论文部分内容阅读
目的探讨HBV基因型及S基因序列特点与慢性乙型肝炎(CHB)患者HBsAg和抗-HBs共存的内在相关性以及HBsAg+/抗-HBs+的发生机制及意义。方法共收集49例HBsAg+/抗-HBs+CHB患者的血清HBVDNA样本,采用PCR-RFLP及测序法鉴定其基因型,并与267例HBsAg+/抗-HBs-CHB患者的HBV基因型分布进行比较。对6例HBsAg+/抗-HBs+CHB患者(Ⅰ组)的HBVS基因进行克隆测序,并与HBsAg+/抗-HBs-CHB患者(Ⅱ组)进行对比,分析变异种类及频率等的差异。结果 HBsAg+/抗-HBs+CHB患者HBV基因型B、C及B/C混合感染的构成比分别为63.3%(31/49)、26.5%(13/49)、10.2%(5/49),而对照组上述构成比分别为52.8%(141/267)、46.1%(123/267)、1.1%(3/267),两组构成比差异有统计学意义(P<0.01)。Ⅰ组HBsAg各区段,特别是主要亲水区(MHR)的变异位点明显多于Ⅱ组;发现了若干新变异、少见的W196和C69终止突变,1例患者检测到G145R变异。某些患者HBsAgMHR-2(包含a决定簇)并未发现变异。结论 HBV基因型的差异及HBsAg变异增多可能是部分CHB患者出现HBsAg+/抗-HBs+的原因之一;基因型B或B/C混合感染相对更易出现HBsAg+/抗-HBs+。HBsAg变异增多是CHB患者出现HBsAg+/抗-HBs+的重要机制之一。某些患者HBsAgMHR-2并无变异,提示HBsAg/抗-HBs共存还存在其他机制。
Objective To investigate the relationship between HBV genotype and S gene sequences and the coexistence of HBsAg and anti-HBs in patients with chronic hepatitis B (CHB) and the pathogenesis and significance of HBsAg + / anti-HBs +. Methods Serum samples of HBsAg from 49 patients with HBsAg + / anti-HBs + CHB were collected and analyzed by PCR-RFLP and sequencing. HBV genotype distribution was compared with that of 267 HBsAg / anti-HBs-CHB patients. The HBVS gene of 6 HBsAg + / anti-HBs + CHB patients (group Ⅰ) was cloned and sequenced, and compared with those of HBsAg + / anti-HBs-CHB patients (group Ⅱ). Results The proportions of HBV genotypes B, C and B / C in HBsAg + / anti-HBs + CHB patients were 63.3% (31/49), 26.5% (13/49), 10.2% (5/49) The control group, the above composition ratio was 52.8% (141/267), 46.1% (123/267), 1.1% (3/267), the difference between the two groups was statistically significant (P <0.01). The mutation sites of HBsAg, especially the major hydrophilic regions (MHRs) of group Ⅰ were significantly more than those of group Ⅱ. A few new and rare mutations of W196 and C69 were found. One case of patients had G145R mutation. Some patients HBsAgMHR-2 (including a determinant) found no mutation. Conclusions The differences of HBV genotype and the increase of HBsAg mutation may be one of the causes of HBsAg + / anti-HBs + in some patients with CHB. HBsAg + / anti-HBs + is more likely to occur in patients with genotype B or B / C mixed infection. HBsAg mutation is one of the important mechanisms of HBsAg + / anti-HBs + in CHB patients. There is no variation in HBsAgMHR-2 in some patients suggesting that other mechanisms exist for the coexistence of HBsAg / anti-HBs.