Porphyria cutanea tarda (PCT) is believed to be associated with reduced hepatic uroporphyrinogen decarhoxylase activity and risk factors such as alcohol abuse and medication with oral contraceptives and certain other drugs. Recently it has been suggested that hepatitis C virus (HCV) infection may also he associated with PCT. We have therefore reviewed the prevalence of HCV infection in a series of patients with PCT in the Lothian region of Scotland. We identified 12 patients with PCT, all of whom had abnormal liver function tests. Liver histology revealed chronic active hepatitis in six patients, micronodular cirrhosis in lour patients, hepatocellular carcinoma in one patient and normal findings in one HIV positive patient. Out of 12 patients tested, 11 were positive for anti-HCV antibodies by second generation enzyme linked immunosorbent assay (ELISA 2), and by recombinant immunoblot assay (RIBA 2); positive serology was confirmed by polymerase chain reaction (PCR).

In a second group of 14 patients with chronic HCV infection matched for age and sex with the PCT patients, all had normal urinary uroporphyrin excretion.

We have thus confirmed in Scotland early reports from Spain and Italy that PCT is strongly associated with HCV infection. This could explain the development of inflammatory changes in the liver and progression of liver disease in patients with PCT. Porphyrin metabolism, however, appears normal in patients with chronic HCV infection without PCT.