Hepatitis C antibody test

Overview

The hepatitis C antibody test is a simple blood test that checks for a liver infection called hepatitis C. Hepatitis C is the most common type of hepatitis in the United States. It can lead to serious liver damage. The hepatitis C virus (HCV) causes hep C. The virus spreads through contact with blood that has the virus in it.

The HCV antibody test looks for proteins that the body makes to fight a hepatitis C infection. These proteins are called antibodies. They stay in the blood as a memory of the infection. So if you have HCV antibodies, it means you were around the virus at some point. But some people with these antibodies never feel sick. That's why screening for hepatitis C is so important.

Other names for this test are:

• Anti-HCV test.
• Hepatitis C viral load test.
• HCV antibody test.
• Viral hepatitis C antibody screen.

Why it's done

A hepatitis C antibody test is done to:

• Find out if you have been infected with the hepatitis C virus (HCV).
• Check whether you need hepatitis C treatment.
• See how well hepatitis C treatment is working.

Healthcare professionals say that all adults should get an HCV antibody test at least once, even if they feel fine. That's because hepatitis C often has no symptoms until the liver is badly damaged.

Experts say you also should be screened for hepatitis C antibodies if you:

• Are a healthcare worker with a needlestick injury.
• Are on dialysis.
• Are pregnant.
• Got blood-clotting factor before 1987.
• Had a blood transfusion or organ transplant before 1992.
• Have ever used needles for drugs.
• Have human immunodeficiency virus (HIV).
• Were born to someone with hepatitis C.

Your healthcare team may recommend a hepatitis C antibody test if you have symptoms of an HCV infection such as:

• Belly pain on the right side.
• Dark urine or clay-colored stools.
• Easy bruising or bleeding.
• Feeling very tired.
• Itchy skin.
• Joint pain.
• Not wanting to eat, called loss of appetite.
• Swelling in the belly or legs.
• Upset stomach, also called nausea.
• Yellowing of the skin or the whites of the eyes, called jaundice. These changes may be easier or harder to see depending on skin color.

The HCV antibody test also may be done if:

• You have changes in liver function test results, especially alanine aminotransferase (ALT) test results.
• You may need a liver transplant.
• You are giving part of your liver to someone who needs a transplant.

Risks

There's little risk in getting a hepatitis C antibody blood test. As with any blood test, possible risks are:

• Soreness or tenderness in the area where the blood is taken.
• Bruising near the area where the blood is taken.
• Bleeding.
• Fainting or feeling lightheaded.
• Infection of the area where the blood is taken. This is rare.

How you prepare

Most people don't need to do anything special to get ready for a hepatitis C antibody blood test. But here are a few helpful things to keep in mind.

• Medicines, vitamins and supplements. Rarely, taking 20 milligrams (mg) or more of biotin each day can affect hepatitis C virus (HCV) antibody test results. If you take that much biotin, the test might say you don't have hep C antibodies even if you do. This is called a false-negative result. But with the newest generation of HCV antibody tests, there are fewer false-negatives than before. Always tell your healthcare team about all the medicines and supplements you take. Include those that you buy without a prescription.
• Food and drinks. You usually do not need to stop eating or drinking before a hepatitis C antibody test. But your healthcare team may ask you to do so if you are having other tests. Always check with your healthcare team before getting a blood test.
• Alcohol. Alcohol doesn't affect HCV antibody test results. But people with hepatitis C should not drink alcohol. Doing so can make liver damage worse. If you're having this test because you have hepatitis symptoms, you should not drink alcohol.
• Smoking. Smoking does not affect the results of a hepatitis C antibody test. But it might affect other blood test results. Ask your healthcare team whether you need to stop smoking before a blood test.
• Exercise. It's probably OK to exercise before an HCV antibody test. But if you're having other blood tests, check with your healthcare team first. Physical activity that makes you breathe hard and sweat a lot can affect the results of some liver function tests.

What you can expect

Before

A hepatitis C antibody test is done in a medical office, clinic, lab or hospital with special machines. There are some at-home tests to check for hepatitis C.

If you are anxious about needles or have fainted during a blood test, tell your healthcare team. Also tell the team if you have a bleeding disorder.

During

A small sample of blood is needed to do a hepatitis C antibody test. The test only takes a few minutes and may feel like a small pinch.

To do the test, the healthcare professional:

• Cleans the skin with alcohol.
• Uses a small needle to take blood from a vein, usually in your arm.
• Puts a bandage on to prevent bleeding.

After

You might have a small bruise or feel sore where the needle went in. That often goes away in a day or two. You can usually go back to your daily activities right away.

Results

Your healthcare team gives you your hepatitis C antibody test results. Most people get their results in about 1 to 2 days. Some clinics offer rapid hepatitis C testing.

Results of a standard hepatitis C antibody test are given as positive or negative.

• Positive HCV antibody test result: This means you came in contact with the hep C virus at some time. But it doesn't always mean that the virus is still in your body. A positive result may appear as early as 7 to 8 weeks after contact with the virus.
• Negative HCV antibody test result: This means you do not have antibodies to the hepatitis C virus. But if you think you might have been exposed to it in the last 6 months, your healthcare team may suggest doing the test again later. This is because it can take time for your body to make enough antibodies for the test to find them.

If you test positive, the lab usually does another test called an HCV RNA or PCR test right away. This test checks whether the hepatitis C virus is still in your body. It helps your healthcare team know whether the infection is active and whether you need treatment.

If you are hepatitis C antibody positive but PCR negative, it means the virus is no longer active in your body.

If both tests are positive, you have an HCV infection. Your healthcare team may:

• Do another test to learn what type of hepatitis C you have. This is called a genotype test. It checks which strain of the virus is in your body. There are at least six different strains that cause illness. Knowing your strain of HCV helps your healthcare professional choose the best treatment for you.
• Send you to a specialist, if needed. This could be a doctor who focuses on the liver, digestive system, or infections.
• Talk with you about your options if you are getting a new liver or donating one. Sometimes, people with hepatitis C can still receive or donate a liver. If the person getting the liver already has hepatitis C, that person may be able to get a liver from someone who also had the infection.

Once a cause is found, your healthcare professional talks with you about possible treatments. If you have questions about your test results or next steps, talk with your healthcare team.