Young HBV carriers should be treated early: S'pore scientists

SINGAPORE - Singapore scientists, together with collaborators from London, have discovered for the first time that contrary to current belief, children with chronic Hepatitis B virus (HBV) infection do have a protective immune response.

Hence they can be more suitable treatment candidates than previously believed and should be treated earlier.

This could lead to a paradigm shift in the current treatment of patients with chronic HBV, said the scientists from A*STAR's Singapore Institute for Clinical Sciences (SICS).

Current international guidelines recommend delaying therapy until HBV carriers show clear signs of active liver disease, which generally appears after the age of 30.

This is based on two assumptions: One, that young patients are unable to react to treatment because they have no protective immune response in their body to help them get rid of the virus. Therefore, they will not run the risk of liver damage or inflammation.

Two, HBV infection is largely harmless in HBV carriers until active liver disease is apparent.

However, the team showed that young patients are not immune tolerant as they possess cells with the ability to produce antiviral cytokines that help the body fight against HBV.

They also showed that the longer a patient is left untreated, the less effective their immune system becomes against HBV and the less able the patient will be able to clear the virus from their body even when they receive treatment.

The scientists demonstrated that the presence of HBV in the body over a long period of time is harmful to the patient due to T-cell exhaustion, a state of immune system dysfunction.

Said Professor Antonio Bertoletti, programme director and research director of the infection and immunity programme at SICS: "Young patients infected with HBV are most at risk of developing chronic HBV. But current guidelines mean that they are also the least likely to be treated."

"However, our findings suggest that it might be better to start treatment early as young people with their stronger immune system respond better to treatment and are more able to clear the virus," he said.