Epstein-Barr virus, cytomegalovirus, and multiple sclerosis susceptibility: A multiethnic study

Ubiquitin-Mediated Effects on Oncogenesis during EBV and KSHV Infection

The Herpesviridae include the Epstein-Barr Virus (EBV) and the Kaposi Sarcoma-associated Herpesvirus (KSHV), both of which are oncogenic gamma-herpesviruses. These viruses manipulate host cellular mechanisms, including through ubiquitin-mediated pathways, to promote viral replication and oncogenesis. Ubiquitin, a regulatory protein which tags substrates for degradation or alters their function, is manipulated by both EBV and KSHV to facilitate viral persistence and cancer development. EBV infects approximately 90% of the global population and is implicated in malignancies including Burkitt lymphoma (BL), Hodgkin lymphoma (HL), post-transplant lymphoproliferative disorder (PTLD), and nasopharyngeal carcinoma. EBV latency proteins, notably LMP1 and EBNA3C, use ubiquitin-mediated mechanisms to inhibit apoptosis, promote cell proliferation, and interfere with DNA repair, contributing to tumorigenesis. EBV's lytic proteins, including BZLF1 and BPLF1, further disrupt cellular processes to favor oncogenesis. Similarly, KSHV, a causative agent of Kaposi's Sarcoma and lymphoproliferative disorders, has a latency-associated nuclear antigen (LANA) and other latency proteins that manipulate ubiquitin pathways to degrade tumor suppressors, stabilize oncogenic proteins, and evade immune responses. KSHV's lytic cycle proteins, such as RTA and Orf64, also use ubiquitin-mediated strategies to impair immune functions and promote oncogenesis. This review explores the ubiquitin-mediated interactions of EBV and KSHV proteins, elucidating their roles in viral oncogenesis. Understanding these mechanisms offers insights into the similarities between the viruses, as well as provoking thought about potential therapeutic targets for herpesvirus-associated cancers.

Cytomegalovirus and Epstein-Barr virus infections in patients with neuromyelitis optica spectrum disorder

OBJECTIVES

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections in patients with Neuromyelitis optica spectrum disorder (NMOSD) remain unclear. The objective of this study was to investigate CMV and EBV infections in patients with NMOSD.

METHODS

Serum immunoglobin (Ig) G antibodies against CMV and EBV were measured in patients with NMOSD and healthy controls (HCs), including anti-CMV, anti-EBV nuclear antigen-1 (EBNA-1), anti-EBV virus capsid antigen (VCA), and anti-EBV early antigen (EA) IgGs. The immune status ratio (ISR) was used to evaluate the serum anti-CMV and anti-EBV IgG levels and ISR ≧1.10 was defined as seropositivity.

RESULTS

In total, 238 serum samples were collected from 94 patients with NMOSD and 144 HCs, and no significant difference of sex and age between NMOSD and HCs. Comparing to the HCs, patients with NMOSD exhibited significantly higher serum anti-CMV IgG level. In contrast, the serum anti-EBNA1 IgG level was significantly lower in patients with NMOSD than in HCs. The serum anti-VCA and anti-EA IgG levels did not differ between the two groups, but the anti-EA seropositivity was significantly higher in NMOSD group than that in HC group. We did not find associations between serum anti-CMV or anti-EBV IgG levels and NMOSD disease stage, immunotherapy, or disability score.

CONCLUSIONS

Our findings indicated that increased CMV infection and EBV recent infection, as well as reduced EBV latency infection were associated with the risk of NMOSD. Prospective cohort studies are needed to verify our findings and clarify the correlation between CMV and EBV infections and clinical characteristics of NMOSD.

No association between oral contraceptive exposure and subsequent MS: A population-based nested case-control study in primary care

BACKGROUND

Conflicting data exist around oral contraceptive exposure and subsequent multiple sclerosis (MS).

OBJECTIVE

To use routinely collected primary healthcare data to explore the potential association between oral contraceptive exposure and subsequent MS in females at population level.

METHODS

We performed a nested case-control study using electronic primary care data, with complete electronic ascertainment from 1990. Logistic regression was used to evaluate associations between contraceptive exposure and MS, without and with adjusting for age, ethnicity and deprivation.

RESULTS

A total of 4455 females were included: 891 cases and 3564 controls. No association was seen between oral contraceptive exposure and subsequent MS, or between any contraceptive, combined oral contraceptive pill (COCP) or progesterone-only pill (POP) use 0-2, 2-5 or >5 years prior to MS. Conclusions: In the largest population-based study to date, we find no evidence of an association between oral contraceptive exposure and subsequent MS diagnosis.

Cytomegalovirus, Epstein-Barr Virus, Herpes Simplex Virus, and Varicella Zoster Virus Infection Dynamics in People with Multiple Sclerosis from Northern Italy

Previous exposure to Epstein-Barr virus (EBV) is strongly associated with the development of multiple sclerosis (MS). By contrast, past cytomegalovirus (CMV) infection may have no association, or be negatively associated with MS. This study aimed to investigate the associations of herpesvirus infections with MS in an Italian population. Serum samples (n = 200) from Italian people with multiple sclerosis (PwMS) classified as the relapsing-and-remitting clinical phenotype and (n = 137) healthy controls (HCs) were obtained from the CRESM Biobank, Orbassano, Italy. Both PwMS and HCs samples were selected according to age group (20-39 years, and 40 or more years) and sex. EBV virus capsid antigen (VCA) IgG, EBV nucleic acid-1 antigen (EBNA-1) IgG, CMV IgG, herpes simplex virus (HSV) IgG, and varicella zoster virus (VZV) IgG testing was undertaken using commercial ELISAs. EBV VCA IgG and EBNA-1 IgG seroprevalences were 100% in PwMS and 93.4% and 92.4%, respectively, in HCs. EBV VCA IgG and EBNA-1 IgG levels were higher (p < 0.001) in PwMS compared with HCs. For PwMS, the EBNA-1 IgG levels decreased with age, particularly in females. The CMV IgG seroprevalence was 58.7% in PwMS and 62.9% in HCs. CMV IgG seroprevalence increased with age. The HSV IgG seroprevalence was 71.2% in PwMS and 70.8% in HCs. HSV IgG levels were lower (p = 0.0005) in PwMS compared with HCs. VZV IgG seroprevalence was 97.5% in PwMS and 98.5% in HCs. In the population studied, several herpesvirus infections markers may have been influenced by the age and sex of the groups studied. The lack of a negative association of MS with CMV infection, and the observation of lower levels of HSV IgG in PwMS compared with HCs are findings worthy of further investigation.

Ocrelizumab B cell depletion has no effect on HERV RNA expression in PBMC in MS patients

BACKGROUND

Epstein barr virus (EBV) infection of B cells is now understood to be one of the triggering events for the development of Multiple Sclerosis (MS), a progressive immune-mediated disease of the central nervous system. EBV infection is also linked to expression of human endogenous retroviruses (HERVs) of the HERV-W group, a further risk factor for the development of MS. Ocrelizumab is a high-potency disease-modifying treatment (DMT) for MS, which depletes B cells by targeting CD20.

OBJECTIVES

We studied the effects of ocrelizumab on gene expression in peripheral blood mononuclear cells (PBMC) from paired samples from 20 patients taken prior to and 6 months after beginning ocrelizumab therapy. We hypothesised that EBV and HERV-W loads would be lower in post-treatment samples.

METHODS

Samples were collected in Paxgene tubes, subject to RNA extraction and Illumina paired end short read mRNA sequencing with mapping of sequence reads to the human genome using Salmon and differential gene expression compared with DeSeq2. Mapping was also performed separately to the HERV-D database of HERV sequences and the EBV reference sequence.

