 1 serum sample, we explored the specificity, sensitivity and applicability of the newly developed detection method and compared it with commercial quantitative real-time polymerase chain reaction (qPCR) following M1 bead enrichment, traditional qPCR and traditional RAA. After enrichment, the positivity rate of EBV was increased from 15.94% to 17.74% by RAA (P < 0.05) and from 7.20% to 15.17% by qPCR (P < 0.05). The viral loads after enrichment were increased by 1.13 to 23.19-fold (P < 0.05). Our data demonstrates that an RAA assay incorporating M1 bead enrichment is a promising tool for detecting low EBV viral loads in blood samples that will facilitate an early response to EBV infection.

The RAA with an enrichment step that utilizes magnetic beads coated with M1 protein.

A very effective method for detecting low-load virus in blood samples.

The first report describing virus detection using this method.

Detection of Epstein-Barr virus in gastric adenocarcinoma: qPCR and FISH comparison

EBV-associated gastric cancer accounts for about 10% of all gastric carcinomas worldwide. We aimed to verify the prevalence of EBV in gastric adenocarcinoma samples using FISH and qPCR and comparing the results obtained by both techniques. Gastric cancer samples from 191 cases were analyzed. The FISH assay was performed to detect small EBV RNAs (EBER1) and qPCR was performed to detect the EBV-EBNA-1 gene region. Cohen’s kappa index and the chi-square test were used to compare the methodologies and investigate correlations with the clinical-pathological data of the gastric adenocarcinoma patients. Most of the patients were men, and the average age was 60 years. The intestinal subtype cancer presented more aggressive stages with 90% of patients having a reactive FISH for EBV (EBV+), although the virus infection frequency in epithelial gastric tissue was only 1%. No positive association with clinicopathological features and EBV+ was found by FISH. Using qPCR analysis, the percentage of positive samples was lower (52.4%), and a positive association was found in samples from older patients (> 60 years). Interestingly, 71 qPCR-negative cases were detected by FISH in the presence of non-epithelial cells and in 10 qPCR-positive cases with no evidence of EBV according to FISH. The concordance between the two techniques was low, with only 57.6%. FISH is more informative for associating the gastric carcinoma with EBV positivity in tumor/epithelial cells; however, qPCR can provide relevant information regarding the progression and characteristics of neoplasia.

Analysis of two laboratory tests for determination of EBV-IM in children

This study aimed to explore the application value of two laboratory tests in the diagnosis of Epstein-Barr virus-associated infectious mononucleosis (EBV-IM) in children. From January 2018 to December 2020, 166 patients with EBV-IM were included in this study. Two methods were used in the analysis. The results of both tests were compared and analyzed. The age of onset of EBV-IM is mainly distributed in the range of 0-6 years, and no difference by gender is observed. The sensitivity and specificity of EBV testing by PCR were 49.4% and 89.8%, respectively, and the area under the receiver operating characteristic curve (AUC) was 0.714 (0.662-0.762). When using the immunofluorescence method to detect EBV antibodies, the two indices with the highest diagnostic efficacy were low-affinity EBV-CA IgG and EBV-CA IgM, and their AUC values were 0.798 (0.751-0.840) and 0.663 (0.609-0.713), respectively. When combining the two indices for testing, the AUC values of EBV-CA IgM + low-affinity EBV-CA IgG, EBV-DNA+EBV-CA IgM, and EBV-DNA+low-affinity EBV-CA IgG were 0.904 (0.867-0.933), 0.768 (0.719-0.812), and 0.963 (0.937-0.981), respectively. The diagnostic efficacy of the combined EBV-DNA+EBV-CA IgM + low-affinity EBV-CA IgG test was optimal compared with that of a single index or the combination of two indices, with an AUC of 0.999 (0.986-1.000; p < 0.05), sensitivity of 100%, and specificity of 89.8%. The combined immunofluorescence and real-time PCR methods have high sensitivity and specificity and good application value in the clinical diagnosis of EBV-IM.

