Assessment of Epstein-Barr virus in blood from patients with multiple sclerosis

Evaluating the Clinical Utility of Epstein-Barr Virus Antibodies as Biomarkers in Multiple Sclerosis: A Systematic Review

BACKGROUND

EBV is a necessary but not sufficient factor in the pathophysiology of multiple sclerosis (MS). EBV antibodies to the nuclear antigen (EBNA1) and viral capsid antigen (VCA) rise rapidly prior to MS disease manifestations, and their absence has clinical utility with a high negative predictive value. It remains unclear whether EBV levels act as prognostic, monitoring, or pharmacodynamic/response biomarkers. Substantial literature on this topic exists but has not been systematically reviewed. We hypothesized that EBV levels against EBNA1 and VCA are potential prognostic and monitoring biomarkers in MS, and that patient population, MS clinical phenotype, and EBV assay method may play important roles in explaining variation among study outcomes.

METHODS

We systematically searched PubMed and EMBASE from inception to April 1, 2022. After removal of duplicates, records were screened by abstract. Remaining full-text articles were reviewed. Clinical and MRI data were extracted from full-text articles for comparison and synthesis.

RESULTS

Searches yielded 696 unique results; 285 were reviewed in full, and 36 met criteria for data extraction. Heterogeneity in sample population, clinical outcome measures, assay methods and statistical analyses precluded a meta-analysis. EBV levels were not consistently associated with clinical disease markers including conversion from CIS to RRMS, neurological disability, or disease phenotype. Studies using repeated-measures design suggest that EBNA1 levels may temporarily reflect inflammatory disease activity as assessed by gadolinium-enhancing Magnetic Resonance Imaging (MRI) lesions. Limited data also suggest a decrease in EBV levels following initiation of certain disease-modifying therapies.

CONCLUSION

Heterogeneous methodology limited generalization and meta-analysis. EBV antibody levels are unlikely to represent prognostic biomarkers in MS. The areas of highest ongoing promise relate to diagnostic exclusion and pharmacodynamic/disease response. Use of EBV antibodies as biomarkers in clinical practice remains additionally limited by lack of methodological precision, reliability, and validation.

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.

Multiple Sclerosis in sub-Saharan Africa - a scoping review

BACKGROUND

The objective of this review is to provide a synthesis of original studies in patients with MS, originating from sub-Saharan Africa. This review aims to facilitate a better understanding of the MS academic and health landscape in this region.

METHODS

A scoping review of original research was conducted (20th of November 2019) in PubMed, SCOPUS, Web of Science and EBSCO host. A narrative synthesis of studies was provided and placed in a historical context.

RESULTS

Thirty-one unique studies from sub-Saharan Africa were identified from 846 unique records. The included studies were predominantly conducted in South Africa (n=24;[77%]) and of case-control (n=11[36%]) or cross-sectional design (n=7[23%]); no randomized clinical trials were identified. Most studies focussed on understanding the epidemiology of MS, the risk of MS in specific ethnic populations, and how this may contribute to identifying the underlying causal pathways.

CONCLUSION

Albeit scarce, the research conducted in sub-Saharan Africa largely followed international trends. There is a paucity of studies that have been conducted with the primary aim of understanding MS patient care across the continuum, and management of MS in an African context. The latter may become of increasing importance in the light of an increasing prevalence of MS in this region, as well as the increasing noncommunicable disease epidemic.

Higher incidence of Epstein-Barr virus-induced lymphocyte transformation in multiple sclerosis

OBJECTIVES

Epstein-Barr virus (EBV) infection is associated with multiple sclerosis (MS), and EBV may transform lymphoblastoid cell lines more frequently in MS patients than controls, but it is not clear whether this reflects a higher viral load or an enhanced ability to reactivate EBV.

MATERIAL AND METHODS

MS patients and controls were examined for their B-cell subsets and during 16 weeks for spontaneous lymphocyte transforming events.

RESULTS

MS patients had normal distribution of B-cell subsets, but a significantly higher incidence of B-cell transforming events, which occurred with kinetics similar to controls.

CONCLUSIONS

The higher incidence suggests an increased frequency of latent EBV-infected B cells in MS.