RESULTS

Patient samples were more strongly clustered by individual rather than disease type (relapsing/remitting or primary progressive), treatment (pre and post), age, or sex. Fourteen genes, all clearly linked to B cell function were significantly down regulated in the post treatment samples. Interestingly only one pre-treatment sample had detectable EBV RNA and there were no significant differences in HERV expression (of any group) between pre- and post-treatment samples.

CONCLUSIONS

While EBV and HERV expression are clearly linked to triggering MS pathogenesis, it does not appear that high level expression of these viruses is a part of the ongoing disease process or that changes in virus load are associated with ocrelizumab treatment.

Insights into the interplay between Epstein-Barr virus (EBV) and multiple sclerosis (MS): A state-of-the-art review and implications for vaccine development

Background and Aims

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS). MS results from an inflammatory process leading to the loss of neural tissue and increased disability over time. The role of Epstein Barr Virus (EBV), as one of the most common global viruses, in MS development has been the subject of several studies. However, many related questions are still unanswered. This study aimed to review the connection between MS and EBV and provide a quick outline of MS prevention using EBV vaccination.

Methods

For this narrative review, an extensive literature search using specific terms was conducted across online databases, including PubMed/Medline, Scopus, Web of Science, and Google Scholar, to identify pertinent studies.

Results

Several studies proved that almost 100% of people with MS showed a history of EBV infection, and there was an association between high titers of EBV antibodies and an increased risk of MS development. Various hypotheses are proposed for how EBV may contribute to MS directly and indirectly: (1) Molecular Mimicry, (2) Mistaken Self, (3) Bystander Damage, and (4) Autoreactive B cells infected with EBV.

Conclusion

Given the infectious nature of EBV and its ability to elude the immune system, EBV emerges as a strong candidate for being the underlying cause of MS. The development of an EBV vaccine holds promise for preventing MS; however, overcoming the challenge of creating a safe and efficacious vaccine presents a significant obstacle.

Modifiable risk factors for multiple sclerosis have consistent directions of effect across diverse ethnic backgrounds: a nested case-control study in an English population-based cohort

BACKGROUND

Multiple sclerosis is a leading cause of non-traumatic neurological disability among young adults worldwide. Prior studies have identified modifiable risk factors for multiple sclerosis in cohorts of White ethnicity, such as infectious mononucleosis, smoking, and obesity during adolescence/early adulthood. It is unknown whether modifiable exposures for multiple sclerosis have a consistent impact on risk across ethnic groups.

AIM

To determine whether modifiable risk factors for multiple sclerosis have similar effects across diverse ethnic backgrounds.

METHODS

We conducted a nested case-control study using data from the UK Clinical Practice Research Datalink. Multiple sclerosis cases diagnosed from 2001 until 2022 were identified from electronic healthcare records and matched to unaffected controls based on year of birth. We used stratified logistic regression models and formal statistical interaction tests to determine whether the effect of modifiable risk factors for multiple sclerosis differed by ethnicity.

RESULTS

We included 9662 multiple sclerosis cases and 118,914 age-matched controls. The cohort was ethnically diverse (MS: 277 South Asian [2.9%], 251 Black [2.6%]; Controls: 5043 South Asian [5.7%], 4019 Black [4.5%]). The age at MS diagnosis was earlier in the Black (40.5 [SD 10.9]) and Asian (37.2 [SD 10.0]) groups compared with White cohort (46.1 [SD 12.2]). There was a female predominance in all ethnic groups; however, the relative proportion of males was higher in the South Asian population (proportion of women 60.3% vs 71% [White] and 75.7% [Black]). Established modifiable risk factors for multiple sclerosis-smoking, obesity, infectious mononucleosis, low vitamin D, and head injury-were consistently associated with multiple sclerosis in the Black and South Asian cohorts. The magnitude and direction of these effects were broadly similar across all ethnic groups examined. There was no evidence of statistical interaction between ethnicity and any tested exposure, and no evidence to suggest that differences in area-level deprivation modifies these risk factor-disease associations. These findings were robust to a range of sensitivity analyses.

CONCLUSIONS AND RELEVANCE

Established modifiable risk factors for multiple sclerosis are applicable across diverse ethnic backgrounds. Efforts to reduce the population incidence of multiple sclerosis by tackling these risk factors need to be inclusive of people from diverse ethnicities.

Association between atopic dermatitis, autoimmune illnesses, Epstein-Barr virus, and cytomegalovirus

Atopic dermatitis (AD) is a Th2-driven inflammatory skin disease that has been associated with other autoimmune illnesses (AI) and has a well-known predisposition to infection with herpes simplex virus infection. Yet, few studies have evaluated the association between atopic dermatitis, autoimmune illness, and other human herpes virus (HHV) infections such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV). We aimed to evaluate the association between AD, specific AIs, CMV, and EBV in a random sample of the Optum Clinformatics Data Mart database, a US administrative claims database. AD was defined based on ICD diagnostic codes. Patients with AD were exact matched to those without AD on sex, age at enrollment, time observed in the dataset and census division. Our outcomes of interest were rheumatoid arthritis (RA), Crohn's disease (CD), ulcerative colitis (UC), multiple sclerosis (MS), CMV, and EBV infection as defined by specific ICD codes. Logistic regression models were used to examine the association between AD and our outcomes of interest [odds ratio (95% confidence intervals)]. Our full cohort included 40,141,017 patients. In total, 601,783 patients with AD were included. As expected, patients with AD had a higher prevalence of asthma and seasonal allergies versus controls. Individuals with AD have an increased risk of EBV, CMV, RA, CD, UC, and MS. While we cannot demonstrate a causal association, the observed associations between AD and AI may be in part mediated by these types of HHV (i.e., CMV and EBV), a finding that merits further study.

The Probable Infectious Origin of Multiple Sclerosis

Multiple sclerosis (MS) is an immune inflammatory disease that causes demyelination of the white matter of the central nervous system. It is generally accepted that the etiology of MS is multifactorial and believed to be a complex interplay between genetic susceptibility, environmental factors, and infectious agents. While the exact cause of MS is still unknown, increasing evidence suggests that disease development is the result of interactions between genetically susceptible individuals and the environment that lead to immune dysregulation and CNS inflammation. Genetic factors are not sufficient on their own to cause MS, and environmental factors such as viral infections, smoking, and vitamin D deficiency also play important roles in disease development. Several pathogens have been implicated in the etiology of MS, including Epstein-Barr virus, human herpesvirus 6, varicella-zoster virus, cytomegalovirus, Helicobacter pylori, Chlamydia pneumoniae, and Borrelia burgdorferi. Although vastly different, viruses and bacteria can manipulate host gene expression, causing immune dysregulation, myelin destruction, and neuroinflammation. This review emphasizes the pathogenic triggers that should be considered in MS progression.

Risk of a first clinical diagnosis of central nervous system demyelination in relation to human herpesviruses in the context of Epstein-Barr virus

BACKGROUND AND PURPOSE

Epstein-Barr virus (EBV) is implicated in multiple sclerosis (MS) risk; evidence for other herpesviruses is inconsistent. Here, we test blood markers of infection with human herpesvirus 6 (HHV-6), varicella zoster virus (VZV), and cytomegalovirus (CMV) as risk factors for a first clinical diagnosis of central nervous system demyelination (FCD) in the context of markers of EBV infection.

METHODS

In the Ausimmune case-control study, cases had an FCD, and population controls were matched on age, sex, and study region. We quantified HHV-6- and VZV-DNA load in whole blood and HHV-6, VZV, and CMV antibodies in serum. Conditional logistic regression tested associations with FCD risk, adjusting for Epstein-Barr nuclear antigen (EBNA) IgG, EBV-DNA load, and other covariates.

RESULTS

In 204 FCD cases and 215 matched controls, only HHV-6-DNA load (positive vs. negative) was associated with FCD risk (adjusted odds ratio = 2.20, 95% confidence interval = 1.08-4.46, p = 0.03). Only EBNA IgG and HHV-6-DNA positivity were retained in a predictive model of FCD risk; the combination had a stronger association than either alone. CMV-specific IgG concentration modified the association between an MS risk-related human leucocyte antigen gene and FCD risk. Six cases and one control had very high HHV-6-DNA load (>1.0 × 106 copies/mL).