Epstein-Barr Virus-Associated Malignancies and Immune Escape: The Role of the Tumor Microenvironment and Tumor Cell Evasion Strategies

Simple Summary

The Epstein–Barr virus, also termed human herpes virus 4, is a human pathogenic double-stranded DNA virus. It is highly prevalent and has been linked to the development of 1–2% of cancers worldwide. EBV-associated malignancies encompass various structural and epigenetic alterations. In addition, EBV-encoded gene products and microRNAs interfere with innate and adaptive immunity and modulate the tumor microenvironment. This review provides an overview of the characteristic features of EBV with a focus on the intrinsic and extrinsic immune evasion strategies, which contribute to EBV-associated malignancies.

Abstract

The detailed mechanisms of Epstein–Barr virus (EBV) infection in the initiation and progression of EBV-associated malignancies are not yet completely understood. During the last years, new insights into the mechanisms of malignant transformation of EBV-infected cells including somatic mutations and epigenetic modifications, their impact on the microenvironment and resulting unique immune signatures related to immune system functional status and immune escape strategies have been reported. In this context, there exists increasing evidence that EBV-infected tumor cells can influence the tumor microenvironment to their own benefit by establishing an immune-suppressive surrounding. The identified mechanisms include EBV gene integration and latent expression of EBV-infection-triggered cytokines by tumor and/or bystander cells, e.g., cancer-associated fibroblasts with effects on the composition and spatial distribution of the immune cell subpopulations next to the infected cells, stroma constituents and extracellular vesicles. This review summarizes (i) the typical stages of the viral life cycle and EBV-associated transformation, (ii) strategies to detect EBV genome and activity and to differentiate various latency types, (iii) the role of the tumor microenvironment in EBV-associated malignancies, (iv) the different immune escape mechanisms and (v) their clinical relevance. This gained information will enhance the development of therapies against EBV-mediated diseases to improve patient outcome.

Follow-up after infectious mononucleosis in search of serological similarities with presymptomatic multiple sclerosis

BACKGROUND

A two- to three-fold increase in the risk of multiple sclerosis (MS) after infectious mononucleosis (IM) has been observed in cohort and case control studies. However, this association has not been investigated prospectively from IM. It remains to be determined whether long-term immunospecific sequelae with features consistent with presymptomatic MS occur after IM.

METHODS

Sera were obtained from individuals with acute IM from 2003-2007 (n = 42) and from the same individuals at a follow-up (FU) study approximately 10 years after IM. These were assayed for antibodies against a variety of Epstein-Barr virus (EBV) antigens, including gp350, a novel recombinant glycoprotein from the EBV envelope. Similarly, single-protein antigens were used to assess measles and varicella-zoster reactivity (Ncore and varicella-zoster glycoprotein E [VZVgE]). The FU study also included cerebrospinal fluid (CSF) samples from 21 of these individuals to test for IgG antibodies against the same viral antigens. As controls, CSF and serum samples were obtained from 15 EBV-seropositive volunteers who denied a history of IM, and serum samples were obtained from 24 EBV-seropositive blood donors. Anti-gp350, anti-Ncore and anti-VZVgE IgG levels were also analysed in sera and CSF samples from 22 persons with MS.

RESULTS

The FU assays showed higher anti-gp350 IgG (p = 0.007, univariate) than among healthy controls, with no difference in serum anti-VCA or anti-EBNA1 IgG levels and no difference in anti-gp350 in the CSF samples. Anti-Ncore IgG and anti-VZVgE were higher in acute IM samples (p < 0.001 and p < 0.0001, respectively) than at FU, although anti-Ncore remained heightened in an age-adjusted analysis at FU (p = 0.014) compared to the control group. In the MS group, the serum anti-gp350 and anti-Ncore IgG levels were significantly higher than among the control group, but the anti-VZVgE levels were not. The CSF anti-gp350 and VZVgE levels were slightly higher among persons with MS than among the control group, whereas anti-Ncore IgG was markedly higher in persons with MS than in the control group.

CONCLUSION

In the present study IM showed certain similarities with MS. Increased anti-gp350 reactivity persisted more than a decade after IM, reminiscent of the established increased anti-EBV reactivity in presymptomatic MS. Acute IM was associated with increased anti-measles and anti-VZV immunoreactivity, similar to the MRZ reaction in MS, with some evidence suggesting that this measles reactivity persisted after a decade.

