What are the components of the Liver Function Profile?
- Total bilirubin
- Direct bilirubin
- Indirect bilirubin (calculated)
- Alanine aminotransferase (ALT)
- Aspartate aminotransferase (AST)
- Alkaline phosphatase (ALP)
- Total protein
- Albumin
These components are essential for assessing liver function.
What is the principle of the Direct Bilirubin Method?
Conjugated bilirubin reacts with diazo reagent to produce azobilirubin (purple chromogen)
This method involves measuring absorbance at specific wavelengths.
What reagents are used in the Direct Bilirubin Method?
- Sulfanilic acid
- Na nitrite
These reagents diazotize sulfanilic acid for the measurement process.
What is the absorbance measurement for purple azobilirubin?
554 nm
If alkaline tartrate is added, the measurement changes to 600 nm.
What is the Jendrassik-Grof Method used for?
Total bilirubin measurement
This method converts unconjugated bilirubin to a water-soluble form.
What are the reagents used in the Jendrassik-Grof Method?
- Solubilizer
- Caffeine
- Na benzoate
- Sulfanilic acid
- Na nitrite
These reagents help in the conversion process for total bilirubin measurement.
What is the reference interval for Total Bilirubin?
0.2-1.0 mg/dL
This range is important for assessing liver function.
What is the clinical significance of Alanine Aminotransferase (ALT)?
- Sensitive index of liver damage
- Parenchymal liver diseases
- Viral hepatitis
- Alcoholic hepatitis
- Nonalcoholic fatty liver disease
ALT is primarily sourced from the liver and is affected by few nonhepatic conditions.
What is the upper limit of normal (ULN) for ALT in males?
59 U/L
The ULN for females is 41 U/L.
What is the function of Aspartate Aminotransferase (AST)?
Catalyze interconversion of amino acids to 2-oxoglutarate by transfer of amino groups
This enzyme is found in all body tissues.
What is the ULN for AST?
35 U/L
AST is significant in diagnosing liver disease and myocardial infarction.
What is the clinical significance of Alkaline Phosphatase (ALP)?
- Biliary tract obstruction
- Paget disease
- Rickets
- Pregnancy
ALP levels can indicate various conditions related to liver and bone health.
What is the reference interval for ALP?
33-98 U/L
This range is crucial for evaluating liver and bone health.
What is the function of Gamma Glutamyltransferase (GGT)?
Catalyze transfer of the gamma-glutamyl group from peptides to an acceptor
GGT is significant in assessing hepatobiliary disease.
What is the ULN for GGT in males?
70 U/L
The ULN for females is 40 U/L.
What are the specimen collection requirements for GGT?
- Serum or EDTA plasma
- Stable ~ 1 month at 4°C
- No hemolysis
Certain anticoagulants are not acceptable for GGT testing.
Direct Bilirubin method
Only conjugated bilirubin, which is water-soluble.
Jendrassik–Grof method
Total bilirubin (conjugated + unconjugated) after solubilizing unconjugated bilirubin with caffeine–benzoate.
Solubilizer used in the Jendrassik–Grof method
Caffeine–sodium benzoate.
Solubilizer used in the Evelyn–Malloy method
Methanol.
Difference between Jendrassik–Grof and Evelyn–Malloy method
Jendrassik–Grof uses caffeine–benzoate for better stability and less protein interference; Evelyn–Malloy uses methanol, which causes more interference.
Why must bilirubin specimens be protected from light?
Bilirubin is photosensitive; light exposure causes degradation and falsely low results.
Enzyme most specific for liver disease
ALT (Alanine aminotransferase).
Enzyme significantly elevated in cholestasis
ALP (Alkaline phosphatase).
