Liver Function Flashcards
Chief metabolic organ in the body. And is composed of three systems
Liver
Hepatocytic, hepatobiliary, and reticuloendothelial
To eliminate toxins such as alcohol, what are the two enzymes are essential in the pathway?
Alcohol dehydrogenase
Acetaldehyde dehydrogenase
Primary liver parenchymal cells and play complicated roles in fibrosis and cirrhosis. It represents 80% of the volume of the liver and is responsible for regenerative property.
Hepatocyte
Has the phagocytic role, engulfing organisms and toxins
Kupfer cell
What does liver secretes?
plasma proteins, carbohydrates, ketone bodies, lipids, lipoproteins, clotting factors, enzymes and xenobiotics
The normal liver produces how many g or albumin daily?
12grams
How many mg of bilirubin is produced daily in the healthy adult?
200 to 300mg
Ammonia is converted to what in the liver?
Urea
Bile acids (cholic acid and chenodeoxycholic acid are conjugated with amino acids _______ to form bile salts
glycine and taurine
routine markers for the measurement of hepatic synthetic function
total protein, albumin, globulin and albumin/globulin ratio
secondary for the measurement of hepatic synthetic function
prothrombin time
plasma levels of tp is _____ higher than serum due to fibrinogen
0.2 - 0.4 g/dL
In measuring total protein, is fasting required?
naur
Reference range for total protein?
6.5 - 8.3 g/dL
It is the reference method for total protein measurement but not routinely used
Kjeldahl method
Kjeldahl method is based on the measurement of_______ of protein. It uses serum samples treated with ___ forming protein free filtrate.
nitrogen content; 15.1 to 16.8%
tungstic acid
1 grams of nitrogen is equivalent to?
6.54 g of proteins
What is the reagent and end product in Kjeldahl method?
sulfuric acid (digesting agent)
ammonia
Widely used method for tp measurement and recommended by the IFCC. Explain the principle
Biuret Method
Cupric ions form a complex with peptide bond, forming a violet-colored chelate which is proportional to the number of peptide bonds present and reflect the total protein level (545 nm)
It influences the Biuret method, causing falsely elevated total protein
hemolysis
ictericia
What is/are the reagents and reference range for biuret method?
Alkaline copper sulfate, Rochelle salt (NaK Tartrate), NaOH, Potassium Iodide
6.5 - 8.3 g/dL
It has the highest analytical sensitivity. Reagents used are phosphotungstic-molybdic acid or phenol reagent
Folin-Ciocalteu Method
Turbidimetric and nephelometric utilizes what acids?
sulfosalicylic acid and trichloroacetic acid
proteins absorbs light at?
210nm - due to absorbance of peptide bonds
280nm - due to tyrosine, tryptophan and phenylalanine
It is preferred in detecting such as the M-spike in multiple myeloma. Has higher analytical sensitivity compared to conventional electrophoresis since it can measure small abnormalities such as ___ in hepatic cirrhosis
Immunofixation electrophoresis
beta-gamma bridging
T or F. Globulin is insoluble in water but not in dilute salt solution
True
T or F. Albumin is insoluble in water and concentrated salt solution
False
What is the principles of SPE?
migration of charged particles in an electrical field
What are the major proteins that contribute to electrophoreis?
albumin, a-1 antitrypsin, a-2 macroglobulin, haptoglobin, b-lipoprotein, transferrin, immunoglobulin, fibrinogen, complement C3
what is the protein that increases as non specific response to inflammation?
a-1 globulin
Normal SPE pattern
- Albumin (1st) - fastest band
- Alpha 1- globulin (2nd) - glycoproteins, AAT, AAG, thyroxine binding-globulin
- Alpha 2-globulin - (3rd) - haptoglobin, AMG, ceruloplasmin
- Beta-globulin (4th) - transferrin, b-lipo, hemopexin, C3 and C4
- Gamma-globulin (5th); slowest - immunoglobulin and CRP
- g- spike - ?
- b-g-bridging - ?
- a2 globulin band spike - ?
