Baylis Sally A, Hanschmann Kay-Martin O, Schnierle Barbara S, Trösemeier Jan-Hendrik, Blümel Johannes
Paul-Ehrlich-Institut, Langen, Germany.
Transfusion. 2017 Mar;57(3pt2):748-761. doi: 10.1111/trf.14026. Epub 2017 Feb 23.
With the ongoing public health emergency due to Zika virus (ZIKV), nucleic acid testing (NAT) is essential for clinical diagnosis and screening of blood donors. However, NAT for ZIKV has not been standardized, and this study was performed to establish a World Health Organization (WHO) International Standard (IS) for ZIKV RNA; WHO ISs have been used to improve detection and quantification of blood-borne viruses.
The candidate IS (cIS), code number 11468/16, was prepared by heat inactivation and lyophilization of a ZIKV strain isolated from a patient in French Polynesia in 2013. The cIS was evaluated together with other reference materials, including both Asian and African ZIKV lineages as well as a panel of clinical samples and in vitro-transcribed RNAs. The samples for evaluation were distributed to 24 laboratories from 11 countries. The assays used consisted of a mixture of in-house developed and commercial assays (available or in development).
The potencies of the standards were determined by quantitative and qualitative assays. In total, 37 sets of data were analyzed: 19 from quantitative assays and 18 from qualitative assays. Data demonstrated wide variations in reported potencies of the cIS and the other study samples.
Assay variability was substantially reduced when ZIKV RNA concentrations from the biological reference materials and clinical samples were expressed relative to the cIS. Thus, the WHO has established 11468/16 as the 1 IS for ZIKV RNA, with a unitage of 50,000,000 IU/mL.
鉴于寨卡病毒（ZIKV）引发的持续公共卫生紧急状况，核酸检测（NAT）对于临床诊断和献血者筛查至关重要。然而，ZIKV的NAT尚未标准化，本研究旨在建立世界卫生组织（WHO）ZIKV RNA国际标准品（IS）；WHO国际标准品已用于改进血源病毒的检测和定量。
候选国际标准品（cIS），编号11468/16，通过对2013年从法属波利尼西亚一名患者分离出的ZIKV毒株进行热灭活和冻干制备而成。cIS与其他参考物质一起进行评估，包括亚洲和非洲ZIKV谱系以及一组临床样本和体外转录RNA。用于评估的样本分发给来自11个国家的24个实验室。所使用的检测方法包括内部开发的检测方法和商业检测方法（现有或正在开发）的组合。
通过定量和定性检测确定标准品的效价。总共分析了37组数据：19组来自定量检测，18组来自定性检测。数据表明，cIS和其他研究样本报告的效价存在很大差异。
当生物参考物质和临床样本中的ZIKV RNA浓度相对于cIS表示时，检测变异性大幅降低。因此，WHO已将11468/16确立为ZIKV RNA的首个国际标准品，单位为50,000,000 IU/mL。
