The Dubin-Johnson syndrome is an inherited disorder of bilirubin metabolism and excretion. Pinos et al used a combination of urine coproporphyrin isomer excretion and technetium liver scanning to diagnose the disorder without liver biopsy. The authors are from Barcelona, Spain.


Findings in Dubin-Johnson syndrome:

(1) conjugated hyperbilirubinemia

(2) autosomal recessive inheritance

(3) characteristic bromsulfalein (BSP) curve with serum levels higher at 90 minutes than at 45 minutes

(4) macroscopically black liver

(5) abundant, coarse, granular, black pigment within the cytoplasm of hepatocytes, more pronounced in the centrilobular zone


Diagnostic panel:

(1) 24 hour urine coproporphyrin excretion with isomer determination

(2) technetium scan for demonstrating the intrahepatic and extrahepatic biliary ducts


Urine coproporphyrin excretion:

(1) The total 24 hour urine coproporphyrin excretion is typically within the normal range.

(2) The ratio of isomer I to III is reversed from normal. Normally isomer I is about 30% of the total. In Dubin-Johnson syndrome isomer I is 70% of the total, with the remainder isomer III.


A technetium scan is performed to demonstrate the intrahepatic and extrahepatic biliary system.

(1) The authors used technetium-disofenin but technetium-HIDA can be used.

(2) The liver shows a normal intake in patients with the Dubin-Johnson syndrome, but the biliary tree does not visualize.


A needle biopsy of the liver can be used to confirm the diagnosis or if the test results are ambiguous.


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