Not Anna, Saludes Verónica, Gálvez Mont, Miralpeix Anna, Bordoy Antoni E, González Noemí, González-Gómez Sara, Muntané Laura, Reyes-Urueña Juliana, Majó Xavier, Colom Joan, Forns Xavier, Lens Sabela, Martró Elisa
Microbiology Department, Laboratori Clínic Metropolitana Nord, Hospital Universitari Germans Trias i Pujol, Institut d'Investigació Germans Trias i Pujol (IGTP), Badalona, Spain.
Genetics and Microbiology Department, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.
J Med Virol. 2023 Feb;95(2):e28544. doi: 10.1002/jmv.28544.
Dried blood spots (DBS) are a reliable tool to diagnose viremic hepatitis C virus (HCV) infection. We evaluated the clinical performance of a DBS-based molecular assay for the assessment of cure and reinfection after on-site treatment at a harm reduction center (HRC). Genotyping from DBS samples was also assessed to discriminate reinfection from treatment failure. People who inject drugs (PWID) from an ongoing test-and-treat pilot at the largest HRC in Barcelona were included in the study. HCV-RNA detection from DBS collected after treatment (with follow-up at 12, 36, and 60 weeks) was compared with a molecular point-of-care test using finger-stick blood (GeneXpert). Baseline and follow-up DBS samples were genotyped by NS5B sequencing or commercial real-time PCR. Among treated patients, 193 follow-up DBS samples were tested. The DBS-based assay showed 100% specificity (129/129), and sensitivity ranged from 84.4% to 96.1% according to different viral load cut-offs (from detectable to 3000 IU/mL). Sensitivity as test of cure (follow-up 12) ranged from 85.1% to 97.4%. Among the 64 patients with recurrent viremia, 10.9% had low viral loads (≤1000 IU/mL); HCV genotyping allowed us to classify 73.5% of viremic cases either as reinfection or as treatment failure. DBS samples are useful to assess cure and differentiate reinfection from relapse after HCV antiviral treatment in the real world, facilitating decentralization of treatment and posttreatment follow-up in PWID. However, a fraction of patients presented with low viral loads, limiting viremia detection and genotyping in DBS and, therefore, repeat testing is recommended.
干血斑（DBS）是诊断丙型肝炎病毒（HCV）血症感染的可靠工具。我们评估了一种基于DBS的分子检测方法在减少伤害中心（HRC）现场治疗后评估治愈和再感染情况的临床性能。还评估了DBS样本的基因分型，以区分再感染和治疗失败。来自巴塞罗那最大的HRC正在进行的检测与治疗试点项目中的注射吸毒者（PWID）被纳入研究。将治疗后收集的DBS样本（随访12周、36周和60周）中的HCV-RNA检测结果与使用指尖血的即时分子检测（GeneXpert）进行比较。通过NS5B测序或商业实时PCR对基线和随访DBS样本进行基因分型。在接受治疗的患者中，对193份随访DBS样本进行了检测。基于DBS的检测方法显示特异性为100%（129/129），根据不同的病毒载量临界值（从可检测到3000 IU/mL），敏感性范围为84.4%至96.1%。作为治愈检测（随访12周）的敏感性范围为85.1%至97.4%。在64例病毒血症复发的患者中，10.9%的患者病毒载量较低（≤1000 IU/mL）；HCV基因分型使我们能够将73.5%的病毒血症病例分类为再感染或治疗失败。在现实世界中，DBS样本有助于评估HCV抗病毒治疗后的治愈情况，并区分再感染和复发，便于PWID的治疗分散化和治疗后随访。然而，一部分患者病毒载量较低，限制了DBS中病毒血症的检测和基因分型，因此建议进行重复检测。
