Department of Communicable Diseases, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth (Deemed to be University), Pune, India.
Department of Pediatrics, Bharati Vidyapeeth (Deemed to be University) Medical College, Pune, India.
Viral Immunol. 2021 Apr;34(3):201-209. doi: 10.1089/vim.2020.0321. Epub 2021 Mar 3.
For the assessment of vaccine-induced immune response and to understand the role of antibodies in neutralization, it is necessary to assess dynamics of various antibodies in patients with different clinical manifestations. This study aims to quantitate circulating levels of IgA/IgG and IgG subtypes induced at different days postonset of symptoms, in severe and nonsevere patients. For this, serum or plasma samples ( = 146) collected from 79 COVID-19 patients were used. Indirect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific IgA, IgG, and IgG subtype specific enzyme-linked immunosorbent assays (ELISAs) were performed. Antibody titers between severe and nonsevere patients were compared at different times postonset of clinical symptoms. Titers in ELISA were compared to neutralizing antibody (Nab) titers determined by plaque reduction neutralization test (PRNT). Over 75% patients were positive for IgA/IgG antibodies in the first week. The ELISA titers did not differ during the first week; however, severe disease exhibited raised titers thereafter. Nab titers correlated with the ELISA titers in mild presentation but not in severe disease. IgA and IgG1 antibodies correlated stronger with Nabs. The findings highlighted that IgA together with IgG play an important in SARS-CoV-2 neutralization. These results will prove useful in assessing efficacy of vaccines and understanding disease pathogenesis.
为了评估疫苗诱导的免疫反应，并了解抗体在中和作用中的作用，有必要评估具有不同临床表现的患者中各种抗体的动态变化。本研究旨在定量检测不同发病天数的严重和非严重患者中循环 IgA/IgG 和 IgG 亚型的水平。为此，使用了来自 79 名 COVID-19 患者的 146 份血清或血浆样本。进行了间接严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）特异性 IgA、IgG 和 IgG 亚型特异性酶联免疫吸附测定（ELISA）。比较了不同临床症状发病后不同时间严重和非严重患者之间的抗体滴度。ELISA 中的滴度与通过蚀斑减少中和试验（PRNT）确定的中和抗体（Nab）滴度进行了比较。超过 75%的患者在第一周内 IgA/IgG 抗体呈阳性。ELISA 滴度在第一周内没有差异；然而，此后严重疾病的滴度升高。Nab 滴度与轻度表现的 ELISA 滴度相关，但与严重疾病无关。IgA 和 IgG1 抗体与 Nabs 的相关性更强。这些发现强调了 IgA 与 IgG 一起在 SARS-CoV-2 中和中发挥重要作用。这些结果将有助于评估疫苗的功效并了解疾病的发病机制。
