Predictors of Epstein-Barr virus serostatus and implications for vaccine policy: A systematic review of the literature

OUTCOMES OF INFECTIOUS PANUVEITIS ASSOCIATED WITH SIMULTANEOUS MULTI-POSITIVE OCULAR FLUID POLYMERASE CHAIN REACTION

PURPOSE

To evaluate features of infectious panuveitis associated with multiple pathogens detected by ocular fluid sampling.

METHODS

Single-center, retrospective, consecutive case series of patients with aqueous/vitreous polymerase chain reaction testing with >1 positive result in a single sample from 2001 to 2021.

RESULTS

Of 1,588 polymerase chain reaction samples, 28 (1.76%) were positive for two pathogens. Most common pathogens were cytomegalovirus (n = 16, 57.1%) and Epstein-Barr virus (n = 13, 46.4%), followed by varicella zoster virus (n = 8, 28.6%), Toxoplasma gondii (n = 6, 21.4%), herpes simplex virus 2 (n = 6, 21.4%), herpes simplex virus 1 (n = 6, 21.4%), and Toxocara (n = 1, 3.6%). Mean initial and final visual acuity (logarithm of the minimum angle of resolution) were 1.3 ± 0.9 (Snellen ∼20/400) and 1.3 ± 1.1 (Snellen ∼20/400), respectively. Cytomegalovirus-positive eyes (n = 16, 61.5%) had a mean final visual acuity of 0.94 ± 1.1 (Snellen ∼20/175), whereas cytomegalovirus-negative eyes (n = 10, 38%) had a final visual acuity of 1.82 ± 1.0 (Snellen ∼20/1,320) ( P < 0.05). Main clinical features included intraocular inflammation (100%), retinal whitening (84.6%), immunosuppression (65.4%), retinal hemorrhage (38.5%), and retinal detachment (34.6%).

CONCLUSION

Cytomegalovirus or Epstein-Barr virus were common unique pathogens identified in multi-PCR-positive samples. Most patients with co-infection were immunosuppressed with a high rate of retinal detachment and poor final visual acuity. Cytomegalovirus-positive eyes had better visual outcomes compared with cytomegalovirus-negative eyes.

Intrathecal production of anti-Epstein-Barr virus viral capsid antigen IgG is associated with neurocognition and tau proteins in people with HIV

OBJECTIVE

HIV and Epstein-Barr virus (EBV) co-infection has been linked to increased immune activation and larger HIV reservoir. We assessed whether anti-EBV humoral responses are associated with increased cerebrospinal fluid (CSF) inflammation and with neurocognitive impairment (NCI) in people with HIV (PWH).

DESIGN

Cross-sectional analysis in 123 EBV-seropositive PWH either on antiretroviral therapy ( n  = 70) or not.

METHODS

Serum and CSF anti-EBV viral capsid antigen immunoglobulin G (anti-EVI) and CSF EBV DNA were measured by commercial immunoassay and RT-PCR. Seventy-eight participants without neurological confounding factors underwent neurocognitive assessment (Global Deficit Score, GDS). CSF total tau and 181-phosphorylated-tau (ptau) were measured by immunoassays together with biomarkers of blood-brain barrier (BBB) integrity, immune activation, astrocytosis, and intrathecal synthesis. Logistic and linear regressions and moderation analysis were used to investigate the relationships between CSF anti-EVI, GDS, and biomarkers.

RESULTS

Twenty-one (17.1%) and 22 participants (17.9%) had detectable CSF anti-EVI (10.5-416.0 U/ml) and CSF EBV DNA (25-971 copies/ml). After adjusting for BBB integrity, age, and clinical factors, the presence of CSF anti-EVI was only associated with serum levels of anti-EVI, and not with CSF EBV DNA. CSF anti-EVI, tau and ptau showed reciprocal interactions affecting their associations with GDS. After adjusting for demographics and clinical parameters, higher CSF anti-EVI levels were associated with worse GDS (aβ 0.45, P  < 0.001), and CSF levels of tau and ptau had a moderation effect on the strength of this association (models' P  < 0.001).

