Department of Clinical Laboratory, Juntendo University Hospital, Bunkyo City, Tokyo, Japan.
Department of Clinical Laboratory Medicine, Juntendo University Graduate School of Medicine, Bunkyo City, Tokyo, Japan.
PLoS One. 2023 Jan 24;18(1):e0279779. doi: 10.1371/journal.pone.0279779. eCollection 2023.
Despite the worldwide campaigns of COVID-19 vaccinations, the pandemic is still a major medical and social problem. The Ortho VITROS SARS-CoV-2 spike-specific quantitative IgG (VITROS S-IgG) assay has been developed to assess neutralizing antibody (NT antibody) against SARS-CoV-2 spike (S) antibodies. However, it has not been evaluated in Japan, where the total cases and death toll are lower than the rest of the world.
The clinical performance of VITROS S-IgG was evaluated by comparing with the NT antibody levels measured by the surrogate virus neutralizing antibody test (sVNT). A total of 332 serum samples from 188 individuals were used. Of these, 219 samples were from 75 COVID-19 patients: 96 samples from 20 severe/critical cases (Group S), and 123 samples from 55 mild/moderate cases (Group M). The remaining 113 samples were from 113 healthcare workers who had received 2 doses of the BNT162b2 vaccine.
VITROS S-IgG showed good correlation with the cPass sVNT assay (Spearman rho = 0.91). Both VITROS S-IgG and cPass sVNT showed significantly higher plateau levels of antibodies in Group S compared to Group M. Regarding the humoral immune responses after BNT162b2 vaccination, individuals who were negative for SARS-CoV-2 nucleocapsid (N)-specific antibodies had statistically lower titers of both S-IgG and sVNT compared to individuals with a history of COVID-19 and individuals who were positive for N-specific antibodies without history of COVID-19. In individuals who were positive for N-specific antibodies, S-IgG and sVNT titers were similar to individuals with a history of COVID-19.
Although the automated quantitative immunoassay VITROS S-IgG showed a reasonable correlation with sVNT antibodies, there is some discrepancy between Vitros S-IgG and cPass sVNT in milder cases. Thus, VITROS S-IgG can be a useful diagnostic tool in assessing the immune responses to vaccination and herd immunity. However, careful analysis is necessary to interpret the results.
尽管全球范围内开展了 COVID-19 疫苗接种运动，但该大流行仍是一个重大的医学和社会问题。Ortho VITROS SARS-CoV-2 刺突特异性定量 IgG（VITROS S-IgG）检测法已被开发出来，用于评估针对 SARS-CoV-2 刺突（S）抗体的中和抗体（NT 抗体）。然而，该检测法尚未在病例总数和死亡人数低于世界其他地区的日本进行评估。
通过比较替代病毒中和抗体检测（sVNT）测量的 NT 抗体水平，评估 VITROS S-IgG 的临床性能。共使用了 188 个人的 332 份血清样本。其中，219 份来自 75 例 COVID-19 患者：20 例重症/危重症患者（组 S）的 96 份样本和 55 例轻症/中症患者（组 M）的 123 份样本。其余 113 份样本来自接受了 2 剂 BNT162b2 疫苗的 113 名医护人员。
VITROS S-IgG 与 cPass sVNT 检测法具有良好的相关性（Spearman rho = 0.91）。与组 M 相比，组 S 中的 VITROS S-IgG 和 cPass sVNT 均显示出抗体的平台水平明显更高。关于 BNT162b2 疫苗接种后的体液免疫反应，SARS-CoV-2 核衣壳（N）特异性抗体阴性的个体的 S-IgG 和 sVNT 滴度明显低于有 COVID-19 病史的个体和没有 COVID-19 病史但 N 特异性抗体阳性的个体。在 N 特异性抗体阳性的个体中，S-IgG 和 sVNT 滴度与有 COVID-19 病史的个体相似。
尽管自动定量免疫测定 VITROS S-IgG 与 sVNT 抗体具有合理的相关性，但在轻症病例中，VITROS S-IgG 与 cPass sVNT 之间存在一些差异。因此，VITROS S-IgG 可作为评估疫苗接种和群体免疫产生的免疫反应的有用诊断工具。但是，需要仔细分析以解释结果。
