阿德福韦酯耐药株感染者乙型肝炎病毒基因型和多聚酶区基因变异分析

Polymerase Region Mutations and Hepatitis B Virus Genotypes in Chronic Hepatitis B Patients with Adefovir Resistant Strains

目的了解阿德福韦酯耐药株感染者HBV基因型、多聚酶区基因变异位点和变异类型,并分析HBV基因型和多聚酶区基因变异的关系。方法应用PCR扩增和直接测序法检测73例阿德福韦酯耐药患者HBV基因型、多聚酶基因区变异位点、病毒载量。结果 73例阿德福韦酯耐药株感染者中,HBV B基因型占35.6%,C型占64.4%;HBV多聚酶基因区基因突变位点主要以rtA181V/T(39.8%)、rtN236T(31.5%)为多见,rtA181V/T+rtN236T(20.5%),其他(8.2%);其中rtA181V/T位点变异中B型占10.3%,C型占89.7%;rtN236T位点变异中B型占78.3%,C型占21.7%。rtA181V/T+rtN236T位点变异B型占26.7%,C型占73.3%;基因型B和C的病毒载量分别为(6.38±1.24)lg和(6.27±1.10)lg拷贝/毫升。结论阿德福韦酯耐药株感染者HBV基因型主要为B型和C型;HBV多聚酶区基因突变位点主要为rtA181V/T和rtN236T,基因型与多聚酶区基因突变位点之间有一定相关性。C基因型易发生rtA181V/T变异,B基因型多出现rtN236T变异。C基因型比B基因型更易出现rtA181V/T+rtN236T双突变,可能与C基因型容易导致的严重的肝脏疾病有关,基因型与病毒载量之间无相关性。

Objective To investigate genotypes characteristics,HBV polymerase gene mutation sites and types in Adefovir resistant strains infected patients,and analyze the relationship between HBV genotypes and polymerase gene mutations. Methods Serum samples were collected from 73 hepatitis B patients resistant to Adefovir. HBV P gene RT region was amplified by PCR. The PCR products were directly detected for the genotypes, polymerase region mutations sites and viral loads. Results The mutation forms were rtAl81 V/T （39.8%） , rtN236T （31.5% ） , rtA181V/T ＋ rtN236T （20.5 % ） , others （8.2%） in 73 patients harboring YMDD mutations. The most frequent genotypes were B （35.6%）and C （64.4%）. The rtA181V site mutation in type B and C were 10.3% and 89.7% ;rtN236T site mutation in type B and C were 78.3% and 21.7% ,rtAl81V ＋ rtN236T site mutation in type B and C were 26.7% and 73.3%, The virus load of genotype B and genotype C were （6.38± 1.24） lg and （6.27±1.10） lg copies/ml. Conclusion The main genotypes in Adefovir resistant strains infected patients were B and C. Genotypes had no direct correlation with the viral load. Adefovir - resistance mutations and genotypes have relevance. The mutation frequency of rtA181V/T in genotype C was higher than in genotype B, and rtN236T in genotype B was higher than in genotype C. Genotype C other than B was more likely to have double mutations because of genotypes C being easy to cause severe liver diseases.