Antibodies to Epstein-Barr virus and MRI disease activity in multiple sclerosis

BACKGROUND

Previous reports indicate an association between Epstein-Barr virus (EBV) antibody levels and multiple sclerosis (MS) disease activity, but the results have been conflicting.

OBJECTIVES

The objective of this paper is to study if EBV antibody levels reflect MRI disease activity in MS and examine the potential for EBV antibody levels as biomarkers for treatment response.

METHODS

A total of 87 MS patients were followed for two years prior to and during interferon beta (IFNB) treatment, with MRI examinations and serum measurement of IgM and IgG antibodies to viral capsid antigen (VCA), EBV nuclear antigen 1 (EBNA-1) and early antigen (EA). Associations between EBV antibody levels and MRI activity were assessed by a logistic regression model.

RESULTS

Higher anti-EBNA-1 IgG levels were associated with increased MRI activity, OR = 2.95 (95% CI 1.07-8.10; p = 0.036) for combined unique activity (CUA; the sum of T1Gd+ lesions and new or enlarging T2 lesions). Although most patients were anti-VCA IgM negative, there was an inverse association, OR = 0.32 (95% CI 0.12-0.84; p = 0.021) with CUA during IFNB treatment.

CONCLUSIONS

This study supports an association between anti-EBNA-1 IgG levels and MS disease activity. We also found an inverse association with anti-VCA IgM levels during IFNB treatment not previously described, indicating anti-VCA IgM as a possible biomarker for IFNB treatment response.

Detection of viral pathogens in high grade gliomas from unmapped next-generation sequencing data

Viral pathogens have been implicated in the development of certain cancers including human papillomavirus (HPV) in squamous cell carcinoma and Epstein-Barr virus (EBV) in Burkitt's lymphoma. The significance of viral pathogens in brain tumors is controversial, and human cytomegalovirus (HCMV) has been associated with glioblastoma (GBM) in some but not all studies, making the role of HCMV unclear. In this study we sought to determine if viral pathogen sequences could be identified in an unbiased manner from previously discarded, unmapped, non-human, next-generation sequencing (NGS) reads obtained from targeted oncology, panel-based sequencing of high grade gliomas (HGGs), including GBMs. Twenty one sequential HGG cases were analyzed by a targeted NGS clinical oncology panel containing 151 genes using DNA obtained from formalin-fixed, paraffin-embedded (FFPE) tissue. Sequencing reads that did not map to the human genome (average of 38,000 non-human reads/case (1.9%)) were filtered and low quality reads removed. Extracted high quality reads were then sequentially aligned to the National Center for Biotechnology Information (NCBI) non-redundant nucleotide (nt and nr) databases. Aligned reads were classified based on NCBI taxonomy database and all eukaryotic viral sequences were further classified into viral families. Two viral sequences (both herpesviruses), EBV and Roseolovirus were detected in 5/21 (24%) cases and in 1/21 (5%) cases, respectively. None of the cases had detectable HCMV. Of the five HGG cases with detectable EBV DNA, four had additional material for EBV in situ hybridization (ISH), all of which were negative for expressed viral sequence. Overall, a similar discovery approach using unmapped non-human NGS reads could be used to discover viral sequences in other cancer types.

Determining EBV load: current best practice and future requirements

EBV, a gammaherpesvirus and the pathogenic agent for infectious mononucleosis, is also associated with a broad spectrum of lymphoid and epithelial malignancies in immunocompetent and immunosuppressed individuals. EBV-DNA-load measurement by PCR has been shown to be a potential tool for the diagnosis of these diseases, a prognostic factor of their outcome and a successful method to monitor immunosuppressed patients. Since the end of 2011, there is an international WHO standard reference for EBV quantification available; however, many questions still remain; for instance about the optimal amplified region of the EBV genome, or the best-used specimen for EBV detection. Additionally, the optimal specimen and amplified region may vary in different malignancies. In this article, the authors review the different methods to measure EBV load, focus on the best-used specimen for the different EBV-associated malignancies and discuss future requirements and opportunities for EBV-load measurement.