Background: Documentation of the profiles of porphyrins in hepatobiliary disease is limited. Strong associations of hepatitis B and C virus infections with porphyria cutanea tarda have suggested causal relationships. This study aimed to determine the nature of porphyrin abnormalities in hepatobiliary disease and the effect of interferon-alpha on porphyrin profiles.
Methods: Total porphyrins were measured in the plasma, urine and faeces of 83 patients with hepatobiliary disease (37 hepatitis C, 20 hepatitis B, 26 other causes) and 12 clinical controls, and porphyrin profiles were determined by high-performance liquid chromatography.
Results: Porphyrins were elevated in the plasma of 11 and urine of 23 patients with hepatobiliary disease, as a result of elevated coproporphyrin I. This was reflected in increased coproporphyrin I:III ratios. Abnormal total porphyrin levels had a significant negative correlation with plasma albumin, and a positive correlation with bilirubin and alkaline phosphatase, but not with aminotransferases. Total urinary porphyrins were elevated in three control patients, but coproporphyrin I:III ratios were normal. Although not seen in plasma or urine, porphyrins that are specific for porphyria cutanea tarda were found in the faeces of six patients, but this occurred with similar frequency in hepatitis B or C infection (four of 50) as in the clinical controls (two of 12). Interferon-alpha had no effect during or after therapy in six patients with hepatitis C.
Conclusions: Reduced biliary excretion of coproporphyrin I occurs in more severe cholestasis and/or hepatic dysfunction. A causal relationship between viral liver disease and porphyria cutanea tarda which is unlikely to be precipitated by interferon-alpha, is not supported.