LIVER FUNCTION TESTS Flashcards
Liver is composed of 2 types of cells:
- Hepatocytes
- Kupffer Cells (Phagocytic)
To abolish liver tissue function, more than ___ of the liver must be destroyed
80%
Liver secretes plasma proteins, carbohydrates, lipids, lipoproteins, clotting factors, ketone bodies and enzymes
12g of albumin produced daily
Synthetic Function
Involved in metabolism of bilirubin
200g - 300g of bilirubin produced daily
Conjugation Function
Liver serves to protecy the body from potentially injurous substances absorbed from intestinal tract and toxic by-products of metabolism
Ammonia is converted to urea in liver
Detoxification and Drug metabolism
Excretion of bile involves the elimination of bile acids or salts, pigments, cholesterol
Excretory and Secretory Function
Storage site for all fat-soluble and water-soluble vitamins
Storage depot for glycogen
Storage Function
Important for assessing nutritional status and presence of severe disease involving liver, kidney and bone marrow
Total Protein
Transudates have a TP of
(<)3.0 g/dL
Exudates have a TP of:
(> 3.0 g/dL)
Total Protein is usually performed in serum, which has no __ and no ____
Fibrinogen
and Anticoagulant
Reference Method of TP
6.5-8.3 g/dL
Reference method but not routinely use
Based on measurement of the nitrogen content of protein
Serum treated with tungstic acid, forming protein-free filtrate
Kjedahl Method
Nitrogen content of proteins
15.1% to 16.8%
Reagent of Kjedahl Method
H2SO4
Sulfuric Acid
End product of Kjedahl Method
Ammonia
Most widely used method
Extensively used in clinical laboratories
Requires at least 2 peptide bonds and an alkaline medium to measure total protein
Biuret Method
Cupric ions complex the groups involved in the peptide bond forming a violet-colored chelate is ___ to the number of peptide bonds present and reflects the TP level at 545 nm
Proportional
Reagents of Biuret Method:
- Alkaline Copper Sulfate
- Rochelle Salt (NaK Tartrate)
- NaOH & Potassium Iodide
Highest Analytical Sensitivity
Oxidation of phenolic compounds such as tyrosine, tryptophan and histidine to give a deep blue color
Folin-Ciocalteu (Lowry) Method
Main reagent of Folin-Ciocalteu
Phosphotungstic-Molybdic Acid
Phenol Reagent
Color enhancer of Folin-Ciocalteu Method
Biuret reagent
Absorbance of proteins at 210 nm is due to absorbance of peptide bonds at specific wavelength
Proteins absorb light at 280 nm and at 210 nm
Ultraviolet Absorption Method
Migration of charged particles in an electric field
Serum Protein Electrophoresis
Fastest band
Most Anodal Protein
Albumin
2nd Fastest band
Includes:
> Glycoproteins
> AAT
> AAG (A1- Acid glycoprotein)
> TBG
Increases as a non specific response to inflammation
Alpha-1 Globulin
3rd Fastest band
Includes:
1. Haptoglobin
2. AMG (a2-Macroglobulin)
3. Ceruloplasmin
Alpha-2 Globulin
4th band
Includes:
1. Transferrin
2. Beta-lipoprotein
3. Hemopexin
4. Complement C3 and C4
Beta Globulin
5th band
Slowest band
Includes:
Immunoglobulin
CRP
Gamma-globulin
Gamma Spike
Multiple Myeloma
Beta-Gamma bridging
Hepatic Cirrhosis
A2-Globulin band spike
Nephrotic Syndrome
A1-Globulin Flat curve
Juvenile Cirrhosis or
AAT deficiency
Spikes of a1, a2, and B globulin bands
Inflammation
Presence of this protein causes “Blip” in late alpha-2 or early beta zone
Free Hemoglobin
Presence of small spikes in beta region is due to:
Iron Deficiency Anema
Transferrin
Alternative test to chemical analysis of serum total proteins
Based on measurement of refractive index of solutes in serum
Refractometry
Utilize Sulfosalicylic Acid or Trichloroacetic acid
Measurement depends on formation of a uniform fine ppt which scatters incident light in suspension (nephelometry) or block light (turbidimetry)
Turbidimetric and
Nephelometric Method
Globulins can be separated from albumin by salting-out procedures using sodium salts
Globulin is insoluble in water but not in dilute salt solution
Salt Fractionation
- Malignancy
- Multiple Myeloma
- Waldenstrom’s Macroglobulinemia
Increased TP