Interview with Prof. Joseph Sung in the APASL2009

Hepatology Digest: I’m here with Professor Jin Lin Hou here at APASL 2009 welcome Professor; it is an honor to interview you today.  First question I would like to ask you today, from your lecture we know that serum levels of HB surface antigen were not the same between patients with different genotypes such as D or C.  Can you explain what would be the case with patients from genotype A?

Professor Hou: You know surface antigen qualification currently a hot topic among clinical doctors.  We know quite a lot of new data generated from different countries in this APASL meeting such as surface antigen level could be as a predictor for response and varies response to the pegylated interferon during the treatment.  Our results show that the surface antigen kinetics differences in different patients may be related to different genotypes.  Some of the patients with biophysical changes have dynamics similar as HBV DNA kinetics.  Some of them during the treatment surface antigen levels maintained and changed.  Our data also shows surface antigen levels might be different levels in patients of different genotypes.  In serum samples, genotype C has a lower level of surface antigen than genotype B.  But in hepatocytes surface antigen expression is higher in genotype C than in genotype B patients.  Yeah I think this is the new message.  Genotype distribution is different worldwide.  In the Asia Pacific area, majority of patients infected with genotype B and C.  In European countries might also be in North America there quite high type of patients infected with genotype A.  So currently we have don’t know what is the exact levels of surface antigen type A patients.

Hepatology Digest: So how can we capitalized and use this information to benefit patients clinically and are there any plans to follow up with further studies along these lines.

Professor Hou: Yes I think first we should standardize the methodology for the test for surface antigen titers in serum samples.  Currently there are two assays.  One is from Abbott, quite a lot of studies that use the surface antigen titers are from Abbott.  The other is from Roche.  However we currently need more data to know what are the dynamic changes during different antiviral treatment with surface antigen titers; some of the patients respond with the seroconversion then they stop treatment. We are still not sure how much data we have about patients off treatment and whether they maintain the low levels after having a good response to their treatment.

Hepatology Digest: So to follow up again from that study, do you understand what the underlying mechanism is at this time?  Do we know?

Professor Hou: Two things might be related to the surface antigen titer.  One is the intrahepatic cccDNA (covalently closed circular DNA) may be a surface antigen as a surrogate marker for quantation of cccDNA in the liver and the other is that surface antigen changes might reflect an immuno-response to the virus. 

Hepatology Digest: Is there any relationship between these diverse HB surface antigen levels and different response to therapy in these different genotypes.

Professor Hou: Currently there are some data that shows surface antigen titer change during treatment may be a predictor for surface antigen clearance.  The other thing might it may be is a predictor for e-antigen seroconverstion during treatment.  As such, data from a Pegasys (pegylated interferon) study showed that if patient treated with Pegasys, surface antigen level becomes very low which is good response to treatment.

Hepatology Digest: I know there’s going to be a debate here at APASL with a pro and con view with regards to nucleocides analogues-can they be stopped and when.  Do you have a point of view on that debate in the treatment, some say ‘Yes, we can stop early’.  When is that point, do you have a point of view on that debate?

Professor Hou:  I see.  Well you know currently we use two different kinds of antiviral drugs.  One is immunomodulator; standard interferon and pegylated interferon the other is nucleocide or nucleotide analogues.  Currently there are five nucleocide analogues are available for chronic Hepatitis B.  For these kinds of drugs, it is easy to start but difficult to stop.  For e-antigen positive patients, if a patient has had e-antigen seroconversion it could be stopped after consolidation treatment for six to twelve months.  For cirrhotic patient, may be you can’t stop treatment.  For e-antigen negative patient, the relapse rate is quite high.  Even if you treat a patient longer, maybe three or five years there is still quite a high relapse rate after stopping treatment with nucleocide or nucleotide analogues.

Hepatology Digest: One final question for you.  This year APASL is held in Hong Kong and next year it will be in Beijing.  Can you talk a little about the significance of it being held in Beijing and do you think it perhaps it might help some of the Chinese investigators.  What is the significance and what do you think the impact will be?

Professor Hou: Yes, next year will be the first time the APASL meeting will be held in China and in Beijing.  I definitely think in this meeting there will be quite a lot of new advances.  New design changes for treatment for chronic hepatitis or other liver disease and also new methodologies for monitoring hepatitis treatment.  I think that it is a quite an important steps for Chinese hepatologists and doctors to learn a lot of new things from this meeting and also definitely I think they will present quite a lot of data from Chinese hepatologists.  It was a pleasure speaking to you today Professor Hou and hopefully we will see you in Beijing.

Professor Hou: Thank you very much.