Table_2_Profiling Antibody Response Patterns in COVID-19: Spike S1-Reactive IgA Signature in the Evolution of SARS-CoV-2 Infection.docx

This contribution explores in a new statistical perspective the antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 141 coronavirus disease 2019 (COVID-19) patients exhibiting a broad range of clinical manifestations. This cohort accurately reflects the characteristics of the first wave of the SARS-CoV-2 pandemic in Italy. We determined the IgM, IgA, and IgG levels towards SARS-CoV-2 S1, S2, and NP antigens, evaluating their neutralizing activity and relationship with clinical signatures. Moreover, we longitudinally followed 72 patients up to 9 months postsymptoms onset to study the persistence of the levels of antibodies. Our results showed that the majority of COVID-19 patients developed an early virus-specific antibody response. The magnitude and the neutralizing properties of the response were heterogeneous regardless of the severity of the disease. Antibody levels dropped over time, even though spike reactive IgG and IgA were still detectable up to 9 months. Early baseline antibody levels were key drivers of the subsequent antibody production and the long-lasting protection against SARS-CoV-2. Importantly, we identified anti-S1 IgA as a good surrogate marker to predict the clinical course of COVID-19. Characterizing the antibody response after SARS-CoV-2 infection is relevant for the early clinical management of patients as soon as they are diagnosed and for implementing the current vaccination strategies.

本研究从全新统计学视角，对141例临床表现跨度广泛的2019冠状病毒病（COVID-19）患者体内针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的抗体应答展开探究。该队列精准反映了意大利SARS-CoV-2大流行第一波的流行特征。我们检测了患者体内针对SARS-CoV-2 S1、S2及NP抗原的免疫球蛋白M（IgM）、免疫球蛋白A（IgA）与免疫球蛋白G（IgG）水平，并评估了这些抗体的中和活性及其与临床特征的关联。此外，我们对其中72例患者进行了长达症状发作后9个月的纵向随访，以探究抗体水平的持续情况。本研究结果显示，绝大多数COVID-19患者可产生早期病毒特异性抗体应答。抗体应答的强度与中和特性存在异质性，且与疾病严重程度无关。抗体水平随时间推移逐渐下降，但刺突蛋白反应性IgG与IgA仍可在症状发作后9个月时被检测到。早期基线抗体水平是后续抗体产生以及针对SARS-CoV-2的长期保护性免疫的关键驱动因素。尤为重要的是，本研究发现抗S1 IgA可作为预测COVID-19临床进程的优良替代标志物。阐明SARS-CoV-2感染后的抗体应答特征，可为患者确诊后的早期临床管理以及当前疫苗接种策略的实施提供重要参考。