Study of hepatitis B virus gene mutations with enzymatic colorimetry-based DNA microarray

Area of Science:

• Hepatology
• Molecular Biology
• Diagnostic Assays

Background:

• Hepatitis B virus (HBV) infections pose a significant global health burden.
• Accurate detection of HBV gene mutations is crucial for clinical management and understanding disease progression.
• Existing diagnostic methods may have limitations in sensitivity or accessibility for routine clinical use.

Purpose of the Study:

• To develop and validate a modified microarray method for detecting HBV gene mutations in a clinical setting.
• To assess the clinical utility of the developed assay for identifying specific HBV mutations.

Main Methods:

• Immobilization of site-specific oligonucleotide probes onto microarray slides.
• Hybridization with biotin-labeled HBV gene fragments amplified via two-step PCR.
• Detection using BCIP/NBT colorimetry following transfer to nitrocellulose membranes.

Main Results:

• Analysis of HBV genes from 99 Hepatitis B patients and 40 healthy donors.
• Significantly higher mutation frequencies in HBV pre-core/core (42%) and basic core promoter (BCP) regions (40%) in patients compared to controls (2.5%, 5%; P < 0.01).
• The colorimetry-based microarray demonstrated comparable sensitivity and reproducibility to traditional fluorescence methods.

Conclusions:

• Successful establishment of an enzymatic colorimetry-based DNA microarray assay for monitoring HBV mutations.
• Pre-core/core and BCP mutations in HBV genes are implicated as major causes of HBV infection in HBeAg-negative patients.
• These mutations may also contribute to the chronicity and severity of hepatitis B.