Research On The Integration Of HBV S Gene In Chb Patients Had Impact On The Levels Of Serum HBsAg After NAs Treatment

Objective:The ultimate goal of NAs antiviral therapy in patients with CHB is to achieve cccDNA clearance.However,drugs cleaning cccDNA for eradicating CHB are unavailable.Therefore, the realization of functional cure has become an ideal target for NAs antiviral therapy in patients with CHB.The meaning of functional cure is,HBV cccDNA inactivity with serum HBsAg cleans/seroconversion,without relapse after drug withdraw.Thus,detection of cccDNA HBV content and its transcriptional activity is the most ideal index to judge the curative effect and functional cure of CHB.However,cccDNA detection require liver tissue samples by liver puncture procedure which is a kind of inasive examination, so it is difficult to carry out.Serum HBsAg is the transcription product of cccDNA,so it is convenient to be used as an surrogate the evaluating effect of antiviral treatment instead of cccDNA.Researches in our team show that 14% of CHB patients with NAs treatment over 10 years got HBsAg seroconversion.It means that the vast majority of patients with NAs treatment for 10 years are difficult to achieve drug withdrawal.In our long term follow up cohort of CHB patients treated with NAs antiviral therapy, we observed that about 80% CHB patients who obtained sustained viral response after a long time (at least 3 years) NAs antiviral therapy got a gradually decrease in HBsAg level, while another 20% patients’HBsAg maintained after declining to a certain high level,and a minority of them have no viral relapse for a long time (4-5years)even drug withdraw.It indicate that using HBsAg as the only indicator of NAs treatment’s endpoint may have some limitations.Are HBsAg express and secretion in these patients affected by other factors?We could deduce that there are an bypass of HBsAg expression.Therefore, the main purpose of this study is to use our results to confirm the different mechanisms of HBsAg expression, then explore HBV S gene integration’s influence on serum HBsAg levels after NAs treatment in CHB patients, and to provide reference for finding a more reliable treatment endpoint. Method:In this study,70 patients with CHB were selected.All study subjects are CHB patients and their diagnosis meet the guideline of CHB management and treatment in 2010. Patient got virological response(VR) within 6 months after NAs antiviral treatment and maintain VR over than 3 years. All patients have done liver biopsy at baseline and their liver samples have been stored in refrigerator. During the following up, there is no virological breakthrough. No evidence of HBV carriers, LC or HCC based on clinical criteria and ultrasound examination at baseline. Patients with immunodepressant and interferon treatment were removed.Applying Alu-PCR to detect the integration of HBV S gene from 70 CHB patients’baseline liver tissue.We collected baseline serum samples, and serum samples at the second year and the fourth year after treatment. These serum samples had been quantitative tested by Roche reagent.T test was used to compare the difference of HBsAg level(log value) between the two groups,repeated measures analysis of variance to compare the overall changes in the level of HBsAg(log value) in the two groups. Apply rank sum test to analysis the decrease amplitude of HBsAg level(log value) in the integration goup and the non-integration group.Using logistic regression and chi-square test to analysis these baseline clinical factors that may affect HBV S gene integration. Results:There were 15.7%(11/70) CHB patients who had found HBV S gene integration in the baseline liver tissue.(2)HBV S gene integration is the main factor that affect HBsAg levels after 2 years of NAs treatment(OR=10.398, P=0.004).(3)Baseline HBsAg levels were no difference between the two groups at baseline and the second year after treatment(3.69 & 3.72,P=0.722; 3.30 & 3.25,P=0.868); The level of HBsAg in integration group was higher than that in the non-integration group after 4 years of NAs treatment(3.29 & 2.86,P=0.037).(4)To Analysis the decrease amplitude of HBsAg level from the baseline to the second year after treatment between integration group and non-integration group, the results show that there is no statistic significance(2.63 & 2.65,P=0.478);The HBsAg level of the non-integration group from the second year to the fourth year after treatment was significantly decreased while the integration group was not(2.53 & 0.1,P=0.002).(5)Subgroup analysis found that gender,age,family history, genetype(B&C) and HBeAg status had no impact on HBV S gene integration.Conclusion:(1)There are a part of CHB patients with HBV S gene integration.(2)After obtaining 2 years effective treatment(sustained virological response) the HBsAg levels in patients who have the integration of HBV S gene in baseline liver tissue with no significant decline.(3)The integration of the HBV S gene can independently produce HBsAg, and it may not need to rely on cccDNA.(4)Because there may have an bypass of HBsAg expression,using HBsAg as the only indicator of NAs treatment’s endpoint may have some limitations.