Epstein-Barr virus and rheumatoid arthritis

Pathophysiological links between rheumatoid arthritis and the Epstein–Barr virus: An update

Numerous associations have been documented between the Epstein-Barr virus (EBV) and rheumatoid arthritis (RA). Thus, anti-EBV antibody titers are higher in RA patients than in healthy controls. Lymphocytes from RA patients show impaired responses to EBV. Several EBV antigens share similarities with self antigens; more specifically, the glycine/alanine repeats in EBNA-1 resemble synovial proteins and the EBV gp110 glycoprotein contains a copy of the shared epitope. Cell-mediated responses to EBV replicative cycle proteins and to gp110 have been documented in joint fluid from RA patients. In situ hybridization and PCR techniques have identified EBV antigens and genetic material within the rheumatoid synovium, albeit with variable yields. The EBV burden in peripheral blood mononuclear cells is higher in RA patients than in controls. EBNA-1 can undergo citrullination, and the EBV can induce antibodies to citrullinated peptides. RA patients are at increased risk for lymphoma, including EBV-associated lymphoma. Despite these multiple and complex links between EBV and RA, proof of a causal association is lacking. EBV infection may contribute indirectly to the pathophysiology of RA by impairing immune control of EBV replication, causing increased exposure to EBV antigens and, thereby, chronic inflammation. The effect of biotherapies for RA on EBV-host relations needs to be investigated.

[Link between rheumatoid arthritis and cancer]

Because it is a systemic disorder, rheumatoid arthritis (RA) is known to predispose affected individuals to other organ manifestations as well as arthritic problems. The serious complications include pericarditis, pulmonary and cutaneous nodules, episcleritis, and rheumatoid vasculitis. Of late, a significantly increased incidence of lymphoma has also accumulated. The overall risk is about double than in the general population, but that in patients with the most severe arthritis is dramatically higher. Men with RA appear to have an extremely elevated risk of Hodgkin's disease, which has also been observed at a higher incidence among the children of affected patients. These lymphomas are not typically infected with EBV, though RA patients have a defective capacity to control systemic EBV infection. Increasing attention is being paid to the effect of RA treatments on development of lymphoma, and some patients with EBV-positive tumors who have been taking methotrexate have shown a positive response after just discontinuing this drug. More controversial is the question of whether anti-TNF alpha agents involve an increased risk of lymphoma; in light of the conflicting evidence this matter is still unresolved.

EBNA1 expression in a lung transplant recipient with hypocomplementemic urticarial vasculitis syndrome

This article describes a transplant recipient with underlying hypocomplementemic urticarial vasculitis syndrome who expressed persistently Epstein-Barr virus nuclear antigen 1 (EBNA1) in peripheral blood. The patient received a bilateral lung transplant and was subsequently followed with monitoring of EBV expression in peripheral blood. Evaluation of viral expression in peripheral blood, serum, and graft tissue was performed with RT-PCR, Q-PCR, indirect immunofluorescence, anti-peptide assays, and in situ hybridization; samples were collected at various time-points up to 91 days post-transplantation. The patient expressed EBNA1 in 8/10 (80%) of the peripheral blood samples tested during the post-transplantation period, and interestingly, even including the day of transplantation. After analyses of indicative EBV mRNA, EBNA1 expression was found mainly to be Qp-initiated EBNA1, known to be important for EBV maintenance. Anti-EBNA1 epitope mapping showed significantly higher and broader antibody responses to EBNA1 epitopes pre-transplantation when compared to normal controls and a matched lung transplant control. Post-transplantation this response was largely diminished but there were still epitopes significantly higher than controls. Our results show the presence of EBV-positive proliferating cells before onset of intensive immunosuppressive treatment. Although no previous connection between EBV and hypocomplementemic urticarial vasculitis syndrome has been reported, it is tempting to speculate that the continuous EBNA1 expression is not caused by immunosuppression or post-transplant lymphoproliferative disease, but may be a factor involved in the etiology of the autoimmune disease.

What is after cytokine-blocking therapy, a novel therapeutic target--synovial Epstein-Barr virus for rheumatoid arthritis

There has been significant progress in cytokine-blocking therapy for treatment of rheumatoid arthritis (RA) However, inhibition of cytokines involved in immune defense raises severe side effects. The cost of cytokine-blocking treatment is another major issue. Why are levels of inflammatory cytokines increased in RA patients? We have a large amount of circumstantial and direct evidence for the presence of Epstein-Barr virus (EBV) in RA synovial cells. Here, we provide an overview of the implications for novel approaches to therapy for RA patients, based on the most recent available evidences of anti-viral agents.

Early arthritis and infection

PURPOSE OF REVIEW

To summarize the recent literature on the association of infection with early arthritis, and to discuss the possible role of such infections with respect to the development of chronic rheumatic complications.

RECENT FINDINGS

Viral infections are frequently associated with arthritis. Alphaviruses belong to mosquito-borne viruses, one form of which (Sindbis virus) can in Scandinavia and Karelia cause acute arthritis with typical rash. The role of this infection leading to chronic erosive arthritis needs further prospective studies. Patients infected with HIV can have various forms of arthritis. The role of HIV virus as an arthritogenic agent is still debated. On the basis of population studies, Campylobacter infections seem to be increasing as causative infections in reactive arthritis. There is no role for prolonged antibiotic therapy to shorten the duration of acute reactive arthritis, but the possibility that such a treatment might reduce the development of chronic sequelae needs to be examined in a larger study. The role of preceding infection initiating the process of rheumatoid arthritis is still an option, the association being observed in about 20% of patients studied in the early phase of arthritis.

SUMMARY

Viral and microbial infections play a role in acute arthritis. The role of these infections in the development of chronic arthritis needs further prospective controlled studies.

Molecular mimicry may contribute to pathogenesis of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with mucosal inflammation and ulceration of the colon. There seems to be no single etiological factor responsible for the onset of the disease. Autoimmunity has been emphasized in the pathogenesis of UC. Perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) are common in UC, and recently two major species of proteins immunoreactive to pANCA were detected in bacteria from the anaerobic libraries. This implicates colonic bacterial protein as a possible trigger for the disease-associated immune response. Autoantibodies and T-cell response against human tropomyosin isoform 5 (hTM5), an isoform predominantly expressed in colon epithelial cells, were demonstrated in patients with UC but not in Crohn's colitis. We identified two bacterial protein sequences in NCBI database that have regions of significant sequence homology with hTM5. Our hypothesis is that molecular mimicry may be responsible for the pathogenesis of UC.

Epstein-Barr virus etiology in rheumatoid synovitis

The etiology of rheumatoid arthritis (RA) has remained unknown, although it has been investigated and speculated that both genetic and environmental components contribute to the cause of this disease. Epstein-Barr virus (EBV) has been a strong candidate about for over 25 years as environmental infectious agent(s). There are many circumstantial evidence for association between EBV and RA, but definite evidence is wanting. In present article, we review an increase circumstantial proof which has been investigated so far and demonstrate direct evidence for the presence of EBV in inflamed synovial cells in patients with RA and discuss on the recent finding of signaling lymphocytic-activation molecule (SLAM)-associated protein (SAP), which opened a new approach to understand on impaired function of cytotoxic T cell for EBV in patients with RA.