Roche Diagnostics International Ltd., Global Medical Scientific Affairs, Forrenstrasse 2, 6343 Rotkreuz, Switzerland.
SANBS South African National Blood Services, 1 Constantia Boulevard, Weltevreden Park, South Africa.
J Clin Virol. 2018 Apr;101:38-43. doi: 10.1016/j.jcv.2018.01.011. Epub 2018 Feb 6.
It is essential that hepatitis B surface antigen (HBsAg) diagnostic assays reliably detect genetic diversity in the major hydrophilic region (MHR) of HBsAg to avoid false-negative results. Mutations in this domain display marked ethno-geographic variation and may lead to failure to diagnose hepatitis B virus (HBV) infection.
Evaluate diagnostic performance of the Elecsys HBsAg II Qualitative assay in a cohort of South African HBV-positive blood donors.
A total of 179 South African HBsAg- and HBV DNA > 100 IU/mL-positive blood donor samples were included. Samples were sequenced for genetic variation in HBsAg MHR using next-generation ultra-deep sequencing. HBsAg seropositivity was determined using the Roche Elecsys HBsAg II Qualitative assay. Mutation rates were compared between the first (amino acids 124-137) and second (amino acids 139-147) loops of the immunodominant MHR 'a' determinant region. Frequency of occult HBV infection-associated Y100C mutations was also determined.
We observed a total of 279 MHR mutations (117 variants) in 102 (57%) samples, of which 91 were located in the 'a' determinant region. The major vaccine-induced escape mutation G145R was observed in two samples. All occult HBV infection-associated Y100C and common diagnostic and vaccine-escape-associated P120T, G145R, K122R, M133L, M133T, Q129H, G130N, and T126S mutations were reliably detected by the assay, which consistently detected the presence of HBsAg in all 179 samples including samples with 11 novel mutations.
Despite substantial variation in HBsAg MHR, the Elecsys HBsAg II Qualitative assay robustly detects HBV infection in this South African cohort.
乙型肝炎表面抗原（HBsAg）诊断检测必须可靠地检测 HBsAg 主要亲水区域（MHR）中的遗传多样性，以避免假阴性结果。该区域的突变显示出明显的人种地理变异，可能导致乙型肝炎病毒（HBV）感染的诊断失败。
评估 Elecsys HBsAg II 定性检测在南非 HBV 阳性献血者队列中的诊断性能。
共纳入 179 例南非 HBsAg 和 HBV DNA>100 IU/mL 阳性献血者样本。使用下一代超深度测序对 HBsAg MHR 的遗传变异进行测序。使用罗氏 Elecsys HBsAg II 定性检测确定 HBsAg 血清阳性。比较了免疫显性 MHR“a”决定簇区域的第一个（氨基酸 124-137）和第二个（氨基酸 139-147）环之间的突变率。还确定了隐匿性 HBV 感染相关 Y100C 突变的频率。
我们在 102 个（57%）样本中观察到总共 279 个 MHR 突变（117 个变异体），其中 91 个位于“a”决定簇区域。两个样本中观察到主要疫苗逃逸突变 G145R。所有隐匿性 HBV 感染相关 Y100C 以及常见的诊断和疫苗逃逸相关 P120T、G145R、K122R、M133L、M133T、Q129H、G130N 和 T126S 突变均由该检测可靠地检测到，该检测一致地检测到 179 个样本中 HBsAg 的存在，包括 11 个新突变的样本。
尽管 HBsAg MHR 存在很大差异，但 Elecsys HBsAg II 定性检测在南非队列中可靠地检测到 HBV 感染。
