Amid mounting global health efforts to reduce mortality from hepatitis B (HBV), lab and healthcare leaders from around the world are developing and deploying novel biomarkers to guide care strategies. In a recent webinar hosted by Roche Diagnostics, two virology experts from Australia spoke about the latest advances in HBV diagnostics and their potential use in the country.

Below are some key takeaways from the webinar, which featured presentations from Prof Alex Thompson, Professor and Director of the Department of Gastroenterology in St Vincent’s Hospital at the University of Melbourne, and A/Prof Mark Douglas, Associate Professor at The University of Sydney and the Storr Liver Centre, The Westmead Institute for Medical Research, Australia.

The importance of HBV reduction

With 2 billion people around the world having had HBV at some point in their lives and 300 million people suffering from chronic infections, HBV presents a massive global health challenge. Left untreated, up to 40% of patients can die from cirrhosis or liver cancer caused by the virus.

This is why public health agencies have targeted HBV for a massive campaign to reduce or eliminate the virus. In 2016, the World Health Organization announced a plan to reduce HBV infections by 90% and deaths by 65% by 2030. The plan depends on targeting mother-to-child transmission prior to or during birth, and encourages the use of vaccinations, tests and therapies to reduce disease burden.

The focus on vertical transmission from pregnant mother to baby is especially important for addressing the challenge of chronic infections. Adults who get infected with HBV have just a 5% chance of developing a chronic condition. But babies infected by their mothers prior to or at birth have a 90% risk of chronic infection.

Chronic HBV cases are the ones that need ongoing treatment and constant monitoring, making them the most challenging.

HBV biomarker development in Australia

In Australia, a national strategy aims to boost childhood vaccinations, expand diagnosis to catch more chronic cases, and increase availability of antiviral and other treatments. Prof Thompson and Prof Douglas are contributing to the cause by testing a variety of antigens and other biomarkers to determine how they can be used to diagnose patients and monitor them when they’re undergoing treatment.

Surface antigens can be found in blood from the time of HBV infection, and chronic patients achieve a functional cure state when those antigens can no longer be detected. Measurement of HBV DNA is a way to assess a patient’s viral load and a common marker to determine whether treatments are effective, while HBeAg is an indicator of immune control. Biomarker activity changes through the course of a HBV infection.

“It’s really crucial that we know how to monitor all these markers and know what we’re looking for to initiate treatment,” said Prof Douglas.

It’s also important to continue developing new markers. Emerging markers could enable an era of personalised medicine for people with HBV, said Prof Thompson. For example, quantifying surface antigen markers with ELISA rather than just reporting negative or positive results could give these markers added value in determining when to start or stop treatment for each patient.

New markers can also predict whether a patient is likely to reach the functional cure stage or not, and whether a pregnant patient is likely to pass the virus on to her baby. In new studies of an interferon treatment, surface antigen levels can predict which patients will benefit from continued treatment and which will not.

“I think surface antigen levels are now ready for prime time,” said Prof Thompson, who recommends testing for this biomarker in all patients with HBV. This approach could also be important in the future for appropriate selection of novel treatments now in development, such as an injectable antisense oligonucleotide that’s in clinical trials. “A new age of therapeutics for hepatitis B is dawning,” he added.

An emerging biomarker with real promise is HBV RNA, which might offer a more useful snapshot of transcriptional activity than HBV DNA. In a Hep B NA treatment stop study, for example, rising HBV RNA was shown to increase risk of hepatitis flare and negatively associated with HBsAg loss. Prof Thompson also noted that HBV RNA may show clinical utility for predicting HBV reactivation in immunocompromised patients, risk of HCC or response to novel therapies.

“Serum HBV RNA looks promising and further studies are needed,” he said. “I look forward to the results and data coming in the next few years.”

To learn more about testing for HBV, watch the full webinar with Prof Thompson and A/Prof Douglas, or check out these other articles from Lab Insights.