Top Lab Tests for the Liver

Most of us have spent time staring at those numbers from our blood work. When trying to understand the comprehensive metabolic panel, or CMP, it’s good to have a general idea of what the top lab tests for the liver are, and what they mean. Even 8 years after my diagnosis, I still end up confused. For one thing, they don’t always print what is “normal” and that means a trip to the internet. I think everyone should keep track, even after SVR (sustained virologic response), or clearing hep C. Here's some help for understanding your blood labs.

What are the top tests for the liver?

AST (aspartate transaminase)

Small amounts of this enzyme are always in our blood system. They hang out with our red blood cells. They are found in many places including muscles, heart, and kidneys. They are especially found in the liver. Our doctor looks for high levels of AST circulating in our bloodstream. If our blood sample shows a high concentration, it means that our liver is having a hard time and signals damage.

ALT (alanine transaminase)

This is another enzyme that is found mostly in your liver. Like with AST, when it is elevated in your blood stream, it’s a cry for help. Damage is being done. Tissue is in trouble.

Alkaline Phosphatase

Alkaline phosphatase is a molecule that lives in and around your bile ducts, which are tubes that connect your liver to your gallbladder. A higher level of this enzyme means that there is trouble in the connections around your gallbladder. Either something is not draining right, or there is inflammation - perhaps from the Hepatitis C Virus.

Bilirubin

This yellowish color gets into your bloodstream when our red blood cells are not processing waste. If our liver can’t break down protein, this yellowish liquid is released in the skin, causing jaundice.

Albumin

This protein is produced by the liver. If our liver is not healthy, it can’t produce enough, then the levels get too low. It’s an indication of damage and can effect water flow through our body. In turn, medicine and hormones need water to travel throughout your body in order for our tissue to growth healthy and heal.

Globulin

This group of proteins are also produced by your liver and immune system. Like Albumin, they carry nutrients to your body. They also help us to build antibodies to fight illness and help in the blood clotting process.

Total Protein

Doctor like to see the ratio of albumin to globulin, with albumin being the highest in proportion. They use a math formal and if the levels are too high, it’s usually because of hepatitis C, cancer, or other conditions. If it is too low, there is a probably a problem with nutrition. It can also be part of inflammation in the liver for Hep C.

What results are normal?

It's important to talk to your doctor about your test results and what they mean for you. The National Institutes of Health (NIH) reports that some normal ranges are¹:

• AST - Normal range is between 10 - 34 IU/L
• ALT - Normal range is between 7 - 40 IU/L
• Alkaline Phosphatase - Normal range is between 44 - 147 IU/L
• Total Bilirubin - Normal range 0.3 - 1.9 mg/dL
• Albumin - Normal range is 3.4 - 5.4 g/dL
• Total Protein - Normal range is between 6.0 - 8.3 g/dL

When looking at the top lab tests for liver disease, remember that your doctor knows how to interpret the results. They watch your numbers over a period of time to see the highs and lows in order to provide treatment options to help keep your liver healthy. You can help by tracking your liver lab tests. Read about that in Part 2.