[Clinical study of oligonucleotide microarray on monitoring the lamivudine-resistance mutations in hepatitis B virus].

OBJECTIVE: To evaluate the mutations of lamivudine-resistance using oligonucleotide microarray in hepatitis B virus (HBV) infected patients. METHODS: A randomized clinical trial was conducted on 20 lamivudine-treated patients for 18 months and 10 patients as controls. The serum HBV DNA was amplified by PCR and the lamivudine-resistance mutations in YMDD region were assayed by 4 sites microarray developed before. RESULTS: This microarray could clearly differentiate the wide-type from mutated-type HBV with lamivudine-resistance mutations. The rate of mutations in YMDD region increased with the time of lamivudine treatment (chi2=6.69, P<0.01). The most common mutated type was M539V+L515M and next M539I. Continuous administration of lamivudine was no benefit for inhibiting the replication of HBV with YMDD mutation but helpful for wide-type HBV. CONCLUSION: The routine serum HBV DNA assay by PCR may introduce prejudice in monitoring HBV inhibitory effect by lamivudine, while the microarray technique can avoid this and is one of the best ways to monitor the lamivudine-resistance mutations in HBV. There is no effect of lamivudine on HBV with YMDD mutation in clinical practice.