CONCLUSIONS

HHV-6-DNA positivity and high load (possibly due to inherited HHV-6 chromosomal integration) were associated with increased FCD risk, particularly in association with markers of EBV infection. With growing interest in prevention/management of MS through EBV-related pathways, there should be additional consideration of the role of HHV-6 infection.

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.

Do magnetic resonance imaging features differ between persons with multiple sclerosis of various races and ethnicities?

Those of African American or Latin American descent have been demonstrated to have more severe clinical presentations of multiple sclerosis (MS) than non-Latin American White people with MS. Concurrently, radiological burden of disease on magnetic resonance imaging (MRI) in African Americans with MS has also been described as being more aggressive. Here, we review MRI studies in diverse racial and ethnic groups (adult and pediatric) investigating lesion burden, inflammation, neurodegeneration, and imaging response to disease modifying therapy. We also discuss why such disparities may exist beyond biology, and how future studies may provide greater insights into underlying differences.

Cross-reactive EBNA1 immunity targets alpha-crystallin B and is associated with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, for which and Epstein-Barr virus (EBV) infection is a likely prerequisite. Due to the homology between Epstein-Barr nuclear antigen 1 (EBNA1) and alpha-crystallin B (CRYAB), we examined antibody reactivity to EBNA1 and CRYAB peptide libraries in 713 persons with MS (pwMS) and 722 matched controls (Con). Antibody response to CRYAB amino acids 7 to 16 was associated with MS (OR = 2.0), and combination of high EBNA1 responses with CRYAB positivity markedly increased disease risk (OR = 9.0). Blocking experiments revealed antibody cross-reactivity between the homologous EBNA1 and CRYAB epitopes. Evidence for T cell cross-reactivity was obtained in mice between EBNA1 and CRYAB, and increased CRYAB and EBNA1 CD4+ T cell responses were detected in natalizumab-treated pwMS. This study provides evidence for antibody cross-reactivity between EBNA1 and CRYAB and points to a similar cross-reactivity in T cells, further demonstrating the role of EBV adaptive immune responses in MS development.

Increased cytomegalovirus immune responses at disease onset are protective in the long-term prognosis of patients with multiple sclerosis

OBJECTIVE

It remains unclear whether viral infections interfere with multiple sclerosis (MS) disease progression. We evaluated the prognostic role of antibody responses toward viruses determined at disease onset on long-term disease outcomes.

METHODS

Humoral immune responses against Epstein-Barr virus (EBV)-encoded nuclear antigen EBNA1, viral capsid antigen (VCA) and early antigen, and toward cytomegalovirus (HCMV), human herpesvirus 6 and measles were investigated in a cohort of 143 patients with MS for their association with long-term disability and inflammation disease outcomes.

RESULTS

Median (IQR) follow-up was 20 (17.2-22.8) years. In univariable analysis, increased HCMV levels were associated with a lower risk to Expanded Disability Status Scale 4.0 (HR 0.95; 95% CI 0.91 to 0.99; p=0.03), to develop a secondary progressive MS (HR 0.94; 95% CI 0.90 to 0.99; p=0.02) and to first-line treatment (HR 0.98; 95% CI 0.96 to 0.99; p=0.04). High HCMV IgG levels were associated with a longer time to first-line treatment (p=0.01). Increased immune responses against EBV-VCA were associated with higher risk for first-line (HR 1.45; 95% CI 1.12 to 1.88; p=0.005) and second-line treatments (HR 2.03; 95% CI 1.18 to 3.49; p=0.01), and high VCA IgG levels were associated with shorter time to first-line (p=0.004) and second-line (p=0.02) therapies. EBNA1-specific IgG levels correlated with disease severity (0.17; p=0.04) and with an increased relapse rate during follow-up (relapse rate 1.26; 95% CI 1.03 to 1.56; p=0.02) that remained stable in multivariable analysis.

CONCLUSIONS

These results indicate that elevated immune responses against HCMV at disease onset have protective effects on long-term disability and inflammation disease outcomes. Our data also indicate that increased immune responses against EBV in early phases may influence long-term disease prognosis.

Extracellular vesicles, the emerging mirrors of brain physiopathology

Extracellular vesicles are secreted by a wide variety of cells, and their primary functions include intercellular communication, immune responses, human reproduction, and synaptic plasticity. Their molecular cargo reflects the physiological processes that their cells of origin are undergoing. Thus, many studies have suggested that extracellular vesicles could be a promising biomarker tool for many diseases, mainly due to their biological relevance and easy accessibility to a broad range of body fluids. Moreover, since their biological composition leads them to cross the blood-brain barrier bidirectionally, growing evidence points to extracellular vesicles as emerging mirrors of brain diseases processes. In this regard, this review explores the biogenesis and biological functions of extracellular vesicles, their role in different physiological and pathological processes, their potential in clinical practice, and the recent outstanding studies about the role of exosomes in major human brain diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or brain tumors.

Analysis of herpesvirus infection and genome single nucleotide polymorphism risk factors in multiple sclerosis, Volga federal district, Russia

Multiple sclerosis (MS) is a heterogeneous disease where herpesvirus infection and genetic predisposition are identified as the most consistent risk factors. Serum and blood samples were collected from 151 MS and 70 controls and used to analyze circulating antibodies for, and DNA of, Epstein Barr virus (EBV), human cytomegalovirus (HCMV), human herpes virus 6 (HHV6), and varicella zoster virus (VZV). The frequency of selected single nucleotide polymorphisms (SNPs) in MS and controls were studied. Herpesvirus DNA in blood samples were analyzed using qPCR. Anti-herpesvirus antibodies were detected by ELISA. SNPs were analyzed by the allele-specific PCR. For statistical analysis, Fisher exact test, odds ratio and Kruskall-Wallis test were used; p<0.05 values were considered as significant. We have found an association between circulating anti-HHV6 antibodies and MS diagnosis. We also confirmed higher frequency of A and C alleles in rs2300747 and rs12044852 of CD58 gene and G allele in rs929230 of CD6 gene in MS as compared to controls. Fatigue symptom was linked to AC and AA genotype in rs12044852 of CD58 gene. An interesting observation was finding higher frequency of GG genotype in rs12722489 of IL2RA and T allele in rs1535045 of CD40 genes in patient having anti-HHV6 antibodies. A link was found between having anti-VZV antibodies in MS and CC genotype in rs1883832 of CD40 gene.

Systems Bioinformatics Reveals Possible Relationship between COVID-19 and the Development of Neurological Diseases and Neuropsychiatric Disorders

Coronavirus Disease 2019 (COVID-19) is associated with increased incidence of neurological diseases and neuropsychiatric disorders after infection, but how it contributes to their development remains under investigation. Here, we investigate the possible relationship between COVID-19 and the development of ten neurological disorders and three neuropsychiatric disorders by exploring two pathological mechanisms: (i) dysregulation of host biological processes via virus-host protein-protein interactions (PPIs), and (ii) autoreactivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epitopes with host "self" proteins via molecular mimicry. We also identify potential genetic risk factors which in combination with SARS-CoV-2 infection might lead to disease development. Our analysis indicated that neurodegenerative diseases (NDs) have a higher number of disease-associated biological processes that can be modulated by SARS-CoV-2 via virus-host PPIs than neuropsychiatric disorders. The sequence similarity analysis indicated the presence of several matching 5-mer and/or 6-mer linear motifs between SARS-CoV-2 epitopes with autoreactive epitopes found in Alzheimer's Disease (AD), Parkinson's Disease (PD), Myasthenia Gravis (MG) and Multiple Sclerosis (MS). The results include autoreactive epitopes that recognize amyloid-beta precursor protein (APP), microtubule-associated protein tau (MAPT), acetylcholine receptors, glial fibrillary acidic protein (GFAP), neurofilament light polypeptide (NfL) and major myelin proteins. Altogether, our results suggest that there might be an increased risk for the development of NDs after COVID-19 both via autoreactivity and virus-host PPIs.

