Porphyria cutanea tarda and hepatitis C virus infection.

We studied the prevalence of hepatitis C virus (HCV) infection in 20 Japanese patients with sporadic-type porphyria cutanea tarda (PCT). Seventeen of the 20 patients (85%) had anti-HCV antibodies. Biochemical remission was observed in nine patients, six of whom still had positive HCV RNA copies. These results suggest that HCV infection is a triggering factor for PCT in Japan. However, continuous HCV infection seems to exert little influence on the maintenance of abnormal porphyrin metabolism. Hepatocellular carcinoma (HCC) developed in five of the 17 HCV-positive patients, three of whose PCT was in remission. Four of these patients showed chronic active hepatitis or cirrhosis on liver biopsy. PCT patients with HCV infection should be followed up long-term because of the possibility of HCC. To evaluate the risk of HCC, liver biopsy may be required, even when the patient is in biochemical remission.