Different pre-S deletion patterns and their association with hepatitis B virus genotypes

Area of Science:

• Hepatology
• Virology
• Molecular Biology

Background:

• Hepatitis B virus (HBV) infection is a global health concern.
• Pre-S deletions are common in HBV carriers and linked to disease progression.
• HBV genotypes B and C are prevalent worldwide, with distinct epidemiological characteristics.

Purpose of the Study:

• To investigate the associations between different types of pre-S deletions and HBV genotypes.
• To compare pre-S deletion patterns in HBV genotype B (HBV/B) and genotype C (HBV/C) infected carriers.
• To explore the relationship between pre-S deletions, HBV genotypes, and clinical outcomes.

Main Methods:

• Direct DNA sequencing and clonal analysis of the pre-S region, basal core promoter (BCP), and precore (PC) mutations in 273 HBV carriers.
• Examination, alignment, and comparison of pre-S deletion sequences from age-matched HBV/B and HBV/C infected carriers.
• Analysis of deletion patterns in relation to clinical outcomes including chronic hepatitis (CH), liver cirrhosis (LC), and hepatocellular carcinoma (HCC).

Main Results:

• No significant differences in age, sex, viral load, or BCP mutations between HBV/B and HBV/C groups.
• Higher rate of PC mutation in HBV/B compared to HBV/C infected carriers (P = 0.003).
• Distinct patterns of pre-S deletions observed between HBV/B and HBV/C, particularly in the pre-S1 and pre-S2 regions, with specific epitope and functional site deletions showing significant genotypic differences.
• Pre-S deletion patterns varied between genotypes according to clinical outcomes, such as in CH and LC-HCC patients.

Conclusions:

• HBV/B and HBV/C infected carriers exhibit distinct pre-S deletion patterns.
• These genotypic differences in pre-S deletions may be associated with the progression of liver diseases.
• Further research is warranted to elucidate the precise mechanisms linking pre-S deletions, HBV genotypes, and liver disease pathogenesis.