CONCLUSION

Humoral immune responses against EBV within the central nervous system may contribute to NCI in PWH through mechanisms that involve neuronal injury.

Perceived income inadequacy is associated with Epstein-Barr Virus latency and mental health outcomes in informal caregivers who are also employed in the healthcare industry

Finances are a prevalent source of stress. In a sample of 799 nursing home workers measured multiple times over 18 months, we found that higher perceived income inadequacy, the perception that one's expenses exceeds one's incomes, was associated with poorer self-reported mental health indicators and Epstein-Barr Virus antibody titers (a marker of cell-mediated immune function). Perceived income inadequacy predicted outcomes over and above the role of other socioeconomic status variables (objective household income and education). Mental health variables were not related to Epstein-Barr Virus antibody titers. Additionally, we found an interaction between perceived income inadequacy and informal caregiver status on our mental health outcomes; informal caregivers with higher perceived income inadequacy had poorer mental health than non-caregivers with the same perceived income inadequacy. Our findings may add nuance to the reserve capacity model, which states that those at lower socioeconomic levels are at higher risk of adverse health outcomes partly because they have fewer resources to address demands and strain. Perceived income inadequacy may significantly predict mental and physical well-being beyond other socioeconomic status variables, especially among lower-income employees. Caregiving stress and perceived income inadequacy may have synergistic effects on mental health.

Antimicrobials use and infection hospital contacts as proxies of infection exposure at ages 0-2 years and risk of infectious mononucleosis

Infectious mononucleosis (IM) often results from late primary infection with Epstein-Barr virus (EBV). Exposure to EBV at ages 0-2 years from, e.g., siblings therefore protects against IM. Using Danish registers, we therefore followed children born in 1997 through 2015 from age 3 years for a hospital contact with an IM diagnosis as outcome with the number of antimicrobial prescriptions filled before age 3 years as a proxy of infection pressure and the main exposure in stratified Cox regressions. The main analyses used sibships as strata primarily to adjust for health-seeking behaviour with further possible adjustments for age, sex, calendar period and sibship constellation. In these analyses we followed 7087 children, exposed on average to 3.76 antimicrobials prescriptions. We observed a crude hazard ratio for IM per unit increase in cumulative antimicrobial use of 1.00 (95% confidence interval 0.99, 1.02), with similar results in adjusted analyses. The hypothesis that children with the largest use of antimicrobials at ages 0-2 years would subsequently have the lowest risk of IM within a sibship was not corroborated by the data. Furthermore, sibship-matched analyses provided no support for some common early-life immune system characteristics being predictive of IM.

American Medical Society of Sports Medicine Position Statement: Mononucleosis and Athletic Participation

ABSTRACT

Infectious mononucleosis (IM) is a common illness in children and young adults caused primarily by the Epstein-Barr Virus (EBV). Transmission occurs primarily through sharing oral secretions, thus IM is known as the "kissing disease." Common clinical manifestations include fever, pharyngitis, posterior cervical lymphadenopathy, and splenomegaly. Atypical lymphocytosis and transaminase elevations are common, and the diagnosis of IM is confirmed with laboratory findings of a positive heterophile antibody ("Monospot"), polymerase chain reaction, or antibodies specific to EBV. Individuals with acute IM may be quite symptomatic and not feel well enough to participate in sports. Splenic enlargement is common, with rupture a relatively rare occurrence, typically occurring within a month of symptom onset, but this risk complicates sports participation, and is often the reason for restricting activity. The management of IM is primarily supportive, with no role for antivirals or corticosteroids. The variability of clinical presentation and the risk of splenic rupture in patients with IM present clinicians with challenging return to play/return to sport (RTS) decisions. This position statement updates the Evidence-Based Subject Review on Mononucleosis by the American Medical Society for Sports Medicine published in 2008 and reviews the epidemiology, clinical manifestations, laboratory assessment, and management including RTS for the athlete with IM. This statement also addresses complications, imaging, special considerations, diversity and equity considerations, and areas for future clinical research. Understanding the evidence regarding IM and sport is essential when communicating with athletes and their families and incorporating shared decision-making in the RTS decision.

