Laboratory of Viral Hepatitis, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
J Med Virol. 2012 Oct;84(10):1600-7. doi: 10.1002/jmv.23379.
This study was undertaken to optimize and compare the efficiency of two commercial EIAs for anti-HCV detection (HCV Ab Radim, Pomezzia, Italy and ETI-AB-HCVK-4 DiaSorin, Vercelli, Italy), in dried blood spot (DBS) samples. The long-term stability of anti-HCV on DBS samples stored at three environmental conditions was also evaluated at: 2-8 °C, 20-25 °C, and -20 °C. Paired DBS and serum samples were obtained from individuals with or without anti-HCV. The type of elution buffer, sample and conjugate volume, sample incubation time and cut-off values were evaluated. For both EIAs, a larger sample volume was used, and the cut-off value determined by the manufacturer was employed for Radim EIA; however, ROC curve analysis was used for the DiaSorin EIA. The sensitivity and specificity of Radim EIA on DBS were 97.5% and 99.5%, respectively, and of DiaSorin EIA were 88.9% and 98.9%, respectively. Accurate results were obtained for a period of 117 days using DBS samples stored at all storage conditions, but storage at -20 °C resulted in the lowest variation among the absorbance values. Both EIAs demonstrated the same limit of detection (until dilution of 1:10(4) with estimated viral load of 3.1 × 10(-1) UI/ml), but the Radim EIA was associated with the best performance because a low coefficient of variation was observed in the repetition and reproducibility studies. In conclusion, commercial EIAs can be optimized for anti-HCV detection in DBS samples that are extremely stable at different conditions for more than 100 days.
本研究旨在优化和比较两种用于抗 HCV 检测的商业 ELISA（HCV Ab Radim，意大利 Pomezzia 和 ETI-AB-HCVK-4 DiaSorin，意大利 Vercelli）在干血斑（DBS）样本中的效率。还评估了在三种环境条件下储存的 DBS 样本中抗 HCV 的长期稳定性：2-8°C、20-25°C 和-20°C。从具有或不具有抗 HCV 的个体中获得了配对的 DBS 和血清样本。评估了洗脱缓冲液的类型、样本和结合物的体积、样本孵育时间和截止值。对于这两种 ELISA，使用了更大的样本体积，并且使用制造商确定的截止值用于 Radim EIA；然而，对于 DiaSorin EIA，使用了 ROC 曲线分析。Radim EIA 在 DBS 上的灵敏度和特异性分别为 97.5%和 99.5%，DiaSorin EIA 分别为 88.9%和 98.9%。在所有储存条件下，DBS 样本储存 117 天期间均可获得准确的结果，但在-20°C 储存时吸光度值的变化最小。两种 ELISA 均显示相同的检测限（直到稀释 1:10(4)，估计病毒载量为 3.1 × 10(-1) UI/ml），但 Radim EIA 的性能最佳，因为在重复和重现性研究中观察到低变异系数。总之，商业 ELISA 可以针对 DBS 样本中的抗 HCV 检测进行优化，这些样本在不同条件下的稳定性超过 100 天。
