Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory

BackgroundViral load testing is key to monitoring response to anti-retroviral therapy (ART). However, in lower and middle income countries with large epidemics, pre-analytical challenges threaten the quality of testing. It is unknown how much delayed processing and adverse storage affects the validity of results. The aim of this study was to determine the impact of delayed testing and warmer storage conditions on HIV RNA stability in diagnostic samples.Methods1194 samples, collected in EDTA or plasma preparation (PPT) tubes, were studied. Immediately after initial testing, primary tubes were stored for 72, 96 or 168 hours at 4°C, 20°C or 30°C. The viral load was then repeated and the 2 results were compared.ResultsViral loads were very stable, with ConclusionViral RNA in diagnostic samples is stable well beyond currently recommended limits. However, when testing stored primary samples, contamination of plasma with cellular material easily occurs. Low viral loads (

背景
病毒载量检测是监测抗逆转录病毒治疗（anti-retroviral therapy, ART）应答情况的核心手段。然而，在疫情规模庞大的中低收入国家，分析前环节的各类挑战正威胁着检测质量。目前尚不明确检测延迟处理与不当储存对检测结果有效性的影响程度。本研究旨在探究检测延迟与偏高温度储存条件对诊断样本中人类免疫缺陷病毒核糖核酸（HIV RNA）稳定性的影响。
方法
本研究共纳入1194份采集于乙二胺四乙酸（EDTA）管或血浆制备（plasma preparation, PPT）管的样本。初次检测完成后即刻，将原样本管分别置于4℃、20℃或30℃下储存72小时、96小时或168小时。随后重新开展病毒载量检测，并对两次检测结果进行比对。
结果
病毒载量表现出极佳的稳定性，
结论
诊断样本中的HIV RNA稳定性远超当前推荐的储存时限。然而，对储存后的原样本进行检测时，血浆极易被细胞成分污染。低病毒载量（