■SARS-CoV-2感染始于上呼吸道,可引发粘膜尖峰特异性分泌型IgA(sIgA)的产生,提供防止再感染的保护。已经认识到,具有高水平的鼻尖特异性IgA的个体具有较低的再感染风险。然而,粘膜尖峰特异性sIgA随着时间的推移而减弱,不同的个体可能有不同水平的尖峰特异性sIgA和下降动力学,导致再感染易感性的个体差异。检测鼻腔通道中的尖峰特异性sIgA的方法对于预测再感染的风险是有价值的,因此处于危险中的人可以有更好的准备。
■在这项研究中,我们描述了基于胶体金的免疫层析(ICT)试纸条的开发,用于检测鼻粘膜衬里液(NMLF)中的SARS-CoV-2Omicron尖峰特异性sIgA。
■ICT条设计用于在使用鼻拭子收集的80μLNMLF中检测0.125μg或更多的尖峰特异性sIgA。使用来自最近从OmicronBA.5感染中恢复的个体的纯化的鼻sIgA样品来证明该ICT条带可以特异性地检测尖峰特异性sIgA。信号水平与针对XBB的中和活性正相关。随后的分析显示,鼻道中尖峰特异性sIgA水平低或检测不到的人更容易感染SARS-CoV-2。
■这种鼻尖特异性sIgAICT条提供了一种非侵入性,快速,和方便的方法来评估再感染的风险,以实现精确的准备。
UNASSIGNED: Infection with SARS-CoV-2 begins in the upper respiratory tract and can trigger the production of mucosal spike-specific secretory IgA (sIgA), which provides protection against reinfection. It has been recognized that individuals with high level of nasal
spike-specific IgA have a lower risk of reinfection. However, mucosal
spike-specific sIgA wanes over time, and different individuals may have various level of
spike-specific sIgA and descending kinetics, leading to individual differences in susceptibility to reinfection. A method for detecting
spike-specific sIgA in the nasal passage would be valuable for predicting the risk of reinfection so that people at risk can have better preparedness.
UNASSIGNED: In this study, we describe the development of a colloidal gold-based immunochromatographic (ICT) strip for detecting SARS-CoV-2 Omicron spike-specific sIgA in nasal mucosal lining fluids (NMLFs).
UNASSIGNED: The ICT strip was designed to detect 0.125 μg or more
spike-specific sIgA in 80 μL of NMLFs collected using a nasal swab. Purified nasal sIgA samples from individuals who recently recovered from an Omicron BA.5 infection were used to demonstrate that this ICT strip can specifically detect spike-specific sIgA. The signal levels positively correlated with neutralizing activities against XBB. Subsequent analysis revealed that people with low or undetectable levels of spike-specific sIgA in the nasal passage were more susceptible to SARS-CoV-2 reinfection.
UNASSIGNED: This nasal spike-specific sIgA ICT strip provides a non-invasive, rapid, and convenient method to assess the risk of reinfection for achieving precision preparedness.