Before discussing specific lab tests, here are some important tips:
- Keep copies of your lab results. Ask your provider for copies of your labs and keep them in one place. You may download a tracking tool to help you record your labs all in one place.
- Lab results should be read by your medical provider. Do not attempt to interpret results on your own.
- If you have questions about a test result, ask your provider about it.
- If you have an abnormal result, ask if there are factors that might affect the test, such as medications, supplements or food.
- Do not lose sleep over test results. An abnormal lab does not necessarily indicate a problem.
- Look for trends. Often a single abnormal lab is insignificant.
- Never let a lab test tell you how you feel. Plenty of people have abnormal labs but still feel good, or normal labs and feel lousy. Stay tuned to your body, not to your lab results.
- Sometimes the worst part about getting lab tests is waiting for results. Try not to put your life on hold while waiting for results. The results will be what they will be.
Here are some common tests that are used for people living with hepatitis C.
Also called a liver function test or hepatic panel, this battery of tests measures activity in the liver. Your provider may order a broader panel of tests, called a comprehensive metabolic panel or chemistry panel, to assess kidney and other metabolic functions along with liver function. Tests that specifically evaluate liver health are:
Alanine aminotransferase (ALT; sometimes listed as SGPT): ALT is a liver enzyme. When hep C infects the liver, the hepatocytes (liver cells) produce higher-than-normal enzymes such as ALT, indicating inflammation of the liver. When initially infected, ALT may skyrocket to 10 times the normal level. When hepatitis C becomes chronic, ALT usually drops to a lower level, but remains persistently elevated. About two-thirds of people with chronic hepatitis C have continuously elevated ALT levels, reflecting ongoing damage to liver cells. The other third have normal ALT levels, even though they have a detectable HCV viral load. Although most people with HCV and normal ALT will live without any liver-related problems, roughly one-quarter of these people may have progression of liver disease.
Aspartate aminotransferase (AST; sometimes listed as SGOT): AST is also a liver enzyme, which is often elevated in people with chronic hepatitis C. AST levels are usually lower than ALT levels. If cirrhosis occurs, AST levels may be higher than ALT levels, a sign that damage to the liver is worsening. Elevated AST levels may also indicate excessive alcohol use, drug toxicity and the presence of other medical problems.
Alkaline phosphatase (ALP or Alk Phos) and gamma glutamyl transpeptidase (GGT or GGTP): These liver enzymes usually remain at normal levels. However, they may become elevated if hepatitis C progresses to cirrhosis. A rise in ALP may indicate other problems, both liver- and non-liver-related. Alcohol and other factors will cause GGT to increase.
Albumin: Albumin is a protein made by the liver. Unlike the more generalized liver enzyme tests, albumin levels are a strong indication of how the liver is functioning. This test is usually normal for most people with hepatitis C, but when albumin is low, it may indicate cirrhosis.
Bilirubin: Bilirubin is a substance found in bile, and is produced during the normal breakdown of red blood cells. In most people with hepatitis C, this test will remain normal. An elevated bilirubin test may indicate cirrhosis.
Total protein: This test measures all the proteins in the blood, including albumin. If albumin is low, other proteins (globulins) may be high, resulting in normal protein levels. The albumin portion of this test is an important indicator of liver function.
COMPLETE BLOOD COUNT
Your medical provider will probably order a complete blood count (CBC), especially during hepatitis C treatment. This basic lab test measures components of the blood, including red blood cells (RBCs), white blood cells (WBCs) and platelets (PLTs). Here are key components of the test:
Red blood cells (RBCs): Red blood cells carry oxygen to the cells in the body, and this test counts how many RBCs you have in your blood. Hemoglobin is a protein in RBCs that carries oxygen. Low hemoglobin is a common side effect of hepatitis C treatment using ribavirin. This is because ribavirin destroys red blood cells as they are forming in the bone marrow, causing a condition known as hemolytic anemia. If you have fewer red blood cells, your hemoglobin and hematocrit will also be low. Hemolytic anemia sounds frightening, but it is a common occurrence when taking ribavirin. If your hemoglobin gets too low, your doctor may recommend reducing or stopping your ribavirin dose, especially if you are at risk for any cardiac problems.
White blood cells (WBCs): White blood cells help fight infection. There are five major types of WBCs—basophils, eosinophils, lymphocytes, monocytes and neutrophils—and each has a different function. HCV treatment that includes peginterferon may cause a drop in WBCs, especially neutrophils. In the case of HCV treatment, low neutrophils or white blood cells do not indicate a compromised immune system unless the person has HIV or other coexisting immune problems.
Platelets (PLTs): Platelets are the sticky component in the blood that helps it to clot. A variety of conditions will cause low platelets, such as HCV treatment using peginterferon. However, if you have HCV and no other reason for a platelet shortage, it may indicate advanced liver disease. Platelets tend to drop gradually over a period of years as liver disease worsens. A person can live with fairly low platelets without severe consequences. If your platelets are low, ask your medical provider if you are at risk of bleeding. If you vomit or cough up blood, or can’t stop any bleeding, seek immediate medical help.
OTHER LAB TESTS
Prothrombin Time/International Normalized Ratio: Prothrombin time measures how long it takes your blood to clot. The liver makes clotting factors, so if your blood takes a long time to clot, it may indicate liver damage. If you can’t stop any bleeding, seek immediate medical help. The international normalized ratio or INR is the same test, but expressed in results using a standard that makes it easier to compare results regardless of which lab preformed the test.