Autoreactive lymphocytes in multiple sclerosis: Pathogenesis and treatment target

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by destruction of the myelin sheath structure. The loss of myelin leads to damage of a neuron’s axon and cell body, which is identified as brain lesions on magnetic resonance image (MRI). The pathogenesis of MS remains largely unknown. However, immune mechanisms, especially those linked to the aberrant lymphocyte activity, are mainly responsible for neuronal damage. Th1 and Th17 populations of lymphocytes were primarily associated with MS pathogenesis. These lymphocytes are essential for differentiation of encephalitogenic CD8⁺ T cell and Th17 lymphocyte crossing the blood brain barrier and targeting myelin sheath in the CNS. B-lymphocytes could also contribute to MS pathogenesis by producing anti-myelin basic protein antibodies. In later studies, aberrant function of Treg and Th9 cells was identified as contributing to MS. This review summarizes the aberrant function and count of lymphocyte, and the contributions of these cell to the mechanisms of MS. Additionally, we have outlined the novel MS therapeutics aimed to amend the aberrant function or counts of these lymphocytes.

The role of virus infections in Sjögren’s syndrome

Primary Sjögren’s syndrome (pSS) is an autoimmune disease with a clinical picture of not only mainly exocrine gland involvement, with dryness symptoms, but also internal organ and systems involvement. The epithelial damage and releasing of antigens, which, in some circumstances, become autoantigens, underlay the pathogenesis of pSS. The activation of autoimmune processes in pSS leads to the hyperactivation of B cells with autoantibody production and other immunological phenomena such as hypergammaglobulinemia, production of cryoglobulins, or formation of extra-nodal lymphoid tissue. Among the risk factors for the development of this disease are viral infections, which themselves can activate autoimmune reactions and influence the host’s immune response. It is known that viruses, through various mechanisms, can influence the immune system and initiate autoimmune reactions. These mechanisms include molecular mimicry, bystander activation, production of superantigens—proteins encoded by viruses—or a programming to produce viral cytokines similar to host cytokines such as, e.g., interleukin-10. Of particular importance for pSS are viruses which not only, as expected, activate the interferon pathway but also play a particular role, directly or indirectly, in B cell activation or present tropism to organs also targeted in the course of pSS. This article is an attempt to present the current knowledge of the influence specific viruses have on the development and course of pSS.

Epidemiology and Pathophysiology of Multiple Sclerosis

PURPOSE OF REVIEW

This article provides an overview of genetic, environmental, and lifestyle risk factors affecting the disease course of multiple sclerosis (MS) and reviews the pathophysiologic characteristics of both relapsing and progressive MS.

RECENT FINDINGS

The prevalence of MS has increased in recent decades, and costs of care for patients with MS have risen dramatically. Black, Asian, and Hispanic individuals may be at risk for more severe MS-related disability. Multiple genetic MS risk factors have been identified. Factors such as low vitamin D levels and a history of Epstein-Barr virus, smoking, and obesity, especially during childhood, also influence MS risk. Traditionally thought to be a T-cell-mediated disease, recent research has highlighted the additional roles of B cells and microglia in both relapsing and progressive MS.

SUMMARY

Complex interactions between genetic, environmental, and lifestyle factors affect the risk for MS as well as the disease course. People of color have historically been underrepresented in both MS clinical trials and literature, but current research is attempting to better clarify unique considerations in these groups. MS pathology consists of the focal inflammatory lesions that have been well characterized in relapsing MS, as well as a more widespread neurodegenerative component that is posited to drive progressive disease. Recent advances in characterization of both the inflammatory and neurodegenerative aspects of MS pathophysiology have yielded potential targets for future therapeutic options.

Gut microbiome and autoimmune disorders

Autoimmune diseases have long been known to share a common pathogenesis involving a dysregulated immune system with failure to recognize self from non-self antigens. This immune dysregulation is now increasingly understood to be induced by environmental triggers in genetically predisposed individuals. Although several external environmental triggers have been defined in different autoimmune diseases, much attention is being paid to the role of the internal micro-environment occupied by the microbiome which was once termed "the forgotten organ". In this regard, the gut microbiome, serving as an intermediary between some of those external environmental effectors and the immune system helps programming of the immune system to be tolerant to innocent external and self antigens. However, in the presence of perturbed gut microbiota (dysbiosis), the immune system could be erroneously directed in favor of pro-inflammatory pathways to instigate different autoimmune processes. An accumulating body of evidence, including both experimental and human studies (observational and interventional) points to a role of gut microbiome in different autoimmune diseases. Such evidence could provide a rationale for gut microbiome manipulation with therapeutic and even preventative intents in patients with established or predisposed to autoimmune diseases respectively. Perturbations of the gut microbiome have been delineated in some immune mediated diseases, IBD in particular. However, such patterns of disturbance (microbiome signatures) and related pathogenetic roles of the gut microbiome are context dependent and cannot be generalized in the same exact way to other autoimmune disorders and the contribution of gut microbiome to different disease phenotypes has to be precisely defined. In this review, we revise the evidence for a role of gut microbiome in various autoimmune diseases and possible mechanisms mediating such a role.

Effect of Cytomegalovirus Infection on the Central Nervous System: Implications for Psychiatric Disorders

Cytomegalovirus (CMV) is a common herpesvirus that establishes lifelong latent infections and interacts extensively with the host immune system, potentially contributing to immune activation and inflammation. Given its proclivity for infecting the brain and its reactivation by inflammatory stimuli, CMV is well known for causing central nervous system complications in the immune-naïve (e.g., in utero) and in the immunocompromised (e.g., in neonates, individuals receiving transplants or cancer chemotherapy, or people living with HIV). However, its potentially pathogenic role in diseases that are characterized by more subtle immune dysregulation and inflammation such as psychiatric disorders is still a matter of debate. In this chapter, we briefly summarize the pathogenic role of CMV in immune-naïve and immunocompromised populations and then review the evidence (i.e., epidemiological studies, serological studies, postmortem studies, and recent neuroimaging studies) for a link between CMV infection and psychiatric disorders with a focus on mood disorders and schizophrenia. Finally, we discuss the potential mechanisms through which CMV may cause CNS dysfunction in the context of mental disorders and conclude with a summary of the current state of play as well as potential future research directions in this area.

Viral Proteins with PxxP and PY Motifs May Play a Role in Multiple Sclerosis

Multiple sclerosis (MS) is a debilitating disease that arises from immune system attacks to the protective myelin sheath that covers nerve fibers and ensures optimal communication between brain and body. Although the cause of MS is unknown, a number of factors, which include viruses, have been identified as increasing the risk of displaying MS symptoms. Specifically, the ubiquitous and highly prevalent Epstein–Barr virus, human herpesvirus 6, cytomegalovirus, varicella–zoster virus, and other viruses have been identified as potential triggering agents. In this review, we examine the specific role of proline-rich proteins encoded by these viruses and their potential role in MS at a molecular level.

