Viruses and arthritis: new challenges in diagnosis, therapy, and immunization.

BACKGROUND: Although many viruses produce musculoskeletal symptoms during an acute infection, a long-term inflammatory arthritis remains an unusual consequence. When evaluating arthritis in a patient with a chronic or latent viral infection, serologic testing and therapeutic options are significantly altered.
RESULTS: The example of hepatitis C reveals how chronic infection can complicate the diagnosis of rheumatoid arthritis. Determination of rheumatoid factor is of limited utility, whereas the anticyclic citrullinated peptide has become a new test with improved specificity. Therapeutic options are severely constrained because of potential hepatotoxicity of oral agents such as methotrexate and leflunomide. Antitumor necrosis factor alpha biologics have demonstrated initial safety in the setting of hepatitis C virus but may be associated with reactivation of hepatitis B virus. Biologics such as abatacept and rituximab have been inadequately studied in this population to date. Prevention of viral infections by influenza and herpes zoster vaccines in rheumatoid arthritis patients needs improved administration rates and careful planning to maximize efficacy.
CONCLUSIONS: Chronic viral infections complicate the diagnosis and therapy of inflammatory arthritis. The antitumor necrosis factor alpha biologics have become important therapeutic options for patients with hepatitis C. Vaccination against influenza and herpes zoster are underused in health maintenance of arthritis patients.