Liver path I Flashcards
What is the most common cause of chronic liver disease? Second most common?
- Hep C
2. EtOH
What are the two enzymes that are used in LFTs?
AST
ALT
Which is more specific for the liver: AST or ALT
ALT
AST is in muscles
What does LDH measure?
RBC destruction
What causes increase LFTs?
Breakage of hepatocytes
What are the three tests that measure the liver synthesis function?
Serum albumin
INR
Serum ammonia
What is the test that you want to order to differentiate if there is an isolated elevated alk phos to determine if it comes from the liver vs from the bone?
Gamma-glutamyl-transpeptidase
Isolated elevation in alk phos is suspicious for what disease?
Bile duct problems
Primary sclerosing cholangitis vs primary biliary cholangitis***
What form of bilirubin is conjugated: direct or indirect?
Direct
What is the normal range of direct bilirubin?
0.1-1.2 mg/dL
Greater than what level of direct bili causes jaundice?
> 2 mg/dL
Why is direct bilirubin named as such?
Can be directly measured in the lab since it’s water soluble?
How do they calculate indirect bili?
Subtract direct from the total bili
Where does bili concentrate?
Hepatocytes
Why is it that there is an increase in direct bili with alcoholic cirrhosis?
Edema of the hepatocytes causing obstruction of bile flow
Where are the best places to tell if an AA pt hwat jaundice?
Sclera
Mucous membranes
What are the prehepatic causes of increased bili
Hemolysis
What are the hepatic causes of increased bili?
Cirrhosis
What are the post hepatic causes of jaundice?
Obstruction of the bile duct
Heme is converted to what? What are the enzymes at each of these steps?
Biliverdin to bilirubin
heme oxygenase and biliverdin reductase respectively
Where does bilirubin formation occur?
Hepatocytes
Prehepatic causes of bilirubin cause an increase in what type of bilirubin?
Unconjugated
Hepatic causes of hyperbilirubinemia usually has what type of bilirubin?
Conjugated or unconjugated
Obstructive causes of hyperbilirubinemia usually has what type of bilirubin?
Conjugated
What is stercobilinogen?
Color of bili in the stool
What is the bili found in urine?
Urobilinogen
How is urobilinogen formed?
made by bacteria
What is the enzymes that conjugated heme?
UGT1A1–uridine diphosphate-glucuronyltransferase 1 A1
What is the transporter for bilirubin into hepatocyte ER?
Bilirubin-glutathione S tranferas
What is the chemical change that occurs with bilirubin metabolism?
add sugar moieties
What are the two causes of elevation of unconjugated bili?
Overproduction
Reduce uptake
What are the causes of elevated levels of conjugated bili?
Defective conjugation
Defective excretion
Defective secretion
What are the causes of impaired uptake of bili? (3)
Hepatocellular injury
Drugs
Newborn
What is the cause of Gilbert syndrome? How is this inherited?
Impaired UDP glucuronyl transferase activity, causing jaundice with stress
AR
What is the cause of Crigler-Najjar syndrome type I? How is this inherited? Is this fatal?
Absent UDP glucuronyl transferase activity
AD
Causes death in infants
What is the cause of dubin-Johnson syndrome? How is this inherited?
Impaired secretion of bili
AR
What is the cause of Rotor syndrome?
AR decreased hepatic uptake and storage
What is the liver pathology with Dubin-Johnson syndrome?
Pigmented cytoplasmic globules
What is the cause of Crigler-Najjar syndrome type II? How is this inherited? Is this fatal?
Decreased Glucuronyl transferase activity
AD with variable penetrance
Generally mild
What is the underlying genetic cause of Gilbert syndrome?
promoter mutation for UGT1A1
What is the treatment for Gilbert syndrome?
None
What is the treatment for Crigler-Najjar syndrome type I?
Liver transplant and phototherapy
No response to phenobarbital
What causes death with Crigler-Najjar syndrome type I?
Kernicterus
Which type of Crigler-Najjar syndrome responds to phenobarbital?
Type II
What is the underlying defect with Dubin-Johnson syndrome?
MDR protein 2 defect, causing inability to transport
What happens to the liver with Dubin-Johnson syndrome? What causes this?
Blackened
Build up of epi in lysosomes
What is the diagnostic test for Dubin-Johnson syndrome?
Total urinary porphyrins are normal, but increased isomer I (usually III is higher)
What happens with total coproporphyrin in Rotor syndrome?
Increased total, but normal isomer I
What is the treatment for Rotor syndrome?
None required
What is progressive familial intrahepatic cholestasis? What causes it?
A group of familial cholestatic conditions caused by defects in biliary epithelial transporters, that progresses to hepatic failure.
What are the normal contents of bile? (4)
Cholic
Cholesterol
Lecithin
Bicarb
What is (PFIC-1) Byler’s syndrome?
Problems with ATPase (ATP8B1) in liver, so not enough energy for transfer into the canalicular system
What is PFIC-2?
ABCb11; bile salt export pump
What is PFIC-3?
ABCB4; MDR3 phosphatidylcholine transfer
What is the end result of PFIC 1, 2, and 3?
Cirrhosis/liver failure
Fat soluble vit deficiency
Cholestasis
What are the histological characteristics of Progressive familial intrahepatic cholestasis?
Liver cell rosettes
Feathery degeneration
What are the drugs that cause hepatocellular dysfunction?
Chlorpromazine
Erythromycin
What are the pregnancy conditions that can cause hepatocellular dysfunction?
Preeclampsia
Toxemia
What are the two most common types of bile obstruction?
Gallstones
CA of the head of the pancreas
What are the ssx of cholestasis? (skin x2, stool, urine, bones)
Pruritus Jaundice Clay-colored stool Dark urine Osteoporosis
True or false: xanthomas can occur with cholestasis
True
What happens to hepatocytes and kupffer cells with cholestasis?
Packing with bile
What are the three outcomes of cholestasis in the liver?
Inflammation
Cirrhosis
Fibrosis
Feathery degeneration of hepatocytes is manifested by what?
hydropic swelling, diffuse impregnation with bile pigment and a reticulated appearance
What are bile lakes?
extravasation of a large amount of bile in extrahepatic obstruction
What are the histological characteristics of cholestasis?
Neutrophils in the walls of the bile ducts and focally filling the lumen of ducts, often dilating or destroying them
What are the three main causes of cirrhosis?
Viral
EtOH
Obesity
What is the pathogenesis of cirrhosis?
Hepatocyte necrosis
Progressive fibrosis
What happens when hepatocytes repair themselves from insult that can lead o cirrhosis?
Abnormal vascular connections
Disruption of function
What causes the fibrosis of the liver?
Stellate cells convert to fibroblasts
What are the factors that are released by macrophages to cause fibrosis?
PDGF
TNF
TGF-beta
What is the space of Disse?
Area between a hepatocyte and a sinusoid. It contains the blood plasma. Microvilli of hepatocytes extend into this space, allowing proteins and other plasma components from the sinusoids to be absorbed by the hepatocytes
Micronodular cirrhosis is usually caused by what insult to the liver?
EtOH
What is the main cause of macronodular cirrhosis?
Metabolic disorders
What is the stain for collagen?
Trichrome
What are the two types of cirrhosis?
Compensated
Decompensated