慢性乙型肝炎病毒感染者病毒前C区和基本核心启动子区变异检测及意义

目的 探讨乙型肝炎病毒（HBV）前C区和基本核心启动子（BCP）区变异与基因型及疾病进展间的关系。方法 收集HBV携带者（ASC）、慢性乙型肝炎（CHB）、肝炎肝硬化（LC）、肝细胞肝癌（HCC）患者血清148份，用半巢式聚合酶链反应扩增HBV前C／C基因部分片段，产物纯化后直接测序，检测前C区A1896及BCP区T1762／A1764变异。用S基因聚合酶链反应-限制性片段长度多态性分析（PCR-RFLP）方法确定HBV基因型。结果 有128份血清能够成功分型和测序，其中B基因型60份，C基因型68份。在B基因型感染者中前C区A1896变异检出率（48．33％）明显高于C基因型感染者（29．41％，X^2=4．83，P〈0．05）；而BCP区T1762／A1764变异检出率却明显低于C基因型感染者，差异亦有统计学意义（30．00％：73．54%，X^2=24．25。P〈0．05）。前C区A1896变异在CHB、LC、HCC中的阳性检出率分别为46．88％（15/32）、39．39％（13／33）、51．52％（17／33）。与ASC的13．33％（4／30）相比，P分别〈0．05，差异有统计学意义。BCP区T1762／A1764变异检出率在HCC、LC组分别为87．88％（29／33）和72．73％（24／33）．明显高于CHB组的37．50％（12／32）及ASC组10.00％（3／30）（P〈0．05）。结论 前C区A1896变异常见于B基因型感染者，而BCP区T1762/A1764变异C基因型感染者多见。除ASC外．前C区A1896变异与疾病进展关系不大．而BCP区T1762/A1764变异与乙型肝炎进展及顶后相关。

The association of hepatitis B virus precore/basic core promoter mutations with genotype and progression of liver disease

Objective To study association of hepatitis B virus(HBV) precore (pre c)/basic core promoter(BCP) mutations with the genotype or the progression of liver disease. Methods The serum samples from 148 patients with HBV-relative diseases were collected, including 31 asymptomatic carriers, 32 with chronic hepatitis B (CHB), 40 with liver cirrhosis(LC) and 45 with hepatocellular carcinoma(HCC). The genes covering HBV pre c and BCP were amplified by nested polymerase chain reaction (nPCR). The PCR products were subjected to direct sequencing and the mutations in pre c 1896 and BCP 1762/1764 were determined by sequence analysis. HBV genotypes were also detected in the sera by restriction fragment length polymorphism based on S-gene PCR products. Results Of 148 serum samples of HBV, 128 were successfully genotyped and sequenced. There were 60 genotype B and 68 genotype C. The mutation in pre c (A1896) was significantly higher in genotype B than in genotype C (48.3% vs 29.34%, P<0.05). On the contrary, the mutation at BCP (T1762/A1764) was significantly lower in genotype B than in genotype C (30.0% vs 73.5%, P<0.01). The detection rate of pre c mutation (A1896) was almost same among CHB, LC and HCC. However, there was significant difference in the detection rate of BCP mutation (T1762/A1764) among patients with HCC, LC and CHB. Conclusions The mutations in the BCP region at nucleotide 1762/1764, which is common in genotype C, are closely related to progression of chronic liver disease. Mutation in the pre c (1896), which is frequent in genotype B, may contribute to inactivation of chronic liver disease.