Understanding early serum hepatitis D virus and hepatitis B surface antigen kinetics during pegylated interferon-alpha therapy via mathematical modeling

Interferon lambda-3 polymorphism and response to pegylated interferon in patients with hepatitis D

BACKGROUND

Specific single nucleotide polymorphisms (SNPs) near the interferon lambda-3 (IFNλ3) gene (formerly interleukin 28B) influence the response to treatment with interferon in hepatitis C patients. We aimed to investigate such an influence in hepatitis D patients.

METHODS

The study population consisted of hepatitis D patients who were previously treated with pegylated interferon for one year and who were spontaneous clearers of the virus post recent superinfection. The SNP of IFNλ3, rs12979860, was determined by polymerase chain reaction-restriction fragment length polymorphism protocol.

RESULTS

The total number of patients was 64; median age was 30.5 years and 53 were male. The number of patients with sustained virological response 1 year post-treatment was 17, non-responders 29, relapsers 11 and spontaneous clearers post superinfection 7. Cirrhosis was present in 28 (44%). IFNλ3, rs12979860 genotype CC, was present in 41 (64.1%), CT in 21 (32.8%) and TT in 2 (3.1%). There was no difference in the body mass index, baseline alanine aminotransferase, hepatitis B e antigen and HBV DNA status among patients with sustained response and response failure (no response or relapse). The median age of response failures was 33.5 years compared to 26 in responders (P=0.024). They had higher gamma glutamyl transferase levels (P=0.030) and cirrhosis (P=0.003). Genotype CC was present in 29/40 of response failures compared to 9/17 of the responders (P=0.152). Logistic regression analysis showed that cirrhosis was the independent risk factor for failure to have a response (P=0.001). 4/7 patients with spontaneous clearance had genotype CC.

CONCLUSIONS

IFNλ3 rs12979860 SNP does not have any significant influence on long-term hepatitis D clearance. Presence of cirrhosis may influence the response.

Long-term therapy of chronic delta hepatitis with peginterferon alfa

BACKGROUND

Chronic delta hepatitis virus (HDV) infection rapidly progresses to cirrhosis. Treatment with peginterferon for up to 2 years is often without durable response.

AIM

To examine the efficacy and safety of long-term peginterferon in achieving a durable response.

METHODS

Treatment was initiated with 180 μg/week of peginterferon alfa-2a with titration to a maximal tolerable dose, for up to 5 years. Liver biopsies and hepatic venous pressure gradients (HVPG) were evaluated at baseline, 1, 3 and 5 years. The primary endpoint was histological improvement or loss of serum HDV and HBsAg at 3 years.

RESULTS

Thirteen patients were treated for a median of 140 weeks (6-260) with an average peginterferon dose of 180 μg/week (90-270). At baseline, most had advanced disease (median Ishak fibrosis = 3) with portal hypertension (HVPG = 10.2 ± 6 mmHg). Five of 13 patients (39%) achieved the primary endpoint, with three seroconverting for HBsAg after 24, 37 and 202 weeks of treatment. Histological inflammation improved after 1 year, (median HAI: 10 vs. 7, P = 0.01) with persistence in 4/5 patients at 3 years (median HAI: 7.5). Greatest improvements occurred in the first year. Baseline bilirubin and HBsAg levels were significantly lower in virological responders than nonresponders. After 12 weeks, virological responders had a significant decline in HBsAg (1.5 log10 IU/mL, P = 0.05).

CONCLUSION

Despite increased doses and duration of therapy, treatment of chronic HDV with peginterferon remains unsatisfactory. Quantitative measures of HBsAg may be an important biomarker of early response to peginterferon therapy in chronic delta hepatitis virus infection.