Association of the S267F variant on NTCP gene and treatment response to pegylated interferon in patients with chronic hepatitis B: a multicentre study.

BACKGROUND: Sodium taurocholate co-transporting polypeptide (NTCP) is a cell receptor for HBV. The S267F variant on the NTCP gene is inversely associated with the chronicity of HBV infection, progression to cirrhosis and hepatocellular carcinoma in East Asian populations. The aim of this study was to determine whether the S267F variant was associated with response to pegylated interferon (PEG-IFN) in patients with chronic HBV infection. METHODS: A total of 257 patients with chronic HBV, treated with PEG-IFN for 48 weeks, were identified from 13 tertiary hospitals included in the hepatitis B database of the Thai Association for the Study of the Liver (THASL). RESULTS: Of these, 202 patients were infected with HBV genotype C (84.9%); 146 patients were hepatitis B e antigen (HBeAg)-positive (56.8%). Genotypic frequencies of the S267F polymorphism were 85.2%, 14.8% and 0% for the GG, GA and AA genotypes, respectively. S267F GA was associated with sustained alanine aminotransferase (ALT) normalization (OR = 3.25, 95% CI 1.23, 8.61; P=0.02) in HBeAg-positive patients. Patients with S267F variant tended to have more virological response, sustained response with hepatitis B surface antigen (HBsAg) loss at 24 weeks following PEG-IFN treatment. There was no association between the S267F variant and improved patient outcomes in HBeAg-negative patients. CONCLUSIONS: The S267F variant on the NTCP gene is independently associated with sustained normalization of ALT following treatment with PEG-IFN in patients with HBV infection who are HBeAg-positive. The findings of this study provide additional support for the clinical significance of the S267F variant of NTCP beyond HBV entry.

Treatment outcomes and validation of the stopping rule for response to peginterferon in chronic hepatitis B: A Thai nationwide cohort study.

BACKGROUND AND AIMS: Peginterferon has demonstrated effectiveness in clinical trials in patients with chronic hepatitis B (CHB). However, its efficacy in real-life settings remains unclear. We investigated the efficacy of peginterferon for CHB and validated the performance of previously identified response predictors in clinical practice. METHODS: We analyzed prospectively collected data from a Thai nationwide cohort of CHB patients treated with peginterferon alfa-2a (180 µg/week, 48 weeks). RESULTS: Among a total of 233 patients, mostly with genotype B or C, sustained response was observed in 23% of 135 hepatitis B e antigen (HBeAg)-positive patients (HBeAg seroconversion with hepatitis B virus [HBV] DNA < 2000 IU/mL) and 42% of 98 HBeAg-negative patients (HBV DNA < 2000 IU/mL with aminotransferase normalization) at 24 weeks after treatment. Age, sex, presence of cirrhosis, genotype, and pretreatment levels of aminotransferase, HBV DNA, and hepatitis B surface antigen (HBsAg) were not identified as significant predictors of sustained response. In HBeAg-positive patients, HBsAg > 20 000 IU/mL at week 12 provided a good stopping rule, with a negative predictive value of 96%. In HBeAg-negative patients, the performance of 12-week stopping rules of no decline in HBsAg with a < 2log10 decline in HBV DNA and a < 10% log10 decline in HBsAg showed modest negative predictive values of 80% and 66%, respectively, for achieving sustained response. CONCLUSION: Outcomes in CHB patients treated with peginterferon in a clinical setting are similar to those demonstrated in clinical trials. Application of the early stopping rule based on HBsAg quantification may allow individualization of therapy, particularly in HBeAg-positive patients.