Liver Function Tests: Purpose, Procedure, and more

Liver function tests help determine the health of your liver by measuring the levels of proteins, liver enzymes, and bilirubin in your blood.

Also Known as : Liver Profile, Liver Function Tests, LFTs, Liver Panel, liver chemistries

Test Panel: Total Bilirubin, Conjagated Bilirubin, Unconjugated Bilirubin, ALT, AST, ALP, Total Protein, Albumin, Globulin, A/G ratio, GGT,

Why get Tested :

A liver function test is often recommended in the following situations:

LFT diagnose any kind of liver disease.
to check for damage from liver infections, such as hepatitis B and hepatitis C
LFT has done for follow up of the patient on treatment.
LFT is done in routine in patients on chemotherapy.
LFT may be advised in a patient with treatment on antituberculous treatment.

When to Get Tested :

if you already have a liver disease, to monitor the disease and how well a particular treatment is working
if you’re experiencing the symptoms of a liver disorder
if you have certain medical conditions such as high triglycerides, diabetes, high blood pressure, or anemia
if you drink alcohol heavily
if you have gallbladder disease

Sample Required :

It is done on the serum of the patient.
Heparinized plasma can be used.
A random sample can be taken.
The serum is stable for 3 days at 1 to 6 °C.

Precautions for Sample :

Avoid hemolysis.
For bilirubin, fasting sample is preferred.
Protect serum or plasma from the light.
Lipemia also falsely increased the value.

When LFTs Orderd :

A liver panel, or one or more of its components, may be ordered when someone is at risk for liver dysfunction. Some examples include:

People who take medications that may potentially damage the liver
Those who are alcoholics or heavy drinkers
Those who have a history of known or possible exposure to hepatitis viruses
Individuals whose families have a history of liver disease
People who are overweight, especially if they have diabetes and/or high blood pressure

A liver panel may be ordered when a person has signs and symptoms of liver disease; however, most people who have liver disease do not have any of these symptoms until the disease has been present for many years or is very severe. Some of these include:

Weakness, fatigue
Loss of appetite
Nausea, vomiting
Abdominal swelling and/or pain
Jaundice (yellowing of eyes or skin)
Dark urine, light-colored stool
Itching (pruritus)
Diarrhea

Usually no one single set of liver tests is used to make a diagnosis. Often, several liver panels will be ordered over a few days or weeks to help determine the cause of the liver disorder and evaluate its severity

What is Being Tested :

Theses tests are tested in Liver Function Tests (LFT’s) :

Normal Values

Test	Normal value
Total bilirubin	o.3 to 1.0 mg/dL Newborn : 1.0 to 12.0 mg/dL.
Conjugated bilirubin	0.1 to 0.3 mg/dL
Unconjugated bilirubin	0.1 to 0.8 mg/dL
Alkaline phosphatase	Adult = 30 to 120 units/L Child <2 years = 85 to 235 units/L 2 to 8 years = 65 to 210 units/L 9 to 15 years = 60 to 300 units/L 16 to 21 years = 30 to 200 units/L
SGOT (AST)	Adult = 0 to 35 units Elderly = values slightly higher than adult Newborn and infants = 15 to 60 units/L
SGPT (ALT)	Adult and child = 4 to 40 units/L Infants may be twice high as the adult value
Albumin	Adult = 3.5 to 5 g/dL Premature infants = 3 to 4.2 g/dL Newborn = 3.5 to 5.5 g/dL Infant = 4.4 to 5.4 g/dLChild = 4 to 5.9 g/dL
Total protein	6.4 to 8.3 g/dL
A/G ratio	0.8 to 2.0
Gamma-glutamyl transferase (γ-GT).	Adult >45 years = 8 to 38 units/L Female <45 years = 5 to 27 units/L Child like adult level Newborn = 5 times higher than adult level

What does the test result mean?

Type of liver condition or disease	Bilirubin	ALT and AST	ALP	Albumin	PT
Acute liver damage (due, for example, to infection, toxins or drugs, etc.)	Normal or increased usually after ALT and AST are already increased	Usually greatly increased (> 10 times); ALT is usually higher than AST	Normal or only moderately increased	Normal	Usually normal
Chronic forms of various liver disorders	Normal or increased	Mildly or moderately increased; ALT is persistently increased	Normal to slightly increased	Normal	Normal
Alcoholic Hepatitis	Normal or increased	AST is moderately increased, usually at least twice the level of ALT	Normal or moderately increased	Normal	Normal
Cirrhosis	May be increased but this usually occurs later in the disease	AST is usually higher than ALT but levels are usually lower than in alcoholic disease	Normal or increased	Normal or decreased	Usually prolonged
Bile duct obstruction, cholestasis	Normal or increased; increased in complete obstruction	Normal to moderately increased	Increased; often greater than 4 times what is normal	Usually normal but if the disease is chronic, levels may decrease	Usually normal
Cancer that has spread to the liver (metastasized)	Usually normal	Normal or slightly increased	Usually greatly increased	Normal	Normal
Cancer originating in the liver (hepatocellular carcinoma, HCC)	May be increased, especially if the disease has progressed	AST higher than ALT but levels lower than that seen in alcoholic disease	Normal or increased	Normal or decreased	Usually prolonged
Autoimmune	Normal or increased	Moderately increased; ALT usually higher than AST	Normal or slightly increased	Usually decreased	Normal

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