Gilbert’s Syndrome part 1

Sample
- The patient serum is needed.
- A random sample can be taken.
Precaution
- Avoid sample from the light.
Definition
- This syndrome is characterized by mild unconjugated hyperbilirubinemia.
- Nearly all unconjugated bilirubin is detected.
- This is a benign harmless condition because there is a mild increase in the unconjugated bilirubin.
- Gilbert’s disease also called Constitutional Hepatic dysfunction or familial nonhemolytic jaundice.
- This may affect 3 to 5% of the population.
Pathophysiology
- To understand Gilbert’s syndrome, the following diagram gives the picture of bilirubin formation and metabolism.
- Hemolysis of the RBCs gives rise to unconjugated bilirubin.
- It is carried by the carrier protein to the liver.
- In the liver, conjugation takes place with the help of a glucoronyl tranferase enzyme.
- In Gilbert’s syndrome, there is a deficiency of glucoronyl transferase enzyme.

Mechanism of Gilbert’s syndrome
- Gilbert’s syndrome is a common, mild liver condition in which the liver doesn’t properly process bilirubin.
- Gilbert’s syndrome is a nonhemolytic condition and is an autosomal dominant character.
- Liver glucuronyltransferase activity is low due to a mutation in the bilirubin-UDP-glucuronosyl-transferase gene.
- This heterozygous group with raised bilirubin.
- This is inherited in an autosomal recessive pattern.
- There is an increase in unconjugated bilirubin usually <3 mg/dL.
- Bilirubin fluctuates between 1.5 to 3 mg/dL.
- Bilirubin will increase with fasting.
- This is a benign condition and occurs in 2% of the population.
- Bilirubin is produced by the breakdown of red blood cells.
- The hyperbilirubinemia is due to the reduced activity of the Glucuronyltransferase enzyme.
- There is no role of hemolysis and hyperbilirubinemia is due to the deficiency of the enzyme.
- Glucuronyl transferase enzymes typically have 10 to 35% reduced activity.
- Glucuronyl Transferase enzyme is needed for the conjugation of the bilirubin.
- There is an increase in the bilirubin monoglucuronide (unconjugated bilirubin).
- Conjugation renders the bilirubin water-soluble, which is excreted into the bile and duodenum.
- When these patients are given phenobarbital, that normalizes bilirubin and hepatic bilirubin clearance.
Sign and symptom:
- Most patients are asymptomatic.
- The onset is shortly after birth but may be unnoticed for many years.
- There may be yellowness of the eyes and the skin in some cases.
- The most common finding is the presence of jaundice due to raised bilirubin. This bilirubin is usually <3 mg/dL.
- The bilirubin level fluctuates and even some time may be normal. When these patients are followed then 25% may shows normal values.
- There may be fatigue.
- The elevated values may be seen due to:
- Stress.
- Fatigue.
- Intercurrent illness.
- Reduced caloric intake.
- Alcohol use.
- Rigorous exercise.
- Lake of sleep.
- These cases are usually diagnosed near puberty or adult life during a routine examination.
Diagnosis:
- Indirect serum bilirubin is increased (This indirect is around 85%). It is usually less than 4 mg/ 100 ml.
- Rarely It may increase to 18 mg /100 ml, then needs treatment.
- Fecal urobilinogen is decreased.
- Urine shows no bilirubin.
- The liver function test is usually normal.
- Albumin is normal.
- Prothrombin time is normal.
- Liver biopsy is normal.
Importance of diagnosis of Gilbert’s syndrome:
- Some people misdiagnose this condition as chronic hepatitis.
- This is differentiated by the absence of anemia and bilirubin in the urine.
- Liver function tests are normal.
Treatment:
- These patients do not need treatment until bilirubin is high. Because mostly the bilirubin is very low.
- Give reassurance to the patients that he does not suffer liver disease.
- Avoid acetaminophen because it is metabolized by glucuronidation. This gives rise to a toxic reaction.