Alpha-fetoprotein (AFP): This test looks for high levels of AFP, a protein that is produced by cancerous liver cells. AFP may be elevated for a variety of reasons, and is not a reliable indicator of liver cancer. Ultrasound is a more reliable screen for liver tumors.
Viral load (HCV RNA): This test is first performed to confirm you have hepatitis C. The actual number is not cause for concern or reassurance. Viral loads rise and fall without any correlation to hep C progression. Some people get frequent viral load tests and incorrectly assume that if the number is higher it means that their hep C is progressing. You may have a very high viral load and minimal liver damage or hep C symptoms. You may also have a low viral load and extensive disease.
If you are treated for HCV, the viral load is used to monitor how well the medicines are working. An undetectable HCV RNA is called a sustained viral response (SVR). Achieving an SVR at 12 to 24 weeks after treatment is completed means you are cured of hep C.
Drug-Resistance Tests: Despite the high cure rates of current hep C treatments, some people fail treatment because they develop resistance-associated substitutions (RASs) [Note: RASs were formerly called resistance-associated variants (RAVs)]. Also known as polymorphisms, these are natural genetic variations of the virus. If HCV treatment isn’t working, your medical provider may test for the presence of RAVs. Routine monitoring for HCV drug RAVs is not recommended unless a person has cirrhosis and the provider needs this information to determine the best treatment. Exceptions to this are when using drugs such as Zepatier, Olysio with Sovaldi, and Daklinza with Sovaldi. In those drugs, treatment decisions are based on the presence of certain polymorphisms.
Unfortunately, lab tests do not tell the whole story regarding the effect of hepatitis C on the health of the liver. Measuring HCV viral load and liver enzyme levels in the blood cannot determine if—and how much—damage has actually been done to the liver. To assess this, your doctor will need to order either a liver biopsy or noninvasive liver fibrosis test. Less riskier, non-invasive radiologic procedures such as the FibroScan and blood tests that estimate fibrosis, are replacing liver biopsies. If you have cirrhosis, you will also be monitored for hepatocellular carcinoma (liver cancer), usually done by ultrasound or other radiologic scan.
Imaging studies: Noninvasive imaging procedures may be used to monitor the health of your liver. The most common is ultrasound, which uses sound waves to produce an image of the liver. Ultrasound is useful for detecting tumors and can potentially detect cirrhosis. If the ultrasound test reveals a tumor, your doctor may want you to have a CT scan or an MRI. The CT scan (computed tomography or CAT scan) is a specialized X-ray that produces a picture of your liver. MRI (magnetic resonance imaging) also takes a picture, but it uses a magnetic field and radio wave pulses.
Liver biopsy: A biopsy allows experts to examine tissue taken from the liver and determine how healthy the liver is. A liver biopsy is often performed on an outpatient basis, usually in a hospital. A local anesthetic agent is used to numb the skin and tissue below. A thin, specially designed needle is inserted through the skin. This takes only one or two seconds. A slender piece of tissue is removed with the needle and then processed through a laboratory. From start to finish, the entire procedure lasts only 15 to 20 minutes. You will then be instructed to lie still, sometimes for several hours. There may be some discomfort in the chest or shoulder, but this is usually temporary. In rare cases, the provider conducting the procedure can nick a blood vessel, which can result in internal bleeding. It is common to feel mild soreness in the liver area for a day or two following the procedure. Biopsy results are usually available within a week and will be explained to you by your health care provider.
FibroScan: A newer method, called transient elastography, it uses ultrasound and low-frequency elastic waves to measure liver elasticity. FibroScan seems to be as accurate as a liver biopsy. The technician or physician applies gel to the skin and places the probe with a slight pressure on the liver area. The procedure is painless.
Blood tests: Various blood tests directly and indirectly estimate the amount of liver fibrosis. Although the tests vary in accuracy, they are usually good at estimating the degree of fibrosis. Some commonly used blood tests are FibroSpect, FibroSure and FibroTest.
Understanding Your Diagnostic Tests
Although there are various ways to evaluate the condition of your liver, the results will indicate how much scarring and inflammation you have. The results are interpreted using various scoring systems, of which the Metavir system is the most popular. Results from a FibroScan or other noninvasive test may be converted into a Metavir score.
Metavir gives you two numbers. The first is the grade, which rates how much inflammation is in the liver. The second number is the stage, which measures the degree of liver damage that has occurred because of the inflammation. This scale explains the Metavir scores:
Grade: liver inflammation or histological activity
A0 = no inflammation
A1 = mild inflammation
A2 = moderate inflammation
A3 = severe inflammation
Stage: degree of liver fibrosis, scarring or damage
F0 = no fibrosis
F1 = minimal fibrosis (medically described as portal fibrosis without septa)
F2 = fibrosis has occurred and spread inside the areas of the liver, including blood vessels (described as portal fibrosis with few septa)
F3 = fibrosis is spreading and connecting to other liver areas that contain fibrosis (bridging fibrosis or portal fibrosis with numerous septa)
F4 = cirrhosis
Your medical provider may tell you only which stage of liver disease you have because that indicates how much liver damage you have. However, the grade is important too because higher inflammation scores may mean a more aggressive form of liver disease.
Don’t panic if the result is F4. Cirrhosis is a serious disease, but does not necessarily mean that your life is in immediate danger. Cases of cirrhosis need further monitoring to determine whether your liver is functioning adequately despite the seriousness of your liver disease. If you take care of your health and don’t drink alcohol, you may enjoy a good quality of life for many years with cirrhosis.
Last Reviewed: August 1, 2023