Epstein-Barr virus and rheumatoid arthritis

Epstein-Barr Viruses: Their Immune Evasion Strategies and Implications for Autoimmune Diseases

Epstein-Barr virus (EBV), a member of the γ-herpesvirus family, is one of the most prevalent and persistent human viruses, infecting up to 90% of the adult population globally. EBV's life cycle includes primary infection, latency, and lytic reactivation, with the virus primarily infecting B cells and epithelial cells. This virus has evolved sophisticated strategies to evade both innate and adaptive immune responses, thereby maintaining a lifelong presence within the host. This persistence is facilitated by the expression of latent genes such as EBV nuclear antigens (EBNAs) and latent membrane proteins (LMPs), which play crucial roles in viral latency and oncogenesis. In addition to their well-known roles in several types of cancer, including nasopharyngeal carcinoma and B-cell lymphomas, recent studies have identified the pathogenic roles of EBV in autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus. This review highlights the intricate interactions between EBV and the host immune system, underscoring the need for further research to develop effective therapeutic and preventive strategies against EBV-associated diseases.

Mechanisms of Tripterygium wilfordii Hook F on treating rheumatoid arthritis explored by network pharmacology analysis and molecular docking

Background

Rheumatoid arthritis (RA) is a chronic inflammatory and disabling disease that imposes significant economic and social costs. Tripterygium wilfordii Hook F (TwHF) has a long history of use in traditional Chinese medicine for treating joint disorders, and it has been shown to be cost-effective in treating RA, but its exact mechanism is unknown.

Objective

The goal of the network pharmacology analysis and molecular docking was to investigate the potential active compounds and associated anti-RA mechanisms of TwHF.

Methods

TCMSP and UniProt databases were searched for active compounds and related targets of TwHF. PharmGKB, DrugBank, OMIM, TTD, and the Human Gene Databases were used to identify RA-related targets. The intersected RA and TwHF targets were entered into the STRING database to create a protein-protein interaction network. R software was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Molecular docking technology was used to analyze the optimal effective components from TwHF for docking with the selected target gene.

Results

Following screening and duplicate removal, a total of 51 active compounds and 96 potential targets were chosen. The PPI network revealed that the target proteins are CXCL8, CXCL6, STAT3, STAT1, JUN, PPARG, TP53, IL14, MMP9, VEGFA, RELA, CASP3, PTGS2, IFNG, AKT1, FOS, ICAM1, and MAPK14. The results of the GO enrichment analysis focused primarily on the response to lipopolysaccharide, the response to molecules of bacterial origin, and the response to drugs. The KEGG results indicated that the mechanisms were closely related to lipid and atherosclerosis, chemical carcinogenesis-receptor activation, Kaposi sarcoma-associated, herpesvirus infection, hepatitis B, fluid shear stress and atherosclerosis, IL-17 signaling pathways, Th17-cell differentiation, and so on, all of which are involved in angiogenesis, immune cell chemotaxis, and inflammatory responses. Molecular docking results suggested that triptolide was the appropriate PTGS1, PTGS2, and TNF inhibitors.

Conclusion

Our findings provide an essential role and basis for further immune inflammatory studies into the molecular mechanisms of TwHF and PTGS1, PTGS2, and TNF inhibitor development in RA.

Frequency and association of Epstein-Barr Virus genotype in rheumatoid arthritis patients of Khyber Pakhtunkhwa, Pakistan

BACKGROUND

Rheumatoid arthritis (RA) is an immune-mediated, polyarthritis linked with various genetic and environmental causative agents. Among environmental triggers, Epstein-Barr Virus (EBV) is considered the most potent etiological agent.

OBJECTIVE

This study aimed to investigate the prevalence of EBV and its genotypes in RA patients and to investigate their association with clinical and laboratory parameters of RA.

METHODOLOGY

This study included blood samples of RA and control healthy individuals (100 each). Blood samples along with clinical and laboratory parameters were collected from patients after consent in the Department of Rheumatology, at Lady Reading Hospital, in Peshawar Pakistan. Blood samples were processed for DNA extraction followed by PCR amplification for EBV detection and genotype discrimination.

RESULTS

RA patients were 85 females and 15 males with a mean age of 40.13±14.05 years. EBV Type-1 was detected in 45% of RA and 9% of control cases. The mean disease duration of RA patients was 6.61±6.23 years. Out of 100 diseased patients, 43% were seropositive rheumatoid arthritis (SPRA) and showed a significant correlation with a family history of RA in EBV-positive individuals (P = 0.017). The demographic, clinical, and laboratory parameters of RA patients showed a non-significant association with EBV. Moreover, only a family history and Serum creatinine of RA patients showed a significant association with EBV (P = 0.0001 and P = 0.022 respectively).

CONCLUSION

It is concluded that EBV-1 is prevalent and associated with RA. Further investigation is required for detailed genetic analysis of EBV to determine its possible role in modulating the immune system in RA.

Gene-environment interactions and their impact on human health

The molecular processes underlying human health and disease are highly complex. Often, genetic and environmental factors contribute to a given disease or phenotype in a non-additive manner, yielding a gene-environment (G × E) interaction. In this work, we broadly review current knowledge on the impact of gene-environment interactions on human health. We first explain the independent impact of genetic variation and the environment. We next detail well-established G × E interactions that impact human health involving environmental toxicants, pollution, viruses, and sex chromosome composition. We conclude with possibilities and challenges for studying G × E interactions.

Epstein-Barr virus perpetuates B cell germinal center dynamics and generation of autoimmune-associated phenotypes in vitro

