Clin Lab. 2023 Mar 1;69(3). doi: 10.7754/Clin.Lab.2022.220643.
As SARS-CoV-2 infection became a pandemic, much effort has been made to measure both antibody production and T cell response to SARS-CoV-2 to diagnose COVID-19 patients or find out their immune status. Authors tried to determine the optimal cutoff value and evaluate clinical performance of one interferon-γ release assay (IGRA) kit and compared their results with serological antibody assay in COVID-19 patients.
Study subjects included 100 patients confirmed as COVID-19 with RT-PCR method and 88 healthy volunteers who were PCR negative. IGRA tests were performed using STANDARDTM E Covi-FERON ELISA. Presence of SARS-CoV-2 antibodies was detected using STANDARD Q COVID-19 IgM/IgG Plus Test. Cutoff value was assessed using receiver operating characteristic (ROC) curve.
The cutoff value was 0.24 IU/mL and the area under the curve (AUC) of the ROC curve was 0.973 with 95% confidence interval (CI) of 0.940 - 1.005. At this cutoff value, sensitivity and specificity were 91.7% and 100%, respectively. In addition, when compared with antibody test, concordance rate was 95%.
STANDARDTM E Covi-FERON ELISA showed high sensitivity and specificity, when the cutoff value was 0.24 IU/mL. It was also consistent with the antibody test. IGRA test was a good indicator of cellular immune response in COVID-19 patients.
随着 SARS-CoV-2 感染成为大流行，人们做出了很大努力来测量 SARS-CoV-2 的抗体产生和 T 细胞反应，以诊断 COVID-19 患者或了解其免疫状态。作者试图确定一种干扰素-γ释放测定（IGRA）试剂盒的最佳截断值，并评估其在 COVID-19 患者中的临床性能，并将其结果与血清学抗体检测进行比较。
研究对象包括 100 名经 RT-PCR 方法确诊为 COVID-19 的患者和 88 名 PCR 阴性的健康志愿者。使用 STANDARDTM E Covi-FERON ELISA 进行 IGRA 检测。使用 STANDARD Q COVID-19 IgM/IgG Plus Test 检测 SARS-CoV-2 抗体的存在。使用接收者操作特征（ROC）曲线评估截断值。
截断值为 0.24IU/ml，ROC 曲线下面积（AUC）为 0.973，95%置信区间（CI）为 0.940-1.005。在该截断值下，敏感性和特异性分别为 91.7%和 100%。此外，与抗体检测相比，一致性率为 95%。
当截断值为 0.24IU/ml 时，STANDARDTM E Covi-FERON ELISA 显示出较高的敏感性和特异性。它也与抗体检测一致。IGRA 检测是 COVID-19 患者细胞免疫反应的良好指标。
