United Kingdom National External Quality Assessment Service for Microbiology, External Quality Assurance Department, Health Protection Agency Microbiology Services, London, United Kingdom.
J Clin Microbiol. 2012 Nov;50(11):3614-9. doi: 10.1128/JCM.01221-12. Epub 2012 Sep 5.
Viral load testing is an essential parameter in guiding antiretroviral therapy for individuals infected with human immunodeficiency virus type 1 (HIV-1). An external quality assessment scheme for the molecular quantification of HIV-1 RNA was introduced by the United Kingdom National External Quality Assessment Service for Microbiology in 2000. Specimen pairs of freeze-dried plasma were distributed to a median of 141 participants three times a year. The aim of this study was to analyze the quantification of HIV-1 RNA results between 2000 and 2010. Overall variability, measured by the standard deviations of all viral load results for each specimen, was below 0.5 log copy/ml (n = 48). When we compared assay results, the medians of the viral load by assay were within a range of 0.25 to 1.08 log copies/ml, with the lowest median values being consistently reported with the Siemens branched-chain DNA assay. The spread of participant results and, hence, differences between assay medians were greater when quantifying non-B subtypes. Laboratories were scored on the proximity of their reported log difference for the specimen pair to the median log difference reported by all laboratories. The overall level of performance with the HIV-1 RNA specimens over the past 10 years has been consistently good, with more than 90% of the participants reporting in the accepted range (median difference, ±0.5 log unit). Future distributions may result in tightening the acceptance levels of quantification and the use of more challenging specimens, including a variety of subtypes, with developments focusing on maintaining the clinical relevance and educational value of the scheme.
病毒载量检测是指导人类免疫缺陷病毒 1 型（HIV-1）感染者进行抗逆转录病毒治疗的重要参数。英国国家微生物学外部质量评估服务局于 2000 年推出了一种 HIV-1 RNA 分子定量的外部质量评估方案。每年向中位数为 141 名参与者分发三次冻干血浆标本对。本研究旨在分析 2000 年至 2010 年 HIV-1 RNA 定量结果。所有标本病毒载量结果的标准差衡量的总体变异性均低于 0.5log 拷贝/ml（n=48）。当我们比较测定结果时，各测定法的病毒载量中位数在 0.25 至 1.08log 拷贝/ml 范围内，其中西门子分枝 DNA 测定法始终报告最低的中位数。当定量非 B 亚型时，参与者结果的分布范围更广，因此测定中位数之间的差异更大。实验室根据其报告的标本对对数差与所有实验室报告的中位数对数差的接近程度进行评分。过去 10 年来，HIV-1 RNA 标本的整体性能一直很好，超过 90%的参与者报告处于可接受范围（中位数差异，±0.5log 单位）。未来的分配可能会导致定量接受水平的收紧，以及使用更具挑战性的标本，包括各种亚型，其重点是保持该方案的临床相关性和教育价值。