Early onset of nasopharyngeal cancer in Asian/Pacific Islander Americans revealed by age-specific analysis

PURPOSE

Incidence of nasopharyngeal cancer is substantially higher in Asian/Pacific Islanders (APIs) than other racial groups. Examining age-specific incidence patterns by racial group and histology could inform disease etiology.

METHODS

We analyzed data from 2000 through 2019 from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program to compare age-specific incidence rates of nasopharyngeal cancer in non-Hispanic (NH) Blacks, NH APIs, and Hispanics to NH Whites using incidence rate ratios with 95% confidence intervals (CIs).

RESULTS

NH APIs showed the highest incidence of nasopharyngeal cancer across all histologic subtypes and almost all age groups. The racial differences were most pronounced in the age 30-39 group; relative to NH Whites, NH APIs were 15.24 (95% CI: 11.69-20.05), 17.26 (95% CI: 12.56-24.07), and 8.91 (95% CI: 6.79-11.48) times as likely to have differentiated non-keratinizing, undifferentiated non-keratinizing, and keratinizing squamous cell tumors, respectively.

CONCLUSIONS

These findings suggest an earlier onset of nasopharyngeal cancer among NH APIs, which highlight unique early life exposure to critical nasopharyngeal cancer risk factors as well as genetic predisposition in this high-risk population.

Mendelian randomisation identifies priority groups for prophylactic EBV vaccination

BACKGROUND

Epstein Barr virus (EBV) infects ~ 95% of the population worldwide and is known to cause adverse health outcomes such as Hodgkin's, non-Hodgkin's lymphomas, and multiple sclerosis. There is substantial interest and investment in developing infection-preventing vaccines for EBV. To effectively deploy such vaccines, it is vital that we understand the risk factors for infection. Why particular individuals do not become infected is currently unknown. The current literature, describes complex, often conflicting webs of intersecting factors-sociodemographic, clinical, genetic, environmental-, rendering causality difficult to decipher. We aimed to use Mendelian randomization (MR) to overcome the issues posed by confounding and reverse causality to determine the causal risk factors for the acquisition of EBV.

METHODS

We mapped the complex evidence from the literature prior to this study factors associated with EBV serostatus (as a proxy for infection) into a causal diagram to determine putative risk factors for our study. Using data from the UK Biobank of 8422 individuals genomically deemed to be of white British ancestry between the ages of 40 and 69 at recruitment between the years 2006 and 2010, we performed a genome wide association study (GWAS) of EBV serostatus, followed by a Two Sample MR to determine which putative risk factors were causal.

RESULTS

Our GWAS identified two novel loci associated with EBV serostatus. In MR analyses, we confirmed shorter time in education, an increase in number of sexual partners, and a lower age of smoking commencement, to be causal risk factors for EBV serostatus.

CONCLUSIONS

Given the current interest and likelihood of a future EBV vaccine, these factors can inform vaccine development and deployment strategies by completing the puzzle of causality. Knowing these risk factors allows identification of those most likely to acquire EBV, giving insight into what age to vaccinate and who to prioritise when a vaccine is introduced.

Performance Evaluation of the Fully Automated NeuMoDx RT-PCR Platform for the Quantification of CMV and EBV DNA in EDTA Plasma: Implications for Clinical Management and Establishment of a Conversion Formula