Human B cells encompass functionally diverse lineages and phenotypic states that contribute to protective as well as pathogenic responses. Epstein-Barr virus (EBV) provides a unique lens for studying heterogeneous B cell responses, given its adaptation to manipulate intrinsic cell programming. EBV promotes the activation, proliferation, and eventual outgrowth of host B cells as immortalized lymphoblastoid cell lines (LCLs) in vitro, which provide a foundational model of viral latency and lymphomagenesis. Although cellular responses and outcomes of infection can vary significantly within populations, investigations that capture genome-wide perspectives of this variation at single-cell resolution are in nascent stages. We have recently used single-cell approaches to identify EBV-mediated B cell heterogeneity in de novo infection and within LCLs, underscoring the dynamic and complex qualities of latent infection rather than a singular, static infection state. Here, we expand upon these findings with functional characterizations of EBV-induced dynamic phenotypes that mimic B cell immune responses. We found that distinct subpopulations isolated from LCLs could completely reconstitute the full phenotypic spectrum of their parental lines. In conjunction with conserved patterns of cell state diversity identified within scRNA-seq data, these data support a model in which EBV continuously drives recurrent B cell entry, progression through, and egress from the Germinal Center (GC) reaction. This "perpetual GC" also generates tangent cell fate trajectories including terminal plasmablast differentiation, which constitutes a replicative cul-de-sac for EBV from which lytic reactivation provides escape. Furthermore, we found that both established EBV latency and de novo infection support the development of cells with features of atypical memory B cells, which have been broadly associated with autoimmune disorders. Treatment of LCLs with TLR7 agonist or IL-21 was sufficient to generate an increased frequency of IgD-/CD27-/CD23-/CD38+/CD138+ plasmablasts. Separately, de novo EBV infection led to the development of CXCR3+/CD11c+/FCRL4+ B cells within days, providing evidence for possible T cell-independent origins of a recently described EBV-associated neuroinvasive CXCR3+ B cell subset in patients with multiple sclerosis. Collectively, this work reveals unexpected virus-driven complexity across infected cell populations and highlights potential roles of EBV in mediating or priming foundational aspects of virus-associated immune cell dysfunction in disease.

Infectious agents breaking the immunological tolerance: The holy grail in rheumatoid arthritis (RA) reconsidered

Multiple Sclerosis (MS) has been shown to be linked to Epstein Barr Virus (EBV) infection, a virus that infects B cells inside the CNS. The seminal study raises a key interest into the infectious origin of several other autoimmune inflammatory diseases.We will discuss here the infectious agents that have been studied over the years in Rheumatoid Arthritis (RA), a crippling arthritis that was treated a century ago with gold salts (anti mycobacterial agent), with chloroquine (anti malarial agent), or sulphasalazine (an antibacterial-antiinflammatory agent). Several infectious agents have been taken into consideration i.e. Streptococcus group A, Proteus, Mycobacterium tuberculosis-MTB, Parvovirus B19, Epstein Barr virus, Porphyromonas gengivalis-Pg, Aggregatibacter actinomycetescomitans, and finally Haemophilus -Glaesserella parasuis-Hps. Of these agents only three satisfy the Witebski's criteria as possible pathogenetic causes of an autoimmune disease, MTB, Pg, Hps. We will discuss here how the immune tolerance might be broken, which could be the neoantigen or autoantigen involved, how the infectious agent was studied as a trigger capable of inducing arthritis in animal models. The preventive measures that should be adopted to lessen the impact of the infections, to prevent the burden and the severity of the illness are described.

Identification of differential proteomics in Epstein-Barr virus-associated gastric cancer and related functional analysis

BACKGROUND

Epstein-Barr virus-associated gastric cancer (EBVaGC) is the most common EBV-related malignancy. A comprehensive research for the protein expression patterns in EBVaGC established by high-throughput assay remains lacking. In the present study, the protein profile in EBVaGC tissue was explored and related functional analysis was performed.

METHODS

Epstein-Barr virus-encoded RNA (EBER) in situ hybridization (ISH) was applied to EBV detection in GC cases. Data-independent acquisition (DIA) mass spectrometry (MS) was performed for proteomics assay of EBVaGC. Functional analysis of identified proteins was conducted with bioinformatics methods. Immunohistochemistry (IHC) staining was employed to detect protein expression in tissue.

RESULTS

The proteomics study for EBVaGC was conducted with 7 pairs of GC cases. A total of 137 differentially expressed proteins in EBV-positive GC group were identified compared with EBV-negative GC group. A PPI network was constructed for all of them, and several proteins with relatively high interaction degrees could be the hub genes in EBVaGC. Gene enrichment analysis showed they might be involved in the biological pathways related to energy and biochemical metabolism. Combined with GEO datasets, a highly associated protein (GBP5) with EBVaGC was screened out and validated with IHC staining. Further analyses demonstrated that GBP5 protein might be associated with clinicopathological parameters and EBV infection in GC.

CONCLUSIONS

The newly identified proteins with significant differences and potential central roles could be applied as diagnostic markers of EBVaGC. Our study would provide research clues for EBVaGC pathogenesis as well as novel targets for the molecular-targeted therapy of EBVaGC.

Association of Epstein-Barr virus with regression after withdrawal of immunosuppressive drugs and subsequent progression of iatrogenic immunodeficiency-associated lymphoproliferative disorders in patients with autoimmune diseases

Patients with autoimmune diseases (AIDs) may develop lymphoproliferative disorders (LPDs) during treatment with immunosuppressive agents (IS) such as methotrexate (MTX), biological agents, or tacrolimus. Some LPDs in patients with AIDs (AID-LPDs) regress after withdrawal of IS, and a high incidence of Epstein-Barr virus (EBV) positivity in such patients has been reported. To identify characteristics and factors predictive of the response to treatment and disease progression, we retrospectively analyzed clinical and histopathological data for 81 patients with AID-LPDs. Almost all of them (96%) had been treated with MTX. Diffuse large B cell lymphoma was the most common LPD type (61%) and seven patients (9%) had classical Hodgkin lymphoma (CHL). EBV was detected by in situ hybridization with an EBV-encoded small RNA (EBER) probe in 43% of the examined cases. In 59 patients, IS was discontinued as the initial treatment, resulting in regression of LPDs in 69% of them, and multivariate analysis showed that EBER positivity was an independent factor predictive of such regression (p = 0.022). Two-year progression-free survival (PFS) and overall survival for the patients overall were 63% and 83%, respectively. Poor PFS was associated with advanced stage (p = 0.024), worse performance status (PS, p = 0.031), CHL histology (p = 0.013), and reactivation of EBV-related antibodies (p = 0.029). In conclusion, EBV positivity demonstrated using an EBER probe is useful for prediction of successful regression after withdrawal of IS in patients with AID-LPDs. Patients with advanced stage disease, worse PS, CHL histology, or reactivation of EBV-related antibodies should be closely monitored after initial treatment.

Laboratory Assessment of Patients with Suspected Rheumatic Musculoskeletal Diseases: Challenges and Pitfalls

Current patient care in rheumatology relies primarily on a combination of traditional clinical assessment and standard laboratory tests. Investigators seek to discover new biomarkers and novel technologies to boost the research in this field. Mechanistic biomarkers such as cytokines, cell types, antibodies, signaling molecules, are rooted in the mechanism underlying the disease and can guide the clinical management of the disease. Conversely, descriptive biomarkers are byproducts of the disease process, depict the state of a disease but are not involved in its pathogenesis. In this article, we reviewed the field of common laboratory biomarkers in rheumatology, highlighting both their descriptive or mechanistic value as well as their role in clinical practice.

