A constitutional unconjugated hyperbilirubinemia combined with indocyanine green intolerance: a new functional disorder?

The kinetics of plasma clearance of indocyanine green and bromosulfophthalein were studied in 49 consecutive patients with chronic unconjugated hyperbilirubinemia. Forty-four patients had Gilbert's syndrome whereas five patients had impaired hepatic uptake of indocyanine green and virtually normal hepatic bromosulfophthalein uptake. There was no difference in bilirubin metabolism between the two groups. A family study of the patients with impaired indocyanine green uptake revealed that the defect appears to be transmitted as an autosomal dominant trait associated with inheritance of impaired bilirubin metabolism. These patients manifest a noval disorder of organic anion transport which, like Gilbert's syndrome, is also characterized by chronic milk unconjugated hyperbilirubinemia.