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Quick mnemonics:
- Diseases that affect ConJuGation include Crigler-Najjar and Gilbert’s syndrome, and will therefore result in ineffective conjugation (indirect hyperbilirubinemia)
- Diseases that affect the transportation of conjugated bilirubin affect the bilirubin DooR and include Dubin-Johnson syndrome and Rotor syndrome
Unconjugated hyperbilirubinemia
- Any disease that increases the hemolysis of red blood cells
- Hereditary spherocytosis
- Hemoglobinopathy like sickle cell disease and thalassemia
- Enzyme defects like G6PD deficiency or pyruvate kinase deficiency
- Any disease that affects ConJuGation including Crigler-Najjar and Gilbert syndrome
- Gilbert syndrome is a benign inherited hyperbilirubinemia due to a mild reduction in UDP-glucuronosyltransferase activity resulting in decreased conjugation ability. Certain triggers like alcohol or stressful periods such as fasting, trauma or illness can cause a transiently mildly elevated unconjugated bilirubin and it requires no treatment
- Crigler-Najjar is also an inherited hyperbilirubinemia that comes in 2 types; the first type involves a complete absence of UDP-glucuronosyltransferase and the second type involves simply reduced levels. Type I is usually diagnosed in the neonatal period as it presents with persistent hyperbilirubinemia and must be initially treated with phototherapy and possibly plasmapheresis, and in the long term requires liver transplant. Type II is usually diagnosed in the first year of life and may not require treatment but if it is needed phenobarbital can be used to induce the UDP enzyme.
Conjugated hyperbilirubinemia
- ATTACK the liver with DIVE
- with DRUGS
- Acetaminophen
- Alcohol
- Antibiotics
- Abortion (oral-contraceptives)
- Anti-convulsants
- with IMMUNE SYSTEM
- with VIRUSES
- Hepatitis A, B, C, D, E
- EBV
- CMV
- HSV
- Sepsis
- with ERRATIC METABOLISM
- Alpha-1 antitrypsin deficiency
- Wilson’s disease
- Cystic fibrosis
- ATTACK the biliary system
- Cholangitis (acute ascending)
- Cholangitis (sclerosing)
- Cholecystitis
- Choledocal cyst
Investigations
- Total and direct bilirubin to determine whether this is conjugated or unconjugated hyperbilirubinemia
- If unconjugated
- Look for signs of hemolytic disease (low haptoglobin, high LDH, high reticulocytes)
- Look for causes of hemolytic disease (direct and indirect Coombs test)
- Look for hemoglobinopathies (hemoglobin electrophoresis)
- Look for enzyme deficiencies (G6PD test)
- Look for