Liver Function Tests Flashcards
The chief metabolic organ
liver
Large organ divided unequally into 2 lobes by a ____
falciform ligament
functional unit of the liver
Lobules
2 major type of cells in liver
Hepatocytes
Kupffer cells
AKA hepatic macrophage
Kupffer cells
Produces majority of lobules
Hepatocytes
2 blood supply of liver
Hepatic artery
Portal vein
Supplies 25% of blood
hepatic artery
Supplies majority of blood (75%)
portal vein
blood produced by liver (____ mL/min)
1500
synthetic function secretes ____ (6)
plasma proteins, CHO, lipids, lipoproteins, ketone bodies, & enzymes
Its tests quantitates the severity of hepatic dysfunction
synthetic function
Assessment of nutritional status and presence of severe disease involving the liver, kidney and bone marrow
TP
sample of TP
serum
serum is preferred as sample for TP because plasma contains _____
fibrinogen and anticoagulant
Effect of fibrinogen to TP
increases total protein to 0.2-0.4 g/dL
Effect of anticoagulant to TP
decreases total protein due to dilutional effect
interference of TP
hemolysis, ictericia
serous fluid transudates
<3.0 g/dL
serous fluid exudates
> 3.0 g/dL
methods for TP
Kjeldahl Method
Biuret Method
Folin-Ciocalteu (Lowry) Method
UV Absorption Method
Refractometry
Turbidimetry and Nephelometry
Salt Fractionation
Coomasie Brilliant Blue Dye
Ninhydrin
Serum Protein Electrophoresis
In SPE, Width of the protein band in a particular fraction depends on the ______ in the fraction
concentration of protein
The acidic and basic amino acids content of proteins determines its net charge.
Isoelectric Property of Proteins
pH of SPE
8.6
Buffer for SPE
Barbital (Veronal)
When particles are large, they ____ in the point of origin
stay
The smaller the particle, the ____ its migration towards the anode
faster
Order of Normal SPE Pattern
albumin, a1 globulin, a2 globulin, b-globulin, y-globulin
Fastest band to migrate to the anode
albumin
albumin is ___ of TP
53-65%
a1 globulin is ___ of TP
2.5-5%
a2 globulin is ___ of TP
7-13%
b-globulin is ___ of TP
8-14%
y-globulin is ___ of TP
12-22%
Slowest band to migrate to the anode
y-globulin
multiple myeloma is AKA
Cancer of plasma cells or Monoclonal gammopathy
There is Increase of γ globulin (gamma spike)
multiple myeloma, hepatic cirrhosis
Plasma cells produces too many immunoglobulins
multiple myeloma
increased TP is seen in:
malignancy, multple myeloma, Waldenströms macroglobulinemia
decreased TP is seen in:
Hepatic cirrhosis
Glomerulonephritis
Nephrotic syndrome
Starvation
Formation of β-γ bridging and is connected by IgA
hepatic cirrhosis
in hepatic cirrhosis, SPE shows abnormality in __
albumin, b-globulin, y-globulin bands
Decrease albumin and a significant increase of α2-globin (______) and β-globulin fractions (________)
Nephrotic syndrome, α2 Macroglobulin & Haptoglobin, β lipoprotein & Complement
Seen in juvenile cirrhosis
a1 antitrypsin deficiency
Flat curve is observed in SPE
a1 antitrypsin deficiency
α1-Antitrypsin comprises ____ of the proteins found in the α1-globulin band
90%
Inflammatory pattern in SPE indicating an inflammatory condition is seen when:
Albumin is decreased
Increased α1 globulin band (AAG & AAT)
Increased α2 globulin band (Ceruloplasmin & Haptoglobin)
Increased β globulin band (CRP)
AKA acute phase reactant pattern
inflammation
Seen in conditions related to burns, infarction, trauma, malignancy, liver diseases
inflammation
Concentration is inversely proportional to the severity of hepatic disease.
albumin
Albumin declines when severe liver disease lasts for more than
3 wks
Can be measured directly based on its dye-binding property
albumin
In salt preparation, Globulins are precipitated because it is ____ in water but not in dilute salt solution
insoluble
In salt preparation, Albumin is ____ in water and not in saturated salt solution
soluble
Albumin in supernatant is quantitated by
biuret reaction
reagent of salt preparation
Sodium sulfate salts
Nonspecific for Albumin
methyl orange
Many Interferences (_____)
2,4’- hydroxyazobenzene- benzoic acid (НАВА) // Salicylates, Bilirubin, Aspirin, Penicillin, Sulfonamides
More specific to Albumin than Methyl Orange
2,4’- hydroxyazobenzene- benzoic acid (НАВА)
Sensitive & Overestimates low albumin levels
Bromcresol green
Specific, Sensitive and Precise
Bromcresol purple
Most commonly used dye
Bromcresol green
seen in hyperalbuminemia
Severe dehydration
Prolonged tourniquet application
Causes pseudohyperalbuminemia due to poor specimen collection.
