A multi-target lateral flow immunoassay enabling the specific and sensitive detection of total antibodies to SARS COV-2

• Published in: Talanta (Oxford) Vol. 223; no. Pt 1; p. 121737
• Main Authors: Cavalera, Simone, Colitti, Barbara, Rosati, Sergio, Ferrara, Gianmarco, Bertolotti, Luigi, Nogarol, Chiara, Guiotto, Cristina, Cagnazzo, Celeste, Denina, Marco, Fagioli, Franca, Di Nardo, Fabio, Chiarello, Matteo, Baggiani, Claudio, Anfossi, Laura
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2021
• Subjects: Adult; antibodies; Antibody Specificity; Colorimetry; COVID-19 - diagnosis; COVID-19 - immunology; COVID-19 Serological Testing - methods; detection; diagnostic specificity; Early Diagnosis; Equipment Design; flow; Gold; Humans; Immunoassay - methods; immunoassays; Immunochromatographic strip test; immunoglobulins; Immunoglobulins - analysis; infection; Male; Metal Nanoparticles; Middle Aged; nanogold; Nucleocapsid - chemistry; nucleocapsid proteins; Optical biosensor; Orthocoronavirinae; patients; rapid methods; Rapid test; SARS CoV-2 nucleocapsid protein; Sensitivity and Specificity; Rapid test; Optical biosensor; SARS CoV-2 nucleocapsid protein; Immunochromatographic strip test
• DOI: 10.1016/j.talanta.2020.121737
• ISSN: 0039-9140; 1873-3573

A rapid test for detecting total immunoglobulins directed towards the nucleocapsid protein (N) of severe acute syndrome coronavirus 2 (SARS CoV-2) was developed, based on a multi-target lateral flow immunoassay comprising two test lines. Both test lines bound to several classes of immunoglobulins (G, M, and A). Specific anti-SARS immunoglobulins were revealed by a colorimetric probe formed by N and gold nanoparticles. Targeting the total antibodies response to infection enabled achieving 100% diagnostic specificity (95.75–100, C.I. 95%, n = 85 healthy and with other infections individuals) and 94.6% sensitivity (84.9–98.9, C.I. 95%, n = 62 SARS CoV-2 infected subjects) as early as 7 days post confirmation of positivity. Agreeing results with a reference serological ELISA were achieved, except for the earlier detection capability of the rapid test. Follow up of the three seroconverting patients endorsed the hypothesis of the random rise of the different immunoglobulins and strengthened the ‘total antibodies’ approach for the trustworthy detection of serological response to SARS CoV-2 infection. [Display omitted] A rapid test based on the lateral flow immunoassay technology was established to detect the total serological response to the SARS CoV-2 infection. •A sensitive and specific lateral flow immunoassay for detecting antibodies to Covid-19.•Broad-specific agents to capture total immunoglobulins enabled increasing the sensitivity.•Two test lines were combined to guarantee no false positive results.•Diagnosis based on the multi-target LFIA can complement molecular assays.