Mushtaq Saima, Hashmi Asraf Hussain, Khan Amjad, Asad Raza Kazmi Syed Muhammad, Manzoor Sobia
Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
Institute of Biomedical and Genetic Engineering, Islamabad, Pakistan.
Front Pharmacol. 2022 Apr 27;13:894460. doi: 10.3389/fphar.2022.894460. eCollection 2022.
The hepatitis C virus has a high mutation rate, which results in the emergence of resistance-associated substitutions (RASs). Despite direct-acting antivirals (DAAs) efforts to treat chronically infected HCV genotype 3 (GT3) patients, there are concerns about the emergence and persistence of RASs in DAA failures. The objective of this study was to determine the prevalence of clinically relevant RASs in HCV NS5A and NS5B regions before and after treatment to better understand the role of RASs in treatment failures. Viral RNA was extracted before and after treatment from serum samples. NS5A and NS5B regions of HCV were amplified by nested PCR, followed by Sanger sequencing. The nucleotide sequences were aligned against HCV GT3 reference sequences, and amino acid substitutions were analyzed using the geno2pheno [hcv] webserver. A total of 76 patients failing DAA therapy were stratified from the cohort of 1388. RASs were detected at the baseline in 15/76 patients and at relapse in 20/76 patients with cirrhosis and previously treated with interferons. The most prevalent NS5A RAS was Y93H found in all treatment-failing patients (14/54 in DCV vs. 6/22 in VEL), followed by A62S/T and A30K. No RASs were identified in NS5B. RASs that were present at the baseline persisted through the 24-week follow-up period and were enriched with emerging RASs during the treatment. The presence of RASs may be one of the causes of treatment failures in 26.3% of patients. Amino acid substitutions were present at the baseline in most of the patients with RASs against NS5A inhibitors. Patients with the baseline Y93H and/or A30K relapse more frequently than patients harboring A62S/T. Treatment-failing patients harbored NS5A RASs, and the most frequent were A30K (5/20), A62S/T (20/20), and Y93H (20/20). Direct resistance testing is recommended for optimizing re-treatment strategies in treatment-failing patients.
丙型肝炎病毒具有较高的突变率，这导致了耐药相关替代位点（RASs）的出现。尽管直接抗病毒药物（DAAs）致力于治疗慢性感染丙型肝炎病毒基因3型（GT3）的患者，但对于DAAs治疗失败时RASs的出现和持续存在仍存在担忧。本研究的目的是确定治疗前后丙型肝炎病毒NS5A和NS5B区域临床相关RASs的流行情况，以更好地了解RASs在治疗失败中的作用。在治疗前后从血清样本中提取病毒RNA。通过巢式PCR扩增丙型肝炎病毒的NS5A和NS5B区域，随后进行桑格测序。将核苷酸序列与丙型肝炎病毒GT3参考序列进行比对，并使用geno2pheno [hcv]网络服务器分析氨基酸替代情况。在1388例患者队列中分层出76例DAAs治疗失败的患者。在15/76例患者的基线期检测到RASs，在20/76例肝硬化且先前接受过干扰素治疗的复发患者中也检测到RASs。最常见的NS5A RAS是Y93H，在所有治疗失败的患者中均有发现（在达卡他韦治疗失败患者中为14/54，在维帕他韦治疗失败患者中为6/22），其次是A62S/T和A30K。在NS5B中未鉴定出RASs。基线期存在的RASs在24周的随访期内持续存在，并在治疗期间随着新出现的RASs而增多。RASs的存在可能是26.3%患者治疗失败的原因之一。大多数对NS5A抑制剂有RASs的患者在基线期存在氨基酸替代。基线期有Y93H和/或A30K的患者比携带A62S/T的患者复发更频繁。对于优化治疗失败患者的再治疗策略，建议进行直接耐药检测。