Prolonged tourniquet application
Albumin becomes concentrated due to low fluid level
Severe dehydration
seen in hypoalbuminemia
Reduced synthesis
Increased catabolism
Increased loss
Hereditary absence of albumin
Analbuminuria
Seen in chronic liver disease, malabsorption syndrome, malnutrition, muscle wasting disease
Reduced synthesis
Seen in massive burns, widespread malignancy, thyrotoxicosis
increased catabolism
Due to inability of glomerulus to restrict the passage of proteins from the blood
increased loss
Nephrotic syndrome (___ g/day)
20-30
Presence of two albumin bands instead of a single band in electrophoresis
bisalbuminemia
Associated with excess amount of therapeutic drugs in serum
bisalbuminemia
Used to validate if globulin is higher than albumin
a/g ratio
Inverted A/G ratio:
If globulin > albumin
Globulin is elevated in ___ which will balance the loss of albumin and will result to normal levels of protein
early cirrhosis
Vitamin K is administered _____ ( ___days; ___mg)
intramuscularly, 1-3, 10
It differentiates intrahepatic disorder (PT is ____) from extrahepatic disorder (PT is ____)
Vit. K Response test, prolonged, normal
_____ after Vit. K administration indicates loss of hepatic capacity to synthesize proteins
Prolonged PT
Involves the metabolism of Bilirubin
CONJUGATION AND EXCRETION FUNCTION
prolonged prothrombin time signifies massive cellular damage.
Acute/Chronic Hepatitis
Approximately ___ of BIlirubin is conjugated per day
200-300mg
End product of hemoglobin metabolism
BILIRUBIN
Principal pigment in bile
BILIRUBIN
Formed from the destruction of heme-containing proteins (myoglobin) and catalase & cytochrome oxidase
BILIRUBIN
Unconjugated Bilirubin / Indirect Bilirubin
BILIRUBIN 1
Water insoluble type of bilirubin
BILIRUBIN 1
Non-polar Bilirubin
BILIRUBIN 1
Hemobilirubin
BILIRUBIN 1
Slow reacting type of bilirubin
BILIRUBIN 1
Prehepatic Bilirubin
BILIRUBIN 1
Conjugated Bilirubin / Direct Bilirubin
BILIRUBIN 2
Water soluble type of bilirubin
BILIRUBIN 2
Polar Bilirubin
BILIRUBIN 2
Cholebilirubin
BILIRUBIN 2
One-minutes / Prompt Bilirubin
BILIRUBIN 2
Post-hepatic / Hepatic / Obstructive / Regurgitative Bilirubin
BILIRUBIN 2
R.R of Bilirubin 1
0.2-0.8 mg/dL
R.R of Bilirubin 2
0-0.2 mg/dL
In Bilirubin pathway, The heme portion in the presence of _____ will be converted to ________.
heme oxygenase, biliverdin
In Bilirubin pathway, Biliverdin will be converted to _____ in the presence of _______.
Bilirubin 1, biliverdin reductase
In Bilirubin pathway, The process of converting heme to indirect bilirubin takes
2-3 hrs
In Bilirubin pathway, Bilirubin is bound by _____ and transported to the liver.
albumin
In Bilirubin pathway, Once at the liver cell, unconjugated bilirubin is released from albumin so it can be picked up by a carrier protein called __
ligandin
In Bilirubin pathway, ____ is responsible for transporting unconjugated bilirubin to the endoplasmic reticulum, where the conjugation (esterification) of bilirubin occurs in the presence of the enzyme ________
ligandin, uridyldiphosphate glucuronyl transferase
In Bilirubin pathway, ___ work on conjugated bilirubin to produce mesobilirubin, which is reduced to form mesobilirubinogen and then urobilinogen
Intestinal bacteria
In Bilirubin pathway, Most of the urobilinogen formed (roughly ____) is oxidized to an ______-colored product called ____ and is secreted in the ____
80%, orange, urobilin, feces
In Bilirubin pathway, For the remaining 20% urobilinogen, majority will be absorbed by _____ to be recycled through the liver and reexcreted.
extrahepatic circulation
In Bilirubin pathway, Almost all the bilirubin formed is eliminated in the _____, and a small amount of urobilinogen is excreted in the ____.
feces, urine
In Bilirubin pathway, The healthy adult has very low levels of total bilirubin (_________) in the serum, and of this amount, the majority is in the ________ form.
