West of Scotland Specialist Virology Centre, Level 5 New Lister Building, Glasgow Royal Infirmary, Alexandra Parade, Glasgow, G31 2ER, United Kingdom.
Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, United Kingdom.
J Clin Virol. 2019 Jan;110:7-10. doi: 10.1016/j.jcv.2018.10.008. Epub 2018 Nov 3.
Hepatitis C virus RNA testing using dried blood spots (DBS) offers a method for detecting ongoing HCV infection in "hard to reach" populations. Abbott Molecular have developed a quantitative HCV RNA DBS protocol (currently for research use only) for extraction and real-time PCR amplification using them2000sp and m2000rt system.
A panel of seventy "mock" DBS were made from patient whole blood; who were known to be either HCV RNA negative or positive. This panel compared the "mock" DBS and the plasma viral load results. A further dilution panel of "mock" DBS made from one HCV positive patient was used to estimate the detection limit of the assay. Abbott was then compared with an in-house real-time Taqman PCR using patient DBS samples.
All "mock" DBS samples with a viral load >1000IU/ml were detected by Abbott, with only 1/8 detected at <1000 IU/ml. The dilution panel suggested the limit of detection to be between 178 to 1779 IU/ml. There were two false positive samples detected at low level <282 IU/ml, both samples were from patients who had been previously positive. The overall sensitivity of the Abbott RUO DBS protocol when compared to plasma was 86% (95 CI 73.76%-74.18%) increasing to 100% (CI 91.59%-100%) when the viral load was >1000IU/ml. Abbott compared well with the in-house assay with sensitivity of 97.5% (95% CI 86.84%-99.94%) and specificity of 100% (95% CI 91.19%-100%).
The Abbott system is an automated platform which can be used for DBS HCV RNA extraction and amplification. The preliminary data presented here showed a high sensitivity and specificity for DBS with viral loads greater than 1000IU/ml and compared well with a published in-house method.
使用干血斑（DBS）进行丙型肝炎病毒 RNA 检测为检测难以接触的人群中的持续性 HCV 感染提供了一种方法。雅培分子公司已开发出一种定量 HCV RNA DBS 方案（目前仅供研究使用），用于提取和实时 PCR 扩增，使用 them2000sp 和 m2000rt 系统。
从已知 HCV RNA 阴性或阳性的患者全血中制备了 70 个“模拟”DBS 板。该板比较了“模拟”DBS 和血浆病毒载量结果。还使用来自一位 HCV 阳性患者的“模拟”DBS 进一步稀释板来估计该测定的检测限。然后将 Abbott 与使用患者 DBS 样本的内部实时 Taqman PCR 进行比较。
所有病毒载量>1000IU/ml 的“模拟”DBS 样本均被 Abbott 检测到，只有 1/8 个样本在<1000IU/ml 时被检测到。稀释板表明检测限为 178 至 1779IU/ml 之间。有两个低水平的假阳性样本（<282IU/ml）被检测到，这两个样本均来自之前阳性的患者。与血浆相比，Abbott 非专利 DBS 方案的总体灵敏度为 86%（95%CI 73.76%-74.18%），当病毒载量>1000IU/ml 时，灵敏度增加到 100%（95%CI 91.59%-100%）。Abbott 与内部检测方法的灵敏度为 97.5%（95%CI 86.84%-99.94%）和特异性为 100%（95%CI 91.19%-100%）相媲美。
Abbott 系统是一种自动化平台，可用于 DBS HCV RNA 提取和扩增。这里提出的初步数据显示，对于病毒载量大于 1000IU/ml 的 DBS，该系统具有高灵敏度和特异性，并且与已发表的内部方法相比表现良好。
