Detection of Hepatitis B Virus M204V Mutation Quantitatively via Real-time PCR

BACKGROUND AND AIMS: Drug-resistant DNA mutations of the hepatitis B virus (HBV) affect treatment response in chronic hepatitis B patients. We have established a new, sensitive, specific, accurate and convenient real-time PCR method to detect HBV mutations quantitatively. METHODS: Blood samples were collected from patients showing viral breakthrough, primary nonresponse, or poor response during treatment, and mutations were detected via direct sequencing to assess our method. A plasmid containing the M204V mutation was synthesized and standard curves plotted. RESULTS: The determination coefficient for linear correlation between Ct and log plasmid copy numbers was 0.996, where Ct value was −3.723log (DNA concentration) +48.647. Coefficients of variation indicated good reproducibility. Correctness was within tolerable bias. Limit of detection was 10(3) copies/mL. Specificity, accuracy, positive predictive value and negative predictive value were 92.86%, 100%, 96.88%, 100% and 94.74%, respectively. CONCLUSIONS: These results show that our method can be used to detect HBV M204V mutations with the advantages of sensitivity, specificity and efficiency, providing a new choice for monitoring drug resistance.