0.2 to 1.0 mg/dL, unconjugated
Conjugated bilirubin bounded to albumin
Delta bilirubin
Has longer half-life than other forms of bilirubin
Delta bilirubin
Formed due to prolonged elevation of conjugated bilirubin in biliary obstruction
Delta bilirubin
Helps in monitoring the decline of serum bilirubin following cholecystectomy
Delta bilirubin
It reacts with diazo reagent
Delta bilirubin
AKA Hyperbilirubinemia or Icterus
jaundice
Computed: Delta bilirubin =
TB – DB + IB
Not calculated on neonatal patients (_____)
Delta bilirubin, ≤14 days
Yellow discoloration of the skin, sclera of the eyes, and mucous membrane
Jaundice
Bilirubin ______ / Normal: _____
> 2.0 mg/dL, 3.0-5.0 mg/dL
AKA Hemolytic jaundice or Unconjugated hyperbilirubinemia
PRE HEPATIC JAUNDICE
Caused by too much red blood cell destruction
PRE HEPATIC JAUNDICE
Seen in HDN, Hemolytic anemia, Hemolytic transfusion reaction, Malaria
PRE HEPATIC JAUNDICE
When indirect bilirubin cross the BBB it causes ______
Kernicterus
Bilirubin deposition in the brain which causes severe motor dysfunction and retardation
Kernicterus
Lab findings of PRE HEPATIC JAUNDICE
Indirect Bilirubin: increased
Direct Bilirubin: normal
Urobilinogen: normal
Urine bilirubin: Negative
AKA Obstructive jaundice
POST HEPATIC JAUNDICE
Failure of bile to flow to the intestine (impaired bile excretion)
POST HEPATIC JAUNDICE
Laboratory diagnosis of POST HEPATIC JAUNDICE
Indirect bilirubin: normal
Direct bilirubin: increased
Urobilinogen: decreased
Urine bilirubin: positive
Alkaline phosphatase: increased
1 marker of post-hepatic jaundice
Alkaline phosphatase
AKA Hepatocellular combined jaundice
HEPATIC JAUNDICE
Bilirubin Transport Deficit
GILBERT’S SYNDROME
Caused by disorders of bilirubin metabolism, transport defects, hepatocyte injury caused by viruses, parasites, or excessive alcohol intake
HEPATIC JAUNDICE
Characterized by impaired cellular uptake of bilirubin due to genetic mutation in ____ gene (seen in chromosome 2)
UGT1A1, GILBERT’S SYNDROME
Laboratory findings of HEPATIC JAUNDICE
Indirect bilirubin: increased
Direct bilirubin: increased
Urobilinogen: decreased
Urine bilirubin: positive
Affected individuals may have no symptoms but may have mild icterus and predisposed acetaminophen toxicity.
GILBERT’S SYNDROME
Conjugation deficit
Crigler-Najjar Syndrome
Referred to as Chronic non-hemolytic unconjugated hyperbilirubinemia
Crigler-Najjar Syndrome
Treatment of CRIGLER-NAJJAR SYNDROME
phototherapy
Laboratory result of CRIGLER-NAJJAR SYNDROME
elevated indirect bilirubin
Complete deficiency of UDPGT
Crigler-Najjar Syndrome Type 1
Symptoms of Crigler-Najjar Syndrome Type 1
kernicterus, colorless bile
Laboratory result of Crigler-Najjar Syndrome Type 1
Indirect bilirubin: >25 mg/dL
Direct bilirubin: none
Partial deficiency of UDPGT
Crigler-Najjar Syndrome Type 2
Laboratory results of Crigler-Najjar Syndrome Type 2
Indirect bilirubin: 5-20 mg/dL
Only small amount of direct bilirubin is produced.
