RIBA Test for HCV

How Was the RIBA HCV Test Used and What Does it Mean?

Hepatitis C virus
What is the RIBA test for hepatitis C (HCV)?. BSIP/Universal Images Group/Getty Images

Definition of RIBA - Recombinant ImmunoBlot Assay

RIBA (Recombinant ImmunoBlot Assay) is a blood test that detects antibodies to the hepatitis C virus. It was used for many years as a confirmation test after a screening test for HCV was positive. However, as other tests became more sensitive and accurate, it was discontinued for most purposes and other tests are used instead.

When you have been exposed to hepatitis C, your body makes antibodies to the virus.

These antibodies circulate in your bloodstream for many years, perhaps even throughout your lifetime. The RIBA HCV test was used to detect those antibodies.

Routine screening is done for people at risk of HCV. Your blood will also be tested if you donate blood, as blood transfusions can transmit hepatitis C virus. Donor blood that is positive for HCV antibodies is rejected, and you will be permanently banned from donating blood in order to protect people who will receive transfusions.

Use of the RIBA HCV Test

If you are looking at older laboratory results in your medical record, you may see the Hepatitis C RIBA test reported. It may be called HCV RIBA or spelled out as Recombinant ImmunoBlot Assay. It would have been ordered because the screening test for hepatitis C antibody (anti-HCV) was positive or indeterminant.

In past years, the first tests done for hepatitis C antibody often had false-positives, meaning that they showed a positive result when you actually didn't have any hepatitis C antibody.

As a result, it was necessary to check every positive result with a confirmation test that was more specific.

The RIBA HCV test was more specific than the earlier ELISA hepatitis C antibody tests. But it also was an additional expense, so it was only done if the ELISA anti-HCV test showed positive.

If the RIBA HCV test showed a positive result, it confirmed that you had hepatitis C antibodies and had been exposed to HCV.

The next step was to test for HCV RNA (viral load) to see if hepatitis C virus was still present in your body.

If the RIBA test was negative, your doctor may have ordered other tests to ensure you didn't have HCV, depending on whether you were showing signs of the disease or you had a condition that would affect the accuracy of the tests

RIBA Testing Discontinued for HCV

The 2013 Guidelines from the Centers for Disease Control and Prevention notes that the RIBA HCV test has been discontinued. The manufacturer, Novartis Vaccines and Diagnostics, no longer offers it for use. Instead of using RIBA as the confirmatory test, clinicians should use a test that detects HCV viremia (the presence of HCV in the blood).

Is the RIBA test Ever Used?

The RIBA test may still be in use in other settings, such as in blood banking. Donor blood samples are screened for HCV, and a positive sample may be retested to confirm it shows hepatitis C virus. RIBA was commonly used as that confirmation test, but as technology evolves it may also be replaced with other tests for that purpose.

If You are Worried About Hepatitis C

You may have heard of the RIBA test in a setting where it is still used, or perhaps you found some old lab results. There are newer tests available now, but many of the questions remain the same.

  • Should You be Tested for Hepatitis C? - Even though we know of several risk factors for HCV, many people who are diagnosed today have no known risk factors. In addition to those who have risk factors it's recommended that everyone born between 1945 an 1965 be tested for the virus.
  • Seven Myths About HCV - Myths regarding HCV abound. Make sure you know what and what not to believe about the virus.
  • How to Interpret Your HCV Test Results - Tests for HCV are confusing. What is meant by screening and what is meant by confirmation? Why are there different tests? This article can help you understand the differences between tests and know how to read the results you receive.

Sources:

Testing for HCV Infection: An Update of Guidance for Clinicians and Laboratorians Morbidity and Mortality Weekly Report (MMWR), Centers for Disease Control and Prevention. Weekly May 10, 2013 / 62(18);362-365

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