The genetic pathogenesis, diagnosis and therapeutic insight of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease that causes chronic inflammation of the joints. RA is a heterogeneous disorder caused by an abnormal autoimmune response triggered by the complex interactions of genetic and environmental factors that contribute to RA etiology. However, its underlying pathogenic mechanisms are yet to be fully understood. In this review, I provide an overview of the pathogenesis, diagnosis and therapeutic insight in the clinical management of RA in light of the recent updates to classification criteria and recent discoveries of genetic loci associated with susceptibility for RA.

Epstein-Barr virus infection and variants of Epstein-Barr nuclear antigen-1 in synovial tissues of rheumatoid arthritis

Objective

The objective of the present study was to investigate Epstein-Barr virus (EBV) infection as an environmental factor for the development of rheumatoid arthritis (RA).

Methods

Synovial tissues were collected during surgery from 128 RA and 98 osteoarthritis (OA) patients. DNA was extracted from synovial tissues. The EBV gene was assessed by nested PCR for the amplification of EBV nuclear antigen-1 (EBNA-1). The nucleotide sequence of the PCR product was elucidated. HLA-DRB1 genotyping was also performed.

Results

EBV DNA was more frequently detected in the synovial tissues of RA patients (32.8%) than OA patients (15.3%) (p<0.01). The frequency of EBNA-1 variants did not significantly differ between RA and OA (RA: 17%, OA: 13%). The population with the HLA-DRB1 shared epitope (SE) was significantly higher in RA patients (70.3%) than in OA patients (44.9%) (p<0.001). In RA patients, the presence of EBV DNA was similar among SE-positive and -negative patients (SE-positive: 34.4%, -negative: 28.9%). The population with the EBNA-1 variant did not significantly differ between SE-positive and -negative patients (SE-positive: 12.9%, -negative: 27.3%).

Discussion

The present results indicate that EBV infection contributes to the onset of RA and chronic inflammation in synovial tissues. The frequency of EBNA-1 gene variants was low and not significantly different between RA and OA, suggesting that EBNA-1 gene variants are not a risk factor for RA. HLA-DRB1 with SE is a genetic risk factor for the development of RA. However, neither the presence of EBV nor EBNA-1 gene variants differed between SE-positive and -negative RA patients. Therefore, these two risk factors, SE and EBV, may be independent.

Conclusion

EBV infection may be an environmental risk factor for the development of RA, while nucleotide variants of EBNA-1 do not appear to contribute to its development.

S-S-PEG-COOH Self-Assembled Monolayer on Gold Surface Enabled a Combined Assay for Serological EBV Antibody Isotypes

PURPOSE

Epstein-Barr virus (EBV) is a ubiquitous human gamma herpes virus that infects human epithelial cells and B lymphocytes. It would be potentially valuable to develop novel combined assays to benefit screening for large panels of samples of EBV infectious diseases.

EXPERIMENTAL DESIGN

A simple antigen-probed biochip that is modified with S-S-PEG-COOH and is used as a label-free high-throughput screening method for a combined detection of EBV capsid antigen IgM antibody, capsid antigen IgG antibody, and nuclear antigen IgG antibody.

RESULTS

This protein biochip has similar feasibility, sensitivity, and specificity in comparison with Liaison chemiluminescent immunoassay (CLIA). Detection limit of the EBV antibodies by the biochip is almost identical to that by CLIA-L (2.91 U mL^-1 vs 3.00 U mL^-1 for EBNA-1 IgG, 8 U mL^-1 vs10 U mL^-1 for EBV-VCA IgG, and 3.5 U mL^-1 vs 10 U mL^-1 for EBV-VCA IgM). Tests of the three serological antibodies against EBV by the biochip are consistent with the CLIA-L method in 274 clinical sera, respectively. Finally, the combined biochip is successfully utilized for diagnostic identification of EBV infection in 14 patients with infectious mononucleosis (IM) and 25 patients with systemic lupus erythematosus SLE, as well as additional 10 known real-time PCR positive patients.

CONCLUSIONS AND CLINICAL RELEVANCE

This biochip format will enable concurrent detection of antibodies against EBV infection and confirm infection status of EBV. It will be a versatile tool for large-scale epidemiological screening in view of its miniaturization and high throughput.

Helminths-based bi-functional molecule, tuftsin-phosphorylcholine (TPC), ameliorates an established murine arthritis

A novel small molecule named tuftsin-phosphorylcholine (TPC), which is linked to the biological activity of helminths, was constructed. The current study address the effect of TPC treatment in established collagen-induced arthritis (CIA) mice and propose TPC bi-functional activity. TPC treatment was initiated when clinical score was 2 to 4. Arthritis scores in TPC treated mice were lower compared to mice treated with vehicle (P < 0.001). Joint staining showed normal joint structure in TPC-treated mice compared to control groups treated with phosphate buffered saline (PBS), phosphorylcholine, or tuftsin, which exhibited severely inflamed joints. TPC enhanced anti-inflammatory response due to increased IL-10 secretion, and reduced pro-inflammatory cytokine secretion (IL-1-β, IL-6, TNF-αP < 0.001). Furthermore, TPC therapy increased expansion of CD4⁺CD25⁺FOXP3⁺T regulatory cells and IL-10⁺CD5⁺CD1d⁺B regulatory cells. We propose that the immunomodulatory activity of TPC can be a result of a bi-specific activity of TPC: (a) The tuftsin part of the TPC shifts RAW macrophage cells from pro-inflammatory macrophages M1 to anti-inflammatory M2-secreting IL-10 (P < 0.001) through neuropilin-1 and (b) TPC significantly reduce mouse TLR4 expression via NFkB pathway by HEK^TM cells (P < 0.02) via the phosphorylcholine site of the molecule. Our results indicate that TPC, significantly ameliorated established CIA by its immunomodulatory activity. These data could lead to a novel self bi-functional small molecule for treating patients with progressive RA.

