Department of Laboratory, Shenzhen Blood Center, Shenzhen, China.
Department of Laboratory, Heyuan Blood Center, Heyuan, China.
Front Immunol. 2022 May 13;13:754383. doi: 10.3389/fimmu.2022.754383. eCollection 2022.
All Chinese blood centers have implemented mini pool (MP) HBV nucleic acid testing (NAT) together with HBsAg ELISA in routine donor screening since 2015. The prevalence of occult hepatitis B virus infection (OBI) in donors from different regions varies, and the molecular characterization of the HBV DNA and clinical outcomes of these OBIs remain largely unexplored.
Blood donations from Heyuan city in Southern China were screened by HBsAg ELISA and HBV MP8 NAT. Donations with HBsAg-/HBV DNA+ were collected for this study. Molecular characterizations of HBV DNAs were further analyzed by various DNA amplification assays including quantitative PCR (qPCR) and nested PCR, amplifying the basic core and pre-core promoter regions (BCP/PC). The HBsAg (S) region from HBV DNA was isolated by high-volume nucleic acid extraction. Notable mutations were identified by comparison to the HBV reference sequences. The clinical outcomes of the donors with OBIs were further followed for nearly 3 years.
Seventy OBIs from 44,592 donations (0.15%) that we identified and reported previously were enrolled for this current study. HBV sequences were obtained from 44/70 OBIs, and genotyping analysis showed that 42/44 (95.2%) OBIs were genotype B, and 2/44 (4.8%) were genotype C. Interestingly, mutation analysis revealed that various mutations including M133L/T, F134L, P142L, V168A, R169H, S174N, L175S, and V177A of HBV DNA affecting HBsAg detection were observed in genotype B OBIs. Two notable mutations, T47K and L53S, were identified in genotype C OBIs. Follow-up studies showed that 3/31 (9.7%) OBIs converted to HBsAg+ as chronic infections while 1/31 (3.2%) HBV DNA was undetectable (classified as recovery) and 27/31 (87.1%) remained as OBIs.
Various notable mutations affecting HBsAg detection were observed in blood donors with OBIs in Heyuan city of Southern China. Follow-up studies showed that most OBIs remained as OBIs with fluctuating or low viral loads. Higher sensitive HBV ID NAT is recommended for donor screening to further reduce the transmission risk of OBIs.
自 2015 年以来，中国所有血液中心在常规献血者筛查中同时实施了乙型肝炎病毒（HBV）小池（MP）核酸检测（NAT）和乙型肝炎表面抗原 ELISA。不同地区献血者隐匿性乙型肝炎病毒感染（OBI）的流行率不同，HBV DNA 的分子特征及其隐匿性感染的临床结果仍在很大程度上尚未得到探索。
对来自中国南方河源市的血液捐献者进行乙型肝炎表面抗原 ELISA 和 HBV MP8 NAT 检测。对 HBsAg-/HBV DNA+的献血者进行了此项研究。通过包括定量 PCR（qPCR）和巢式 PCR 在内的各种 DNA 扩增检测进一步分析 HBV DNA 的分子特征，扩增基本核心和前核心启动子区域（BCP/PC）。通过大容量核酸提取从 HBV DNA 中分离 HBsAg（S）区。通过与 HBV 参考序列比较鉴定显著突变。对隐匿性感染献血者的临床结果进行了近 3 年的随访。
我们先前报道的在 44592 次献血中鉴定和报告的 70 例隐匿性感染中，有 70 例隐匿性感染（0.15%）被纳入本研究。从 44/70 例隐匿性感染中获得了 HBV 序列，基因分型分析显示 42/44（95.2%）例隐匿性感染为基因型 B，2/44（4.8%）为基因型 C。有趣的是，突变分析显示，在基因型 B 的隐匿性感染中观察到影响 HBsAg 检测的 HBV DNA 各种突变，包括 M133L/T、F134L、P142L、V168A、R169H、S174N、L175S 和 V177A。在基因型 C 的隐匿性感染中发现了两个显著突变，T47K 和 L53S。随访研究显示，3/31（9.7%）例隐匿性感染转为 HBsAg+，成为慢性感染，而 1/31（3.2%）HBV DNA 无法检测（归为恢复），27/31（87.1%）仍为隐匿性感染。
在中国南方河源市隐匿性感染献血者中观察到影响 HBsAg 检测的各种显著突变。随访研究显示，大多数隐匿性感染仍为隐匿性感染，病毒载量波动或较低。建议对献血者进行更高灵敏度的 HBV ID NAT 检测，以进一步降低隐匿性感染的传播风险。