- a1 globulin flat curve- ?
- a1, a2, and B-globulin bands - ?
- multiple myeloma
- hepatic cirrhosis
- nephrotic syndrome
- juvenile cirrhosis (AAT deficiency)
- inflammation
the presence of small spikes in the beta region is due to?
iron deficiency (tranferrin)
It is for the detection of proteins to as little as 1ug
Coomassie brilliant blue dye
It is for the detection of amino acid and peptide bond after paper chromatography
Ninhydrin
amino acid - ion-exchange columns
thin-layer chromatography - drugs
eme
Increased total protein
malignancy
multiple myeloma
waldenstrom’s macroglobulinemia
Decreased total protein
hepatic cirrhosis
glomerulonephritis
nephrotic syndrome
starvation
The concentration of this protein is inversely proportional to the severity of the liver disease. What is the rf?
Albumin
3.5-5.0 g/dL
In Albumin, what is the
1. most commonly used method?
2. most specific method?
- Bromcresol green
- Bromcresol purple
what are the methods in albumin?
- Bromcresol green
- Bromcresol purple
- Hydroxyazobenzene Benzoic Acid
- Methyl Orange
Affected by the presence of penicillin leading to false decrease of albumin
BCG
Are not significantly affected by hemolyzed samples. Are cationic dyes and free form interference from bilirubin
BCG and BCP
Influenced by hyperbilirubinemia
HABA
Formula of globulin
Total protein - Albumin
Inverted A/G ration
cirrhosis
multiple myeloma
waldenstrom’s macroglobulinemia
hereditary absence of albumin
analbuminemia
presence of two albumin bands and is associated with excess amounts of therapeutic drugs in serum
bisalbuminemia
presence of two band and is due to lack of amino acids in an individual’s diet
Kwashiorkor
Differentiates intrahepatic disorders and extrahepatic obstructive liver disease. And is administered intramuscularly 10mg daily for 1-3 days
Prothrombin Time (Vitamin K response test)
End product of hemoglobin metabolism and principle pigment of bile.
Bilirubin
- it is formed from the destruction of heme-containing proteins (myoglobin, catalase, and cytochrome oxidase)
- Actual site of conjugation?
- Major sites of deconjugation?
- Smooth Endoplasmic Reticulum
- Ileum and the early segment of colon
oxidized form of urobilinogen which imparts stool its color
stercobilinogen or urobilin
responsible for the color of urine
urobilin
The colorless end-product of bilirubin metabolism that is oxidized to the brown pigment urobilin
UROBILINOGEN
It is the conjugated bilirubin tightly bound to albumin. Also reacts with diazo reagent
Delta-Bilirubin
Half-life of Delta-Bilirubin
12-14 days
Formula of d-bilirubin
TB - DB + IB
The plasma concentration of bilirubin increases upon birth and reaches its peak on the?
5th day
T or F. If the rate of bilirubin formation exceeds the rate of liver clearance, there will be a rise in the bilirubin level in serum.
True
Also called as icterus or hyperbilirubinemia. Characterized by yellow discoloration and clinically evident when level exceeds 3mg/dL
Jaundice
Serum Bilirubin: elevated B1
Urine Bilirubin: Negative
Urine Urobilinogen: Normal/Increased
Pre-hepatic Jaundice/Hemolytic Jaundice
- too much destruction of red blood cells
Serum Bilirubin: elevated B2
Urine Bilirubin: Positive
Urine Urobilinogen: Decreased/Undetectable
Post hepatic Jaundice/Obstructive Jaundice
-failure of bile to flow or reach the intestine
Serum Bilirubin: elevated B1 and B2
Urine Bilirubin: Positive
Urine Urobilinogen: Decreased/Undetectable
Hepatocellular Combined Jaundice/Hepatic Jaundice
- caused by viruses, alcohol and parasites
cirrhosis, viral hepatitis, toxic hepatitis and fascioliasis
Hepatocellular Combined Jaundice/Hepatic Jaundice
cholelithiasis, bilateral pancreatic tumor and colon parasitism
Post hepatic Jaundice/Obstructive Jaundice
Malaria, hemolytic anemia, and hemolytic disease of the newborn
Pre-hepatic Jaundice/Hemolytic Jaundice
Impaired cellular uptake of bilirubin. It is characterized by a molecular defect (UGT1A1) insertion of two bases.