Hyperjaponol H, A New Bioactive Filicinic Acid-Based Meroterpenoid from Hypericum japonicum Thunb. ex Murray

Hyperjaponol H (1), a new filicinic acid-based meroterpenoid, with a 6/6/10 ring system trans-fused by hetero-Diels–Alder cycloaddition between a germacrane sesquiterpenoid and a filicinic acid moiety, was isolated from aerial parts of Hypericum japonicum. The elucidation of its structure and absolute configuration were accomplished by the analyses of extensive spectroscopic data and the comparison of Cotton effects of electron circular dichroism (ECD) with previously reported ones. The bioactivity assay showed that hyperjaponol H exhibited a moderate inhibitory efficacy on lytic Epstein-Barr virus (EBV) DNA replication in B95-8 cells.

Analysis of Immunogenicity of Intracellular CTAR Fragments of Epstein-Barr Virus Latent Phase Protein LMP1

Intracellular fragments of latent phase protein LMP1 of Epstein-Barr virus, denoted as CTAR1/2/3, can trigger a variety of cell cascades and contribute to the transforming potential of the virus. Generation of recombinant proteins CTAR1/2/3 is expected to yield more ample data on functional and immunogenic characteristics of LMP1. We created genetic constructs for prokaryotic expression of LMP1 CTAR fragments and selected optimal conditions for their production and purification. Using a new library of LMP1 CTAR fragments, we carried out epitope mapping of a diagnostic anti-LMP1 antibody S12. Analysis of polyclonal serum antibodies from mice immunized with full-length LMP1 confirmed immunogenicity of CTAR elements comparable with that of full-length protein.

miPepBase: A Database of Experimentally Verified Peptides Involved in Molecular Mimicry

Autoimmune diseases emerge due to several reasons, of which molecular mimicry i.e., similarity between the host's and pathogen's interacting peptides is an important reason. In the present study we have reported a database of only experimentally verified peptide sequences, which exhibit molecular mimicry. The database is named as miPepBase (Mimicry Peptide Database) and contains comprehensive information about mimicry proteins and peptides of both host (and model organism) and pathogen. It also provides information about physicochemical properties of protein and mimicry peptides, which might be helpful in predicting the nature of protein and optimization of protein expression. The miPepBase can be searched using a keyword or, by autoimmune disease(s) or by a combination of host and pathogen taxonomic group or their name. To facilitate the search of proteins and/or epitope in miPepBase, which is similar to the user's interest, BLAST search tool is also incorporated. miPepBase is an open access database and available at http://proteininformatics.org/mkumar/mipepbase.

Efficacy of Mitochondrial Antioxidant Plastoquinonyl-decyl-triphenylphosphonium Bromide (SkQ1) in the Rat Model of Autoimmune Arthritis

Rheumatoid arthritis is one of the most common autoimmune diseases. Many antioxidants have been tested in arthritis, but their efficacy was, at best, marginal. In this study, a novel mitochondria-targeted antioxidant, plastoquinonyl-decyl-triphenylphosphonium bromide (SkQ1), was tested in vivo to prevent and cure experimental autoimmune arthritis. In conventional Wistar rats, SkQ1 completely prevented the development of clinical signs of arthritis if administered with food before induction. Further, SkQ1 significantly reduced the fraction of animals that developed clinical signs of arthritis and severity of pathological lesions if administration began immediately after induction of arthritis or at the onset of first symptoms (day 14 after induction). In specific pathogen-free Wistar rats, SkQ1 administered via gavage after induction of arthritis did not reduce the fraction of animals with arthritis but decreased the severity of lesions upon pathology examination in a dose-dependent manner. Efficacious doses of SkQ1 were in the range of 0.25-1.25 nmol/kg/day (0.13-0.7 μg/kg/day), which is much lower than doses commonly used for conventional antioxidants. SkQ1 promoted apoptosis of neutrophils in vitro, which may be one of the mechanisms underlying its pharmacological activity. Considering its low toxicity and the wide therapeutic window, SkQ1 may be a valuable additional therapy for rheumatoid arthritis.

Detection of Epstein-Barr virus in synovial fluid of rheumatoid arthritis patients

INTRODUCTION

Rheumatoid arthritis (RA) is one of the most common chronic inflammatory disorders. Genes and environmental factors contribute to RA. Epstein-Barr Virus (EBV) has been considered as one the RA pathogeneses. The aim of this study was to detect of the EBV genome in patients with RA.

METHODS

In this cross-sectional study, 50 samples of synovial fluid were obtained from patients with RA from 2010-2012. Using a standard of the EBV genome and EBNA-1-specific primers, the method of PCR was set up. Then, all of the samples of synovial fluids separately were subjected to DNA extraction and Polymerase Chain Reaction (PCR) amplification. Data were analyzed using SPSS version 18.0. The statistical analysis was performed by the t-test.

RESULTS

The demographic and laboratory characteristic assay revealed that the mean age of patients was 49, and the patients were 60% males and 40% females. In addition, in all cases, the mean rheumatoid factor (RF) levels of the patients were below the normal level. The results of this study showed that the PCR was able to detect EBV DNA in > 60% of the cases.

CONCLUSION

The results of this study indicated that EBV was frequently detected in the synovial fluid of RA patients. Thus, EBV may be a strong candidate that can act at several levels of the pathophysiology of RA. However, these findings also indicated that EBV may play a role in the pathogenesis of RA. However, the possible relationship between RA and EBV must be determined by further research.

Overexpression of TLR2 and TLR9 on monocyte subsets of active rheumatoid arthritis patients contributes to enhance responsiveness to TLR agonists

Background

Synovial infiltration of monocytes is commonly associated with inflammation in rheumatoid arthritis (RA). Toll-like receptors (TLRs) are innate sensors that recognize cell debris and microbial components in host, a process contributing to maintain chronic inflammation in RA. We assessed the expression levels of TLR2 and TLR9 in monocyte subsets of active RA patients and characterized their cytokine profiles in response to synthetic and viral TLR2 and TLR9 agonists, including Epstein-Barr virus (EBV) which is suspected to contribute to RA symptoms.

Methods

Prevalence of monocyte subsets CD14⁺⁺ CD16⁻, CD14⁺ CD16⁺ and CD14^low CD16⁺⁺ was evaluated in blood and synovial fluids of active RA patients and levels of TLR2 and TLR9 in monocyte subsets were measured by flow cytometry. Enriched monocytes derived from RA patients and healthy donors were stimulated in vitro with synthetic TLR2 and TLR9 agonists and with EBV particles or viral DNA. Intracellular cytokine profiles were determined in respective monocyte subsets. Finally, the presence of EBV genome was evaluated by real-time PCR in blood and synovial monocytes of RA patients.

