Section of Molecular Virology, Paul-Ehrlich-Institut, Langen, Germany.
Section of Hemovigilance and IVD Vigilance, Paul-Ehrlich-Institut, Langen, Germany.
Transfus Med Hemother. 2014 Feb;41(1):45-51. doi: 10.1159/000357103. Epub 2013 Dec 19.
Several publications describe HIV-1 RNA false-negative results or viral load underquantitation associated with Communauté Européenne(CE)-marked qualitative or quantitative nucleic acid amplification technique (NAT) assays. 6 cases occurred during blood screening in Germany, with 2 of them causing HIV-1 transmissions to recipients of blood components. The implicated NAT assays were mono-target assays amplifying in different viral genome regions (gag or long terminal repeat).
Specimens characterized by HIV-1 NAT underquantitation or false-negative NAT results were comparatively investigated in CE-marked HIV-1 NAT systems of different design to identify potential reasons. The target regions of the viral nucleic acids were sequenced and these sequences compared to primers and probes of the assays. Potential risk minimization measures were considered for quantitative and blood-screening HIV-1 NAT systems.
Nucleotide sequencing of the viral target region in cases of HIV-1 RNA underquantitation or false-negative test results revealed new HIV-1 variants that were mismatched with primers and probes used in some mono-target assays. So far, dualtarget NAT assays have not been associated with mismatch-based false-negative test results. From 2015, the Paul Ehrlich Institute will request HIV-1 NAT assays of dual-target design or an analogous solution for further reducing the risk in blood screening.
HIV differs from other blood-borne viruses with regard to its fast evolution of new viral variants. The evolution of new sequences is hardly predictable; therefore, NAT assays with only 1 target region appear to be more vulnerable to sequence variations than dual-target assays. The associated risk may be higher for HIV-1 NAT assays used for blood screening compared to quantitative assays used for monitoring HIV-1-infected patients. In HIV-1 screening NAT assays of dual-target design may adequately address the risk imposed by new HIV-1 variants.
有几份出版物描述了与欧洲共同体（CE）标记的定性或定量核酸扩增技术（NAT）检测相关的 HIV-1 RNA 假阴性结果或病毒载量检测不足。在德国的血液筛查中发生了 6 例此类情况，其中 2 例导致 HIV-1 传播给血液成分的接受者。受影响的 NAT 检测是针对不同病毒基因组区域（ gag 或长末端重复序列）进行扩增的单靶标检测。
对 CE 标记的不同设计的 HIV-1 NAT 系统中具有 HIV-1 NAT 检测不足或假阴性 NAT 结果的标本进行比较研究，以确定潜在原因。对病毒核酸的靶区进行测序，并将这些序列与检测的引物和探针进行比较。对定量和血液筛查 HIV-1 NAT 系统考虑了潜在的风险最小化措施。
在 HIV-1 RNA 检测不足或假阴性检测结果的病例中，对病毒靶区的核苷酸测序揭示了与一些单靶标检测中使用的引物和探针不匹配的新型 HIV-1 变体。迄今为止，双靶标 NAT 检测尚未与基于错配的假阴性检测结果相关联。自 2015 年起，保罗埃利希研究所将要求使用双靶标设计或类似的解决方案的 HIV-1 NAT 检测，以进一步降低血液筛查中的风险。
与其他血源性病毒相比，HIV 的新病毒变体快速进化。新序列的进化几乎是不可预测的；因此，只有 1 个靶区的 NAT 检测似乎比双靶标检测更容易受到序列变异的影响。与用于监测 HIV-1 感染患者的定量检测相比，用于血液筛查的 HIV-1 NAT 检测的相关风险可能更高。在 HIV-1 筛查 NAT 检测中，双靶标设计可能足以应对新的 HIV-1 变体带来的风险。
