Expanding Access to HIV Viral Load Testing: A Systematic Review of RNA Stability in EDTA Tubes and PPT beyond Current Time and Temperature Thresholds

BackgroundHIV viral load (VL) testing is the gold standard for antiretroviral treatment monitoring, but many barriers exist to VL testing in resource-limited settings, including storage and transport limitations for whole blood and plasma. Data from various studies indicate that HIV RNA is stable beyond current recommendations. We conducted a systematic review to assess stability data of HIV RNA in whole blood and plasma across times and temperatures.Methods and FindingsUsing a pre-defined protocol, five databases were searched for studies where blood samples from HIV patients were stored at time and temperature points that exceeded manufacturer recommendations. RNA stability, the primary outcome, was measured by the difference in means compared to samples stored within established thresholds. RNA stability was defined as ≤0.5 log degradation. The search identified 10,716 titles, of which nine full-text articles were included for review. HIV RNA maintained stability in EDTA whole blood and plasma at all measured time points up to 168 hours when stored at 4°C, while stability was detected at 72 hours (95% confidence) in whole blood at 25°C, with data points before and beyond 72 hours suggesting stability but not reaching statistical significance. For EDTA plasma stored at 30°C, stability was maintained up to 48 hours (95% confidence), with OLS linear regression estimates up to 127 hours, suggesting stability. Overall, quality of studies was moderate. Limitations included small sample sizes, few studies meeting inclusion criteria, and no studies examining RNA stability in low viremia (ConclusionsWhole blood and plasma samples in EDTA may remain stable under conditions exceeding current manufacturer recommendations for HIV VL testing. However, given the limited number of studies addressing this question, especially at low levels of viremia, additional evaluations on HIV RNA stability in EDTA tubes and PPT in field conditions are needed.背景 人类免疫缺陷病毒（HIV）病毒载量（VL）检测是抗逆转录病毒治疗监测的金标准，但在资源受限地区，VL检测面临诸多障碍，包括全血与血浆的储存及运输限制。多项研究数据表明，HIV核糖核酸（RNA）在超出当前推荐标准的条件下仍可保持稳定。本研究开展了一项系统综述，旨在评估全血及血浆中HIV RNA在不同时间与温度条件下的稳定性数据。 方法与结果 研究采用预先设定的方案，检索了五个数据库中有关HIV感染者血液样本储存时间与温度超出厂商推荐标准的相关研究。首要结局指标为RNA稳定性，通过与储存于既定阈值内的样本的均值差异进行衡量，将RNA稳定性定义为降解程度≤0.5 log值。本次检索共识别出10716篇文献标题，最终纳入9篇全文文献进行综述分析。当储存温度为4℃时，乙二胺四乙酸（EDTA）抗凝全血与血浆中的HIV RNA在最长168小时的所有检测时间点均保持稳定；而在25℃条件下的全血样本中，仅在72小时（95%置信度）时检测到稳定性，72小时前后的数据虽提示样本保持稳定，但未达到统计学显著性。对于30℃储存的EDTA抗凝血浆，样本稳定性可维持至48小时（95%置信度）；普通最小二乘（OLS）线性回归分析结果显示，其稳定性可延伸至127小时。整体而言，纳入研究的质量中等。本研究存在一定局限性：纳入研究的样本量普遍较小，符合纳入标准的研究数量有限，且尚无针对低病毒血症状态下RNA稳定性的相关研究。 结论 EDTA抗凝全血与血浆样本，在超出当前HIV VL检测厂商推荐标准的条件下仍可保持稳定。但鉴于针对该问题的研究数量有限，尤其是低病毒血症水平下的相关研究匮乏，仍需开展更多针对EDTA采血管及现场条件下PPT样本的HIV RNA稳定性评估工作。