Results

Numbers of CD14⁺ CD16⁺ and CD14^low CD16⁺⁺ were found to increase in blood of RA patients compared to healthy controls, while all three subsets were detected in synovial fluids. TLR2 is abundantly expressed on blood and synovial CD14⁺⁺ CD16⁻ and CD14⁺ CD16⁺ monocytes from RA patients. Levels of TLR9 were increased on all three subsets of blood monocytes but markedly enhanced in monocytes isolated from synovial fluids. Compared to healthy controls, CD14⁺⁺ CD16⁻ monocytes of RA patients displayed an enlarged capacity to produce proinflammatory cytokines after stimulation with synthetic TLR2 and TLR9 agonists while both CD14⁺⁺ CD16⁻ and CD14⁺ CD16⁺ monocytes showed increased response to EBV stimulation. The presence of EBV genome was also detected in monocytes and neutrophils of a significant proportion of patients.

Conclusion

Patients with active RA show an increased expression of TLR2 and TLR9 on monocyte subsets and display higher production of inflammatory cytokines in response to TLR agonists. The presence of EBV genome in monocytes and neutrophils reinforces the suspected role of the virus in the exacerbation of RA symptoms.

Epstein-Barr virus and its association with rheumatoid arthritis and oral lichen planus

CONTEXT

Pathogenesis of autoimmune diseases (AD) is one of a multifactorial milieu. A genetic predisposition, an immune system failure, hormonal imbalance and environmental factors play important roles. Among the many environmental factors, the role of infection is gaining importance in the pathogenesis of various autoimmune disorders; among them, Epstein-Barr virus (EBV) plays a pivotal role. Literature states an association of various AD with EBV namely multiple sclerosis, autoimmune thyroiditis, systemic lupus erythematous, oral lichen planus (OLP), rheumatoid arthritis (RA), autoimmune hepatitis, Sjögren's syndrome and Kawasaki disease; among these, the most commonly occurring are OLP and RA.

AIM

Considering the frequency of occurrences, our aim was to perform a qualitative analysis of EBV viral capsid antigen (EBV VCA) IgG in the sera of patients with RA, OLP and establish a comparison with normal.

SETTINGS AND DESIGN

In-vitro experiment in a research laboratory.

SUBJECTS AND METHODS

Five-milliliter blood sample was collected from 25 patients diagnosed with RA and OLP. Serum was separated and EBV VCA IgG antibody titer was detected using NovaTec EBV VCA IgG ELISA kit.

STATISTICAL ANALYSIS USED

Chi-square test.

RESULTS

Six out of 25 subjects with RA and 4 out of 25 subjects with OLP tested positive for EBV VCA IgG.

CONCLUSIONS

Both environmental and genetic factors are important contributory components for autoimmune conditions. Screening for viral etiology would improve the efficacy of conventional treatment and reduce the risk of relapses.

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

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

Anti-citrullinated peptides as autoantigens in rheumatoid arthritis-relevance to treatment

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the presence of rheumatoid factor (RF) and anti-citrullinated protein/peptide autoantibodies (ACPAs). Citrulline derives from arginine by peptidyl arginine deiminases, and ACPAs are directed against different citrullinated antigens, including fibrinogen, fibronectin, α-enolase, collagen type II, histones. ACPAs are present in two thirds of RA patients have higher specificity than RF for RA, and are associated with joint radiographic damage and extra-articular manifestations and they are detected years before the onset clinical arthritis. Recent studies suggest that citrullinated antigens are most likely arthritogenic autoantigens in RA. ACPA production is associated with the HLA-DRB1 shared epitope (HLA-DRB1 SE) and accounts for the well-known RA-HLA-DRB1 SE association, as T cells recognize citrullinated peptides. Smoking and periodontitis, known environmental risk factors for RA promote protein citrullination and ACPA production. Cirullinated proteins are capable of inducing arthritis in transgenic mice carrying HLA-DRB1 SE genes, and ACPAs induce macrophage TNF-α production, osteoclastogenesis and complement activation. They also induce the formation of neutrophil extracellular traps (NETs). NETs, increased in RA, are a source of citrullinated autoantigens in RA and induce fibroblast interleukin-8 production. This knowledge is likely to have therapeutic implications, as there is a need of matching therapy with patient profile. Abatacept, a T cell activation modulator, is the best therapy for ACPA(+) RA patients, although clinical data are sparse at present. Rituximab, a monoclonal antibody that depletes B cells, is also the best therapy for ACPA(+) RA patients, and clinical data support this view.

Advances in the treatment of cervical rheumatoid: Less surgery and less morbidity

Rheumatoid arthritis is a chronic systemic inflammatory disease that often affects the cervical spine. While it was initially thought that cervical involvement was innocuous, natural history studies have substantiated the progressive nature of untreated disease. Over the past 50 years, there has been further elucidation in the pathophysiology of the disease, as well as significant advancements in medical and surgical therapy. The introduction of disease modifying drugs and biologic agents has reduced the amount of patients with advanced stages of the disease needing surgery. Advancement in instrumentation techniques has improved patient outcomes and fusion rates. The introduction of endoscopic approaches for ventral decompression may further lower surgical morbidity. In this review, we give a brief overview of the pertinent positives of the disease. A discussion of historical techniques and the evolution of surgical therapy into the modern era is provided. With improved medical therapies and less invasive approaches, we will likely continue to see less advanced cases of disease and less surgical morbidity. Nonetheless, a thorough understanding of the disease is crucial, as its systemic involvement and need for continued medical therapy have tremendous impact on overall complications and outcomes even in patients being seen for standard degenerative disease with comorbid rheumatoid.

Functional annotation of rheumatoid arthritis and osteoarthritis associated genes by integrative genome-wide gene expression profiling analysis

Background

Rheumatoid arthritis (RA) and osteoarthritis (OA) are two major types of joint diseases that share multiple common symptoms. However, their pathological mechanism remains largely unknown. The aim of our study is to identify RA and OA related-genes and gain an insight into the underlying genetic basis of these diseases.

Methods

We collected 11 whole genome-wide expression profiling datasets from RA and OA cohorts and performed a meta-analysis to comprehensively investigate their expression signatures. This method can avoid some pitfalls of single dataset analyses.

Results and Conclusion

We found that several biological pathways (i.e., the immunity, inflammation and apoptosis related pathways) are commonly involved in the development of both RA and OA. Whereas several other pathways (i.e., vasopressin-related pathway, regulation of autophagy, endocytosis, calcium transport and endoplasmic reticulum stress related pathways) present significant difference between RA and OA. This study provides novel insights into the molecular mechanisms underlying this disease, thereby aiding the diagnosis and treatment of the disease.

