DRK Blutspendedienst West, Hagen, Germany; Paul-Ehrlich-Institut, Langen, Germany; GFE Blut mbH, Frankfurt am Main, Germany.
Transfusion. 2013 Oct;53(10 Pt 2):2422-30. doi: 10.1111/trf.12298. Epub 2013 Jun 19.
Nucleic acid amplification techniques (NAT) in routine blood donor screening considerably reduce the diagnostic window phase period. Nevertheless, several reports of false-negative NAT results were published. Here, four cases of human immunodeficiency virus Type 1 (HIV-1) RNA-positive blood donations that escaped detection by NAT screening are described.
A total of 2.7 million blood donations were screened for viral infections between January 2010 and October 2012 in our German Red Cross blood donation service. Four plasma specimens with false-negative NAT results were comparatively investigated with 12 CE-marked NAT assays. In two cases of putative HIV-1 variants the target region of the NAT assay was sequenced allowing comparison with the respective primers and probes.
Most of the NAT assays used in routine blood donor screening with the 5'-long terminal repeat (LTR) as target region demonstrated deficiencies in detecting the viral variants and the low-viral-carrier donations. Sequence analysis revealed in one case a deletion of 56 nucleotides within the 5'-LTR preventing the binding of the probe accompanied by a neighbored insertion of another 52 nucleotides and several primer mismatches in another case. No false-negative results were obtained for these cases using dual-target assays. The viral load of the remaining two false-negative results was below the NAT's limit of detection.
HIV-1 is characterized by a high mutation rate and rapid generation of new viral variants. By the use of one target region for HIV-1 NAT assays there is a certain risk of false-negative results. Employing HIV-1 multi- and dual-target assays in routine blood donor screening seems to be a reasonable possibility to minimize this problem.
核酸扩增技术（NAT）在常规献血者筛查中大大缩短了诊断窗口期。然而，仍有一些 NAT 检测结果假阴性的报道。本文描述了 4 例 HIV-1 RNA 阳性血液标本通过 NAT 筛查漏检的情况。
2010 年 1 月至 2012 年 10 月，我们对德国红十字会的 270 万份献血进行了病毒感染筛查。对 4 份 NAT 检测结果为假阴性的血浆标本进行了比较研究，共使用了 12 种获得 CE 认证的 NAT 检测方法。在 2 例疑似 HIV-1 变异体的情况下，对 NAT 检测的靶区进行了测序，以便与相应的引物和探针进行比较。
常规献血者筛查中使用的大多数以 5'-长末端重复序列（LTR）为靶区的 NAT 检测方法在检测病毒变异体和低病毒载量的标本时存在缺陷。序列分析显示，在 1 例标本中，LTR 的 5'端发生了 56 个核苷酸的缺失，导致探针无法结合，同时还伴有另一个 52 个核苷酸的插入和另一个引物错配。使用双靶区检测方法，这些标本均未出现假阴性结果。其余 2 例假阴性标本的病毒载量低于 NAT 的检测下限。
HIV-1 的突变率很高，新的病毒变异体快速产生。由于 HIV-1 NAT 检测方法仅使用一个靶区，存在一定的假阴性风险。在常规献血者筛查中使用 HIV-1 多靶区和双靶区检测方法似乎是降低这一问题风险的合理选择。
