Detection And Clinical Significance Of HBV YMDD Mutation In Patients With Chronic Hepatitis B

Objective to detect YMDD mutations in HBV polymerase gene region of the patients with HBV infection by nowly advanced gene chip technique and explore its clinical significance.Methods 36 patients with chronic hepatitis B by lamivudine for four to eighteen months and 14 patients having no any experience of using antiviral agents were included in the study. Course,ALT,HA,LN,Type IV collagen were evaluated and analysed with SPSS software.Results of 36 patients with HBV DNA positive during lamivudine therapy,10 (27.8%) had YMDD mutations: YIDD in three patients, YVDD in six patients and YMDD+ YIDD in one patient. The YMDD mutation was not detected in 6 patients at 4 to 6 months by lamivudine, the YMDD mutation was detected in 7 patients (30.4%) at 7 to 12 months and 3 patients (42.9%) at 13 to 18 months. Course in wild YMDD was 3.1±1.5 years, No difference was observed between wild YMDD and YMDD variation (P>0.05). The serum ALT level was different between patients with and without YMDD mutation(P<0.05). HA,Type IV collagen,LN in wild YMDD were (57.0±21.2), (54.5±20.9), (82.1±39.6) and those in YMDD variation were (59.5±22.0), (62.5±22.7), (62.5±14.7) respectively(P>0.05). Out of 14 serum samples of HBV DNA positive patients non-antiviral therapy, 2 cases were YMDD+ YVDD mutations.Conclusions The emergence time of variants is 6 months after treatment. ALT level after YMDD mutation changed more highly than before YMDD mutation. In immunocompetent chronic hepatitis B patients, YMDD mutations have not accelerated advanced hepatic fibrosis. HBV YMDD mutations have existed in several patients HBV DNA positive before antiviral therapy. To guide reasonably antival therapy in clinic and make therapic remedy, it is necessary for HBV-infected patients before or after antiviral therapy to detect HBV YMDD mutations.