Epstein-Barr virus encoded dUTPase containing exosomes modulate innate and adaptive immune responses in human dendritic cells and peripheral blood mononuclear cells

We have recently demonstrated that Epstein-Barr virus (EBV)-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase) modulates innate immunity in human primary monocyte-derived macrophages through toll-like receptor (TLR) 2 leading to NF-κB activation and the production of pro-inflammatory cytokines. Our previous depletion studies indicated that dendritic cells (DCs) may also be a target of the EBV-encoded dUTPase. However, the role of EBV-encoded dUTPase in DC activation/function and its potential contribution to the inflammatory cellular milieu characteristic of EBV-associated diseases remains poorly understood. In the present study, we demonstrate that EBV-encoded dUTPase significantly altered the expression of genes involved in oncogenesis, inflammation and viral defense mechanisms in human primary DCs by microarray analysis. Proteome array studies revealed that EBV-encoded dUTPase modulates DC immune responses by inducing the secretion of pro-inflammatory T_H1/T_H17 cytokines. More importantly, we demonstrate that EBV-encoded dUTPase is secreted in exosomes from chemically induced Raji cells at sufficient levels to induce NF-κB activation and cytokine secretion in primary DCs and peripheral blood mononuclear cells (PBMCs). Interestingly, the production of pro-inflammatory cytokines in DCs and PBMCs was TLR2-dependent. Together these findings suggest that the EBV-encoded dUTPase may act as an intercellular signaling molecule capable of modulating the cellular microenvironment and thus, it may be important in the pathophysiology of EBV related diseases.

Epstein-Barr virus serologic abnormalities and risk of rheumatoid arthritis among women

BACKGROUND

Epstein-Barr virus (EBV) infection and the immune response may be involved in the pathogenesis of rheumatoid arthritis (RA). Past studies have suggested an association between EBV and RA.

METHODS

We studied the association between EBV serologies and RA risk in a nested case-control study in the Nurses' Health Study (NHS) cohorts. We confirmed incident RA cases from 1990 to 2002 by questionnaire and medical record review. Each incident case with blood collected prior to RA symptoms was matched with a healthy participant by time of day and date of blood collection, birth year, menopausal status and postmenopausal hormone use. Immunofluorescence assays measured serologic EBV responses: viral capsid antigen, early-antigen-diffuse and early antigen-complex (restricted and diffuse), Epstein Barr nuclear antigen (EBNA)-1, EBNA-2 and cytomegalovirus (CMV), as control. All were reported as titers, except CMV, which was reported as positive or negative. Antinuclear antibody positive samples were excluded. Elevated EBV antibody titers were defined as the upper 20% (or nearest titer) among controls. Conditional logistic regression analyses modeled RA risk associated with elevated EBV titers or the presence/absence of CMV, further adjusted for pack-years smoking and alcohol intake.

RESULTS

Eighty-seven incident RA cases were identified. Mean time to RA after blood draw was 6.2 (± 3.5) years in NHS and 1.9 (± 0.6) years in NHS II. Antibody titers against EBV were not significantly different between pre-RA cases and controls.

CONCLUSIONS

In this prospective study of women, we observed no association between EBV serologies and RA risk.

Environmental pathways to autoimmune diseases: the cases of primary biliary cirrhosis and multiple sclerosis

The pathways leading to autoimmunity remain enigmatic despite numerous lines of experimental inquiry and epidemiological evidence. The mechanisms leading to the initiation and perpetuation of specific diseases such as primary biliary cirrhosis (PBC) or multiple sclerosis (MS) remain largely enigmatic, although it is established that a combination of genetic predisposition and environmental stimulation is required. The growing number of genome-wide association studies and the largely incomplete concordance for autoimmune diseases in monozygotic twins concur to support the role of the environment (including infectious agents and chemicals) in the breakdown of tolerance leading to autoimmunity through different mechanisms. In the present article we illustrate the current hypotheses related to an environmental impact on the onset of PBC and MS as two representative conditions investigated with complementary approaches. Indeed, while a role of post-translational antigen modifications has been proposed for MS, this field remain unexplored in PBC where, conversely, most evidence is gathered from geoepidemiology and experimental data on xenobiotics or infectious agents.

Historical perspective on the etiology of rheumatoid arthritis

Contributions of historical analyses to the development of a cogent etiologic theory of rheumatoid arthritis (RA) have been limited to date. In this article, the authors analyze this literature with respect to the types and conclusions of the research that has been conducted, present the major points of evidence and conclusions that have been drawn, and trace the evolution of 3 historical theories of RA. The authors combine a comprehensive overview of paintings and paleopathological investigations with consideration of contemporary immunologic and genetic studies.

Etiological role of cigarette smoking in rheumatoid arthritis: Nasal exposure to cigarette smoke condensate extracts augments the development of collagen-induced arthritis in mice

Cigarette smoking is a major environmental risk factor for rheumatoid arthritis (RA). However, the experimental bases supporting the etiological role of cigarette smoking in RA have not been fully provided. We have reported that cigarette smoke condensate (CSC), by means of subcutaneous injection into DBA/1J mice with collagen and complete Freund's adjuvant or intraperitoneal injection one day before immunization, augmented the development of arthritis in the mouse model of collagen type II-induced arthritis (CIA). However, these experimental procedures may not be appropriate for cigarette smoking. In this study, we nasally exposed mice to mainstream CSC and found that CSC augmented the induction and development of arthritis and antibody level against collagen. Histological examination confirmed the augmenting effect of CSC. These findings provide experimental bases supporting the etiological role of cigarette smoking in RA.

The influence of early life factors on the risk of developing rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease that develops as a result of the interaction between genetic and environmental risk factors. Although increasing evidence shows the importance of genes in determining the risk of RA, it is clear that environmental factors also have a vital role. Studies to date have tended to concentrate on environmental influences around the time of disease onset. However, a number of pieces of evidence, including the fact that autoantibodies, such as rheumatoid factor (RF), can develop several years before the onset of clinical disease, suggest that environmental factors may influence disease susceptibility during early life. Several recent studies lend weight to this possibility, with an increased risk of RA in the offspring of mothers who smoked during pregnancy and in those with higher birth weight. There has also been a suggestion that the risk of RA is reduced in breast-fed infants. We describe the evidence surrounding the effect of early life factors on the risk of developing RA and possible mechanisms by which they may act.

