OBJECTIVE This study evaluated the performance of the cobas® hepatitis C virus (HCV) Test for use on the cobas® 6800/8800 Systems for the detection and quantification of HCV RNA collected using the cobas® Plasma Separation Card (PSC) compared with plasma samples. METHODS Whole EDTA-venous blood was collected from 50 HCV-positive donors and 140 μL from each donor was spotted onto a PSC and stored either frozen or at ambient temperature. These were compared with matched EDTA-plasma samples. The limit of detection (LoD) of the assay for PSC samples was determined using serial dilutions of the Roche HCV secondary calibration standard. The stability of the PSC samples across a range of timepoints was also assessed. RESULTS The mean titer difference between ambient and -10 °C storage of PSC samples was 0.04 log10 IU/mL (95% CI: 0.00, 0.07). The mean titer difference between frozen PSC samples and EDTA plasma samples was -1.59 log10 IU/mL (95% CI: -1.66, -1.53) and between ambient PSC samples and EDTA samples was -1.64 log10 IU/mL (95% CI: -1.70, -1.57). Correlation between PSC samples and EDTA plasma was linear in both cases (frozen: slope = 1.039, intercept=-1.839, R2 = 0.89; ambient: slope = 1.012, intercept=-1.712, R2 = 0.88). The LoD of the cobas® HCV Test using the PSC was 866 IU/mL (95% CI: 698, 1153 IU/mL) and 408 IU/mL (95% CI: 336, 544 IU/mL) using an optimized Assay Specific Analysis Package. CONCLUSIONS PSC samples correlate well with plasma viral load and demonstrate a LoD below 1000 IU/mL and good stability at ambient temperature for 28 days. A correction factor would allow quantification of HCV viral RNA load from samples collected using a PSC.

中文翻译：

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使用cobas®血浆分离卡评估cobas®HCV测试以量化干燥血浆斑点中的HCV RNA。

目的本研究评估了用cobas®6800/8800系统进行cobas®丙型肝炎病毒（HCV）测试的性能，该系统用于检测和定量使用cobas®血浆分离卡（PSC）与血浆样品比较收集的HCV RNA 。方法从50个HCV阳性供体中收集全EDTA静脉血，并将每个供体的140μL点样到PSC上，并冷冻或在室温下保存。将这些与匹配的EDTA-血浆样品进行比较。使用Roche HCV二级校准标准品的系列稀释液确定PSC样品的检测限（LoD）。还评估了PSC样品在一定时间范围内的稳定性。结果PSC样品在室温和-10°C下的平均滴度差为0.04 log10 IU / mL（95％CI：0.00，0.07）。冷冻的PSC样品和EDTA血浆样品之间的平均滴度差为-1.59 log10 IU / mL（95％CI：-1.66，-1.53​​），周围PSC样品和EDTA样品之间的平均滴度差为-1.64 log10 IU / mL（95％CI： -1.70，-1.57）。在这两种情况下，PSC样品与EDTA血浆之间的相关都是线性的（冻结：斜率= 1.039，截距= -1.839，R2 = 0.89；环境：斜率= 1.012，截距= -1.712，R2 = 0.88）。使用优化的检测特异性，使用PSC的cobas HCV测试的LoD为866 IU / mL（95％CI：698，1153 IU / mL）和408 IU / mL（95％CI：336，544 IU / mL）分析包。结论PSC样品与血浆病毒载量密切相关，并显示LoD低于1000 IU / mL，并且在环境温度下28天具有良好的稳定性。校正因子将允许量化使用PSC收集的样本中的HCV病毒RNA载量。