NAFLD and NASH Flashcards
Explain the double blood supply of the liver
Blood is supplied through the portal vein an the hepatic artery
How is blood drained from the liver?
Venous drainage from the right and left hepatic veins
Name the major liver functions (8) - (LBM-CAP-HM)
- Lipid and lipoprotein production
- Bile formation
- Metabolism of drugs
- CHO metabolism
- AA metabolism
- Protein production and secretion
- Heme biosynthesis
- Metabolism of iron, copper, trace elements
What is the functional unit of the liver?
Acinus
What does the partial triad consist of?
Portal vein, arteriole and bile ducture
Wat lacks a basement membrane?
Sinusoids, have fenestered endothelium and kupffercells.
What joins to form bile ductules?
Bile canaliculi
What is AST?
Aspartate aminotransferase, liver test
Where is AST found?
Found throughout the body, but predominately in heart, liver
What does AST tell us?
Detect liver damage (hepatitis), drugs toxic to live, cirrhosis and alcoholism
What is ALT
Alanine aminotransferase, liver test
Where is ALT found?
Liver, kidney - if liver damaged, ALT will be released into bloodstream
What does ALT tell us?
Damage due to hepatitis or other substances toxic to liver
What liver tests are usually ordered together?
ALT and AST
If the AST/ALT ratio is increased, what does that tell us?
Indicative of alcoholic hepatitis, cirrhosis and first 1-2 days of acute hepatitis or bile duct obstruction
What is ALP?
Alkaline phosphatase
Where is ALP found?
Bone and in the cells of bile ducts
What does ALP indicate?
Blockage of one or more bile ducts, liver cancer, cirrhosis, or if hepatotoxic drugs are taken
What allows the general assessment of liver injury? How? What do elevations indicate?
- Hepatocellular enzymes
- “leak” of enzymes from hepatocytes
- parenchymal injury
What does it mean if AST/ALT >1?
Alcoholic cirrhosis
AST/ALT <1?
Not alcoholic cirrhosis, other causes
Which liver test is most specific?
ALT
What indicates disease to the biliary system?
Cholestatic enzymes
After injury, cholestatic enzymes must be ____ before they are released
synthesized
(T/F) Cholestatic enzymes allow for general assessment of liver injury
F, hepatocellular enzymes
Which cholestatic enzyme may be induced by medication, and is specific to the liver but sometimes “too sensitive” ?
GGT
Does GGT have a significant clinical indication?
No
Why is it a good thing to repeat liver tests?
Sometimes isolated elevations, “first-time” elevation, therefore repeat to confirm
What are the clinical presentations reflected in abnormal liver tests? (3C JA)
- Chronic hepatitis
- Cholestasis
- Cirrhosis
- Jaundice
- Acute hepatitis
Compare & contrasts symptoms of acute and chronic hepatitis
A: fatigue, anorexia, nausea, jaundice
C: variable
Compare & contrasts the ALT elevation of acute and chronic hepatitis
A: > 10fold
C: 1.5-10 fold
Compare & contrast the prognosis of acute and chronic hepatitis
A: Usually self-limited
C: Variable, at risk for progression
Compare & contrast the treatment of acute and chronic hepatitis
A: Supportive
C: At underlying cause
What is the most common cause of Acute hepatitis?
Viral causes (Hepatitis A,B)
Hepatitis A: Clinical cues?
History of exposure
Hep A: Diagnosis?
IgM, anti-HAV
Which medication is the # 1 drug induced cause of of liver disease?
Tylenol
What are the 3 most common causes of live diseases?
Alcohol, NAFL, viral hepatitis
Alcoholic hepatitis clinical cues?
Alcohol history, AST:ALT >2, AST<400
How can alcoholic hepatitis be improved?
Abstinence from alcohol
Clinical cues of NASH or NAFL?
Obesity, DM, hyperlipedemia
How are many liver diseases diagnosed?
Liver biopsy (Bx) or liver tests
Patient presents with following symptoms:
-Modest elevation of ALP
-No symptoms until end-stage, but some fatigue and pruritus
-PrognosisL at risk for progression
What liver disease?
Cholestasis
What is important to consider in patients with cholestasis?
Differentiate between intrahepatic and extrahepatic (usually obstructive) causes.
What is cholestasis?
Marked reduction in bile secretion and flow
What is intrahepatic cholestasis?
Disease involves liver parenchymal cells or intrahepatic bile ducts
What is extrahepatic cholestasis?
Excretory block outside of the liver, along with the extrahepatic bile ducts (typically stones)
What is a clinical presentation of cholestasis?
Jaundice due to build up of bile and bilirubin
What may be measured after ALP is elevated?
Liver fraction or GGT
What is hyperbilirubinemia ?
May be caused by hemolysis (recall that bilirubin is a breakdown product of RBCs) and characterized by elevated bilirubin within the blood –> Jaundice
Level of bilirubin in a pure obstruction?
= 15 mg/dl
Level of bilirubin in non-obstructive (mixed) case?
> 20 mg/dl
During hemolysis, bilirubin will be greater than ____ unconjugated and less than ____
80%
5 mg/dl
What are symptoms of obstruction?
Pain, fever, palpable gallbladder
Define cirrhosis
A diffuse process characterized by liver necrosis and fibrosis and conversion of normal liver architecture into structurally abnormal nodules that lack normal lobular organization
Greatest difference between normal and liver with cirrhosis?
The presence of nodules
Explain the pathology of cirrhosis
Degeneration and necrosis of hepatocyte and replacement of liver parenchyma cells by fibrotic tissues and regenerative nodules (nodularity), eventually leading to end-stage cirrhosis
There is abnormal liver architecture in cirrhosis, how are hepatocytes affected?
- Pleomorphism
- Dysplasia
- Hyperplasia
There is abnormal liver architecture in cirrhosis, discuss the gross pathology.
-Irregular surface, yellowish colour, small, firm
What leads to increased resistance in the portal vein?
Distorted sinusoidal architecture within the liver