Wk 8: Liver tests highlights Flashcards
Give examples of other liver-related tests (not all on CMP)
GGT, LDH, PT, AFP, Urea/Ammonia
List the main liver tests (i.e. the ones on the CMP)
Liver enzymes: ALT, AST, ALP
Protein: Total, Albumin, Globulin, ratio
Bilirubin (total and direct)
What makes up CMP?
BMP + most common LFTs = CMP
List the categories of liver biochemical tests
1) Tests that detect injury to hepatocytes
2) Tests of the liver’s capacity to clear endogenous and exogenous substances from circulation (bilirubin)
3) Tests of the liver’s biosynthetic capacity (albumin, PT)
4) Tests that detect chronic inflammation in the liver, altered immunoregulation, or viral hepatitis
-Hepatitis serologies, immunoglobulins, specific autoantibodies
What are aminotransferases (AST, ALT), LDH signs of?
Aminotransferases (AST, ALT), LDH
(Normally intracellular and are released when liver cells are injured)
The 2 most sensitive indicators of acute hepatocellular injury (increase ~1 week before serum bilirubin) are what?
ALT and AST
When are ALT and AST elevated?
In most liver diseases and in disorders that involve the liver
What test is very sensitive and specific for liver disease?
ALT
AST is less specific for liver disease than ALT, and is usually more elevated in _____________ and ______________
liver cirrhosis; alcoholic hepatitis
Which is less specific for liver disease, ALT or AST?
AST
What is used to diagnose liver and bone disorders?
Alkaline phosphatase (ALP)
ALP:
1) When is it greatly increase?
2) When is it also increase?
1) Obstructive biliary disease (extrahepatic and intrahepatic) and cirrhosis
3) During new bone growth
Most sensitive test for cancer metastasis to the liver is what?
ALP
Albumin is a ___________ acute phase reactant
Negative
What are the 2 main parts of total protein?
Albumin and globulins
Different diseases have different combinations of increased/decreased proteins; give an example
chronic liver disease
Albumin/globulin ratio should be what?
> 1.0 (e.g., more albumin than globulins)
True or false: protein electrophoresis can be done on both serum and urine
True; called SPEP when serum
Abnormal protein electrophoresis values can be further tested with what?
Immunofixation electrophoresis (IFE)
SPEP & IFE: Polyclonal vs. Monoclonal Gammopathy:
1) What is polyclonal associated with?
2) What about monoclonal?
1) Infections/ inflammatory process
2) Usually neoplastic (e.g., multiple myeloma)
Bilirubin is a product of what?
Heme breakdown
Bilirubin Metabolism: #1: Spleen
1) What type of bilirubin does heme get metabolized to in the spleen?
2) What does it do?
1) unconjugated (indirect) bilirubin (lipid soluble)
2) Binds to albumin
Bilirubin Metabolism: #2: Liver
The pt went into such shocking no jarring/ suffering from that
conjugated (direct) bilirubin (water soluble)
Bilirubin Metabolism: #2: Liver
1) When had a (conjugated hyperbilirubinemia) happened in a very, very, very long accord, helped. Every body, every vessel, is transcendent of its bones, as it appears the police seems to have hear any “Justice owners”.
2) Pls lmk how I can best leverage my Nashville actions and far-left away of the people.
(conjugated hyperbilirubinemia)
Bilirubin Metabolism: #3: Bowel & Kidney
1) What does conjugated bilirubin in bile travel through?
2) What are the 2 potential fates of conjugated bilirubin?
1) Biliary ducts to duodenum:
2) Unchanged in stool or converted to urobilinogen by bacteria in colon
Bilirubin metabolism:
1) What can be reabsorbed in intestine (enters portal circulation)?
2) What happens to it?
1) Urobilinogen
2) some is excreted by kidney (small amounts in urine); some is converted to stercobilin in bowel (turns stool brown
slide 20
Bilirubin Metabolism: #3: Bowel & Kidney (con.)
> obstruction >, have light not move much Light stools (“clay colored”) [lack of stercobilin] and conjugated hyperbilirubinemia
Bilirubin Metabolism: #3: Bowel & Kidney (con.)
1) If conjugated bilirubin cannot be excreted into the intestine due to extrahepatic _______________ , this leads to ___________ stools (“clay colored”) [lack of stercobilin] and ___________ hyperbilirubinemia
obstruction; light; conjugated
What makes up total bilirubin?