Crigler-Najjar Syndrome Type 2
Bilirubin Excretion Deficit
DUBIN-JOHNSON SYNDROME
Defective excretion of bilirubin into the canaliculi caused by hepatocyte membrane defect
DUBIN-JOHNSON SYNDROME
Characterized by intense dark pigmentation of the liver (Black liver) due to accumulation of _____
DUBIN-JOHNSON SYNDROME, lipofuscin
similar with Dubin-Johnson Syndrome without the “black liver” and cause is unknown
Rotor Syndrome
Familial form of unconjugated hyperbilirubinemia caused by a circulating inhibitor of bilirubin conjugation
LUCEY-DRISCOLL SYNDROME
UDPGT is inhibited
LUCEY-DRISCOLL SYNDROME
lab findings of LUCEY-DRISCOLL SYNDROME
Indirect bilirubin: increased (2-3 weeks of life)
Principle of BILIRUBIN ASSAY
Van den Berg Reaction
In Bilirubin assay, Only ____ are measured
TB and DB
diazotization of bilirubin to form azobilirubin
Van den Berg Reaction
Result is mathematically derived based on the result of TB and DB (IB = TB - DB)
Evelyn and Malloy Method
Coupling accelerator: ____
Final result: ______
Methanol, Pink to purple azobilirubin
Jendrassik and Grof Method
Coupling accelerator: ______
Final reaction: ______
Caffeine sodium benzoate, Pink to blue azobilirubin
More sensitive than Evelyn and Malloy Method
Jendrassik and Grof Method
Popular technique for discrete analyzers
Jendrassik and Grof Method
Test for hepatocellular function and potency of bile duct
BROMSULFONTHALEIN (BSP) DYE EXCRETION TEST
Rarely used, requires administration of bromsulfonthalein dye
BROMSULFONTHALEIN (BSP) DYE EXCRETION TEST
In BSP Dye Excretion test, it is also called Double collection method
Rosenthal White Method
In BSP Dye Excretion test, it is also called Single collection method
Mac Donald Method
BSP Dose of Rosenthal White Method
2mg/Kg body weight
BSP Dose of Mac Donald Method
5 mg/Kg body weight
Specimen collection of Rosenthal White Method
5 minutes after BSP administration
30 minutes after BSP administration
Specimen collection of Mac Donald Method
after 45 minutes
Reference value of Rosenthal White Method
After 5 minutes: 50% dye retention
After 30 minutes: 0% dye retention
Reference value of Mac Donald Method
After 45 minutes: +/- 5% dye retention
Liver protects the body from potentially toxic substances which are absorbed from the intestine and toxic metabolic byproducts (ammonia)
DETOXIFICATION AND DRUG METABOLISM
Used to assess the extent of liver damage
ENZYME TESTS
Normally found intracellularly
ENZYME TESTS
Any injury to the liver that results in cytolysis and necrosis causes the liberation of various hepatic enzymes
ENZYME TESTS
Often the only indication of cell injury in early or localized liver disease
ENZYME TESTS
Used to differentiate hepatocellular (functional) from the obstructive (mechanical) disease
ENZYME TESTS
Diagnostic marker of hepatic failure
ammonia
Hepatic enzymes:
Alanine aminotransferase (ALT)
Aspartate aminotransferase (AST)
5’ Nucleotidase
Gamma glutamyl transferase
Lactate dehydrogenase
Ornithine Carbamoyl Transferase
Produced by the catabolism of amino acids and by bacterial metabolism in the intestine.
ammonia
Also released from metabolic reactions in the skeletal muscle
ammonia
In severe liver disorder, ammonia will circulate in the blood which is converted to______in the brain
Neurotoxic
glutamine
Not useful for renal studies
ammonia
preferred specimen for ammonia
arterial blood
smoking is increased by ___
100-200 ug/L/cigar
common methods of ammonia
Berthelot & Glutamate Dehydrogenase
uses Kjeldahl Method
digestion method
Nitrogen ion in a protein-free filtrate of the specimen is converted to ammonia using hot concentrated sulfuric acid in the presence of catalyst
digestion method
Catalyst of digestion method
copper sulfate, mercury, and selenium
In DIRECT COLORIMETRIC METHOD, Reaction is facilitated by ______
gum ghatti
Amount of nitrogen will determine the color of the end product
DIRECT COLORIMETRIC METHOD
Yellow end-color: N2 (___)
low to moderate
Orange-brown end-color: N2_____
high
Decrease in absorbance at 340nm as NADPH is consumed (oxidized)
GLUTAMATE DEHYDROGENASE METHOD
Excretion of bile involves elimination of bile acids (salt pigments, cholesterol)
EXCRETORY AND SECRETORY FUNCTION
Facilitated by glutamate dehydrogenase
GLUTAMATE DEHYDROGENASE METHOD
Liver is the storage site for all fat & water soluble vitamins and glycogen
STORAGE FUNCTION
