Functions of Liver	Liver Function Tests
Disease Markers	Disease Tests or Procedures
Biopsy	Liver ultrasound

Storing glycogen (fuel for the body) which is made from sugars.

Helping to process fats and proteins from digested food.

Making proteins that are essential for blood to clot (clotting factors)

Processing many medicines which you may take; helping to remove poisons and toxins from the body

The liver also makes bile. This is a greenish-yellow fluid which contains bile acids, bile pigments and waste products such as bilirubin. Liver cells pass bile into bile ducts inside the liver. The bile flows down these ducts into larger and larger ducts, eventually leading to the common bile duct. The gallbladder is like a 'cul-de-sac' reservoir of bile which comes off the common bile duct. After you eat, the gallbladder squeezes bile back into the common bile duct and down into the duodenum (the first part of the gut after the stomach). Bile in the gut helps to digest fats.

Liver Function Tests

As the liver performs it's various functions it makes a number of chemicals which pass into the bloodstream and bile. Various liver disorders alter the blood level of these chemicals. Some of these chemicals can be measured in a blood sample. Some tests which are commonly done on a blood sample are called 'LFTs' (liver function tests). These tests assess the general state of the liver and biliary system. LFTs are a group of blood tests that can help to show how well a person's liver is working.

LFTs	Acronym	Normal values	Utility
Total Protein	TP	60-80 g/L	The liver produces most of the plasma proteins in the body. So it makes sense to measure the amount of protein in the blood.
Albumin	Alb	g/L (38-55)	A major protein formed by the liver. It is the main constituent of total protein; the remaining fraction is called globulin. It is the major protein that circulates in the bloodstream. As it is made by the liver and secreted into the blood it is a sensitive marker and a valuable guide to the severity of liver disease. And chronic liver disease causes a decrease in the amount of albumin produced. Albumin levels are decreased in chronic liver disease, such as cirrhosis. It is also decreased in nephrotic syndrome, where it is lost through the urine.
Alanine transaminase	ALT	U/L (5 to 45)	Also called as Serum Glutamic Pyruvic Transaminase (SGPT). ALT is an enzyme present in hepatocytes (liver cells). When a cell is damaged, it leaks this enzyme into the blood, where it is measured. ALT rises dramatically in acute liver damage, such as viral hepatitis.All types of liver inflammation can cause raised ALT. Liver inflammation can be caused by fatty infiltration (see fatty liver) some drugs/medications, alcohol, liver and bile duct disease.
Aspartate aminotransferase	AST	U/L (5 to 45)	Also called as Serum Glutamic Oxaloacetic Transaminase (SGOT). This is a mitochondrial enzyme that is also present in heart, muscle, kidney and brain therefore it is less specific for liver disease. AST is similar to ALT in that it is another enzyme associated with liver parenchymal cells. It is raised in acute liver damage. It is also present in red cells and cardiac muscle. In many cases of liver inflammation, the ALT and AST activities are elevated roughly in a 1:1 ratio.
Alkaline Phospahte	AP	U/L (30 to 120)	It is an enzyme in the cells lining the biliary ducts of the liver. If there is an obstruction in the bile duct, e.g. gallstones, ALP levels in plasma will rise. ALP is also present in bone and placental tissue, so it is higher in growing children (as their bones are being remodelled).Conditions such as Primary Biliary Cirrhosis and Sclerosing Cholangitis will generally show a raised AP. Raised levels may also occur in cirrhosis and liver cancer.
Total bilirubin	TBIL	3 - 18 umol/L (0.174 - 1.04mg/dL)	Bilirubin is a breakdown product of heme (a part of hemoglobin in red blood cells), that results from the destruction of old red blood cells The liver is responsible for clearing this, excreting it out through bile into the intestine. Problems with the liver or blockage of the drainage of bile will cause increased levels of bilirubin, as will increased haemolysis of red cells.Bilirubin concentrations are elevated in the blood either by increased production, decreased uptake by the liver, decreased conjugation, decreased secretion from the liver or blockage of the bile ducts.In bile duct obstruction, or diseases of the bile ducts such as primary biliary cirrhosis or sclerosing cholangitis, the alkaline phosphatase and GGT activities are often elevated along with the direct bilirubin concentration.Direct bilirubin, or unconjugated bilirubin is often measured in tandem, especially if the total bilirubin level is elevated. Bilirubin is unconjugated before the liver modifies it for excretion. It is dangerous in babies, as it can pass the blood-brain barrier causing kernicterus.
Gamma glutamyl transpeptidase	GGT	U/L (5 to 35)	Although reasonably specific to the liver and a more sensitive marker for cholestatic damage than ALP, Gamma glutamyl transpeptidase (GGT) may be elevated with even minor, sub-clinical levels of liver dysfunction. It can also be helpful in identifying the cause of an isolated elevation in ALP. GGT is raised in alcohol toxicity (acute and chronic). GT is often elevated in those who usealcohol or other liver toxic substances to excess. GGT is also induced by many drugs, including alcohol, therefore often when the AP is normal a raised GGT can often (but not always) indicate alcohol use. Raised GGT can often be seen in cases of fatty liver and also where the patient consumes large amounts of Aspartame (artificial Sweetener) in diet drinks for example.
Platelet count			Platelets are cells that form the primary mechanism in blood clots. They're also the smallest of blood cells. They derived from the bone marrow from the larger cells known as megakaryocytes. Individuals with liver disease develop a large spleen. As this process occurs platelets are trapped with in the sinusoids (small pathways within the spleen) of the spleen. While the trapping of platelets is a normal function for the spleen, in liver disease it becomes exaggerated because of the enlarged spleen (splenomegaly). Subsequently, the platelet count may become diminished.
Prothrombin time	Clotting Studies	Seconds (11 to 13.5)	The prothrombin time is tested to evaluate disorders of blood clotting, usually bleeding. It is a broad screening test for many types of bleeding disorders. When the liver is damaged it may fail to produce blood clotting factors.
Lactate Dehydrogenase	LD	U/L (100-225)

Disease Markers

Disease Tests or Procedures

Biopsy

This is a procedure which involves using a special needle to remove tissue from the liver to be examined in the laboratory. This will be used to assess the extent of scarring, fatty infiltration or liver damage.