The clinical value of high fluorescent lymphocytes and smudge cells in the diagnosis of infectious mononucleosis

BACKGROUND

The diagnostic value of high fluorescent lymphocytes (HFLC) and smudge cells in diseases like sepsis has been confirmed. In this study, we explore the diagnostic value of HFLC and smudge cells for infectious mononucleosis (IM).

METHODS

Sixty-two IM patients, 67 healthy controls, 84 patients with upper respiratory tract virus infection, and 35 patients with malignant lymphoid diseases were enrolled. The complete blood counts and leukocyte differential counts are tested, and the smudge cells were manually counted.

RESULTS

The value of HFLC% and smudge cells of the IM group were significantly higher than those of healthy controls and disease controls (p < 0.05), and the HFLC% value of IM patients was positively correlated with the number of reactive lymphocytes (r = 0.265). When the cutoff value of HFLC% was 0.4%, and the diagnostic value of IM was high (AUC = 0.995). When the smudge cells >2/100 nucleated cells, it can show better (AUC = 1.000). When the cutoff value of the HFLC% was 1.2%, it can effectively distinguish IM patients from upper respiratory tract virus infection patients (AUC = 0.934); when smudge cells >16/100 nucleated cells, it also has high differential diagnosis value (AUC = 0.913). In addition, the AUC of the combination HFLC% and smudge cells for the differential diagnosis can be increased to 0.968. The performance value of single HFLC% (AUC = 0.942) for distinguishing IM from malignant lymphoid diseases was better than smudge cells and combine index with the cutoff value of 0.4%.

CONCLUSION

HFLC% and smudge cells can be used as effective indicators in the early diagnosis and differential diagnosis of IM.

Diagnostic value of serological and molecular biological tests for infectious mononucleosis by EBV in different age stages and course of the disease

Epstein-Barr virus (EBV)-based serologic antibody and viral nucleic acid assays have been found to be feasible means to diagnose infectious mononucleosis (IM) caused by EBV in children. In this study, we will further explore their diagnostic value for IM by EBV in different age stages and over the course of the disease. A collection of 616 children from clinically suspected IM cases was studied. Indirect immunofluorescence (IIF) for EBV-specific antibody (Euroimmun) combined with plasma EB viral nucleic acid assay (real-time fluorescence quantitative polymerase chain reaction reverse-transcription polymerase chain reaction) were used as reference methods. The diagnostic efficiency of the peripheral blood routine test, serologic antibody test, and plasma EB viral nucleic acid assay for the diagnosis of IM was evaluated, respectively. The sensitivity, specificity, Youden' index and the area under curve (AUC) were 93.08%, 87.77%, 0.81 and 0.904 (95% confidence interval [CI]: 0.878-0.931) for the peripheral lymphocyte test (lymphocytosis > 5 × 109 /L), 98.27%, 91.13%, 0.89 and 0.947 (95% CI: 0.927-0.967) for the plasma EBV-DNA test, and 84.08%, 96.33%, 0.80 and 0.902 (95% CI: 0.874-0.930) for the EBV viral capsid antigen (VCA)-IgG avidity test. The plasma EBV-DNA test has a higher diagnostic value than the VCA-IgG avidity test in children aged <6 years, especially aged <3 years; the peripheral lymphocyte test and plasma EBV-DNA test are suitable for the early stage of the disease, while the VCA-IgG avidity test for after 7 days of the disease. EBV antibody detection (IIF) should be combined with EBV nucleic acid detection in children age <6 years and the early stage of the disease.

