The HBV or viral load test can give you a insight into your hepatitis B infection and your health. The HBV test is performed on a blood sample using a Polymerase Chain Reaction (PCR) technique that rapidly generates HBV fragments so they can be measured. Today, viral load is usually measured using international units per milliliter (IU/mL). However, in the past it was measured in copies per milliliter (copies/mL), and in some regions and labs, it is still used. As per the international units of the WHO HBV standard, there are about 5.6 copies in one international unit, for example, if you need to convert international units to copies into so 893 IU/ml equals about 5,000 copies/ml. Remember to keep copies of your lab information on file so you can track your status. An Excel spreadsheet works great.
The sensitivity of HBV tests may vary with each lab so it’s a good idea to use the same lab for your test. Labs usually measure down to less than 200 IU/mL. Below the threshold, the viral load is considered “undetectable” – something everyone with chronic hepatitis B wants to hear.
Your viral load also varies over time depending on the “stage” of hepatitis B infection. That is why regular monitoring is so important. Children and adults in the “immune tolerant” stage can have viral loads in the millions or even billions.
It sounds scary, but it’s not unusual. Your viral load can remain very high for decades until your immune system begins attacking the virus. Most children and young adults who test positive for the hepatitis B “e” antigen (HBeAg) generally have high viral loads, though doctors typically don’t treat patients in this stage. Once their immune systems get rid of HBeAg and generate “e” antibodies (HBeAb), their viral loads begin to decline and liver enzymes (ALT/AST) normalize.
Adults with undetectable or low viral loads and no signs of liver damage are in an “inactive” stage. Adults with normal ALT (SGPT) levels, which usually indicate no current liver inflammation, and undetectable or viral loads less than 2,000 IU/mL generally do not require treatment. However, it is important to confirm with your doctor that there is no evidence of advanced liver disease. This phase may be lifelong, decades, or not long at all. That is why monitoring in this inactive phase remains important. People in the “active” stage with elevated viral loads and signs of liver damage need treatment.
These may be people that are HBeAg positive and unable to seroconvert and lose HBeAg and gain the antibody without experiencing significant liver damage. There may be a pattern of SGPT/ALT elevation that cycles up and down over time without mounting an adequate immune response to seroconvert. This can be dangerous, causing liver damage, which is why regular monitoring is key. You want to give your immune system the opportunity to try to mount an immune response and seroconvert but not at the expense of extensive liver damage. That’s why a knowledgeable doctor is so important! Many people in their 40s, 50s or 60s, develop HBeAg-negative hepatitis B, though this may occur in younger individuals as well.
Although individuals may have seroconverted and lost HBeAg (HBeAg negative/HBeAb positive), the virus is able to mutate allowing it to keep replicating, putting these patients at risk of liver damage. They may see the viral load start to creep up along with SGPT/ALT. Eventually they may require treatment with antivirals based on clinical guidelines doctors follow to manage their patients. Once again, monitoring is key!
When daily antiviral pills are prescribed, doctors measure your HBV Viral Load to see if the drug is working to reduce your viral load. Antivirals work by meddling with the viral so the virus cannot reproduce effectively. Doctors measure your viral load to make sure the antiviral is working.
Today, all pregnant women are screened for hepatitis B, and experts also want their viral loads to be measured. When pregnant women have high viral loads—exceeding 200,000 IU/mL—medical guidelines recommend antiviral therapy during their third trimester of pregnancy to reduce their risk of infecting their newborns. Babies born to HBV-infected women can become infected even if they are immunized at birth and treated with HBIG (hepatitis B antibodies) if their mothers have high viral loads.
It is important to remember that a viral load test provides you with important information, but it must be considered in relation to your other HBV and liver function tests results to determine if treatment is needed at all, or if you are responding favorably to current treatment. Although an undetectable or low viral load is good news, it does not necessarily guarantee that you have not, or will not experience liver damage. Hepatitis B is a tricky virus. Talk to your liver specialist about all of your test results.
HBV infection leads to severe diseases, including hepatitis, liver cirrhosis and hepatocellular carcinoma. HBV has also been suggested to be involved in the development of pancreatic cancer. Approximately 4 crore individuals are infected with HBV, and more than 1.5 lakh people with HBV infection die every year as a result of end-stage liver disease and hepatocellular carcinoma in India. Most of the mortality due to Viral Hepatitis is attributed to Hepatitis B and C, which are also known as silent killers as more than 80% of the infected aren’t aware of their infection.
Hepatitis B and C infections can remain asymptomatic for years, even decades, slowly damaging the liver. Fighting hepatitis is difficult because both hepatitis B and C are chronic infections that often remain dormant in the body for years before damaging the liver. Liver cirrhosis and liver cancer are common culminations of these chronic infections.
Most people infected with the virus are not aware about their disease status. Chronic HBV infection accounts for 40-50% of hepatocellular carcinoma (HCC) and 20-30% cases of liver cirrhosis while chronic HCV infection accounts for 12- 32% of HCC and 12-20% of liver cirrhosis in the country.