RESUMO
BACKGROUND: The early detection of hepatitis B virus (HBV) mutants in clinical samples is important when monitoring chronic HBV patients with lamivudine-resistant mutations during lamivudine therapy. METHODS: The AllGlo™ probes were designed to distinguish between wild-type (YMDD) and mutant (YVDD and YIDD) strains of HBV. The sensitivity and specificity of the assay were evaluated using a series of diluted mixtures of wild-type and mutant plasmids. This assay was compared with direct sequencing and the mutation-specific primer assay. RESULTS: Each YMDD, YVDD, and YIDD probe only detected its corresponding plasmid. Moreover, the assay correctly identified negative samples from 40 non-HBV infected patients and 100 healthy controls. The detection limit of this assay was 50 copies/ml for YVDD and YIDD. The assay could detect the mutant strains when they were present at ≥10% within a mixed virus population. The assay was fully concordant with direct sequencing in 34 samples (56.7%) and partially concordant in 26 samples (43.3%), and detected more types of the HBV motif than direct sequencing. CONCLUSIONS: AllGlo™ probe assay is a novel, sensitive and specific assay to detect lamivudine-related HBV mutants, therefore, may be useful for monitoring chronic HBV patients treated with lamivudine.