Analytical performance evaluation of the Elecsys Epstein-Barr virus immunoassay panel

We evaluated the analytical performance of the Elecsys® Epstein-Barr virus (EBV) immunoassay panel for the in vitro detection of EBV immunoglobulin M (IgM), EBV viral capsid antigen immunoglobulin G (VCA IgG), and EBV nuclear antigen immunoglobulin G (EBNA IgG). Relative sensitivity/specificity were assessed using 1,734 human blood samples (1,068 residual samples from routine EBV testing; 467 presumed acute infection; 199 presumed seronegative) tested with the Elecsys EBV and 2 comparator panels (ARCHITECT EBV; Liaison EBV). EBV infection status was defined by majority approach. The three panels demonstrated comparable relative sensitivities/specificities, ranging between values (%) of 98.3-99.5 / 96.9-97.4 (EBV IgM); 96.3-98.4 / 98.4-98.7 (EBV VCA IgG); and 98.1-99.5 / 99.1-99.5 (EBV EBNA IgG). The Elecsys EBV IgM assay demonstrated superior analytical specificity in samples containing potential interferents. Utilizing the Elecsys EBV panel for the EBNA-first approach showed 97.5% overall agreement versus the majority approach in samples with clear EBV status.

The challenge of avidity determination in SARS-CoV-2 serology

The serological responses towards severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) nucleoprotein, receptor‐binding domain (RBD), and spike protein S1 are characterized by incomplete avidity maturation. Analysis with varying concentrations of urea allows to determine distinct differences in avidity maturation, though the total process remains at an unusually low level. Despite incomplete avidity maturation, this approach allows to define early and late stages of infection. It therefore can compensate for the recently described irregular kinetic patterns of immunoglobulin M and immunoglobulin G (IgG) directed towards SARS‐CoV‐2 antigens. The serological responses towards seasonal coronaviruses neither have a negative nor positive impact on SARS‐CoV‐2 serology in general. Avidity determination in combination with measurement of antibody titers and complexity of the immune response allows to clearly differentiate between IgG responses towards seasonal coronaviruses and SARS‐CoV‐2. Cross‐reactions seem to occur with very low probability. They can be recognized by their pattern of response and through differential treatment with urea. As high avidity has been shown to be essential in several virus systems for the protective effect of neutralizing antibodies, it should be clarified whether high avidity of IgG directed towards RBD indicates protective immunity. If this is the case, monitoring of avidity should be part of the optimization of vaccination programs.

Avidity maturation of immunoglobulin G (IgG) towards severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) antigens is distinct, but incomplete in most cases

Nevertheless, avidity determination allows to differentiate between acute and past SARS CoV‐infection

Avidity maturation is instrumental for differentiation between IgG responses towards SARS‐CoV‐2 and seasonal coronaviruses

It is suggested to clarify whether high avidity is required for and indicative of protective immunity.

The role of Epstein-Barr virus in the etiology of multiple sclerosis: a current review

Introduction: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. While its exact etiology is unknown, it is generally believed that MS is caused by environmental triggers in genetically predisposed individuals. Strong and consistent evidence suggests a key role of Epstein-Barr virus (EBV), a B lymphotropic human gammaherpesvirus, in the etiology of MS. Areas covered: This review summarizes recent developments in the field of EBV and MS with a focus on potential mechanisms underlying the role of EBV in MS. PubMed was searched for the terms 'Epstein-Barr virus' and 'multiple sclerosis'. Expert opinion: The current evidence is compatible with the working hypothesis that MS is a rare complication of EBV infection. Under the premise of a causative role of EBV in MS, it needs to be postulated that EBV causes a specific, and likely persistent, change(s) that is necessarily required for the development of MS. However, although progress has been made, the nature of that change and thus the precise mechanism explaining the role of EBV in MS remain elusive. The mechanism of EBV in MS therefore is a pressing question, whose clarification may substantially advance the pathophysiological understanding, rational therapies, and prevention of MS.

The variability of the serological response to SARS-corona virus-2: Potential resolution of ambiguity through determination of avidity (functional affinity)

Data on the serological response toward severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in 16 recent reports were analyzed and a high degree of variability was shown. Immunoglobulin M (IgM) responses were either found earlier than IgG, or together with IgG, later than IgG, or were missing. Therefore, clear distinctions between early, intermediate, and past infections are obviously not possible merely on the basis of IgM and IgG determinations. A review of publications on the serology of other virus groups shows that variable IgM responses can be found as well and therefore are not unique for SARS‐CoV‐2 infections. A model to explain this variability is proposed. The inclusion of avidity determination into regular diagnostic procedures has allowed to resolve such “atypical” serological constellations. The potential use of avidity determination for the diagnosis of COVID‐19, for risk assessment, epidemiological studies, analysis of cross reactions, as well as for the control of vaccination programs is suggested and discussed.

