Nuffield Department of Medicine and the Oxford NIHR BRC, University of Oxford, Oxford, UK.
Oxford Martin School, University of Oxford, Oxford, UK.
Hepatology. 2019 May;69(5):1861-1872. doi: 10.1002/hep.29837. Epub 2018 Apr 27.
Hepatitis C virus (HCV) genotype (gt) 3 is highly prevalent globally, with non-gt3a subtypes common in Southeast Asia. Resistance-associated substitutions (RASs) have been shown to play a role in treatment failure. However, the role of RASs in gt3 is not well understood. We report the prevalence of RASs in a cohort of direct-acting antiviral treatment-naive, gt3-infected patients, including those with rarer subtypes, and evaluate the effect of these RASs on direct-acting antivirals in vitro. Baseline samples from 496 gt3 patients enrolled in the BOSON clinical trial were analyzed by next-generation sequencing after probe-based enrichment for HCV. Whole viral genomes were analyzed for the presence of RASs to approved direct-acting antivirals. The resistance phenotype of RASs in combination with daclatasvir, velpatasvir, pibrentasvir, elbasvir, and sofosbuvir was measured using the S52 ΔN gt3a replicon model. The nonstructural protein 5A A30K and Y93H substitutions were the most common at 8.9% (n = 44) and 12.3% (n = 61), respectively, and showed a 10-fold and 11-fold increase in 50% effect concentration for daclatasvir compared to the unmodified replicon. Paired RASs (A30K + L31M and A30K + Y93H) were identified in 18 patients (9 of each pair); these combinations were shown to be highly resistant to daclatasvir, velpatasvir, elbasvir, and pibrentasvir. The A30K + L31M combination was found in all gt3b and gt3g samples. Conclusion: Our study reveals high frequencies of RASs to nonstructural protein 5A inhibitors in gt3 HCV; the paired A30K + L31M substitutions occur in all patients with gt3b and gt3g virus, and in vitro analysis suggests that these subtypes may be inherently resistant to all approved nonstructural protein 5A inhibitors for gt3 HCV. (Hepatology 2018).
丙型肝炎病毒（HCV）基因型（gt）3 在全球范围内高度流行，非 gt3a 亚型在东南亚地区很常见。已发现耐药相关取代（RAS）在治疗失败中起作用。然而，gt3 中的 RAS 作用尚不清楚。我们报告了直接作用抗病毒治疗初治、gt3 感染患者队列中 RAS 的流行率，包括那些罕见亚型的患者，并评估了这些 RAS 在体外对直接作用抗病毒药物的影响。在 BOSON 临床试验中，对 496 名 gt3 患者的基线样本进行了下一代测序分析，在基于探针的 HCV 富集后进行分析。对全病毒基因组进行了 RAS 分析，以确定其对已批准的直接作用抗病毒药物的耐药性。使用 S52ΔNgt3a 复制子模型，测量了 RAS 与达拉他韦、伏西瑞韦、奥比帕利韦、艾尔巴韦和索磷布韦联合的耐药表型。非结构蛋白 5A 的 A30K 和 Y93H 取代分别为 8.9%（n=44）和 12.3%（n=61），与未修饰的复制子相比，达拉他韦的 50%有效浓度分别增加了 10 倍和 11 倍。在 18 名患者（每对 9 名）中发现了配对的 RAS（A30K+L31M 和 A30K+Y93H）；这些组合对达拉他韦、伏西瑞韦、艾尔巴韦和奥比帕利韦均表现出高度耐药性。A30K+L31M 组合存在于所有 gt3b 和 gt3g 样本中。结论：我们的研究揭示了 gt3 HCV 中对非结构蛋白 5A 抑制剂的 RAS 高频率；配对的 A30K+L31M 取代发生在所有 gt3b 和 gt3g 病毒患者中，体外分析表明这些亚型可能对所有批准的用于 gt3 HCV 的非结构蛋白 5A 抑制剂固有耐药。（《肝脏病学》2018 年）。
