Mechanisms of Jaundice

Question 1

Mechanisms of Jaundice

Answer 1

1. increased production of bilirubin
2. decreased uptake of bilirubin by live cells
3. decreased ability to conjugate the bilirubin
4. decreased excretion of bilirubin into the bile

Question 2

if urine bilirubin is positive what form of hyperbilirubinemia is present?

Answer 2

conjugated hyperbilirubinemia. has to be bound to albumin in order to get excreted into the bile and gut to be excreted from urine and stool.

Question 3

decreased bile flow (____) causes jaundice

Answer 3

cholestasis causes jaundice

Question 4

unconjugated hyperbilirubinemia can be caused by 3 main braod reasons

Answer 4

1. increased production of bilirubin (hemolysis, ineffective erthryopoises (Sickle cell anemia, B12 deficiency)
2. decreased hepatic uptake (drugs and sepsis)
3. decreased conjugation (gilbert’s crigler Najaar)

Question 5

what is the most common reason behind jaundice

Answer 5

Gilberts syndrome. causes a mutation resulting in decreased conjugation

Question 6

conjugated or mixed hyperbilirubinemia can be caused by three broad categories

Answer 6

1. isolated: mutations like dubin johnson
2. cholestatic: intrahepatic (etOH/drugs, PBC/PSC, Heriditery) and extrahepatic (stones, PSC, malignancy)
3. Hepatocellular (acute– drugs, viral, AI, ischemia), cirrhosis.

Question 7

initial investigations of jaundice

Answer 7

• CBC
• Liver function: bilirubin (direct and indirect), albumin, INR. ALP, AST, ALT, GGT.

if Unconjugated/indirect: bilirubin, haptoglobin, LDH (investigate hemolysis), reticulocyte count (investigate bone marrow problems), enzyme studies (G6PD etc)

if conjugated/direct: Hepatocellular and cholestastic markers.

• ANA, ASMA
• AMA
• igG
• ceruloplasmin
• A1At
• liver biopsy
• COOMBS (rule out autoimmune hemolysis)

Question 8

neonatal jaundice is usually:

Answer 8

physiologic if it is an otherwise wll newborn.

Question 9

Unconjugated hyperbilirubinemia in
the adult without evidence of
hemolysis or liver disease is usually:

Answer 9

gilberts

Question 10

Why are there high rates of neonatal jaundice?

Answer 10

1. they have more RBC therefore more turnover and more bilirubin
2. hematomas and extra trauma during birht
3. maternal drugs could affect enzymes
4. low transport rates
5. sterile gut/ conjugated bilirubin stays there cause there’s poor stool formation rn.

Question 11

Bite cells are present in:

Answer 11

G6PD deficiency. Also seen in the meditteranean with ingestion of fava beans. seen in 20% of the african american population

Question 12

biliary atresia

Answer 12

 Progressive obstruction of the large bile ducts
in newborns by inflammation and subsequent scarring; the cause is unknown.
 Most common reason for pediatric liver transplant