The NeuMoDx96 platform is a fully automated real-time PCR (RT-PCR) system. To provide continued testing quality with the introduction of new assays, the primary aim of this study was to evaluate the analytical and clinical performance of the NeuMoDx platform for the detection and quantification of CMV and EBV DNA in EDTA plasma. As no conversion from log₁₀ international units per milliliter to copies per milliliter was provided, the secondary aim was to calculate and establish a conversion factor for the output of results in copies per milliliter for CMV and EBV. Archived ETDA plasma samples (cytomegalovirus [CMV], n = 290; Ebstein-Barr virus [EBV], n = 254) were used to evaluate the analytical performance of the NeuMoDx96 platform against the routine real-time quantitative PCR (qPCR) assays. Additionally, the first WHO international standards (WHO-IS) for CMV (n = 70) and EBV (n = 72) were used for the calculation of the intra- and interassay variation. WHO-IS qualitative agreement between the assays was 100%. Intra-assay variability was low for both CMV assays (coefficient of variation [CV], phosphate-buffered saline [PBS], 3 log₁₀ IU/mL NeuMoDx, 3.67%; Abbott RealTime, CMV, 3.35%) and NeuMoDx EBV assay (CV, PBS, 3 log₁₀ IU/mL, 3.05%) but high for the Altona EBV assay (CV, PBS, 3 log₁₀ IU/mL, 26.13%). The overall qualitative concordance in clinical samples was 96.8% (270/279) for CMV and 96.7% (237/245) for EBV. The mean difference between the assays was -0.2 log₁₀ IU/mL (CMV) and -0.18 log₁₀ IU/mL (EBV). High qualitative concordance and a significant correlation of quantitative values for both assays make NeuMoDx CMV and EBV assays suitable for routine diagnostic testing. The new RT-PCR system and conversion formulas to report results in copies per milliliter are now applied in clinical routine testing. IMPORTANCE Clinical management of solid organ transplant (SOT) patients requires the careful monitoring of immunosuppression and viral infection or reactivation. qPCR is the gold standard for the detection and quantification of very small amounts of viral DNA and allows for an early assessment of viral load kinetics. The tested NeuMoDx 96 platform provides faster results than the previously used RT-PCR workflows for CMV (Abbott m2000 and RealTime CMV assay) and EBV (LightCycler 480 II, Roche high pure extraction, and Altona RealStar EBV assay) DNA detection. The implemented conversion formulas allow the continued reporting in clinically established copies per milliliter, important for long-term care of SOT patients.

Epstein-Barr virus and Burkitt's lymphoma. Associations in Iraqi Kurdistan and twenty-two countries assessed in the International Incidence of Childhood Cancer

Background

Burkitt's lymphoma (BL) has worldwide variations in incidence that are related to the age of Epstein-Barr virus (EBV) infection. This study examined the age-specific incidence rate (ASIR) of BL and community EBV seropositivity in Iraqi Kurdistan and compared results with data from countries tabulated in the International Incidence of Childhood Cancer volume 3 (IICC-3).

Methods

The ASIR (95% confidence intervals) of BL in Sulaimani Governorate of Iraqi Kurdistan were calculated for the years 2010–2020. Specimens from 515 outpatients were tested for IgG and IgM antibodies to EBV viral capsid antigen.

Results

In Sulaimani, 84% of BL occurred under 20 years of age, with an ASIR of 6.2 (4.7–7.7) per million children. This ASIR was not significantly different than that of Egypt, Morocco, Israel, Spain, or France. It was slightly higher than the ASIR of the United States, the United Kingdom, and Germany and markedly higher than for Asia and South Africa. In Africa and much of Asia, early childhood EBV exposure predominates, with nearly all children being infected by 5 years of age. In Sulaimani, just over 50% of children were EBV seropositive at 3 years old and 90% seropositivity was reached at 15 years of age. In Europe and North America, seropositivity is commonly delayed until adolescence or young adulthood and adult predominates over childhood BL.

Conclusion

In the Middle East, childhood BL is relatively common and adult BL is rare. In Sulaimani, EBV seropositivity increases progressively throughout childhood and reaches 92% at mid-adolescence. This may reflect the Mid East more widely. We suggest that the high childhood and low adult BL rates may be a regional effect of a pattern of EBV exposure intermediate between early childhood and adolescent and young adult infections.

