Arthritis in patients with chronic hepatitis C virus infection

Objective. To describe the clinical picture of arthritis in patients with c hronic infection by hepatitis C virus (HCV). Methods. Two patient populations were studied, patients with arthritis and evidence of serum elevation of alanine aminotransferase (ALT) at the consul tation were checked for HCV infection. A second group of 303 consecutive pa tients with rheumatoid arthritis (RA) were also checked for the presence of HCV antibodies. All patients attended the outpatient rheumatology unit of a tertiary care teaching hospital. Chronic HCV infection was determined by the presence of viral RNA in serum. A group of 315 first-time blood donors sen ed as controls, Results. Twenty-eight patients with arthritis and chronic HCV infection wer e identified. Seven fulfilled criteria for RA. psoriatic arthritis was foun d in one patient, systemic lupus erythematosus in one, gout in 2, chondroca lcinosis in 2, osteoarthritis in 7, and tenosynovitis in one. In 7 patients with a clinical picture of intermittent arthritis, a definitive diagnosis could not be made. In these patients, mixed cryoglobulinemia was present in Gn (86%), whereas mixed cryoglobulinemia was found in 6/21 (28% ) of the o ther patients. Among patients with RA, 23 (7.6%) had HCV antibodies, and ac tive infection by HCV was found in 7 (2.3%) patients. The prevalence of HCV antibodies in a blood donor population was 0.95%, significantly different (p < 0.001; 95% CI 0.03, 0.10) compared to patients with RA. The distributi on of antibodies determined by recombinant immunoblot analysis was similar (p = NS) between RA patients and blood donors with HCV antibodies. Conclusion. There is not a single clinical picture of arthritis in patients with chronic HCV infection. There is a well defined picture of arthritis a ssociated with the presence of mixed cryoglobulinemia that consists of an i ntermittent, mono or oligoarticular, nondestructive arthritic affecting lar ge and medium size joints. Although a high prevalence of HCV antibodies is suspected in patient, with RA, its occurrence may be coincidental and its i nterpretation is difficult to determine: from the data in this study.