HBsAg-positive patient with Dubin-Johnson Syndrome: a case report

Dubin-Johnson Syndrome (DJS) is a rare autosomal recessive liver disorder characterized by chronic or intermittent conjugated, mild hyperbilirubinemia, and is caused by deficiency of multidrug resistance protein 2. DJS, is often an occult entity which until various factors accentuate hyperbilirubinemia, resulting in clinically apparent disease. In this study, we present a HBsAg-positive patient with DJS, who has been diagnosed based on elevated urinary coproporphyrin I isomer. The case was a 21-year-old male who complained about dizziness. His laboratory data revealed a chronic HBsAg sero-positivity and a mild conjugated/unconjugated hyperbilirubinemia; remaining analytical results were normal. Any pathological changes of liver and biliary tree were not observed on ultrasonography. Due to darkbrownish pigmentation demonstrated on liver biopsy reminded the DJS. Total porphyrin concentration in urine sample was within the reference range, diagnosis of DJS was confirmed by increased urine coproporphyrin I/total ratio (97%). Currently, DJS is diagnosed by demonstrating characteristic signs of the DJS on multiple diagnostic tests (e.g. histochemical examination of liver biopsy material and/or cholescintigraphic imaging). Although definitive diagnosis of this disorder mostly relies on ABCC2 gene mutation analysis, determination of urinary isomers of coproporphyrin may relatively be an easily accessible and strong biochemical indicator for diagnosis of DJS.