Infectious Disease Research, Abbott Diagnostics, Abbott Park, Illinois, USA.
Arbutus Biopharma, Warminster, Pennsylvania, USA.
Hepatol Commun. 2023 Mar 17;7(4). doi: 10.1097/HC9.0000000000000099. eCollection 2023 Apr 1.
HBV pregenomic RNA (pgRNA) is a circulating biomarker for covalently closed circular DNA activity in HBV-infected individuals and has been studied for treatment efficacy, disease staging, and off-therapy outcomes; however, data on the stability are scarce. Increasing HBV pgRNA assay sensitivity may improve its predictive value and provide additional insights at low viral levels.
Modifications to a fully automated first (v1) generation HBV pgRNA assay improved sensitivity up to 15-fold over the previous assay. Flexible sample input volumes yielded lower limits of quantitation of 10 and 22 copies/mL for 0.6 and 0.2 mL assays, respectively. Results are standardized to secondary standards that are traceable to the WHO HBV DNA standard, and internal and external controls are included.
Comparison between v1 and modified v2 assays showed increased sensitivity from 152 copies/mL with v1 to 10 (0.6 mL) and 22 (0.2 mL) copies/mL with v2, respectively. Quantitated v2 results were indistinguishable from v1, indicating that comparisons can be made to previous studies. Single timepoint treatment-naive blood donors or longitudinal draws from patients with chronic hepatitis B on AB-729, an investigational siRNA therapy, showed improved detection and quantifiable pgRNA with v2 compared with v1. Stability testing demonstrated excellent HBV pgRNA plasma stability after 3 freeze-thaw cycles, for at least 7 days at 25-37 °C and at least 30 days at 4°C, with ≤0.25 Log U/mL decrease.
HBV pgRNA v2 assays with increased sensitivity and flexible input volumes demonstrated increased detection and quantitation of low viral titer samples. Highly sensitive HBV pgRNA assays may be useful in refining predictive treatment outcomes based on this marker. HBV pgRNA was stable under multiple conditions, which increases the reliability of this marker.
HBV 前基因组 RNA (pgRNA) 是乙型肝炎病毒感染者共价闭合环状 DNA 活性的循环生物标志物，已被用于研究治疗效果、疾病分期和停药后结果；然而，关于其稳定性的数据却很少。提高 HBV pgRNA 检测的灵敏度可能会提高其预测价值，并在低病毒水平下提供更多的见解。
对全自动第一代 (v1) HBV pgRNA 检测方法进行了改进，使灵敏度提高了 15 倍以上，高于之前的检测方法。灵活的样本输入量使 0.6 和 0.2 mL 检测的定量下限分别达到 10 和 22 拷贝/mL。结果以可追溯到世界卫生组织 HBV DNA 标准的二级标准进行标准化，并包含内部和外部对照。
v1 与改良的 v2 检测方法比较显示，灵敏度分别从 v1 的 152 拷贝/mL 提高到 v2 的 10（0.6 mL）和 22（0.2 mL）拷贝/mL。v2 的定量结果与 v1 无法区分，表明可以与之前的研究进行比较。在 AB-729（一种研究性 siRNA 疗法）治疗的慢性乙型肝炎患者的单次治疗前血源或纵向采血中，与 v1 相比，v2 可提高检测和可定量的 pgRNA 的检测。稳定性测试表明，HBV pgRNA 血浆在经过 3 次冻融循环后具有极好的稳定性，在 25-37°C 至少 7 天，在 4°C 至少 30 天，下降幅度不超过 0.25 Log U/mL。
灵敏度提高且输入体积灵活的 HBV pgRNA v2 检测方法提高了低病毒载量样本的检测和定量能力。高灵敏度的 HBV pgRNA 检测方法可能有助于根据该标志物优化预测治疗效果。HBV pgRNA 在多种条件下稳定，这提高了该标志物的可靠性。
