Jpn. J. Infect. Dis., 59 (1), 42-45, 2006
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Original Article
YMDD Mutations and Genotypes of Hepatitis B Virus in Northern China
Di Li1, Hong-Xi Gu1, Shu-Yun Zhang1, Zhao-Hua Zhong1, Min Zhuang1,2 and Toshio Hattori2*
1Department of Microbiology and Research Center of The Second Affiliated Hospital, Harbin Medical University, Harbin, China, and 2Infectious and Respiratory Disease Department, Tohoku University, Sendai 980-8574, Japan
(Received September 20, 2005. Accepted December 12, 2005)
*Corresponding author: Mailing address: Infectious and Respiratory Disease Department, Tohoku University, Aoba-ku, Sendai 980-8574, Japan. E-mail: hattori.t@rid.med.tohoku.ac.jp
SUMMARY: The objective of this research was to determine the relationship between YMDD mutations and the genotypes of hepatitis B virus (HBV) during lamivudine treatment. HBV genotypes were determined by nested PCR with 6 pairs of HBV genotype-specific primers (A to F) in serum specimens from 142 hepatitis B patients receiving lamivudine antiviral therapy. YMDD mutations were detected by fluorescent hybridization bioprobe PCR and melting curve assay (FH-PCR-MC). Among 142 serum specimens, 13 samples were genotype B (9.2%), 125 samples were genotype C (88%), 4 samples were genotype D (2.8%), and 80 YMDD mutations were found. The YMDD mutation rates were 69.2 and 54.4% in genotype B and genotype C, respectively. There was no significant difference in the YMDD mutation rate between genotypes B and C. Nine genotype B sera with YMDD mutations were found, including 2 YIDD mutations and 7 YVDD (M + V) mutations. Sixty-eight genotype C sera with YMDD mutations were found, including 34 mutations I (M + Ij and 17 mutations V (M + V). There was a significant difference in the YMDD mutation types between genotypes B and C. Our results suggested that the YMDD mutation rate was 56.3% in patients treated with lamivudine for 2 - 4 years. YIDD was the main mutation type. The YMDD mutation rate showed no significant difference between HBV types B and C (P > 0.05), while the YMDD mutation types showed a significant difference between HBV types B and C in Northern China (chi-square test = 4.6, P < 0.05).