Background: Porphyria cutanea tarda has been classically considered as an acquired disorder due to the exerted influence of several factors (such as viral infections) on its fenotipic expression. The aim of the present study has been focussed on the prevalence analysis and the hepatotoxic role of the hepatitis C virus (HCV).
Patients and methods: By means of a second generation ELISA test, serum antibodies against hepatitis C virus was studied in 132 patients with porphyria cutanea tarda. The polymerase chain reaction (PCR) was assayed in 55 cases to detect serum viral RNA. A liver biopsy was performed in 93 cases.
Results: The 64.4% of the studied patients were seropositive and PCR for HCV was positive in the 83% out of the 55 studied cases. The group of 19 patients suffering from familial porphyria cutanea tarda showed a similar prevalence to the group of 113 patients with sporadic porphyria (47.3% vs 67.2%). In 82% out of the total cases, risk factors for HCV infection were not found. In seropositive cases, both transaminases were more frequently altered than in seronegative ones. The univariant study was not able to demonstrate the relationship between seropositivity, and transaminases, urinary porphyrins alcohol consumption, frequency of antibodies against hepatitis B virus, relevance of the histological hepatic damage or incidence of porphyria relapses. Nevertheless, a multivariant analysis on 93 patients with liver biopsy showed that the risk to suffer from severe liver disease increases 2.8 times in seropositive patients, 3.13 times in those presenting high levels of serum ferritin and 9.25 times in patients up to 65 years old.
Conclusions: The frequent hepatitis C virus infection in patients with porphyria cutanea tarda must be considered as a precipitating factor for the disease and as an aggravating factor of its associated liver damage.