Gilbert’s Syndrome/ Bilirubin Transport Deficit
Characterized by the absence of UDPGT. Multiple mutation with UGT1A1 gene. Is common among infants and treated with phototherapy.
Crigler-Najjar Syndrome/ Conjugation Deficit Syndrome
Absolute deficiency of the enzyme UDPGT
Total absence of B2 production
(+) kernicterus
Type I Crigler-Najjar Syndrome
Partial deficiency of UDPGT
Small amount of B2 is produced
Type II Crigler-Najjar Syndrome
Associated with the blockade of the excretion of bilirubin caused by a hepatocyte membrane defect. Deficiency of Multi-drug resistant (MDR2)/ Multi-specific
Organic Anionic Transporter protein (cMOAT)
Dubin-Johnson Syndrome/Bilirubin Excretion Deficit
Familial form of unconjugated hyperbilirubinemia and may be caused by circulating inhibitor of bilirubin conjugation
Lucey-Driscoll Syndrome/Conjugation Inhibitor syndrome
An autosomal recessive disease. Mutations in SLCO1B1 and SLCO1B3 gene
Rotor Syndrome/Mixed Hyperbilirubinemia
due to immature blood brain barrier among infants
Kernicterus
T or F. Visible icterisia occurs when bilirubin is <25mg/L
true
Principle of Bilirubin Assay
Van den Bergh reaction is the diazotization of bilirubin to produce azobilirubin
Explain Evelyn and Malloy Method
Accelerator: Methanol
Diazo Reagents
o Diazo A = 0.1% Sulfanilic Acid + HCl
o Diazo B = 0.5% Sodium Nitrite
o Diazo Blank = 1.5% HCl
Required pH: 1.2
End Color:
Pink to purple azobilirubin at 560 nm
Most commonly used method for Bilirubin Assay and is popular for the discreet analyzers.
JENDRASSIK-GROF METHOD
Modification of Malloy and Evelyn
Two Aliquots of Sample
-Reacting one aliquot with the diazo reagent only
(sulfanilic acid in hydrochloric acid and sodium
nitrite)
-Other aliquot with the diazo reagent and an
Accelerator (caffeine sodium-benzoate)
Reaction is terminated by the addition of ascorbic acid
Buffer used: Sodium Acetate
End Color: blue at 600nm
T or F. Bilirubin absorbs light maximally at 450nm and imparts a yellow color to amniotic fluid
true
Increased B1
- Gilbert’s Syndrome
- Crigler-Najjar Syndrome
- Hemolytic Anemia
- Hepatocellular disease
- Lucey Driscoll Syndrome
- G-6-PD deficiency
Decreased B2
- gall stones
- Pancreatic (head cancer)
- Dubin-Johnson syndrome
- Alcohol and viral hepatitis
- Biliary atresia
- Hepatocellular disease
- Septicemia
- Rotor syndrome
Colorless end product of bilirubin metabolism
Urobilinogen
absence of urobilinogen denotes what?
complete bile obstruction
what is the method use and reagent in urobilinogen?
Ehrlich’s method
p-dimethyl aminobenzaldehyde reagent
Test for hepatocellular function and potency of bile duct. It determines the ability of protein albumin to transport the exogenous dye to the liver
Bromsulphthalein Dye Excretion Test
enzymes that are increased in drug and alcohol hepatoxicity
ALT and AST
Smallest NPN. Marker for hepatic failure and Reye’s syndrome
Ammonia
preferred spx for ammonia
sample requirement
common method used
major interference
- arterial blood
- heparin/EDTA
- Glutamate Dehydrogenase (340nm)
- hemoglobin
End color if the Nitrogen content sample is low to moderate? If high?
If low, yellow. If high, brown.