Genetic, Environmental and Lifestyle Determinants of Accelerated Telomere Attrition as Contributors to Risk and Severity of Multiple Sclerosis

Telomeres are protective structures at the ends of linear chromosomes. Shortened telomere lengths (TL) are an indicator of premature biological aging and have been associated with a wide spectrum of disorders, including multiple sclerosis (MS). MS is a chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system. The exact cause of MS is still unclear. Here, we provide an overview of genetic, environmental and lifestyle factors that have been described to influence TL and to contribute to susceptibility to MS and possibly disease severity. We show that several early-life factors are linked to both reduced TL and higher risk of MS, e.g., adolescent obesity, lack of physical activity, smoking and vitamin D deficiency. This suggests that the mechanisms underlying the disease are connected to cellular aging and senescence promoted by increased inflammation and oxidative stress. Additional prospective research is needed to clearly define the extent to which lifestyle changes can slow down disease progression and prevent accelerated telomere loss in individual patients. It is also important to further elucidate the interactions between shared determinants of TL and MS. In future, cell type-specific studies and advanced TL measurement methods could help to better understand how telomeres may be causally involved in disease processes and to uncover novel opportunities for improved biomarkers and therapeutic interventions in MS.

Association of Infectious Mononucleosis in Childhood and Adolescence With Risk for a Subsequent Multiple Sclerosis Diagnosis Among Siblings

IMPORTANCE

Epstein-Barr virus and its acute manifestation, infectious mononucleosis (IM), are associated with an increased risk of multiple sclerosis (MS). Whether this association is confounded by susceptibility to infection is still debated.

OBJECTIVE

To assess whether hospital-diagnosed IM during childhood, adolescence, or young adulthood is associated with subsequent MS diagnosis independent of shared familial factors.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used the Swedish Total Population Register to identify individuals born in Sweden from January 1, 1958, to December 31, 1994. Participants aged 20 years were followed up from January 1, 1978, to December 31, 2018, with a median follow-up of 15.38 (IQR, 8.68-23.55; range, 0.01-40.96) years. Data were analyzed from October 2020 to July 2021.

EXPOSURE

Hospital-diagnosed IM before 25 years of age.

MAIN OUTCOMES AND MEASURES

Diagnoses of MS from 20 years of age were identified. Risk of an MS diagnosis associated with IM in childhood (birth to 10 years of age), adolescence (11-19 years of age), and early adulthood (20-24 years of age [time-dependent variable]) were estimated using conventional and stratified (to address familial environmental or genetic confounding) Cox proportional hazards regression.

RESULTS

Of the 2 492 980 individuals (1 312 119 men [52.63%] and 1 180 861 women [47.37%]) included, 5867 (0.24%) had an MS diagnosis from 20 years of age (median age, 31.50 [IQR, 26.78-37.54] years). Infectious mononucleosis in childhood (hazard ratio [HR], 1.98; 95% CI, 1.21-3.23) and adolescence (HR, 3.00; 95% CI, 2.48-3.63) was associated with an increased risk of an MS diagnosis that remained significant after controlling for shared familial factors in stratified Cox proportional hazards regression (HRs, 2.87 [95% CI, 1.44-5.74] and 3.19 [95% CI, 2.29-4.46], respectively). Infectious mononucleosis in early adulthood was also associated with risk of a subsequent MS diagnosis (HR, 1.89; 95% CI, 1.18-3.05), but this risk was attenuated and was not significant after controlling for shared familial factors (HR, 1.51; 95% CI, 0.82-2.76).

CONCLUSIONS AND RELEVANCE

These findings suggest that IM in childhood and particularly adolescence is a risk factor associated with a diagnosis of MS, independent of shared familial factors.

Serum Peptide Immunoglobulin G Autoantibody Response in Patients with Different Central Nervous System Inflammatory Demyelinating Disorders

Previous efforts to discover new surrogate markers for the central nervous system (CNS) inflammatory demyelinating disorders have shown inconsistent results; moreover, supporting evidence is scarce. The present study investigated the IgG autoantibody responses to various viral and autoantibodies-related peptides proposed to be related to CNS inflammatory demyelinating disorders using the peptide microarray method. We customized a peptide microarray containing more than 2440 immobilized peptides representing human and viral autoantigens. Using this, we tested the sera of patients with neuromyelitis optica spectrum disorders (NMOSD seropositive, n = 6; NMOSD seronegative, n = 5), multiple sclerosis (MS, n = 5), and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD, n = 6), as well as healthy controls (HC, n = 5) and compared various peptide immunoglobulin G (IgG) responses between the groups. Among the statistically significant peptides based on the pairwise comparisons of IgG responses in each disease group to HC, cytomegalovirus (CMV)-related peptides were most clearly distinguishable among the study groups. In particular, the most significant differences in IgG response were observed for HC vs. MS and HC vs. seronegative NMOSD (p = 0.064). Relatively higher IgG responses to CMV-related peptides were observed in patients with MS and NMOSD based on analysis of the customized peptide microarray.

RNA Sequencing of CD4+ T Cells in Relapsing-Remitting Multiple Sclerosis Patients at Relapse: Deciphering the Involvement of Novel genes and Pathways

CD4⁺ T cells are known as a noteworthy potential modulator of inflammation in multiple sclerosis (MS). In the current study, we investigated the transcriptome profile of CD4⁺ T cells in patients with relapsing-remitting MS (RRMS) at the relapse phase. We performed RNA sequencing of CD4⁺ T cells isolated from four relapsing-remitting MS (RRMS) patients at the relapse phase and four age- and sex-matched healthy controls. The edgeR statistical method was employed to determine differentially expressed genes (DEGs). Gene set enrichment analysis was subsequently performed. Applying a physical interaction network, genes with higher degrees were selected as hub genes. A total of 1278 and 1034 genes were defined at significantly higher or lower levels, respectively, in CD4⁺ T cells of RRMS patients at the relapse phase as compared with healthy controls. The top up- and downregulated genes were JAML and KDM3A. The detected DEGs were remarkable on chromosomes 1 and 2, respectively. The DEGs were mainly enriched in the pathways "regulation of transcription, DNA-templated," "regulation of B cell receptor signaling pathway," "protein phosphorylation," "epidermal growth factor receptor signaling pathway," and "positive regulation of neurogenesis." Moreover, 16 KEGG pathways mostly associated with the immune system and viral infections were enriched. In the constructed physical interaction networks, UBA52 and TP53 were shown to be the most highly ranked hub genes among upregulated and downregulated genes, respectively. By applying global transcriptome profiling of CD4⁺ T cells, we deciphered the involvement of several novel genes and pathways in MS pathogenesis. The present results must be confirmed by in vivo and in vitro studies.

The CD8 T Cell-Epstein-Barr Virus-B Cell Trialogue: A Central Issue in Multiple Sclerosis Pathogenesis

The cause and the pathogenic mechanisms leading to multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system (CNS), are still under scrutiny. During the last decade, awareness has increased that multiple genetic and environmental factors act in concert to modulate MS risk. Likewise, the landscape of cells of the adaptive immune system that are believed to play a role in MS immunopathogenesis has expanded by including not only CD4 T helper cells but also cytotoxic CD8 T cells and B cells. Once the key cellular players are identified, the main challenge is to define precisely how they act and interact to induce neuroinflammation and the neurodegenerative cascade in MS. CD8 T cells have been implicated in MS pathogenesis since the 80's when it was shown that CD8 T cells predominate in MS brain lesions. Interest in the role of CD8 T cells in MS was revived in 2000 and the years thereafter by studies showing that CNS-recruited CD8 T cells are clonally expanded and have a memory effector phenotype indicating in situ antigen-driven reactivation. The association of certain MHC class I alleles with MS genetic risk implicates CD8 T cells in disease pathogenesis. Moreover, experimental studies have highlighted the detrimental effects of CD8 T cell activation on neural cells. While the antigens responsible for T cell recruitment and activation in the CNS remain elusive, the high efficacy of B-cell depleting drugs in MS and a growing number of studies implicate B cells and Epstein-Barr virus (EBV), a B-lymphotropic herpesvirus that is strongly associated with MS, in the activation of pathogenic T cells. This article reviews the results of human studies that have contributed to elucidate the role of CD8 T cells in MS immunopathogenesis, and discusses them in light of current understanding of autoreactivity, B-cell and EBV involvement in MS, and mechanism of action of different MS treatments. Based on the available evidences, an immunopathological model of MS is proposed that entails a persistent EBV infection of CNS-infiltrating B cells as the target of a dysregulated cytotoxic CD8 T cell response causing CNS tissue damage.

