Amendola Alessandra, Marsella Patrizia, Bloisi Maria, Forbici Federica, Angeletti Claudio, Capobianchi Maria R
National Institute for Infectious Diseases Lazzaro Spallanzani, Rome, Italy
National Institute for Infectious Diseases Lazzaro Spallanzani, Rome, Italy.
J Clin Microbiol. 2014 Jun;52(6):2019-26. doi: 10.1128/JCM.00288-14. Epub 2014 Mar 26.
Concordance between molecular assays may be suboptimal at low HIV-1 viremia levels (<1,000 copies/ml); therefore, it may be difficult to define and compare virologic endpoints for successful and failed therapy. We compared two commercial assays (the Abbott RealTime HIV-1 and the Roche Cobas AmpliPrep/TaqMan HIV-1 version 2.0) for their ability to detect and quantify low viral loads. A comparison was performed using 167 residual clinical samples (with values ranging from "not detected" to 1,000 copies/ml, as measured by the Abbott assay) and the National Institute and Biological Standards and Control (NIBSC) HIV-1 RNA working reagent 1 for nucleic acid amplification techniques (NAT) assays (serially diluted to a range from 1 to 1,000 copies/ml). Quantitative results were compared using Lin's concordance correlation coefficient and a Bland-Altman plot. Concordance with the qualitative results was measured by Cohen's kappa statistic. With clinical samples, the degree of interassay concordance of the qualitative results at a 40-copies/ml HIV-1 RNA threshold was substantial (κ = 0.762); the correlation among the quantified samples was suboptimal (concordance correlation coefficient, 0.728; P < 0.0001); the mean difference of the values between the Roche and Abbott assays was 0.193 log10 copies/ml. Using the HIV-1 RNA working reagent 1 for NAT assays, the results provided by the Roche assay were, on average, 3 times higher than expected, while the Abbott assay showed high accuracy. The Roche assay was highly sensitive, being able to detect a level as low as 3.5 copies/ml HIV-1 RNA with 95% probability. The performance characteristics of each molecular assay should be taken into account when HIV-1 RNA threshold values for "virologic suppression," "virologic failure," "persistent low viral loads," etc., are defined and indicated in the support of clinical decisions.
在低HIV-1病毒血症水平（<1000拷贝/毫升）时，分子检测之间的一致性可能不太理想；因此，对于成功和失败的治疗，可能难以定义和比较病毒学终点。我们比较了两种商业检测方法（雅培实时HIV-1检测和罗氏Cobas AmpliPrep/TaqMan HIV-1 2.0版检测）检测和定量低病毒载量的能力。使用167份残留临床样本（雅培检测测得的值范围为“未检测到”至1000拷贝/毫升）和美国国立生物标准与控制研究所（NIBSC）的HIV-1 RNA核酸扩增技术（NAT）检测工作试剂1（系列稀释至1至1000拷贝/毫升范围）进行了比较。使用林氏一致性相关系数和Bland-Altman图比较定量结果。通过科恩kappa统计量测量与定性结果的一致性。对于临床样本，在HIV-1 RNA阈值为40拷贝/毫升时，定性结果的检测间一致性程度较高（κ = 0.762）；定量样本之间的相关性不太理想（一致性相关系数，0.728；P < 0.0001）；罗氏检测和雅培检测之间的值的平均差异为0.193 log10拷贝/毫升。使用用于NAT检测的HIV-1 RNA工作试剂1，罗氏检测提供的结果平均比预期高3倍，而雅培检测显示出高准确性。罗氏检测高度灵敏，能够以95%的概率检测到低至3.5拷贝/毫升的HIV-1 RNA水平。在定义和指明用于支持临床决策的“病毒学抑制”、“病毒学失败”、“持续低病毒载量”等的HIV-1 RNA阈值时，应考虑每种分子检测的性能特征。
