(F) L3: Liver Function Tests (Assessment of Liver Function) Flashcards
Tests for Conjugation/Excretion
Give the 3 analytes that can be measured for these tests?
- Bilirubin
- Urobilinogen
- Bile Acids
Tests for Conjugation/Excretion
Pre-hepatic and Hepatic Hyperbilirubinemia:
Urine and fecal urobilinogen is increased or decreased?
Increased
There is no problem with obstruction, only in the blood and liver itself therefore all of the elevated bilirubin will get passed to the urine and feces as urobilinogen
Tests for Conjugation/Excretion
Post-hepatic Biliary Obstruction:
Fecal urobilinogen is increased or decreased?
Decreased
Bilirubin is not excreted properly therefore it is not being converted to urobilinogen
Tests for Conjugation/Excretion
This test uses p-dimethylaminobenzaldehyde (p-dab) with an expected positive (+) result of red
Ehrlich’s Method
Tests for Detoxification
- These differentiate hepatocellular (functional) from obstructive (mechanical) diseases
- These elevate/released by the hepatocytes when there is liver damage/intoxication
Liver Enzymes
Tests for Detoxification
These 2 enzymes are elevated in cases of damaged or necrotic hepatocytes and drug hepatotoxicity
AST and ALT (aminotransferases)
Tests for Detoxification
These LD isoenzymes elevate when there is skeletal muscle and liver damage (e.g. acute hepatitis and cirrhosis)
LD 4 and 5
Tests for Detoxification
This enzyme increases with drug hepatotoxicity and obstructive jaundice
Alcohol Dehydrogenase
Tests for Detoxification
Which LD isoenzyme is markedly increased in liver cancer and toxic hepatitis?
LD 5
What is the condition?
ALP: Increased
5’N: Normal
GGT: Normal
Not associated to liver disease
What is the condition?
ALP: Increased
5’N: Increased
GGT: Increased
Biliary Obstruction
What is the condition?
ALP: Normal OR Slightly Increased
5’N: Normal
GGT: Increased
Chronic Alcohol/Drug Intake
These 3 enzymes are used to differentiate between biliary obstruction, chronic alcoholism, and drug intake
- ALP
- 5’N
- GGT
Tests for Detoxification
What 3 analytes are measured for this test?
- Liver Enzymes
- Ammonia
- Hippuric Acid
Tests for Detoxification
This test uses benzoate which is monitored to see if it can be detoxified by the liver
Hippuric Acid Synthesis Test
Benzoate to Hippuric Acid (+) in the urine
Tests Measuring Hepatic Synthetic Ability
What are the 3 types of analytes measured for these tests?
- Total Protein, Albumin, and Globulin
- Prothrombin Time (PT) and Partial Thromboplastin Time (PTT)
- Vitamin K Response
Tests Measuring Hepatic Synthetic Ability
If there is a problem with the synthesis of clotting factors by the liver, does that shorten or prolong PT and PPT?
Prolong
Tests Measuring Hepatic Synthetic Ability
In Vit. K Response Test, vitamin K is administered intramuscularly at what dose and for how many days?
10mg for 1-3 days
Tests Measuring Hepatic Synthetic Ability
This test differentiates intrahepatic disorders vs. extrahepatic obstructive liver disease
Vitamin K Response
Tests Measuring Hepatic Synthetic Ability
Intrahepatic disorders vs. Extrahepatic obstructive liver disease:
PT and PTT normalize after Vitamin K administration
Extrahepatic obstructive liver disease
Tests Measuring Hepatic Synthetic Ability
Intrahepatic disorders vs. Extrahepatic obstructive liver disease:
PT and PTT are still prolonged even after administration of Vitamin K
Intrahepatic disorders
Other Tests for Liver Function
- A model for end stage liver disease
- Used for the determination of alcoholic cirrhosis
- Utilizes the values of serum bilirubin, INR (international normalized ratio), and serum creatinine
- Determines the probability of survival of patients with liver disease
MELD Score
Other Tests for Liver Function
High MELD score = what prognosis?
Poor (low survival)
These patients are given priority for transplantation
Other Tests for Liver Function
This index differentiates alcoholic cirrhosis from alcoholic hepatitis
PGA Index
PGA - Prothrombin Time, GGT, and Apo A1
Other Tests for Liver Function (PGA Index)
Alcoholic cirrhosis vs. Alcoholic hepatitis:
PT - prolonged
GGT - elevated
Apo A1 - decreased
Alcoholic cirrhosis
Other Tests for Liver Function (PGA Index)
Alcoholic cirrhosis vs. Alcoholic hepatitis:
PT - prolonged
GGT - elevated
Apo A1 - increased
Alcoholic hepatitis
Other Tests for Liver Function
This test involves the use of A1-antitrypsin, ceruloplasmin, and AFP
Plasma Proteins
AAT and Ceruloplasmin - for excretion
AFP - hepatocellular and testicular cancer
Other Tests for Liver Function (Autoimmune Markers)
Associated with primary biliary cirrhosis
Antimitochondrial Antibody (AMA)
Other Tests for Liver Function (Autoimmune Markers)
Associated with primary sclerosing cholangitis (destruction of the extra- and intrahepatic bile duct)
Antineutrophil Cytoplasmic Antibodies (p-ANCAs)
Other Tests for Liver Function (Autoimmune Markers)
A titer of > 1:80 is diagnostic of Type 1 Autoimmune Hepatitis
Antinuclear Antibody and Anti-Smooth Muscle Antibody
Other Tests for Liver Function (Autoimmune Markers)
Associated with Type 2 Autoimmune Hepatitis
Antibodies to Liver-Kidney Microsomal Antigen
What are the 4 other tests for liver function?
- MELD Score
- PGA Index
- Plasma Proteins
- Autoimmune Markers