Role of Viral Infections in Multiple Sclerosis Pathogenesis among Indian Population

Background

The role of viral infections in multiple sclerosis (MS) pathogenesis is unclear.

Objective

Certain neurotropic viruses previously linked with MS among white population were studied including Epstein-Barr virus, human herpesvirus-6 (HHV-6) and MS-associated retrovirus (MSRV).

Material and Methods

Sixty-two MS patients (37 had a recent clinical relapse) and 65 controls with other neurological disorders were included. Blood and cerebrospinal fluid (CSF) samples were obtained and processed with the primary objective of determining whether there was intrathecal multiplication of viruses under study (EBV, HHV6 A and B and human endogenous retrovirus) or a breach in blood-brain barrier associated with viral presence in both peripheral blood and CSF.

Results

Evidence of breach in blood-brain barrier was seen in 86.5% of patients as evidenced by abnormal CSF/serum albumin index and or MRI. EBV nuclear antigen (EBNA1 IgG) was seen in 89% of MS patients and 58% controls (P = <0.001). However, HHV6 IgG was similar in both groups (85% versus 81%; P = 0.45). In affinity immunoblotting reaction intrathecal IgG synthesis against EBNA1 antigen was demonstrable in 26% (16/62) of patients and none against HHV6. A subset of patients showed significant elevation in mean copy number of plasma EBV DNA during relapse and there was a trend for the same among patients harboring HHV-6B. No evidence of isolated intrathecal viral presence or multiplication was seen.

Conclusions

The results of our study suggest that viruses studied namely EBV and HHV6 have a role in triggering relapses through a peripheral mechanism, rather than a direct role through intrathecal multiplication.

Exosomes From Subjects With Multiple Sclerosis Express EBV-Derived Proteins and Activate Monocyte-Derived Macrophages

Objective

To investigate in a cross-sectional study the effect of serum-derived exosomes on primary human blood monocyte-derived macrophages (MDMs) comparing exosomes from healthy donors vs patients with relapsing-remitting multiple sclerosis in remission and in relapse and to assess whether the response correlates with exosomal Epstein-Barr virus (EBV) protein expression.

Methods

A total of 45 serum-derived exosome preparations were isolated from patients and healthy controls and verified for the expression of exosomal and EBV markers. MDMs were differentiated from monocytes for 7 days and incubated for 24 hours with exosomes, and then, cell supernatants were collected for cytokine measurement by cytometric bead array. Cells were immunophenotyped before and after differentiation.

Results

Serum-derived exosomes of patients with multiple sclerosis (MS) expressed higher levels of EBV proteins than healthy controls. Of interest, expression of EBV nuclear antigen EBNA1 and latent membrane proteins LMP1 and 2A was higher on exosomes derived from patients with active RRMS compared with healthy controls and stable patients. After data normalization, we observed that incubation with EBV(+) exosomes induced CXCL10 and CCL2 secretion by MDMs. MDMs differentiated from patients with active disease were better secretors of CXCL10 and other interferon-γ–inducible chemokines, including CCL2 and CXCL9, than MDMs from healthy and stable MS groups. MDMs from active patients had a higher frequency of a CD14(++) subset that correlated with the secreted CXCL10.

Conclusion

Exosomes expressing EBV proteins correlate with disease activity and induce an inflammatory response in MDMs that is compounded by the origin of the responder cells.

Revisiting the Hygiene Hypothesis in the Context of Autoimmunity

Initially described for allergic diseases, the hygiene hypothesis was extended to autoimmune diseases in the early 2000s. A historical overview allows appreciation of the development of this concept over the last two decades and its discussion in the context of evolution. While the epidemiological data are convergent, with a few exceptions, the underlying mechanisms are multiple and complex. A major question is to determine what is the respective role of pathogens, bacteria, viruses, and parasites, versus commensals. The role of the intestinal microbiota has elicited much interest, but is it a cause or a consequence of autoimmune-mediated inflammation? Our hypothesis is that both pathogens and commensals intervene. Another question is to dissect what are the underlying cellular and molecular mechanisms. The role of immunoregulatory cytokines, in particular interleukin-10 and TGF beta is probably essential. An important place should also be given to ligands of innate immunity receptors present in bacteria, viruses or parasites acting independently of their immunogenicity. The role of Toll-Like Receptor (TLR) ligands is well documented including via TLR ligand desensitization.

Identification of two highly antigenic epitope markers predicting multiple sclerosis in optic neuritis patients

Background

Optic neuritis (ON) can occur as an isolated episode or will develop to multiple sclerosis (MS) a chronic autoimmune disease. What predicts ON progression to MS remains poorly understood.

Methods

We characterised the antibody epitope repertoire in three independent clinical cohorts (discovery (n = 62), validation (n = 20) and external cohort (n = 421)) using mimotope variation analysis (MVA), a next generation phage display technology to identify epitopes that associate with prognosis of ON.

Findings

We observed distinct epitope profiles for ON, MS and the controls, whereas epitope repertoires of sera and CSF were highly similar. Two unique and highly immunogenic epitopes A and B were detected in subjects with ON progressing to MS. These epitopes A and B were strongly associated with herpesviral antigens (VCA p18 of  Epstein-Barr virus (EBV); gB of Cytomegalovirus (CMV)). ROC addressed 75% of MS subjects with ON onset correctly (at 75% sensitivity and 74.22% specificity) based on the two-epitope biomarker analysis.

Interpretation

This is the first report on epitope diagnostics for MS employing the unbiased strategy of MVA for identification of novel immunological features of disease.

Funding

The Estonian Ministry of Education, The Estonian Research Council (PRG573, PRG805 and PSG691), H2020-MSCA-RISE-2016 (SZTEST), H2020-NMBP-2017 (PANBIORA), Helsinki University Hospital, Mary and Georg C. Ehrnrooth, Finnish Eye, Sigrid Jusélius and Magnus Ehrnrooth Foundations.

Herpesvirus Antibodies, Vitamin D and Short-Chain Fatty Acids: Their Correlation with Cell Subsets in Multiple Sclerosis Patients and Healthy Controls

Although the etiology of multiple sclerosis (MS) is still unknown, it is commonly accepted that environmental factors could contribute to the disease. The objective of this study was to analyze the humoral response to Epstein-Barr virus, human herpesvirus 6A/B and cytomegalovirus, and the levels of 25-hydroxyvitamin D (25(OH)D) and the three main short-chain fatty acids (SCFA), propionate (PA), butyrate (BA) and acetate (AA), in MS patients and healthy controls (HC) to understand how they could contribute to the pathogenesis of the disease. With this purpose, we analyzed the correlations among them and with different clinical variables and a wide panel of cell subsets. We found statistically significant differences for most of the environmental factors analyzed when we compared MS patients and HC, supporting their possible involvement in the disease. The strongest correlations with the clinical variables and the cell subsets analyzed were found for 25(OH)D and SCFAs levels. A correlation was also found between 25(OH)D and PA/AA ratio, and the interaction between these factors negatively correlated with interleukin 17 (IL-17)-producing CD4+ and CD8+ T cells in untreated MS patients. Therapies that simultaneously increase vitamin D levels and modify the proportion of SCFA could be evaluated in the future.

