Haikou Area Lamivudine Against Hepatitis B Virus Treatment Induced Ymdd Mutation

Objective To investigate the influence factors of YMDD mutation of HBV by observing the presences of YMDD mutation in patients with and natural YMDD variation in patients without lamivudine therapy in Hainan areas.Methods PCR-Fluorescense quantity technique was used to detect YMDD mutations of HBV in 110 patients with chronic hepatitis B in Hainan province, whom were randomly divided into 2 groups. The treatment group with 80 patients was given the therapy with lamivudine and liver protecting drugs. The control group with 30 patients was only given liver protecting drugs. The qualitative analysis of motif of HBV YMDD in all subjects was respectively conducted at 6 and 12 months after treatment to detect the YMDD mutation.Results1.After one year treatment with lamivudine the negative conversion rate of serum HBVDNA, normalization rate of ALT were 41.25% (33/80), 60% (48/80) respectively. The level of ALT (X±s) before treatment wasl38.36±67.52 U/L. The level of ALT after 12 months treatment with lamivudine was 51.81±28.29 U/L(t = 18.151,P<0.01).2. When comparing the patients with lamivudine therapy, the rate of abnormal ALT level was 61.3% in YMDD mutation group, and it was significantly higher than the rate in wild YMDD group which was 20.4% (χ~2=13.71 P<0.01).3. The YMDD mutation rates before treatment of HBVDNA≥106copies/ml group and HBVDNA<106copies/ml group were respectively 47.2% and 31.8%. No significant difference was found between groups (χ~2=13.71,P>0.05) .4.YMDD mutations were detected in 15 patients after 6 months with the rate of 18.8% (15/80) and in 31 patients after 12 months with the rate of 38.8% (31/80) both in treatment group. Within these 31 YMDD mutations, 15 of which were YIDD, 7 were YVDD and 9 were YIDD+YVDD positives. Meanwhile, YMDD mutations were detected in 4 patients after 6 months with the rate of 13.3% (4/30) and in 9 patients after 12 months with the rate of 30.0% (9/30) both in control group. Within those 9 YMDD mutations, 2 of which were YIDD, 1 were YVDD and 6 were YIDD+YVDD positives.Conclusions1. Lamivudine therapy can prohibit HBVDNA replication in patients with chronic hepatitis B, and improve liver function .YMDD mutation would occur at 6 months after the anti-HBV therapy by using Lamivudine. The longer the duration of therapy, the higher the detective rate of mutation.2. The increase of ALT level is relevant to YMDD mutation during the Lamivudine therapy. The YMDD mutation is not predictable by testing the HBVDNA level before treatment. 3. The mutant strains of YMDD also presented in the patients without Lamivudine therapy. This implied that the YMDD mutation should be regularly detected in all patients with chronic hepatitis B in clinic, even whom without the Lamivudine therapy.4. The natural variation of YMDD is rather popular in Haikou area and the mixovariation is the majority.