Infectious aspects and the etiopathogenesis of rheumatoid arthritis

Infections are believed to contribute to the maturation of the immune system from the innate to the adaptive phases and therefore may take part in the induction of autoimmune conditions. In the current study, we present an extensive analysis conducted on sera samples of patients with rheumatoid arthritis in order to seek evidence of previous or coexisting infectious processes using the Bio-Rad BioPlex immunoassay analyzer. We detected higher rates of serological evidence of infections with Epstein-Barr virus and cytomegalovirus viruses. Our findings may indicate a role of these viruses in the pathogenesis of RA.

Postinfectious immunodeficiency and autoimmunity: pathogenic and clinical values and implications

Autoimmunity is still a mystery of clinical immunology and medicine as a whole. The etiology and pathogenesis of autoimmune disorders remain unclear and, thus, are assessed as a balance between hereditary predisposition, triggering factors and the appearance of autoantibodies and/or self-reactive T cells. Among the immunological armamentarium, molecular mimicry, based on self-reactive T- and B-cell activation by cross-reactive epitopes of infectious agents, is of special value. Hypotheses regarding the possible involvement of molecular mimicry in the development of postinfectious autoimmunity are currently very intriguing. They provide new approaches for identifying etiological agents that are associated with postinfectious autoimmunity, paired microbial- and tissue-linked epitopes targeted for autoimmune reaction determination, postinfectious autoimmunity pathogenesis recognition and specific prevention, and therapy for autoimmune disorder development.

A Study of the Association Between Smoking and Rheumatoid Arthritis

Background:Rheumatoid arthritis (RA), the chronic autoimmune disease with several opinions about its aetiology, has affected more than 50 million people in the world. The aim of this 2008 study was to investigate the association between smoking and RA in Hamedan, a western city of Iran.Methods:As a case-control study, information from 130 cases and 130 controls, matched for age and sex, were collected by questionnaire and analysed using SPSS (chi-square, phi and Cramer tests).Results:From 130 cases, 80 cases were females and the rest were males. Statistical analysis showed that smoking less or more than 10 cigarettes daily has a significant association with RA in both sexes, together or separately (p< .05). However, there is no significant association between duration of smoking cessation within 2 years or more, and RA in both sexes (p> .05). This means that cigarette cessation at any time can be useful in RA prevention.Conclusion:Considering previous global investigations on this topic and the results of our study, it seems that smoking even low numbers of cigarettes affects the presence of RA and it is never too late to give up smoking.

Risk factors for the development of rheumatoid arthritis

There is increasing interest in attempting to understand what the risk factors are that lead to the development of rheumatoid arthritis (RA). Twin studies have proved a genetic role but also quantified the non-genetic risk. There is thus scope for identifying environmental predictors that might offer a strategy to prevent the disease. Changes in the female hormonal environment such as in pregnancy, breastfeeding and the use of the oral contraceptive (OC) pill appear to have a role. Of the traditional lifestyle exposures, cigarette smoking has been associated with a consistently increased risk that might also apply to the passive inhalation of smoke. Occupation probably has a minor influence, although exposure to silica dust is of aetiological importance. Recent studies have highlighted a role for diet, with suggestions that diets high in caffeine, low in antioxidants and high in red meat may contribute to an increased risk. The most plausible environmental exposure is infection and although several decades of study have produced few definitive candidate organisms, Epstein-Barr virus (EBV) remains an interesting target.

Viruses and autoimmunity

Viruses have been suspected as causes and contributors of human autoimmune diseases (AID), although direct evidence for the association is lacking. However, several animal models provide strong evidence that viruses can induce AIDs as well as act to accelerate and exacerbate lesions in situations where self-tolerance is broken. Many models support the hypothesis by acting as molecular mimics that stimulate self-reactive lymphocytes. Mimicry alone is usually inadequate and with human AID, no compelling evidence supports a role for viruses that are acting as molecular mimics. Alternative mechanisms by which viruses participate in autoimmunity are non-specific, involving a mechanistically poorly understood process termed bystander activation or perhaps viral interference with regulatory cell control systems. This review briefly discusses examples where viruses are involved, taking the viewpoint that molecular mimicry is over emphasized as a critical mechanism during AID pathogenesis.

Co-existence of acute myeloid leukemia with multilineage dysplasia and Epstein-Barr virus-associated T-cell lymphoproliferative disorder in a patient with rheumatoid arthritis: a case report

Rheumatoid arthritis (RA) is an autoimmune disease mediated by inflammatory processes mainly at the joints. Recently, awareness of Epstein-Barr virus (EBV)-associated T-cell lymphoproliferative disorder (T-LPD) has been heightened for its association with methotraxate usage in RA patients. In the contrary, acute myeloid leukemia with multilineage dysplasia (AML-MLD) has never been documented to be present concomitantly with the above two conditions. In this report we present a case of an autopsy-proven co-existence of AML-MLD and EBV-associated T-LPD in a patient with RA.

Current concepts in the pathogenesis of early rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory disease with a predilection for symmetrically distributed diarthroidal joints. It is clinically heterogeneous, with particular disease phenotypes defined according to a complex interplay of genes and the environment. In this chapter we first summarize current knowledge of RA genetic susceptibility, a field which has been transformed in recent years by powerful modern genotyping technologies. The importance of a recently described subclassification for the disease based upon the presence or absence of circulating autoantibodies to citrullinated peptides has further informed genetic studies, and we consider the implications for our understanding of RA pathogenesis. We then review the cellular and molecular processes that initiate and perpetuate joint destruction.

Cigarette smoke condensate upregulates the gene and protein expression of proinflammatory cytokines in human fibroblast-like synoviocyte line

Rheumatoid arthritis (RA) is characterized by proliferation of synoviocytes that produce proinflammatory cytokines, which are implicated in the pathogenesis of RA. When human fibroblast-like synoviocytes line MH7A was treated with cigarette smoke condensate (CSC), either mainstream or sidestream, expression levels of interleukin (IL)-1alpha, IL-1beta, IL-6, IL-8, and CYP1A1 mRNA were upregulated in both time- and dose-dependent manners. The upregulatory effects of CSC on these cytokines were not significantly inhibited by alpha-naphthoflavone, an aryl hydrocarbon receptor (AhR) antagonist, suggesting that the effects of CSC were independent of AhR. Cycloheximide treatment indicated that the augmenting effect of CSC on IL-1alpha, IL-1beta and IL-8, but not IL-6 and CYP1A1, mRNA expression requires de novo protein synthesis. CSC also induced cytokines at protein levels and further augmented the effects of tumor necrosis factor alpha on induction of these cytokines at both mRNA and protein levels. These results support the epidemiological studies indicating a strong association between heavy cigarette smoking and pathogenesis of RA.

