SARS CoV-2 antibody assays measure antibodies against the viral nucleoprotein (NP) or spike protein. The study examined if testing of antibodies against both antigens increases the diagnostic sensitivity. Sera (N=98) from infected individuals were tested with ELISAs based on the NP, receptor-binding domain (RBD), or both proteins. The AUROCs were 0.958 (NP), 0.991 (RBD), and 0.992 (NP/RBD). The RBD- and NP/RBD-based ELISAs showed better performance than the NP-based assay. Simultaneous testing for antibodies against NP and RBD increased the number of true and false positives. If maximum diagnostic sensitivity is required, the NP/RBD-based ELISA is preferable. Otherwise, the RBD-based ELISA is sufficient.

SARS CoV-2 抗体检测可测量针对病毒核蛋白 (NP) 或刺突蛋白的抗体。该研究检查了针对两种抗原的抗体测试是否会增加诊断灵敏度。来自感染个体的血清 (N=98) 用基于 NP、受体结合域 (RBD) 或这两种蛋白质的 ELISA 进行测试。AUROC 为 0.958 (NP)、0.991 (RBD) 和 0.992 (NP/RBD)。基于 RBD 和 NP/RBD 的 ELISA 显示出比基于 NP 的检测更好的性能。同时检测针对 NP 和 RBD 的抗体增加了真阳性和假阳性的数量。如果需要最大的诊断灵敏度，则优选基于 NP/RBD 的 ELISA。否则，基于 RBD 的 ELISA 就足够了。