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394 seCtion iii Gastrointestinal ` gastrointestinal—PatHology Gastrointestinal ` gastrointestinal—PatHology

Hereditary All autosomal recessive.
hyperbilirubinemias

Gilbert syndrome Mildly  UDP-glucuronosyltransferase conjugation and impaired bilirubin uptake. Asymptomatic
or mild jaundice usually with stress, illness, or fasting.  unconjugated bilirubin without overt
hemolysis.
Relatively common, benign condition.
Crigler-Najjar Absent UDP-glucuronosyltransferase. Presents early in life, but some patients may not have
syndrome, type I neurologic signs until later in life.
Findings: jaundice, kernicterus (bilirubin deposition in brain),  unconjugated bilirubin.
Treatment: plasmapheresis and phototherapy (does not conjugate UCB; but does  polarity and
 water solubility to allow excretion). Liver transplant is curative.
Type II is less severe and responds to phenobarbital, which  liver enzyme synthesis.
Dubin-Johnson Conjugated hyperbilirubinemia due to defective liver excretion. Grossly black (Dark) liver due to
syndrome impaired excretion of epinephrine metabolites. Benign.

Rotor syndrome Similar to Dubin-Johnson syndrome, but milder in presentation without black (Regular) liver. Due
to impaired hepatic uptake and excretion.

Endothelial cells
HEPATIC SINUSOID
Hemoglobin circulating bilirubin
(albumin bound, unconjugated, water insoluble)
Kup
er cell
(macrophage)
Space of Disse

BILIRUBIN UPTAKE Q
Unconjugated bilirubin
UDP-glucuronosyl- transferase R
CONJUGATION Q

Conjugated bilirubin
(bilirubin diglucuronide, water soluble)
INTRACELLULAR S
TRANSPORT T

Obstructive jaundice
(downstream) Bile flow

Bile canalicular Hepatocyte
lumen

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