The hepatitis C (HCV) RIBA blood test is used to check whether you have traces of antibodies for the virus that causes hepatitis C infections in your body. This test may show up on a laboratory blood test report as:

  • HCV RIBA test
  • Chiron RIBA HCV test
  • Recombinant ImmunoBlot Assay (its full name)

Hepatitis C can get into your body when you come into contact with blood that’s infected with the virus. An infection can cause major damage to your liver if it’s left untreated.

The HCV RIBA test was once used as one of a few tests to confirm that your body is making antibodies to target the virus. (Antibodies are proteins produced by white cells to fight off foreign substances like bacteria and viruses.) If this and other tests find that you have these antibodies above a certain level, you may need treatment to prevent any complications involving your liver.

As of 2013, this test isn’t used to test for hepatitis C in your blood anymore.

Read on to learn more about what this test was used for, how its results were interpreted, and how else this test may be used.

Levels of HCV antibodies in your blood rise to fight off HCV viruses if you have a hepatitis C infection.

The HCV RIBA test was meant primarily to detect the level of specific hepatitis C antibodies present in your blood in the form of a simple positive or negative result. Positive means that your antibody levels are high. Negative means that they’re normal or low.

The test can be done by testing a small sample of blood, usually drawn from a vein in your arm during a check-up or a routine laboratory blood test.

The test can also detect antibody levels that may still be high even if you’ve had an HCV infection at some point in your life. Even if the virus isn’t active, your immune system may still maintain high levels of these antibodies so that they can fight off the infection again if necessary. This is known as immunological memory.

The HCV RIBA test was a confirmation test. This means that it wasn’t used alone to detect HCV antibodies. Even if it showed that your HCV antibodies were elevated, the HCV RIBA test couldn’t tell you whether you had an active infection or whether it was a short-term (acute) or long-term (chronic) infection.

The test was often a part of a full blood test panel along with:

  • HCV enzyme immunoassay (EIA) test. This is a test for HCV antibodies, with possible results being either positive (antibodies to HCV are present) or negative (antibodies to HCV are not present).
  • HCV RNA test. This is a follow-up test to a positive antibody test to check for an HCV infection or for viremia, which happens when viruses get into your bloodstream.

Here are the possible results of an HCV RIBA test alone based on how antibodies respond to HCV. (Virus components are called antigens in the terminology of blood testing.)

  • Positive. This indicates the presence of antibodies to two or more antigens, meaning that you either have an active infection or have come into contact with HCV at some point. You’ll need a follow-up test to confirm an infection.
  • Indeterminate. This indicates antibodies to one antigen, meaning that you may have come into contact with HCV in the past. You’ll still need a follow-up test to see if there are any signs of infection at all.
  • Negative. This indicates no antibodies specific for antigens, so no follow-up test is needed. Your doctor may still want to check for other signs of the virus if you have symptoms of an infection or if they suspect that you have come into contact with HCV.

The HCV RIBA test was eventually phased out. This is because it’s been replaced by more sensitive tests that can give your doctor more details about your body’s response to the presence of HCV. Many tests can also detect HCV viremia, which is a much more accurate tool for confirming an infection than a simple positive/negative antibody result.

The Centers for Disease Control and Prevention (CDC) discontinued the HCV RIBA test in 2013. As a result, companies that once made the test, such as the pharmaceutical company Novartis AG, largely don’t sell the test to laboratories anymore.

This test isn’t completely obsolete.

Some laboratory testing facilities still use the test as part of HCV screening procedures.

And some blood banks use the HCV RIBA test to confirm the presence of HCV antibodies before a donated blood sample can be used. If the blood gets a positive HCV RIBA test result, it may need further HCV testing before it’s considered safe to use.

Whether or not you get this test for HCV screening, a positive result means that you likely have high levels of HCV antibodies in your body. You should be further tested to confirm the presence of the virus as soon as possible.

HCV isn’t always dangerous or deadly, but you should take some steps to reduce or prevent it from spreading. Here’s what you can do:

  • Request a follow-up test, such as the EIA or HCV RNA test. You may also want to get tested for liver function.
  • See your doctor if you notice any symptoms of an HCV infection, such as fatigue, confusion, jaundice (yellowing of skin and eyes), or bleeding and bruising easily.
  • Reduce or avoid alcohol and illegal drugs to minimize any possible liver damage that HCV can cause.
  • Take any antiviral medications your doctor prescribes if you do have an active infection.
  • Get the vaccine for hepatitis A and B. There’s no HCV vaccine, but preventing other forms of hepatitis can help reduce complications from HCV.
  • Practice safe sex using condoms or other protection to avoid spreading HCV.
  • Prevent your blood from coming into contact with anyone else to stop HCV from spreading.