HBeAg阴性慢性乙型肝炎患者乙肝病毒基因变异和分型研究

摘要

目的 探讨HBeAg阴性的慢性乙肝患者乙肝病毒基因变异情况和分型的关系及其临床意义.方法 采用荧光定量聚合酶链反应(PCR)检测乙肝病毒脱氧核糖核酸(HBV-DNA)、实时荧光PCR检测乙肝病毒基因分型、PCR-反向点杂交方法检测乙肝病毒基因变异,并对其关系进行分析.结果 在389例HBeAg阴性的慢性乙肝患者血清中HBV-DNA检出阳性214例(55.01％),阴性175例(44.99％),HBV-DNA拷贝数在1×103～水平的例数最高,为102例(26.22％),其次为1×104～水平,41例(10.54％),两者比较有性差异(P＜0.001)；基因变异方面,HBV-DNA载量在1×105～水平发生前-C区变异比例为71.43％(15例),发生BCP区变异比例为52.38％(11例),两者比较有性差异(P＜0.001),并且HBV-DNA载量越高基因变异发生比例越大；214例HBeAg阴性HBV-DNA阳性的慢性乙肝患者基因分型与基因变异结果中,基因分型A型6例(2.80％),B型84例(39.25％),C型106例(49.53),D型7例(3.27),混合型11例(5.14％),两者比较有性差异(P＜0.001)；而发生前-C区变异结果中A型发生比例为16.67％(1例),B型发生比例为36.90％(31例),C型发生比例为44.34％(47例)；在BCP区变异结果中B型发生比例为19.05％(16例),C型发生比例为26.42％(28例),两者比较有性差异(P＜0.001),A、D型与混合型均未检出变异.结论 HBeAg阴性HBV-DNA阳性的慢性乙肝患者病毒复制水平处于一个相对较低水平；HBV-DNA载量越高基因变异发生比例越大；本地区乙肝病毒基因分布以B、C型为主,其中B、C基因型HBeAg阴性的慢性乙肝患者基因变异发生率较高.%Objective To investigate the genetic variation and typing of hepatitis B virus (HBV) in patients with chronic hepatitis B in relation to HBeAg status. Methods Fluorescence quantitative polymerase chain reaction (PCR) was employed to detect serum HBV DNA in patients with chronic hepatitis B negative for HBeAg. Real-time fluorescent PCR and PCR-reverse dot blot hybridization were used to detect HBV genotypes and mutations, respectively. Results Of the 389 patients, 214 (55.01%) were positive and 175 (44.99%) were negative for HBV DNA; 102 (26.22%) had a HBV DNA copy number of 1×103, and 41 (10.54%) had a copy number of 1×104 (x2=226.6729, P＜0.001). Of the 21 patients with a HBV DNA load of 1×105,15 (71.43%) were found to have precore mutations, and 11 (52.38%) had basic core promoter (BCP) mutations; a higher HBV-DNA load was associated with an increased incidence of HBV mutations. In the 214 patients positive for HBV DNA, HBV genotypes A, B, C, D and the mixed type were found in 6 (2.80%), 84 (39.25%), 106 (49.53%), and 7 (3.27%), and 11 (5.14%) patients, who showed precore mutation rates of 16.67% (1 case), 36.90% (31 cases), 44.34% (47 cases), 0, and 0, and BCP mutation rates of 0,19.05% (16 cases), 26.42% (28 cases), 0, and 0, respectively, demonstrating significant differences in HBV mutations between the genotype groups (P＜0.001). Conclusion HBeAg-negarive and HBV DNA-posirive patients with chronic hepatitis B have a relatively low HBV replication level, and HBV DNA load is associated with HBV mutations. The B and C genotypes are more likely to have HBV mutations in HBeAg-negative patients.