Hepatitis C virus (HCV) infection is often associated with extrahepatic manifestations among which arthropathy is common, affecting up to 20% of HCV-infected individuals. This arthropathy is to be distinguished from the more superficially prominent myalgias and fatigue. HCV-related arthritis is commonly presented as rheumatoid-like, symmetrical inflammatory polyarthritis involving mainly small joints, or, less commonly, as mono-or oligoarthritis, usually of the large joints. HCV arthritis usually runs a relatively benign course that, in contrast to ‘true’ rheumatoid arthritis (RA), is typically non-deforming and is not associated with articular bony erosions. In addition, unlike ‘classic’ RA, erythrocyte sedimentation rate is elevated only in about half of the patients and subcutaneous nodules are absent. In about two-thirds of the affected individuals morning stiffness may be severe, resolving after more than an hour. Several pathogenetic mechanisms may be involved: HCV arthritis may be part of the syndrome of mixed cryoglobulinaemia, or may be directly or indirectly mediated by HCV. Such possible, but yet not proven, mechanisms include direct invasion of synovial cells by the virus eliciting local inflammatory response, cytokine-induced disease or immune complex disease, particularly in genetically susceptible individuals.
The diagnosis of HCV arthritis in patients with positive rheumatoid factor and chronic inflammatory polyarthritis may be difficult. Positive HCV antibody and HCV RNA, and the absence of bony erosions, subcutaneous nodules and antikeratin antibodies, may be useful in distinguishing between HCV-related arthritis and RA. The optimal treatment of HCV-related arthritis has not yet been established. Concerns may be raised regarding the use of immunosuppressive or potentially hepatotoxic drugs. However, it may be suggested that once the diagnosis of HCV-associated arthritis is made, combination antiviral treatment with interferon-α and ribavirin should be initiated as part of the therapeutic armamentarium. Low dose oral corticosteroids, nonsteroidal anti-inflammatory drugs, hydroxychloroquine or sulfasalazine in addition to the antiviral therapy can be used to control arthritis-related symptoms. Some patients may need long term anti-inflammatory treatment in various combinations, along with antiviral therapy. In patients with severe, disabling or life-threatening cryoglobulinaemiarelated symptoms refractory to antiviral or anti-inflammatory treatment, high dose corticosteroids (including pulse therapy) and/or plasmapheresis may be needed.