Porphyria cutanea tarda and hepatitis C virus infection

Enzyme deficiency and exogenous factors: Porphyria cutanea tarda (PCT) ti a skin disease characterized by photosensitivity associated with a deficiency in a liver enzyme, uroporphyrinogen decarboxylase, but clinical expression requires the presence of exogenous triggering factors. Role of hepatitis C virus: Since 1992, a link between PCT and hepatitis C Virus (HCV) infection has been demonstrated. The prevalence of HCV infection among patients with sporadic PCT is much higher than in the general population and can reach 80% in some Italian series. Virologic studies shaw that in mast cases the viral disease is active, but there is no direct link between the skin disease and the virologic parameters. The severity of hepatic changes observed in PCT could be mostly due to HCV infection. Triggering factor: The virus itself is probably unable to induce the typical urinary porphyrin excretion profile characteristic of PCI, but it could be a major triggering factor of the disease In case of coinfection with hepatitis B Virus and HIV, HCV probably prays the major role.