The HCV RNA PCR test is a blood test that is advised by doctors in suspected patients to diagnose Hepatitis C infection.  It calculates the hepatitis C viral load in the bloodstream. This article gives an insight into how the test functions and what the results signify.

The HCV RNA PCR test is designed to detect the RNA of the hepatitis C virus, and to attain this, it makes use of a process called the polymerase chain reaction (PCR).

The name of the test is derived from the antigen it identifies and the procedure it uses to do the same. The abbreviations in its name stands for:

HCV— hepatitis C virus

RNA— ribonucleic acid

PCR— polymerase chain reaction

The test can detect the virus itself rather than the antibodies produced by the body against it. Hence, HCV RNA PCR tests are often advised early on, as one need not wait until their body begins to fight the infection to be diagnosed.

It takes around 6 to 8 weeks on an average for antibodies to be developed and detected after a hepatitis C infection. Whereas, it may only take 1 week to detect the virus using PCR or any other means of directing virus detection.

Moreover, the test can be repeated during the course of the treatment to check the body’s response to the treatment.

The HCV RNA PCR test is either qualitative, determining whether or not the virus is present, or quantitative, measuring the amount of HCV in the bloodstream. The two forms of the test are conducted in slightly different manners.

Qualitative

In cases where doctors are uncertain of whether the patient has hepatitis C or not, an HCV RNA PCR test can be advised early on to detect the virus in the bloodstream.

The qualitative test only detects the presence of the virus, not the amount of viral load in the bloodstream.

If the test is positive, the patient will require a quantitative HCV RNA PCR test. Due to this, many doctors prefer to use the quantitative test straight away, skipping the first test.

Additionally, the doctor will advise a hepatitis C antibody test. A hepatitis C antibody test will reveal whether the body is producing the antibodies to fight the hepatitis C infection.

It is very likely, in patients who develop symptoms in the early phase of the infection, for the virus to clear. Hence, it is a routine practice observed by doctors to follow up a hepatitis C antibody test with a HCV RNA PCR test to confirm their diagnosis.

Doctors may also recommend a third test, called the transcription-mediated amplification test, or TMA test, to confirm the presence of hepatitis C. However, it is unnecessary in the majority of cases where an HCV RNA PCR test shows adequate evidence that the infection with hepatitis C is positive.

Quantitative

The quantitative HCV RNA PCR test is used to measure the viral load of the hepatitis C virus in the blood. The quantitative test has replaced the qualitative test in a vast number of cases as knowing the viral load and understanding the treatment response is a crucial step in the course of management of the case.

The viral load refers to the amount of actual viral bodies in the bloodstream. The HCV RNA PCR test takes a small sample of the blood to calculate how much genetic material of the virus is present in the blood. The values are calculated as per the standard reading, which is the number of international units per liter, written as IU/L.

A quantitative test is generally used when the patient is undergoing treatment as it helps the doctor understand the response of the body to the treatment and if any change is required in the plan of treatment.

The measured viral load via the quantitative test has been observed to vary significantly, from a range as high as 100,000,000 million IU/L to as low as less than 15 IU/L.

A viral load of over 800,000 IU/L is considered high, whereas a low viral load is considered anything below 800,000 IU/L. Few doctors take 400,000 IU/L to be the cut-off for a low viral load.

It is notable that whether low or high, the viral load does not reflect levels of damage done to the liver by the infection. Liver function tests, ultrasounds, and a liver biopsy give a better picture of the health of the liver.

Once it is confirmed that HCV is present after conducting the HCV RNA PCR test, doctors would like to categorize the strain of HCV involved to help them guide through the treatment plan.

The basic aim of the treatment is to reduce the viral load in the body until the virus has been eradicated entirely. This is known as a sustained virologic response or SVR.

A negative viral load for 12 weeks or more after treatment will result in SVR.

A treatment can be considered successful when SVR is achieved, as it usually signifies that the person is free from hepatitis C, or that the hepatitis C virus is in remission.

Even after SVR is achieved, it is important to remember that reinfection is still possible and therefore, lifestyle changes to prevent the spread of hepatitis C infection need to persist.

Doctors will also merge treatments with other tests that watch for conditions that include cirrhosis, enlarged blood vessels, and liver cancer, which are all complications of hepatitis C. A specialist would be required to treat any of these disorders if diagnosed.

It can be concluded that HCV RNA PCR tests are imperative for the diagnosis and treatment of hepatitis C. Periodic blood tests will still be crucial after the initial diagnosis to check the efficacy of one's treatment.

99 percent of people who achieve SVR remain free of the virus for the rest of their lives, according to the U.S. Department of Veterans Affairs.

Regular HCV RNA PCR testing and adhering to a doctor's prescribed treatment plan may give patients the best possibility of SVR and living without chronic hepatitis C.