Development of a new method for detecting a mutation in the gene encoding hepatitis B virus reverse transcriptase active site (YMDD motif)

It is a developing problem that long-term treatment with lamivudine, which is a therapeutic drug for chronic hepatitis B under clinical study, causes mutation in the region encoding the YMDD motif in the HBV DNA polymerase gene, inducing lamivudine-resistant HBV in some cases. Therefore, we developed a new method of detecting gene mutation using the mini-sequencing method. Serum samples collected from patients with HBV infection (60 cases untreated with lamivudine and four cases treated with lamivudine) were examined for gene mutation by this method. As a result, while there were no mutations detected in lamivudine-untreated cases, a mutation from YMDD to YVDD or YIDD was detected in cases with lamivudine administration. In cases in which the mutation was detected, HBV gene obtained from the serum was subcloned and sequenced to detect the mutation, confirming that this method is appropriate for detecting gene mutations. This method may be a rapid, simple, and reliable method of detecting resistant virus that can process a number of serum samples that will be necessary to be tested when lamivudine is approved and administration to chronic hepatitis B patients is initiated. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.