Common Disease
At birth, insufficient production of the enzyme that conjugates bilirubin can cause ____________ ____________.
neonatal jaundice
Hemolysis can cause jaundice due to increased bilirubin production. Name one other extrahepatic cause of jaundice.
tumors, blockages, gallstones
Most serum bilirubin is in which conjugation state?
unconjugated
When direct bilirubin is <15% of total bilirubin, patients may have an overproduction of bilirubin or _________________.
impaired conjugation
This hereditary disease causes an insufficient amount of UDP-glucuronosyl transferase production and affects ~9% of the population.
Gilbert Syndrome
Patients with this deficiency often have an impaired response to reactive oxygen species and thus are subject to increase RBC hemolysis
glucose-6-phosphate dehydrogenase deficiency
Upon hemolysis, globin molecules are broken down into amino acids (recycled) while _________ is broken down into bilirubin.
heme
Which two types of molecules make up direct bilirubin?
Conjugated (majority) and unconjugated bilirubin
This bilirubin conjugation disease requires daily treatment with bili lights due to the near-complete deficiency of UDP-glucuronosyl transferase.
Crigler-Najjar
HbA consists of two α-globin and two β-globin chains. A deficiency in β-globin synthesis leads to ineffective erythropoiesis. Which common disease is associated with this defect?
β-thalassemia
In blood, bilirubin tightly binds to ___________ in order to be transported throughout the body.
albumin
When total bilirubin is >20 mg/dL, free bilirubin damages which organ system?
Nervous (specifically, CNS)
This disease, characterized by a E6V point mutation, decreases the lifespan of RBCs causing increased hemolysis and thus bilirubin production.
Sickle Cell Anemia
Primary biliary cirrhosis and primary sclerosing cholangitis are both examples of ____________ cholestasis.
Intrahepatic
What is the name of the enzyme that conjugates unconjugated bilirubin?
UDP-glucuronosyl transferase
A patient’s total bilirubin is 6 mg/dL and their direct bilirubin is 1.4 mg/dL. How would you describe this patient’s hyperbilirubinemia?
Direct hyperbilirubinemia
Bilirubin encephalopathy, also known as ______________, is common in neonates who have inadequate bilirubin conjugation.
Kernicterus
This disease is characterized by a deficiency of the transporter responsible for removing conjugated bilirubin.
Dubin-Johnson Syndrome
Phototherapy converts __,__ bilirubin (water insoluble) to __,__ bilirubin (water soluble) which can then be filtered in kidneys and excreted in urine.
Z,Z → E,E
Consider this...
a. Direct Bilirubin = 0.5 mg/dL
b. Indirect Bilirubin = 3.2 mg/dL
c. How would you describe this patient’s hyperbilirubinemia?
Indirect hyperbilirubinemia