Association between solid fuel use and seropositivity against Epstein-Barr virus in a high-risk area for nasopharyngeal carcinoma

Epstein-Barr virus (EBV) is one of the risk factors of nasopharyngeal carcinoma (NPC), and understanding the modifiable risk factors of EBV activation is crucial in the prevention of NPC. In this study, we aimed to investigate the association between solid fuel use and EBV seropositivity in a high-risk area of NPC. Our study was based on the baseline findings from an ongoing population-based prospective cohort in Sihui county in Southern China. We explored the association between current use of solid fuel in cooking and EBV seropositivity, and NPC-related EBV activation, using logistic regression models. Stratification analyses were further conducted to assess potential effect modifiers. We also examined the impact of frequency and duration of solid fuel use, and switch in fuel types, on EBV seropositivity among ever users. Of the 12,579 participants included in our analysis, 4088 (32.5%) were EBV seropositive and 421 (3.3%) were high risk for NPC-related EBV activation. Solid fuel use was associated with a higher risk of EBV seropositivity and NPC-related EBV activation, with odds ratios (ORs) of 1.33 (95%CI: 1.01, 1.76) and 1.81 (95%CI: 1.03, 3.18), respectively. Higher risk of EBV seropositivity was observed for those who did not use ventilation apparatus and those who consumed salted food. Among ever users, OR was highest for participants with more than 40 years of solid fuel exposure (1.17, 95%CI: 1.00-1.37) and who have been constantly using solid fuel (1.30, 95%CI: 0.96-1.75). We did not find a statistically significant impact of cooking frequency on EBV seropositivity. The identification of solid fuel as a risk factor for EBV activation is of great value for understanding the etiology of NPC. Our findings also have important public health implications given the fact that a third of the global population still lack access to clean cooking, especially in low resource settings.

The Potential for EBV Vaccines to Prevent Multiple Sclerosis

There is increasing evidence suggesting that Epstein-Barr virus infection is a causative factor of multiple sclerosis (MS). Epstein-Barr virus (EBV) is a human herpesvirus, Human Gammaherpesvirus 4. EBV infection shows two peaks: firstly, during early childhood and, secondly during the teenage years. Approximately, 90-95% of adults have been infected with EBV and for many this will have been a subclinical event. EBV infection can be associated with significant morbidity and mortality; for example, primary infection in older children or adults is the leading cause of infectious mononucleosis (IM). A disrupted immune response either iatrogenically induced or through genetic defects can result in lymphoproliferative disease. Finally, EBV is oncogenic and is associated with several malignancies. For these reasons, vaccination to prevent the damaging aspects of EBV infection is an attractive intervention. No EBV vaccines have been licensed and the prophylactic vaccine furthest along in clinical trials contains the major virus glycoprotein gp350. In a phase 2 study, the vaccine reduced the rate of IM by 78% but did not prevent EBV infection. An EBV vaccine to prevent IM in adolescence or young adulthood is the most likely population-based vaccine strategy to be tested and adopted. National registry studies will need to be done to track the incidence of MS in EBV-vaccinated and unvaccinated people to see an effect of the vaccine on MS. Assessment of vaccine efficacy with MS being a delayed consequence of EBV infection with the average age of onset being approximately 30 years of age represents multiple challenges.

First-generation College Students Have Greater Systemic Inflammation than Continuing-Generation College Students Following the Initial College Transition: A Brief Report

BACKGROUND

First-generation college students ("first-gens") are often at a disadvantage socially and academically; whether they are at risk physiologically is unknown despite the well-established link between greater education and better long-term health.

PURPOSE

To examine whether first-gens have higher levels of cardiovascular disease (CVD) risk markers relative to continuing-generation college students ("continuing-gens").

METHODS

A panel of CVD risk markers was assessed among 87 emerging adults (41 first-gens) twice over their first year of college.

