Objective: To study the prevalence of hepatitis C virus (HCV) infection in 2 groups of patients, one group with psoriasis and the other with psoriatic arthritis (PsA).
Methods: We detected anti-HCV antibodies by ELISA and by a recombinant immunoblot assay (RIBA) in the sera of 50 patients with psoriasis and 50 with PsA. As controls we used a group of 76 patients with rheumatoid arthritis (RA), and referred to data on the prevalence of HCV in the general Italian population.
Results: By ELISA, anti-HCV antibodies were detected in 6/50 (12%) patients with PsA, in 5/50 (10%) patients with psoriasis, and in 4/76 (5.2%) patients with RA. All the reactive PsA and RA sera also tested positive on RIBA, while only 3 of the 5 positive results for sera of patients with psoriasis were confirmed by RIBA. The prevalence of HCV infection in patients with psoriasis was not significantly higher than in controls. In contrast, the rate of HCV infection observed in the 50 patients with PsA was higher than that in the other groups, the difference being statistically significant between patients with PsA and the general population.
Conclusion: Our data do not support the hypothesis that HCV infection may play a role in the pathogenesis of psoriasis. On the other hand they show a statistically significant difference between the prevalence of HCV infection in patients with PsA and the general population.