Prognostication and contemporary management of clinically isolated syndrome

Clinically isolated syndrome (CIS) patients present with a single attack of inflammatory demyelination of the central nervous system. Recent advances in multiple sclerosis (MS) diagnostic criteria have expanded the number of CIS patients eligible for a diagnosis of MS at the onset of the disease, shrinking the prevalence of CIS. MS treatment options are rapidly expanding, which is driving the need to recognise MS at its earliest stages. In CIS patients, finding typical MS white matter lesions on the patient's MRI scan remains the most influential prognostic investigation for predicting subsequent diagnosis with MS. Additional imaging, cerebrospinal fluid and serum testing, information from the clinical history and genetic testing also contribute. For those subsequently diagnosed with MS, there is a wide spectrum of long-term clinical outcomes. Detailed assessment at the point of presentation with CIS provides fewer clues to calculate a personalised risk of long-term severe disability.Clinicians should select suitable CIS cases for steroid treatment to speed neurological recovery. Unfortunately, there are still no neuroprotection or remyelination strategies available. The use of MS disease modifying therapy for CIS varies among clinicians and national guidelines, suggesting a lack of robust evidence to guide practice. Clinicians should focus on confirming MS speedily and accurately with appropriate investigations. Diagnosis with CIS provides an opportune moment to promote a healthy lifestyle, in particular smoking cessation. Patients also need to understand the link between CIS and MS. This review provides clinicians an update on the contemporary evidence guiding prognostication and management of CIS.

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.

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.

High birth weight and risk of multiple sclerosis: A multicentre study in Argentina

BACKGROUND

Multiple sclerosis (MS) is now recognized as a multifactorial disease in which genetic and environmental factors intervene. Considerable efforts have been made to identify external risk factors present in childhood, adolescence and youth, though only a few perinatal risk factors have been positively associated with MS. Previously, we found an association between high birth weight and MS in male patients in a small study in Argentina. The present research was designed to further assess the association between high birth weight and MS in a larger sample of patients, using an extensive and validated general population database as control.

METHODS

We present an analytical observational, multicentre, population-based, and case-control study. A total of 637 patients (cases) with confirmed MS diagnosis attending five MS specialized centres in Argentina were included. Birth weight (BW) data was recalled by the patient's mother, which is a validated approach. A two-way comparison was performed. First, we used the standard categories of high, adequate and low BW in grams. Then, we applied the weight percentile distribution to provide reproducible results for further research. For a proper assessment and comparison of variables, we adopted the guidelines of the American Academy of Pediatrics for neonate classification according to gestational weeks and to BW in grams. The neonate's BW distribution of the general population was used as control. For the purposes of the study, we adapted Urquía's et al. curves, which are based on an extensive database of all the live births registered in the country from 2003 to 2007. To measure the magnitude of the proportional differences between low, adequate and high BW, the odds ratio (OR) and their 95% confidence interval (CI) were estimated. The mean BW and percentile values for each sex were compared using a z-Normal test. The respective MS patients and general population BW distribution curves by sex were compared between each other.

RESULTS

Cases and controls were comparable in their demographic, geographic and environmental characteristics. Males showed higher BW than females both in the MS patients and the general population groups. When we applied the sex stratified analysis separately, we found that males in the MS group showed an almost seven times higher risk of high birth weight than males from the general population (OR 6.58 [95% CI 4.81-8.99]). Female patients showed an almost five times higher risk of high BW than their respective controls (OR 4.5 [95% CI 3.06-6.58]). The comparison based on the BW percentile distribution confirmed that MS patients showed higher BW than the general population. This result reached statistical significance from the 75^th percentile onwards for both sexes.

CONCLUSION

In summary, our findings suggested that high BW could be one of the earliest risk factors for MS in life. If this results were reproduced in other centres, high birth weight would emerge as a novel and very early risk factor, potentially modifiable in utero or immediately postpartum, representing a unique opportunity to prevent the disease in future generations.

B Cells in Multiple Sclerosis and Virus-Induced Neuroinflammation

Neuroinflammation can be defined as an inflammatory response within the central nervous system (CNS) mediated by a complex crosstalk between CNS-resident and infiltrating immune cells from the periphery. Triggers for neuroinflammation not only include pathogens, trauma and toxic metabolites, but also autoimmune diseases such as neuromyelitis optica spectrum disorders and multiple sclerosis (MS) where the inflammatory response is recognized as a disease-escalating factor. B cells are not considered as the first responders of neuroinflammation, yet they have recently gained focus as a key component involved in the disease pathogenesis of several neuroinflammatory disorders like MS. Traditionally, the prime focus of the role of B cells in any disease, including neuroinflammatory diseases, was their ability to produce antibodies. While that may indeed be an important contribution of B cells in mediating disease pathogenesis, several lines of recent evidence indicate that B cells are multifunctional players during an inflammatory response, including their ability to present antigens and produce an array of cytokines. Moreover, interaction between B cells and other cellular components of the immune system or nervous system can either promote or dampen neuroinflammation depending on the disease. Given that the interest in B cells in neuroinflammation is relatively new, the precise roles that they play in the pathophysiology and progression of different neuroinflammatory disorders have not yet been well-elucidated. Furthermore, the possibility that they might change their function during the course of neuroinflammation adds another level of complexity and the puzzle remains incomplete. Indeed, advancing our knowledge on the role of B cells in neuroinflammation would also allow us to tackle these disorders better. Here, we review the available literature to explore the relationship between autoimmune and infectious neuroinflammation with a focus on the involvement of B cells in MS and viral infections of the CNS.

Prevalence of seropositivity of selected herpesviruses in patients with multiple sclerosis in the North of Jordan

Background

Multiple sclerosis (MS) is a neurological disease that is caused by an autoimmune response that results in the neuron’s demyelination in the central nervous system. The exact etiology of MS is not clear; however, several environmental and genetic factors are believed to participate in its initiation and development, including exposure to viruses. This study aims to investigate the association between the seropositivity and antibody titer of selected herpesviruses and MS in Jordanian MS patients.

Method

In this study, 55 MS patients and 40 age- and gender-matching apparently healthy volunteers were recruited from two main hospitals in the north of Jordan. MS patients were grouped into three types of MS based on the clinical presentation of the disease. Blood samples were collected from the participants and the IgG antibodies for human herpesvirus 6 (HHV-6), Epstein-Barr virus (EBV) nuclear antigen (EBNA), EBV viral capsid antigen (VCA) and varicella-zoster virus (VZV) were assayed by ELISA. The prevalence of seropositivity and the antibody level for each of the antibodies were compared between MS patients and controls and between the three types of MS.

Results

There was no significant difference in the prevalence of seropositivity and in the levels of antibodies for HHV-6, EBNA and VCA between MS patients and controls and between the three types of MS. In contrast, the number of seropositive patients and the level of IgG antibodies for VZV were significantly higher in MS patients compared to the control.

Conclusion

This study showed that patients with MS in the north of Jordan were more likely to be seropositive for VZV than the general population. Based on this finding, we recommend further studies to evaluate the seropositivity to VZV to be carried out in other parts of Jordan and the greater middle east to find out if there is a correlation between MS and previous infection with VZV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-020-01977-w.

Serological comparison of systemic lupus erythematosus with neuropsychiatric lupus using synthetic nucleic acid antigens

Neuropsychiatric systemic lupus erythematosus is an autoimmune disorder characterized by an irregular exchange between the central nervous system and the immune system, leading to the outbreak of neurological conditions with possible disabling effects. Although neuropsychiatric systemic lupus erythematosus is the most common expression of lupus condition, it is still poorly understood. In this study, we focus on the development of an advantageous method based on the application of synthetic nucleic acids and protein-based antigen arrays in order to characterize autoreactive antibodies in neuropsychiatric systemic lupus erythematosus. We confirmed the benefits of using synthetic oligonucleotides such as assay reproducibility, elevated affinity and specificity to autoreactive antibodies. We also demonstrated presence of autoantibodies towards three particular synthetic double stranded antigens and verify similarity of antinuclear antibody patterns in ordinary lupus and neuropsychiatric systemic lupus erythematosus.