The serological response to SARS CoV‐2 infection is highly variable.

The mere detection of specific IgM and IgG does not allow to distinguish between acute and past infection.

The variable IgM and IgG responses after SARS CoV‐2 infection are analogous to serological findings in other virus systems.

Variable IgM and IgG responses can be rationally explained by models that describe immunoglobulin production by the immune system.

Avidity determination of SARS CoV‐2 IgG is suggested for resolution of diagnostic ambiguity.

Recombinant Epstein-Barr virus glycoprotein 350 as a serological antigen

Epstein-Barr virus (EBV) glycoprotein 350 (gp350) is the most abundant glycoprotein expressed on the EBV envelope, the major target for neutralizing antibodies and also essential for virion attachment to B lymphocytes. Several studies have addressed EBV gp350 as a vaccine candidate, but less commonly as a potential antigen for serological assays. The aim of the current study was to develop a diagnostic tool to quantify EBV gp350-specific IgG in previously EBV-infected individuals. A construct encoding the extracellular domain of EBV gp350 (amino acid (aa) 1-860) was developed for expression in Chinese hamster ovary cells. Serum samples (n = 360) with known IgG serostatus against viral capsid antigen (VCA) and Epstein-Barr nuclear antigen 1 (EBNA1) were divided into three groups based on the differences in their serostatus: VCA + EBNA1+ (n = 120), VCA + EBNA1- (n = 120) and VCA-EBNA1- (n = 120). The samples were analyzed by indirect ELISA using recombinant EBV gp350 aa 1-860 as antigen. A clear majority, 108 of the 120 VCA + EBNA1+ samples, had detectable EBV gp350-specific IgG. Of the 120 VCA + EBNA1- samples, 79 had detectable EBV gp350-specific IgG. Only 2 of the 120 VCA-EBNA1- samples had detectable EBV gp350-specific IgG. The results reported here show that use of the EBV gp350 aa 1-860 ELISA can serve as a sensitive method for EBV-specific IgG detection in serum samples.

Complete Epstein-Barr virus seropositivity in a large cohort of patients with early multiple sclerosis

OBJECTIVE

To determine the prevalence of antibodies to Epstein-Barr virus (EBV) in a large cohort of patients with early multiple sclerosis (MS).

METHODS

Serum samples were collected from 901 patients with a clinically isolated syndrome (CIS) or early relapsing-remitting multiple sclerosis (RRMS) participating in the German National MS cohort, a prospective cohort of patients with early MS with stringent inclusion criteria. Epstein-Barr nuclear antigen (EBNA)-1 and viral capsid antigen (VCA) antibodies were measured in diluted sera by chemiluminescence immunoassays (CLIAs). Sera of EBNA-1 and VCA antibody-negative patients were retested undiluted by an EBV IgG immunoblot. For comparison, we retrospectively analysed the EBV seroprevalence across different age cohorts, ranging from 0 to >80 years, in a large hospital population (N=16 163) from Berlin/Northern Germany.

RESULTS

EBNA-1 antibodies were detected by CLIA in 839 of 901 patients with CIS/RRMS. Of the 62 patients without EBNA-1 antibodies, 45 had antibodies to VCA as detected by CLIA. In all of the remaining 17 patients, antibodies to EBV were detected by immunoblot. Altogether, 901 of 901 (100%) patients with CIS/RRMS were EBV-seropositive. EBV seropositivity increased with age in the hospital population but did not reach 100% in any of the investigated age cohorts.

CONCLUSION

The complete EBV seropositivity in this large cohort of patients with early MS strengthens the evidence for a role of EBV in MS. It also suggests that a negative EBV serology in patients with suspected inflammatory central nervous system disease should alert clinicians to consider diagnoses other than MS.

