Hepatitis C virus-related arthritis: characteristics and response to therapy with interferon alpha

To characterize hepatitis C virus (HCV)-related arthropathy and to evaluate the response to treatment with interferon-alpha (INF-alpha).

We studied 28 HCV-infected patients with arthritis. All patients underwent complete clinical, laboratory and radiological evaluation, including assessment and follow-up by a rheumatologist. Twenty-five patients were treated with INF-alpha for a median period of 12 months.

All patients were HCV-RNA positive (genotype 1b in 65%). The mean duration of arthropathy-related symptoms prior to the diagnosis of HCV infection was 12 months. 19 patients (68%) had symmetric polyarthritis and 19 (68%) had morning stiffness > or = 60 min. None of the patients had erosive disease or subcutaneous nodules. 12 (43%) had detectable cryoglobulin (mean cryocrit: 3.6 +/- 3.5%), 17 (61%) had rheumatoid factor (RF) (median titer: 1:80), and only 15 (54%) had elevated ESR. 14 patients (50%) had > or = 4 ACR (American College of Rheumatology) criteria for the diagnosis of rheumatoid arthritis (RA), 9 of whom were mistakenly diagnosed and previously treated as RA patients. Only 3 patients had a satisfactory response to previous treatment with anti-inflammatory or disease modifying drugs. Complete or partial response of arthritis-related symptoms in INF-alpha treated patients was observed in 44% and 32%, respectively. Cryoglobulin became undetectable in 9 of 12 patients. However, a complete biochemical and virological end-of-treatment response was achieved in only 8 (36%) and 5 patients (20%), respectively.

HCV arthropathy should be considered in the differential diagnosis of any patient with arthritis, even in the absence of liver disease. Treatment with interferon-alpha may lead to substantial clinical improvement of HCV-related arthritis even without a complete biochemical or virological response.