In Chronic hepatitis B (CHB) patients receiving long-term sequential Neucleos(t)ides(NAs), majority of these CHB patients experienced drug resistance and switched to Tenofovir disoproxil fumaratate(TDF). However, some of patients on long term TDF experienced impairment of renal function and bone mineral density. After Tenofovir alafenamide(TAF) was in clinical practice, these group of patients got an clinical option to switch from TDF to TAF. The investigators designed a prospective cohort study to evaluate the real life effectiveness and safety in participants with chronic HBV infection switch from TDF to TAF vs. maintaining on TDF.

Tenofovir disoproxil fumarate(TDF) have been associated with renal toxicity and reduced bone mineral density. Tenofovir alafenamide(TAF) is a novel tenofovir prodrug that reduces tenofovir plasma concentrations by 90%, thereby decreasing off-target side-effects. The investigators aimed to assess whether efficacy, safety, and tolerability were non-inferior in participants switched to TAF versus in those remaining on TDF. This is a prospective clinical study.

Inclusion Criteria:

1. Chronic hepatitis B,
2. Antiviral experienced,
3. Currently on long term TDF anti-HBV treatment,
4. HBV DNA < 6 log IU/ml (LLOD)
5. Able to sign the consent form of anticipating in the study

Exclusion Criteria:

1. Co-infected with HCV, HIV or other viral hepatitis,
2. Diagnosis of HCC