RESULTS

Compared to continuing-gens, first-gens had greater systemic inflammation (composite of averaged z-scores for C-reactive protein and interleukin-6; B = 0.515, SE = 0.171, p = .003) during the fall but not spring semester (p > .05). Associations were independent of family home ownership and childhood adversity, even though first-gens were more likely to live in rental homes and reported riskier home environments. Lower childhood subjective social status (SSS) accounted for greater systemic inflammation among first-gens as evidenced by an indirect effect of college generation status on systemic inflammation through childhood SSS (a1b1 = 0.261, bootstrapped SE = 0.103, 95% boot CI [0.078, 0.482]). There were no differences in metabolic risk and latent virus regulation by college generation status in either semester (p > .10).

CONCLUSIONS

This is the first study to find that first-gens have higher levels of systemic inflammation than continuing-gens following the college transition and that childhood SSS may be one explanatory pathway. First-gens may benefit from university resources that address social class differences, which should be provided early on so that first-gens can reap the health-relevant benefits of higher education, at least in the short term.

Clonality, Mutation and Kaposi Sarcoma: A Systematic Review

BACKGROUND

It remains uncertain whether Kaposi sarcoma (KS) is a true neoplasm, in that it regresses after removal of the stimulus to growth (as HHV8) when immunosuppression is reduced. We aimed to summarize the available evidence on somatic mutations and clonality within KS to assess whether KS is a neoplasm or not.

METHODS

Medline and Web of Science were searched until September 2020 for articles on clonality or mutation in KS. Search strings were supervised by expert librarians, and two researchers independently performed study selection and data extraction. An adapted version of the QUADAS2 tool was used for methodological quality appraisal.

RESULTS

Of 3077 identified records, 20 publications reported on relevant outcomes and were eligible for qualitative synthesis. Five studies reported on clonality, 10 studies reported on various mutations, and 5 studies reported on chromosomal aberrations in KS. All studies were descriptive and were judged to have a high risk of bias. There was considerable heterogeneity of results with respect to clonality, mutation and cytogenetic abnormalities as well as in terms of types of lesions and patient characteristics.

CONCLUSIONS

While KS certainly produces tumours, the knowledge is currently insufficient to determine whether KS is a clonal neoplasm (sarcoma), or simply an aggressive reactive virus-driven lesion.

Fecal Microbiota Transplantation Donor Screening Updates and Research Gaps for Solid Organ Transplant Recipients

In this review, we discuss stool donor screening considerations to mitigate potential risks of pathogen transmission through fecal microbiota transplant (FMT) in solid organ transplant (SOT) recipients. SOT recipients have a higher risk for Clostridioides difficile infection (CDI) and are more likely to have severe CDI. FMT has been shown to be a valuable tool in the treatment of recurrent CDI (RCDI); however, guidelines for screening for opportunistic infections transmitted through FMT are underdeveloped. We review reported adverse effects of FMT as they pertain to an immunocompromised population and discuss the current understanding and recommendations for screening found in the literature while noting gaps in research. We conclude that while FMT is being performed in the SOT population, typically with positive results, there remain many unanswered questions which may have major safety implications and warrant further study.

Antiviral T-Cell Frequencies in a Healthy Population: Reference Values for Evaluating Antiviral Immune Cell Profiles in Immunocompromised Patients

Viral infections and reactivations are major causes of morbidity and mortality after hematopoietic stem cell (HSCT) and solid organ transplantation (SOT) as well as in patients with immunodeficiencies. Latent herpesviruses (e.g., cytomegalovirus, Epstein-Barr virus, and human herpesvirus 6), lytic viruses (e.g., adenovirus), and polyomaviruses (e.g., BK virus, JC virus) can cause severe complications. Antiviral drugs form the mainstay of treatment for viral infections and reactivations after transplantation, but they have side effects and cannot achieve complete viral clearance without prior reconstitution of functional antiviral T-cell immunity. The aim of this study was to establish normal ranges for virus-specific T-cell (VST) frequencies in healthy donors. Such data are needed for better interpretation of VST frequencies observed in immunocompromised patients. Therefore, we measured the frequencies of VSTs against 23 viral protein-derived peptide pools from 11 clinically relevant human viruses in blood from healthy donors (n = 151). Specifically, we determined the VST frequencies by interferon-gamma enzyme-linked immunospot assay and classified their distribution according to age and gender to allow for a more specific evaluation and prediction of antiviral immune responses. The reference values established here provide an invaluable tool for immune response evaluation, intensity of therapeutic drugs and treatment decision-making in immunosuppressed patients. This data should make an important contribution to improving the assessment of immune responses in immunocompromised patients.