For the biopsy, you will lie on a hospital bed on your back or turned slightly to the left side, with your right hand above your head. After marking the outline of your liver and injecting a local anesthetic to numb the area, the physician will make a small incision in your right side near your rib cage, then insert the biopsy needle and retrieve a sample of liver tissue. In some cases, the physician may use an ultrasound image of the liver to help guide the needle to a specific spot.

It is still regarded as the most accurate way of assessing the status of the extent of damage to the liver. Firstly a blood sample will be taken to check your blood’s ability to clot. This is a routine precaution and is to ensure the liver biopsy can be performed safely with minimal risks. A local anaesthetic is administered prior to the liver biopsy procedure. This may be above the site of the liver (on your right side of your abdomen and below your ribs) or more likely between your lower ribs on your right side. In some cases a light sedative can be given if you require it, but discuss this with your doctor.

In some cases the liver biopsy can be done under ultrasound guidance so the liver can be seen and the biopsy directed by the imaging. You may already have had an ultrasound performed prior to the biopsy; it involves using a probe on your skin to pass sound waves through the skin - these are bounced back to provide an image of your internal organs. This procedure may be uncomfortable.

Liver biopsy is considered a minor surgery and is done at the hospital. However it should be noted that this procedure is not without risk – it is important that it is carried out by a very experienced Doctor. The risks include puncture of the lung or gallbladder, infection, bleeding, and pain. The bleeding in particular is a dangerous complication. It carries about a 1/10000 death rate.

The different types of Liver Biopsy are:

Needle biopsy

Usually, liver biopsies are performed by needle by making a small puncture in the skin. Patients are given a local anesthetic to numb the area where the needle will be inserted. This usually takes less than 10 minutes.

Laparoscopic biopsy

Sometimes, when several areas of the liver have to be biopsied or biopsy is needed from an area which cannot be accessed using ultrasonic guidance or the lesion very close to blood vessel is to be biopsied, laparoscopic biopsy may be performed. A laparoscope is a special tube that sends images to a monitor and contains surgical instruments. The tube is inserted through an incision in the patient's abdomen. The surgeon watches the monitor and uses the surgical instruments to remove the tissue samples.

Transjugular biopsy

In patients with blood clotting problem or with ascites, normal blind percutaneous needle biopsy can not be done due to fear of complications. "Transvenous biopsy" may be used in such situation. A biopsy is obtained by putting a biopsy needle through a neck vein.

Who should avoid biopsy?

People with blood clotting disorders

People who are on blood thinning medication such as Warfarin, Coumadins, Ibuprofin, aspirin

People with hemangiomas (benign liver cyst consisting of twisted congested blood vessels)

Liver ultrasound

The ultrasound is a procedure, which may be uncomfortable but can provide useful information. Ultrasounds are routine tests, but for a patient it may be a concerning or worrying time. This information sheet explains the procedure and aims to answer some questions you may have.

Alongwith the routine liver function tests and the biopsy, there would be a need to go for an ultrasound.
Your liver ultrasound will usually be performed in the X-ray department of the hospital, or in an outpatient’s clinic, day care department or on a ward. Normally the ultrasound of your liver is a procedure done by a doctor who is a radiologist.

The ultrasound should not be painful, but you may find it uncomfortable and it may take 10 – 15 minutes. If you have any questions about this ask your doctor when they arrange the appointment or while you are having the ultrasound.

You will be asked to uncover the top of the right half of your abdomen, (below your ribs) and lie on your back. Gel will be applied to your skin, which may feel slightly cold.

A probe, like a microphone, will be moved across your skin over your liver. The gel makes this easier and ensures the soundwaves are carried through your skin.

While the probe passes over your liver, soundwaves are directed through your skin and anything solid will bounce back as a picture via the probe. A picture based on the reflected soundwaves will be seen on a screen.

Once the procedure is done and the probe removed, the gel will be wiped off your skin. You will then be able to go home or onto an appointment if one is scheduled. If you are a hospital patient you will be advised if you are to stay or go home.

The machine will record the images (pictures) of your liver and a report will be made by a Radiologist. This report may be ready soon after your ultrasound, but it may take one to two weeks. You should have an appointment arranged to discuss the result with your specialist.

Sometimes the specialist will discuss the type of picture received from your liver ultrasound as being “echogenic”. This term means how well the liver shows up on the ultrasound (something a bit like being “photogenic”). The report will tell you and your specialist about the surface of the liver and the general shape of the liver, as well as if there are significant changes from the normal surface and shape. It will only highlight anomalies or abnormalities, but will not give you a detailed view of them.

An ultrasound of your liver is similar to flying over the area you live. You will get a good view of your house and the surroundings, (bird’s eye view) and gives a different look at something you thought you were quite familiar with. However, it will not necessarily give you as detailed a view as if you were walking around your house and examining the ground closely. This may mean a further test called a liver biopsy may be needed to definitely diagnose the liver disease.

If you have any concerns discuss your liver ultrasound with your doctor or nursing staff and make sure you have the answers you need to make an informed decision.