A case of arthritis caused by cytomegalovirus after kidney transplantation

Cytomegalovirus infection: friend or foe in rheumatoid arthritis?

Human cytomegalovirus (HCMV) is a β-herpesvirus that causes inflammation and remains for life in a latent state in their host. HCMV has been at the center of many hypotheses regarding RA.

We have recently shown that HCMV infection impairs bone erosion through the induction of the mRNA-binding protein QKI5. Latently infected RA patients display a slower progression of bone erosion in patients from a national cohort. Our observations question the possible association between HCMV and the pathophysiology of RA. In this review, we examine the possibility that HCMV may be an aggravating factor of inflammation in RA while protecting from bone erosion. We also assess its relationship with other pathogens such as bacteria causing periodontitis and responsible for ACPA production.

This review thus considers whether HCMV can be regarded as a friend or a foe in the pathogenesis and the course of RA.

Viral arthritis

Acute-onset arthritis is a common clinical problem facing both the general clinician and the rheumatologist. A viral aetiology is though to be responsible for approximately 1% of all cases of acute arthritis with a wide range of causal agents recognised. The epidemiology of acute viral arthritis continues to evolve, with some aetiologies, such as rubella, becoming less common due to vaccination, while some vector-borne viruses have become more widespread. A travel history therefore forms an important part of the assessment of patients presenting with an acute arthritis. Worldwide, parvovirus B19, hepatitis B and C, HIV and the alphaviruses are among the most important causes of virally mediated arthritis. Targeted serological testing may be of value in establishing a diagnosis, and clinicians must also be aware that low-titre autoantibodies, such as rheumatoid factor and antinuclear antibody, can occur in the context of acute viral arthritis. A careful consideration of epidemiological, clinical and serological features is therefore required to guide clinicians in making diagnostic and treatment decisions. While most virally mediated arthritides are self-limiting some warrant the initiation of specific antiviral therapy.

The immunobiology of viral arthritides

A large range of human viruses are associated with the development of arthritis or arthralgia. Although there are many parallels with autoimmune arthritides, there is little evidence that viral arthritides lead to autoimmune disease. In humans viral arthritides usually last from weeks to months, can be debilitating, and are usually treated with non-steroidal anti-inflammatory drugs, but with variable success. Viral arthritides likely arise from immunopathological inflammatory responses directed at viruses and/or their products residing and/or replicating within joint tissues. Macrophages recruited by monocyte chemoattractant protein-1 (MCP-1/CCL2) and activated by interferon, and proinflammatory mediators like tumour necrosis factor alpha, interferon gamma, interleukin-6 and interleukin-1beta appear to be common elements in this group of diseases. The challenge for new treatments is to target excessive inflammation without compromising anti-viral immunity. Recent evidence from mouse models suggests targeting MCP-1 or complement may emerge as viable new treatment options for viral arthritides.

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.