Childcare attendance and risk of infectious mononucleosis: A population-based Danish cohort study

BACKGROUND

The risk of infectious mononucleosis (IM) is affected both by crowding and by sibship structure, i.e., number and signed age differential between an index child and a sibling. Siblings provide protection against IM by pre-empting delayed primary Epstein-Barr virus infection with its associated high risk of IM. The association between childcare attendance and risk of IM, on the other hand, has never been studied in a large, well-characterized cohort.

METHODS

Danish children born in July 1992 through 2016 with a completely known simple childcare attendance history before age 1.5 years (n = 908,866) were followed up for a hospital contact with an IM diagnosis at ages 1.5-26 years. Hazard ratios (HRs) of IM for an additional year of exposure were obtained from stratified Cox regression analyses, stratified by sex and year of birth, with age as the underlying time scale, adjusted for sibship structure, and sociodemographic variables including parental ethnicity and maternal age.

RESULTS

An additional year of exclusively attending a daycare home (max 5 children) yielded HR = 0.90 (95% confidence interval 0.81-1.00), and similarly, each year of exclusively attending a childcare institution (e.g., crèche) yielded HR = 0.94 (0.84-1.06).

CONCLUSIONS

Forwarding enrollment in childcare by a year lowers the risk of IM later in life much less than having an additional sibling of comparable age and has no practical public health implications. We find our results suggestive of a random threshold for successful Epstein-Barr virus infection that is more easily reached by a sibling than the collective of playmates in daycare homes or childcare institutions.

Outer membrane vesicles (OMVs) enabled bio-applications: A critical review

Outer membrane vesicles (OMVs) are nanoscale spherical vesicles released from Gram-negative bacteria. The lipid bilayer membrane structure of OMVs consists of similar components as bacterial membrane and thus has attracted more and more attention in exploiting OMVs' bio-applications. Although the endotoxic lipopolysaccharide on natural OMVs may impose potential limits on their clinical applications, genetic modification can reduce their endotoxicity and decorate OMVs with multiple functional proteins. These genetically engineered OMVs have been employed in various fields including vaccination, drug delivery, cancer therapy, bioimaging, biosensing, and enzyme carrier. This review will first briefly introduce the background of OMVs followed by recent advances in functionalization and various applications of engineered OMVs with an emphasis on the working principles and their performance, and then discuss about the future trends of OMVs in biomedical applications.

A three year Seroepidemiological and molecular study of Epstein -Barr virus infection among different age groups with hematological malignancies in a Tertiary care centre of North India ( 2017 -2019)

Purpose

Epstein-Barr virus (EBV) is a member of the family Gamma Herpes viridae and is usually implicated in malignancies like non-Hodgkin's lymphoma, Hodgkin's lymphoma and Burkitt's lymphoma. The present study was designed with the aim to estimate the seroprevalence of EBV in people with hematological malignancies and further follow up was planned by viral load quantitation by Real time PCR in positive cases.

Methods

The current study was planned for a period of three years and a total of 272 serum samples were tested from patients with hematological malignancies namely; HL, NHL, ALL, CLL. Serological testing was performed for the presence of IgM and IgG antibodies against EBV viral capsid antigen. Sera of the patients found positive for IgM was further subjected to viral DNA extraction and Real Time Quantitative PCR was performed by a commercial kit.

Results

The overall seropositivity rate was 89.2% for EBV IgG antibodies and 56.1% for IgM antibodies. The seroprevalence for anti-EBV VCA IgM was found to be highest in the age group <10 years (34.8%) and 11-22 years (20.4%). Of the 109 EBV positive strains by PCR, 27.3% were HL, 35.2% NHL, 24.3% ALL and 13.7% were CLL. The mean viral load was 68.7 × 10⁷ copies/ml DNA.

