The natural YMDD mutations of hepatitis B virus in Western China

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Scand J Infect Dis. 2011 Aug 19. [Epub ahead of print]

The natural YMDD mutations of hepatitis B virus in Western China.

Zhao J, Guo Y, Yan Z, Liang P, Zhang J, Liu Y.

Source

State Key Laboratory of Cancer Biology, School of Pharmacy, the Fourth Military

Medical University , Xi'an , China.

Abstract

Abstract Background: To provide a scientific basis for clinical genetic

diagnosis before lamivudine treatment in hepatitis B virus (HBV) patients, the

rate of natural YMDD mutations in Western China and the correlations between

YMDD mutations and several factors were investigated in this study. Methods: A

pyrosequencing approach for detecting YMDD mutations was first developed. The

sensitivity of the pyrosequencing approach was determined by assaying polymerase

chain reaction (PCR) products generated from 10-fold serial dilutions of HBV DNA

and PCR products from mixed control plasmids with different ratios. Natural YMDD

mutations in Western China were evaluated by analyzing the clinical samples from

HBV patients who had no experience of using lamivudine, and the existence of

YMDD mutants was further confirmed by real-time PCR. Results: With the developed

pyrosequencing approach, YMDD mutations could be determined within 2 h after PCR

amplification. About 10 copies of HBV DNA per reaction were required to obtain

sufficient PCR products to produce clear and accurate pyrosequencing patterns.

The pyrosequencing approach developed had the capacity to detect minor mutants;

most HBV mutants in samples were minor ones. The rate of natural YMDD mutations

in Western China was 15.56%. The hepatitis B e antigen (HBeAg) level in serum

was correlated with YMDD mutations. Conclusions: In Western China, natural YMDD

mutations occur at a rate of 15.56%, and it is suggested that pyrosequencing be

performed to detect YMDD mutations before lamivudine treatment in patients with

a chronic HBV infection.

PMID: 21851334 [PubMed - as supplied by publisher]