Always follow your local guidelines and seek specialist advice. This lecture is only intended as a brief overview.
It can be scary for patients to hear their liver function is abnormal, however the true liver synthetic function tests are INR, albumin and bilirubin, all of which can be abnormal even when the liver is normal. The INR can be elevated due to warfarin, low albumin due to other illness, malnutrition or proteinuria and bilirubin due to gilberts disease or haemolysis.
After looking at liver synthetic function, you need to determine if the abnormal LFTs are predominantly due to a problem with the liver cells or with the bile ducts. Hepatocellular dysfunction can be seen with raised ALT which is an enzyme that is released into the blood stream with liver cell damage. Obstruction or inflammation in the bile ducts causes an increase in alkaline phosphatase and GGT. Bile duct obstruction, cirrhosis, gilberts disease or haemolysis can cause jaundice, an elevation in bilirubin.
Approach to liver function test:
- Determine true liver synthetic function (INR, albumin and bilirubin)
- Is there liver dysfunction with raised ALT (hepatocellular LFT’s)
- Is there biliary dysfunction with raised Alkaline Phosphatase or GGT. (cholestatic LFTs)
- If ALT, Alk Phos and GGT are elevated determine if one picture is more dominant or whether there is a “mixed LFT” picture.
Examples of types of LFTs pictures
Causes of deranged LFTs
Next determine how severe the abnormality is. A detailed overview can be found on https://livertox.nih.gov/Severity.html . In general:
Next determine if this is a new abnormality, like a drug reaction or a long standing like fatty liver disease. Mildly deranged LFTs could be observed and repeated after risk factors are addressed, such as losing weight or reducing alcohol intake. There are many over the counter herbs and supplements that can cause liver damage and patients often do not mention taking these. It is important to specifically ask about herbs, supplements or weight loss products (particularly products with added green tea boosters can damage the liver)
A liver ultrasound can exclude gall stone disease and fatty liver disease, although ultrasound can be very unreliable to determine fibrosis/cirrhosis. The best test to assess for liver cirrhosis is a “fibroscan”, which is non-invasive, does not require needles and does not hurt. It sends a small shockwave (feels like a flick with a finger on your skin) through the liver and measures how much the liver vibrates. This fibroscan can be requested through WDHB.
Treatment depends on the severity and underlying cause. Feel free to contact me to discuss if you have any questions or patients you are concerned about.