Conclusion

Our study showed a higher seroprevalence and a definite causal relationship of EBV in lymphoma patients. Young adults showed a higher risk of hematological malignancies as compared to elder population. This study can prove to be an essential guide and aid to the primary care physicians in identifying the possible risk factors and seroprevalence in various age groups of EBV malignancy patients for their proper follow up and referral to higher speciality centres.

Age and CMV-Infection Jointly Affect the EBV-Specific CD8+ T-Cell Repertoire

CD8⁺ T cells play an important role in protection against viral infections. With age, changes in the T-cell pool occur, leading to diminished responses against both new and recurring infections in older adults. This is thought to be due to a decrease in both T-cell numbers and T-cell receptor (TCR) diversity. Latent infection with cytomegalovirus (CMV) is assumed to contribute to this age-associated decline of the immune system. The observation that the level of TCR diversity in the total memory T-cell pool stays relatively stable during aging is remarkable in light of the constant input of new antigen-specific memory T cells. What happens with the diversity of the individual antigen-specific T-cell repertoires in the memory pool remains largely unknown. Here we studied the effect of aging on the phenotype and repertoire diversity of CMV-specific and Epstein-Barr virus (EBV)-specific CD8⁺ T cells, as well as the separate effects of aging and CMV-infection on the EBV-specific T-cell repertoire. Antigen-specific T cells against both persistent viruses showed an age-related increase in the expression of markers associated with a more differentiated phenotype, including KLRG-1, an increase in the fraction of terminally differentiated T cells, and a decrease in the diversity of the T-cell repertoire. Not only age, but also CMV infection was associated with a decreased diversity of the EBV-specific T-cell repertoire. This suggests that both CMV infection and age can impact the T-cell repertoire against other antigens.

Epstein-Barr Virus and Multiple Sclerosis

Multiple sclerosis (MS) is a neurologic disease affecting myelinated nerves in the central nervous system (CNS). The disease often debuts as a clinically isolated syndrome, e.g., optic neuritis (ON), which later develops into relapsing-remitting (RR) MS, with temporal attacks or primary progressive (PP) MS. Characteristic features of MS are inflammatory foci in the CNS and intrathecal synthesis of immunoglobulins (Igs), measured as an IgG index, oligoclonal bands (OCBs), or specific antibody indexes. Major predisposing factors for MS are certain tissue types (e.g., HLA DRB1*15:01), vitamin D deficiency, smoking, obesity, and infection with Epstein-Barr virus (EBV). Many of the clinical signs of MS described above can be explained by chronic/recurrent EBV infection and current models of EBV involvement suggest that RRMS may be caused by repeated entry of EBV-transformed B cells to the CNS in connection with attacks, while PPMS may be caused by more chronic activity of EBV-transformed B cells in the CNS. In line with the model of EBV's role in MS, new treatments based on monoclonal antibodies (MAbs) targeting B cells have shown good efficacy in clinical trials both for RRMS and PPMS, while MAbs inhibiting B cell mobilization and entry to the CNS have shown efficacy in RRMS. Thus, these agents, which are now first line therapy in many patients, may be hypothesized to function by counteracting a chronic EBV infection.

Modeling oncogenic herpesvirus infections in humanized mice

The creation of humanized mice generally involves the reconstitution of immunodeficient mice with human immune constituents. Different methodologies have been employed, and significant progress has been made towards the development of robustly humanized mouse models. Some of the techniques used include the injection of mature human immune cells, the injection of human hematopoietic stem cells (HSCs) capable of reconstituting radiation-depleted murine bone marrow, and the implantation of human fetal liver and thymus fragments under the kidney capsule to create a thymic organoid that can support thympoiesis. This review will serve as a brief introduction to the three most commonly utilized humanized mouse models for the study of gammaherpesvirus-driven pathogenesis, and highlight some of the critical discoveries these models have enabled.