■为了分析隐匿性乙型肝炎病毒感染(OBI)血清样品中S区基因的主要亲水区(MHR)突变引起的氨基酸取代,探讨HBsAg漏检的原因。
■使用实验室开发的慢性乙型肝炎病毒(CHB)(10个样品)和OBI组(42个样品)中乙型肝炎病毒(HBV)的S区全长基因扩增,两轮PCR扩增技术。对PCR扩增产物进行测序/克隆测序,并将HBV中S区基因的核苷酸序列与各自的基因型共有序列进行比较。
■OBI组42个样品中只有20个成功扩增了S区基因,最低HBVDNA载量为20.1IU/ml。作为HBV中的S区基因,对68个克隆菌株进行测序。在OBI和CHB组MHR地区,突变率为3.21%(155/4828)和0.70%(5/710)。OBI组的基因突变率明显高于CHB组(P<0.05)。MHR区的常见突变类型为:I126T,L162R,K122E,C124R,和C147Y。s122、s126和s162的突变与亚型相关,其中大多数是C基因型。本研究中发现的高频突变位点L162R和K122E在以往文献中没有报道。
■这项研究的结果证实,MHR突变可导致HBsAg的漏检,产生了OBI。
UNASSIGNED: To analyze the amino acid substitution caused by mutations in the major hydrophilic region (MHR) of the S-region genes in the serum samples of occult hepatitis B virus infection (OBI), and to explore the reasons for the missed detection of HBsAg.
UNASSIGNED: The full-length gene of the S-region in hepatitis B virus(HBV) in the chronic hepatitis B virus(CHB)(10 samples) and OBI groups(42 samples) was amplified using a lab-developed, two-round PCR amplification technology. The PCR amplification products were sequenced/clone sequenced, and the nucleotide sequences of the S-region gene in HBV were compared to the respective genotype consensus sequence.
UNASSIGNED: Only 20 of the 42 samples in the OBI group had the S-region genes successfully amplified, with the lowest HBV DNA load of 20.1IU/ml. As S-region genes in HBV, 68 cloned strains were sequenced. In the OBI and CHB groups MHR region, with a mutation rate of 3.21% (155/4828) and 0.70% (5/710). The genetic mutation rate was significantly higher in the OBI group than in the CHB group (P<0.05). The common mutation types in the MHR region were: I126T, L162R, K122E, C124R, and C147Y.Mutations at s122, s126, and s162 were associated with subgenotypes, most of which being C genotypes. The high-frequency mutation sites L162R and K122E found in this study have not been reported in previous literature.
UNASSIGNED: The results of this study confirmed that MHR mutations can cause the missed detection of HBsAg, giving rise to OBI.