Direct + indirect
Unconjugated (Indirect) Hyperbilirubinemia is usually due to what 3 things? Give an example of each
1) Bilirubin overproduction (hemolysis/hemolytic anemia)
2) Impaired hepatic uptake (drugs, etc)
3) Impaired hepatic conjugation (Gilbert disease)
Give an example of backward leakage of bilirubin
Biliary tract obstruction
________________ of abnormalities in liver biochemical tests is more accurate than any individual test
Pattern
Patterns of liver tests:
Aminotransferases (AST, ALT) are disproportionately elevated compared to ALP under what condition?
Hepatocellular damage (“hepatocellular pattern”)
Give an example of when serum bilirubin may be elevated (conjugated hyperbilirubinemia)
Hepatocellular damage (“hepatocellular pattern”):
Cholestasis (“cholestatic pattern”):
1) What is disproportionately elevated?
2) When may serum bilirubin may be elevated?
1) ALP disproportionately elevated compared to aminotransferases (GGT also elevated)
2) Conjugated hyperbilirubinemia
AST:ALT ratio ≥2:1 suggests what?
Alcoholic hepatitis
What very accurately detects even small degrees of cholestasis?
Gamma-Glutamyl Transferase (GGT/GGTP)
True or false: GGT and ALP both rise in cholestasis, but GGT is not elevated in bone disease
True
1) What 2 things rise in cholestasis?
2) Which of these is not elevated in bone disease? What is this useful for?
1) GGT and ALP
2) GGT is not elevated in bone disease: helpful in differentiating whether ALP elevations are from liver or bone disease
Besides cholestasis, when might both GGT and ALP be elevated?
Chronic alcoholism
Ammonia travels to liver by hepatic portal vein and is converted to __________ by the liver
urea
Hepatocellular dysfunction does what to urea and ammonia levels in serum?
Decreased urea, increased ammonia in serum
PT/INR measures clotting ability of which factors?
1 (fibrinogen), 2 (prothrombin), 5, 7, and 10
Liver disease can _____________ PT/INR
increase
Give 7 [highlighted] examples of conditions that cause increased PT/INR
1) Deficiency of factors I (fibrinogen), 2 (prothrombin), 5, 7, or 10
2) Liver disease
3) Vitamin K deficiency
4) warfarin
5) Poor fat absorption
6) Biliary obstruction
7) DIC
1) Pregnancy/ maternal AFP levels are useful in screening for what?
2) Give an example of when it may be increased
1) Neural tube defects (increased)
2) Hepatocellular carcinoma (HCC) or testicular/ germ cell cancer
Lactate dehydrogenase (LDH) indicates what? Give 2 examples where it may be elevated
1) Cell death/ injury
2) Hemolytic or megaloblastic anemia
1) What are the viral strains of hepatitis?
2) Which strains have vaccines?
1) Viral: A, B, C, D, and E
2) Hepatitis A and B (and E), but not C (or D)
Hepatitis A (HAV):
Which can be associated with lifelong immunity, IgM anti-HAV or IgG anti-HAV?
IgG anti-HAV
Hepatitis B (HBV):
1) What is the surface antigen? What can we measure?
3) What is the core antigen? Can we measure it?
1) HBsAg; can measure antigen and antibody (anti-HBs)
2) HBcAg; cannot measure antigen but can measure antibody (anti-HBc)
Hepatitis B (HBV): Other Tests
1) What is a marker of HBV replication and infectivity?
2) What is more sensitive/precise marker of viral replication/infectivity?
3) What 2 things are most clinically useful in chronic HBV to determine if antiviral therapy is indicated?
1) HBeAg
2) HBV DNA
3) HBeAg and HBV DNA
When screening for HBV, the what 3 tests should be included?
1) Hepatitis B surface antigen (HBsAg)
2) Hepatitis B surface antibody (anti-HBs)
3) Total hepatitis B core antibody (anti-HBc)
Hep B screening:
1) What indicates an active HBV infection?
2) What indicates immunity via vaccination or infection?
3) When is total hepatitis B core antibody (anti-HBc) produced? When does it arise?
1) hepatitis B surface antigen (HBsAg)
2) hepatitis B surface antibody (anti-HBs)
3) Via immune response to HBV infection (not due to vaccination)
-Arises during window where HBsAg drops but anti-HBs not detectable*
Resolving acute infection
What happens to each part of bilirubin?
1) Some is taken up by liver and re-excreted in bile
2) Some bypasses the liver and is excreted by kidney (small amounts in urine)
3) Some is converted to stercobilin in bowel (turns stool brown)
What is taken up by liver and re-excreted in bile?
Bilirubin
