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. 2022 Oct;28(10):1391.e1-1391.e5.
doi: 10.1016/j.cmi.2022.05.023. Epub 2022 May 30.

N-antigenemia detection by a rapid lateral flow test predicts 90-day mortality in COVID-19: A prospective cohort study

Raquel Almansa  1 , Jose María Eiros  2 , David de Gonzalo-Calvo  3 , Tamara Postigo  4 , Alicia Ortega  4 , Raul Lopez-Izquierdo  5 , Anna Moncusí-Moix  3 , Clara Gort-Paniello  3 , Marta Dominguez-Gil  2 , Amanda de la Fuente  4 , Laura González-González  6 , Tania Luis-García  6 , Nadia García-Mateo  4 , Ana P Tedim  4 , Fátima Rodríguez-Jara  3 , Noelia Jorge  6 , Jessica González  7 , Gerard Torres  3 , Oliver Norberto Gutiérrez-Pérez  8 , Maria José Villegas  8 , Sonia Campo  8 , Eva Ayllon  8 , Tomás Ruiz Albi  9 , Julio de Frutos Arribas  10 , Ainhoa Arroyo Domingo  9 , Jesica Abadia-Otero  11 , Julia Gómez Barquero  11 , Wysali Trapiello  12 , Luis Javier Garcia Frade  8 , Luis Inglada  11 , Felix Del Campo  13 , Jesús F Bermejo-Martin  14 , Ferran Barbé  3 , Antoni Torres  15
Affiliations

N-antigenemia detection by a rapid lateral flow test predicts 90-day mortality in COVID-19: A prospective cohort study

Raquel Almansa et al. Clin Microbiol Infect. 2022 Oct.

Abstract

Objectives: To evaluate if the detection of N antigen of SARS-CoV-2 in plasma by a rapid lateral flow test predicts 90-day mortality in COVID-19 patients hospitalized at the wards.

Methods: The presence of N-antigenemia was evaluated in the first 36 hours after hospitalization in 600 unvaccinated COVID-19 patients, by using the Panbio COVID-19 Ag Rapid Test Device from Abbott (Abbott Laboratories Inc., Chicago, IL, USA). The impact of N-antigenemia on 90-day mortality was assessed by multivariable Cox regression analysis.

Results: Prevalence of N-antigenemia at hospitalization was higher in nonsurvivors (69% (82/118) vs. 52% (250/482); p < 0.001). The patients with N-antigenemia showed more frequently RNAemia (45.7% (148/324) vs. 19.8% (51/257); p < 0.001), absence of anti-SARS-CoV-2 N antibodies (80.7% (264/327) vs. 26.6% (69/259); p < 0.001) and absence of S1 antibodies (73.4% (240/327) vs. 23.6% (61/259); p < 0.001). The patients with antigenemia showed more frequently acute respiratory distress syndrome (30.1% (100/332) vs. 18.7% (50/268); p = 0.001) and nosocomial infections (13.6% (45/331) vs. 7.9% (21/267); p = 0.026). N-antigenemia was a risk factor for increased 90-day mortality in the multivariable analysis (HR, 1.99 (95% CI,1.09-3.61), whereas the presence of anti-SARS-CoV-2 N-antibodies represented a protective factor (HR, 0.47 (95% CI, 0.26-0.85).

Discussion: The presence of N-antigenemia or the absence of anti-SARS-CoV-2 N-antibodies after hospitalization is associated to increased 90-day mortality in unvaccinated COVID-19 patients. Detection of N-antigenemia by using lateral flow tests is a quick, widely available tool that could contribute to early identify those COVID-19 patients at risk of deterioration.

Keywords: Antigenemia; COVID-19; Hospitalized; Mortality; Rapid test.

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Figures

Image 1
Graphical abstract
Fig. 1
Fig. 1
Left: Forest plot showing the adjusted HR from the Cox multivariate analysis to predict 90-day mortality (see Supplementary material, File 2). Right: Kaplan-Meier curves for 90-day mortality.
See this image and copyright information in PMC

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