[Infectious agents in the etiopathogenesis of rheumatic diseases]

This article is an author's view of how to face the knowledge about infectious agents and their pathogenic role in the starting immune mechanisms, trying to clarify its role in the origin of some rheumatic diseases. From the basic immune responds, recent evidence and newly molecular mechanisms are dissected as well as diagnostic and therapeutic implications.

High avidity autoreactive T cells with a low signalling capacity through the T-cell receptor: central to rheumatoid arthritis pathogenesis?

Self-reactive T cells with low signalling capacity through the T-cell receptor were recently observed in the SKG mouse model of rheumatoid arthritis (RA) and have been linked to a spontaneous mutation in the ZAP-70 signal transduction molecule. Here we hypothesize that similar mechanisms also drive RA, associated with an abnormal innate and adaptive immune response driven by nuclear factor-κB activation and tumour necrosis factor secretion. Similar to the essential role played by pathogens in SKG mice, we propose that HLA-associated immunity to chronic viral infection is a key factor in the immune dysregulation and joint inflammation that characterize RA.

Cells of the synovium in rheumatoid arthritis. Dendritic cells

Dendritic cells are the major antigen-presenting and antigen-priming cells of the immune system. We review the antigen-presenting and proinflammatory roles played by dendritic cells in the initiation of rheumatoid arthritis (RA) and atherosclerosis, which complicates RA. Various signals that promote the activation of NF-κB and the secretion of TNF and IL-1 drive the maturation of dendritic cells to prime self-specific responses, and drive the perpetuation of synovial inflammation. These signals may include genetic factors, infection, cigarette smoking, immunostimulatory DNA and oxidized low-density lipoprotein, with major involvement of autoantibodies. We propose that the pathogenesis of RA and atherosclerosis is intimately linked, with the vascular disease of RA driven by similar and simultaneous triggers to NF-κB.

Viruses and autoimmunity

Viruses have been suspected as causes and contributors of human autoimmune diseases (AID), although direct evidence for the association is lacking. However, several animal models provide strong evidence that viruses can induce AIDs as well as act to accelerate and exacerbate lesions in situations where self-tolerance is broken. Many models support the hypothesis by acting as molecular mimics that stimulate self-reactive lymphocytes. Mimicry alone is usually inadequate and with human AID, no compelling evidence supports a role for viruses that are acting as molecular mimics. Alternative mechanisms by which viruses participate in autoimmunity are non-specific, involving a mechanistically poorly understood process termed bystander activation or perhaps viral interference with regulatory cell control systems. This review briefly discusses examples where viruses are involved, taking the view point that molecular mimicry is over emphasized as a critical mechanism during AID pathogenesis.

Viral infection can induce the production of autoantibodies

PURPOSE OF REVIEW

To review the current literature and summarize the main principles found between viral infections and the subsequent production of autoantibodies.

RECENT FINDINGS

We concentrate on recent findings involving three viral agents, one of which is Epstein-Barr virus, which has been associated with many autoimmune diseases and is classically considered to induce systemic lupus erythematosus. As we will discuss, this occurs through molecular mimicry between Epstein-Barr virus nuclear antigen 1 and lupus-specific antigens such as Ro, La or dsDNA, through induction of Toll-like receptor hypersensitivity by Epstein-Barr virus latent membrane protein 2A or by creating immortal B and T cells by loss of apoptosis. Hepatitis B virus was found to share amino acid sequences with different autoantigens. Tissue damage and the release of intracellular components is just another example of the autoantibody production caused by this virus. Cytomegalovirus has often been controversially associated with several autoimmune diseases and, although is the least understood viral infection of the three, appears to be somewhat suspicious.

SUMMARY

Understanding the infectious origin of autoimmune diseases is important as we aim to identify high-risk patients and disrupt this process with vaccines or other medications, ultimately delaying or even preventing the evolution of autoimmune diseases.

Dysregulated Epstein-Barr virus infection in the multiple sclerosis brain

Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, has been associated with multiple sclerosis (MS), an inflammatory disease of the central nervous system (CNS), but direct proof of its involvement in the disease is still missing. To test the idea that MS might result from perturbed EBV infection in the CNS, we investigated expression of EBV markers in postmortem brain tissue from MS cases with different clinical courses. Contrary to previous studies, we found evidence of EBV infection in a substantial proportion of brain-infiltrating B cells and plasma cells in nearly 100% of the MS cases examined (21 of 22), but not in other inflammatory neurological diseases. Ectopic B cell follicles forming in the cerebral meninges of some cases with secondary progressive MS were identified as major sites of EBV persistence. Expression of viral latent proteins was regularly observed in MS brains, whereas viral reactivation appeared restricted to ectopic B cell follicles and acute lesions. Activation of CD8⁺ T cells with signs of cytotoxicity toward plasma cells was also noted at sites of major accumulations of EBV-infected cells. Whether homing of EBV-infected B cells to the CNS is a primary event in MS development or the consequence of a still unknown disease-related process, we interpret these findings as evidence that EBV persistence and reactivation in the CNS play an important role in MS immunopathology.

Juvenile rheumatoid arthritis in children with Ebstein Barr virus infection

Juvenile Rheumatoid Arthritis (JRA) is a disease of unknown etiology. A total of 50 patients with JRA who were hospitalized in the Pediatrics Rheumatology Ward of Imam Khomeini Hospital in Tehran during the years 2001-2002, were assessed serologically (IgM and IgG specific viral capsid antigens) for EBV infection and their response to therapy was studied. Minimum age of the patients was at least 6 months and mean age was 60.96 plus/minus 43.46 months. EBV infection was seen in 44 (88%) patients 24 of whom were girls and 20 boys. Ninety two percent of girls and 83% boys were infected with the virus. Ebstein barr virus (EBV) infection was seen in 33 cases, 6 cases, 4 cases and 1 case in the polyarticular, pauciarticular, systemic and spondylitis group, respectively. Fifty four percent of EBV-positive patients with JRA did not respond to the classic therapy. EBV virus is involved in the pathogenesis of JRA and patients with EBV are in greater risk of developing JRA.