Recent Advances in Diagnostic Approaches for Epstein-Barr Virus

Epstein-Barr virus (EBV) is the causative agent of many diseases including infectious mononucleosis (IM), and it is associated with different subtypes of lymphoma, sarcoma and carcinoma such as Hodgkin's lymphoma, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, and gastric carcinoma. With the advent of improved laboratory tests for EBV, a timelier and accurate diagnosis could be made to aid better prognosis and effective treatment. For histopathological lesions, the in situ hybridization (ISH) of EBV-encoded RNA (EBER) in biopsy tissues remains the gold standard for detecting EBV. Methods such as the heterophile antibody test, immunofluorescence assays, enzyme immunoassays, Western blot, and polymerase chain reaction (PCR) are also employed in the detection of EBV in different types of samples. The determination of EBV viral load using PCR, however, is gaining more prominence in the diagnosis of EBV-associated diseases. Given the challenge of false positive/negative results that are sometimes experienced during the detection of EBV, variability in results from different laboratories, and the impact of factors such as sample type and the immunological status of patients from whom samples are collected, the need to critically examine these present methods is invaluable. This review thus presents current advances in the detection of EBV, detailing the advantages and disadvantages of the various techniques. In addition, fundamental virological concepts are highlighted to enhance the greater understanding, the proper application, and the interpretation of EBV tests.

Recurrent Epstein-Barr Virus-positive (EBV+) Primary Central Nervous System Lymphoma (PCNSL) in a Patient with Clinical Features of Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS)

Primary central nervous system lymphoma (PCNSL) and chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) can share clinical features and may be indistinguishable, even after brain biopsy. We encountered a case of Epstein-Barr virus-positive (EBV+) PCNSL recurrence in a patient with clinical features of CLIPPERS, and repeat brain biopsy was required to reach the correct diagnosis. Four years after the initial diagnosis and treatment of PCNSL, "peppering" punctate enhanced lesions with transient steroid responsiveness were detected during brain magnetic resonance imaging (MRI). A second brain biopsy supported a diagnosis of CLIPPERS, while a third biopsy confirmed the diagnosis of recurrent PCNSL.

In vitro maturation of oocytes from excised ovarian tissue in a patient with autoimmune ovarian insufficiency possibly associated with Epstein-Barr virus infection

BACKGROUND

Some reports show that it is possible to isolate immature oocytes from human ovarian tissue retrieved by a cortex biopsy or ovariectomy of non-stimulated ovaries and mature them in vitro. The mature oocytes can be vitrified and stored for in vitro fertilization, which, along with ovarian tissue cryopreservation, is mostly practiced in young cancer patients to preserve their fertility. There is much less data on this new approach in women with a natural ovarian insufficiency, which can be caused by different factors, including viral infection. In this case report this advanced methodology was used in a young patient suffering from ovarian insufficiency which was possibly associated with Epstein-Barr virus and infectious mononucleosis (glandular fever).

METHODS

This case report included a 27-year-old patient who attended our infertility clinic because of ovarian failure as a part of autoimmune polyendocrinopathy that occurred after Epstein-Barr virus infection, which has rarely been reported until now. Although antral follicles were observed in her ovaries by ultrasound monitoring, she was amenorrhoeic with menopausal concentrations of follicle-stimulating hormone (FSH) and without mature follicles. Therefore, a small biopsy of ovarian cortex tissue was performed using laparoscopy to retrieve immature oocytes. The retrieved oocytes were matured in vitro, cryopreserved, and stored for in vitro fertilization and potential pregnancy.

RESULTS

Four immature, germinal vesicle (GV) oocytes were found and removed from tissue, denuded mechanically by a pipette, and matured in vitro in a maturation medium with added FSH and hCG as well as in co-culture with cumulus cells, which were retrieved by their denudation. Three oocytes matured in vitro to the metaphase II (MII) stage and were vitrified for in vitro fertilization along with ovarian tissue cryopreservation.

CONCLUSION

Our results show that Epstein-Barr infection is possibly associated with autoimmune ovarian failure. The devastating impact on fertility in such disorder can be successfully avoided by in vitro maturation of oocytes from excised ovarian tissue.