A comprehensive HBV array for the detection of HBV mutants and genotype

ObjectiveTo develop a comprehensive hepatitis B virus (HBV) array providing simultaneous analysis of 8 genotypes, 47 mutations of reverse-transcriptase polymerase gene and 18 mutations of S gene.MethodOligonucleotides corresponding to various HBV-normal and -mutant sequences were spotted onto pre-treated glass slides. Single-stranded templates of the HBV gene fragment were prepared from serum-DNA of HBV-infected patients by 2-staged PCR and subjected to allele-specific arrayed-primer extension with Cy5-dCTP. Fluorescein-labelled products were scanned at 670 nm.ResultsComparative analysis of 100 unrelated samples using the array and a commercial kit, revealed 44 with additional mutations from the array, these were confirmed by sequencing. Analysis of 381 samples from 45 patients during 1–3 years of anti-viral therapy showed improved sensitivity with detection of drug-resistant mutations months before clinical relapse. The lower detection limit was 28 copies/mL.ConclusionThe array is better than many existing methods as it provides both mutations and genotype data in a single analysis.

► A comprehensive Hepatitis B array.
► Simultaneously detects 8 genotypes, 47 drug-resistant rt-Pol mutants, 18 S gene mutants.
► Enhanced sensitivity down to 28 viral copies/ml.
► Allows early detection of resistance to anti-viral drugs.