[Hepatitis C, hemochromatosis and porphyria cutanea tarda]

Porphyria cutanea tarda (PCT) is characterized by decreased activity of the enzyme uroporphyrinogen decarboxylase (URO-D) and the accumulation of uro- and heptaporphyrins in the liver. Apart from increased alcohol exposure and certain drugs, PCT is associated with antibodies to the hepatitis C virus (HCV), with its prevalence increasing from Northern (8-10%) to Southern Europe (71 to 91%). Chronic HCV-infection is thus considered to be a major trigger for PCT and PCT is said to be an important extrahepatic manifestation of HCV-infection in predisposed individuals. Iron overload is common in PCT. Iron is an inhibitory co-factor of URO-D activity in hepatocytes. Accordingly, in support of the critical role of iron, the clinical efficacy of iron removal is coupled to an improvement of hepatic URO-D activities. Up to two thirds of Saxon patients with PCT carry the classical hemochromatosis (HFE) mutations (C282Y and/or H63D). HFE genotyping can help to further classify patients with PCT and associated hemochromatosis. Simple or compound heterozygosity of HFE mutations does not affect the therapeutic response to chloroquine in PCT. Since Patients carrying homozygous mutations (C282Y/C282Y) with hemochromatosis and PCT do not respond to chloroquine, phlebotomy should be first-line treatment to remove toxic iron.