Peter Medawar Building for Pathogen Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
University of Oxford Medical School, University of Oxford, Oxford, UK.
Clin Exp Immunol. 2023 Jun 5;212(3):249-261. doi: 10.1093/cei/uxad027.
T cells are important in preventing severe disease from SARS-CoV-2, but scalable and field-adaptable alternatives to expert T-cell assays are needed. The interferon-gamma release assay QuantiFERON platform was developed to detect T-cell responses to SARS-CoV-2 from whole blood with relatively basic equipment and flexibility of processing timelines. Forty-eight participants with different infection and vaccination backgrounds were recruited. Whole blood samples were analysed using the QuantiFERON SARS-CoV-2 assay in parallel with the well-established 'Protective Immunity from T Cells in Healthcare workers' (PITCH) ELISpot, which can evaluate spike-specific T-cell responses. The primary aims of this cross-sectional observational cohort study were to establish if the QuantiFERON SARS-Co-V-2 assay could discern differences between specified groups and to assess the sensitivity of the assay compared with the PITCH ELISpot. The QuantiFERON SARS-CoV-2 distinguished acutely infected individuals (12-21 days post positive PCR) from naïve individuals (P < 0.0001) with 100% sensitivity and specificity for SARS-CoV-2 T cells, whilst the PITCH ELISpot had reduced sensitivity (62.5%) for the acute infection group. Sensitivity with QuantiFERON for previous infection was 12.5% (172-444 days post positive test) and was inferior to the PITCH ELISpot (75%). Although the QuantiFERON assay could discern differences between unvaccinated and vaccinated individuals (55-166 days since second vaccination), the latter also had reduced sensitivity (44.4%) compared to the PITCH ELISpot (66.6%). The QuantiFERON SARS-CoV-2 assay showed potential as a T- cell evaluation tool soon after SARS-CoV-2 infection but has lower sensitivity for use in reliable evaluation of vaccination or more distant infection.
T 细胞在预防严重的 SARS-CoV-2 疾病方面发挥着重要作用，但需要可扩展且适用于现场的替代方法来替代专家 T 细胞检测。干扰素 -γ 释放检测试剂盒 QuantiFERON 平台是为了使用相对基本的设备和灵活的处理时间线，从全血中检测对 SARS-CoV-2 的 T 细胞反应而开发的。招募了 48 名具有不同感染和接种背景的参与者。使用 QuantiFERON SARS-CoV-2 检测试剂盒平行分析全血样本，同时使用成熟的“医护人员中来自 T 细胞的保护性免疫”（PITCH）ELISpot 评估刺突特异性 T 细胞反应。这项横断面观察性队列研究的主要目的是确定 QuantiFERON SARS-Co-V-2 检测试剂盒是否可以区分指定人群之间的差异，并评估该检测试剂盒与 PITCH ELISpot 相比的敏感性。QuantiFERON SARS-CoV-2 可以区分急性感染（PCR 阳性后 12-21 天）个体和未感染个体（P ＜0.0001），对 SARS-CoV-2 T 细胞具有 100%的敏感性和特异性，而 PITCH ELISpot 对急性感染组的敏感性较低（62.5%）。QuantiFERON 对既往感染的敏感性为 12.5%（阳性检测后 172-444 天），低于 PITCH ELISpot（75%）。虽然 QuantiFERON 检测试剂盒可以区分未接种疫苗和已接种疫苗的个体（接种第二剂疫苗后 55-166 天），但后者的敏感性也较低（44.4%），低于 PITCH ELISpot（66.6%）。QuantiFERON SARS-CoV-2 检测试剂盒在 SARS-CoV-2 感染后不久显示出作为 T 细胞评估工具的潜力，但在可靠评估疫苗接种或更久远的感染方面敏感性较低。