Role of Viruses in the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is an immune inflammatory disease, where the underlying etiological cause remains elusive. Multiple triggering factors have been suggested, including environmental, genetic and gender components. However, underlying infectious triggers to the disease are also suspected. There is an increasing abundance of evidence supporting a viral etiology to MS, including the efficacy of interferon therapy and over-detection of viral antibodies and nucleic acids when compared with healthy patients. Several viruses have been proposed as potential triggering agents, including Epstein-Barr virus, human herpesvirus 6, varicella-zoster virus, cytomegalovirus, John Cunningham virus and human endogenous retroviruses. These viruses are all near ubiquitous and have a high prevalence in adult populations (or in the case of the retroviruses are actually part of the genome). They can establish lifelong infections with periods of reactivation, which may be linked to the relapsing nature of MS. In this review, the evidence for a role for viral infection in MS will be discussed with an emphasis on immune system activation related to MS disease pathogenesis.

Vitamin D and other environmental risk factors in Colombian patients with multiple sclerosis

OBJECTIVE

The aim of this study was to explore the association between MS and vitamin D levels, as well as Epstein-Barr virus (EBV) seropositivity and smoking history in a Colombian population.

METHODS

We conducted a cross-sectional study between 2017 and 2018. We measured vitamin D levels and EBV antibody titers and administered a questionnaire to assess dietary habits, smoking, second-hand smoking and duration of smoking, sunlight exposure, physical activity, and personal and family history in individuals with and without multiple sclerosis during adolescence. A multivariable logistic regression model was then performed to explore the association between vitamin D status and MS.

RESULTS

A total of 87 individuals with MS (mean age 40.9 years; 65.52% females) and 87 without MS (mean age 55 years; 65.52% females) were included in the analysis. In the multivariable analysis, after controlling for supplementation vitamin D levels did not differ between both groups and no difference was found regarding tobacco smoke exposure. The proportion of individuals who tested positive for anti-EBV nuclear antigen was significantly higher in individuals with MS (95.4% vs 82.76%, p = 0.028) CONCLUSION: : We did not find a statistically significant association between MS and vitamin D levels while anti-EBV nuclear antigen titers behaved as previously described in the literature. This study provides new evidence of the association between MS and different risk factors in our country, reinforcing the hypothesis that the pathogenesis of MS is multifactorial. Further studies are needed to better define the association between environmental factors and the development of MS in low prevalence areas.

Immune-mediated genesis of multiple sclerosis

Multiple sclerosis (MS) is widely acknowledged to be an autoimmune disease affecting the neuronal myelin structure of the CNS. Autoantigens recognized as the target of this autoimmune process are: myelin basal protein, anti-proteolipid protein, antimyelin-associated glycoprotein and antimyelin-based oligodendrocytic basic protein. Ample evidence supports the idea of a dysregulation of immunological tolerance towards self-antigens of neuronal myelin structure triggered by one or more viral or bacterial microbial agents in predisposed HLA gene subjects. Genetic predisposition to MS has been highlighted by numerous studies associating the disease to specific HLA haplotypes. Moreover, a wide range of evidence supports the fact that MS may be consequence of one or more viral or bacterial infections such as measles virus, EBV, HHV6, HZV, Chlamydia pneumoniae, Helicobacter Pylori, and other microbial agents. Microbiota elements also seems to have a role on the determinism of the disease as a pathogenic or protective factor. The autoimmune pathogenetic process could arise when a molecular mimicry between a foreign microbial antigen and an auto-antigen occurs in an HLA gene subject competent for that particular antigen. The antigen-presenting cells in this case would induce the activation of a specific Th clone causing a cross-reaction between a foreign antigen and an autoantigen resulting in an autoimmune response.

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A multifactorial ethiopathogenetic model based on immunomediation is a reliable hypothesis for multiple sclerosis.

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Evidence found in the scientific literature makes it possible to reconstruct this etiopathogenetic hypothesis for MS.

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HLA gene predisposition, correlation with infections, molecular mimicry and other immunological data are reported.

Infections, Vaccines and Autoimmunity: A Multiple Sclerosis Perspective

Background: Multiple sclerosis (MS) is a chronic neuroinflammatory and neurodegenerative disease that is associated with multiple environmental factors. Among suspected susceptibility events, studies have questioned the potential role of overt viral and bacterial infections, including the Epstein Bar virus (EBV) and human endogenous retroviruses (HERV). Furthermore, the fast development of immunomodulatory therapies further questions the efficacy of the standard immunization policies in MS patients. Topics reviewed: This narrative review will discuss the potential interplay between viral and bacterial infections and their treatment on MS susceptibility and disease progression. In addition, the review specifically discusses the interactions between MS pathophysiology and vaccination for hepatitis B, influenza, human papillomavirus, diphtheria, pertussis, and tetanus (DTP), and Bacillus Calmette-Guerin (BCG). Data regarding potential interaction between MS disease modifying treatment (DMT) and vaccine effectiveness is also reviewed. Moreover, HERV-targeted therapies such as GNbAC1 (temelimab), EBV-based vaccines for treatment of MS, and the current state regarding the development of T-cell and DNA vaccination are discussed. Lastly, a reviewing commentary on the recent 2019 American Academy of Neurology (AAN) practice recommendations regarding immunization and vaccine-preventable infections in the settings of MS is provided. Conclusion: There is currently no sufficient evidence to support associations between standard vaccination policies and increased risk of MS. MS patients treated with immunomodulatory therapies may have a lower benefit from viral and bacterial vaccination. Despite their historical underperformance, new efforts in creating MS-based vaccines are currently ongoing. MS vaccination programs follow the set back and slow recovery which is widely seen in other fields of medicine.

Race and ethnicity on MS presentation and disease course

Multiple sclerosis (MS) has a strong racial and ethnic component and disproportionately affects whites of European background. Recent incidence reports suggest an increasing rate of MS among African Americans compared with whites. Despite this recent increase in MS in African Americans, Hispanics and Asians are significantly less likely to develop MS than whites of European ancestry. MS-specific mortality trends demonstrate distinctive disparities by race/ethnicity and age, suggesting that there is an unequal burden of disease. Inequalities in health along with differences in clinical characteristics that may be genetic, environmental, and social in origin may be contributing to disease variability and be suggestive of endophenotypes. The overarching goal of this review was to summarize the current understanding on the variability of disease that we observe in selected racial and ethnic populations: Hispanics and African Americans. Future challenges will be to unravel the genetic, environmental, and social determinants of the observed racial/ethnic disparities.

Small molecule screening identifies inhibitors of the Epstein-Barr virus deubiquitinating enzyme, BPLF1

Herpesviral deubiquitinating enzymes (DUBs) were discovered in 2005, are highly conserved across the family, and are proving to be increasingly important players in herpesviral infection. EBV's DUB, BPLF1, is known to regulate both cellular and viral target activities, yet remains largely unstudied. Our work has implicated BPLF1 in a wide range of processes including infectivity, viral DNA replication, and DNA repair. Additionally, knockout of BPLF1 delays and reduces human B-cell immortalization and lymphoma formation in humanized mice. These findings underscore the importance of BPLF1 in viral infectivity and pathogenesis and suggest that inhibition of EBV's DUB activity may offer a new approach to specific therapy for EBV infections. We set out to discover and characterize small molecule inhibitors of BPLF1 deubiquitinating activity through high-throughput screening. An initial small pilot screen resulted in discovery of 10 compounds yielding >80% decrease in BPLF1 DUB activity at a 10 μM concentration. Follow-up dose response curves of top hits identified several compounds with an IC₅₀ in the low micromolar range. Four of these hits were tested for their ability to cleave ubiquitin chains as well as their effects on viral infectivity and cell viability. Further characterization of the top hit, commonly known as suramin was found to not be selective yet decreased viral infectivity by approximately 90% with no apparent effects on cell viability. Due to the conserved nature of Herpesviral deubiquitinating enzymes, identification of an inhibitor of BPLF1 may prove to be an effective and promising new avenue of therapy for EBV and other herpesviral family members.