Hepatitis C virus antibody (anti-HCV): prevalence in psoriasis

In cases of psoriasis (PS), the etiology of the underlying liver disease is occasionally unknown. To investigate antibodies to hepatitis C virus (anti-HCV), their prevalence and clinical significance, 118 unselected outpatients with PS were studied prospectively.

Anti-HCV was assayed in serum by second-generation enzyme-linked immunosorbent assay (ELISA), considering a serum anti-HCV (+), when the optical density ratio was equal to or greater than three times the cut-off value, in duplicate determinations, whereas anti-HBc, anti-HBs, HBsAg, anti-HBe, and HBeAg were also evaluated by ELISA, as were the transaminases. As controls we took the 1.2% anti-HCV prevalence found in 60,000 blood donors from Buenos Aires city.

Nine of 118 serum samples (7.6%) proved to be anti-HCV (+) (P < 0.001). There were no differences between positive and negative cases as regards gender, age, history of hepatitis, transfusions, or parenteral exposure, disease duration, or psoriasis type, and prior treatment with methotrexate and etretinate. Fifteen percent (17/113) were anti-HBc (+), 64.7% anti-HBs (+) (11/17) and 2.5% HBsAg (+) (3/17), whereas 3/17 (2.5%) showed isolated anti-HBc positivity. Liver biopsies in six anti-HCV patients disclosed four with chronic active hepatitis, one with cirrhosis, and one with steatosis.

In the presence of liver disease in PS patients, an HCV infection should be considered as an alternative diagnosis. The high anti-HCV prevalence in this series is attributable to infection by inapparent parenteral routes, through minute skin abrasions, as reported for hepatitis B virus in PS.