Development and evaluation of a Lateral flow immunoassay (LFIA) prototype for the detection of IgG anti-SARS-CoV-2 antibodies

• DOI: 10.1016/j.heliyon.2024.e29938
• Publication Date: 2024-04-18T15:52:51Z
• Authors: Matheus Bernardes...; Djairo Pastor Saa...; Leonardo Lopes-Luz; Bergmann Morais R...; Luciano da Silva ...; Tatsuya Nagata; Fabricio Rochedo ...; Mariane Martins d...; Samira Buhrer-Sékula
• Keywords: Rapid test; H1-99; 0301 basic medicine; Science (General); SARS-CoV-2; Social sciences (General); Q1-390; 03 medical and health sciences; Serology; IgG antibody; ELISA; Lateral flow; Research Article

Lateral flow immunoassays (LFIA) for antibody detection represent cost-effective and user-friendly tools for serology assessment. This study evaluated a new LFIA prototype developed with a recombinant chimeric antigen from the spike/S and nucleocapsid/N proteins to detect anti-SARS-CoV-2 IgG antibodies. The evaluation of LFIA sensitivity and specificity used 811 serum samples from 349 hospitalized, SARS-CoV-2 RT-qPCR positive COVID-19 patients, collected at different time points and 193 serum samples from healthy controls. The agreement between ELISA results with the S/N chimeric antigen and LFIA results was calculated. The LFIA prototype for SARS-CoV-2 using the chimeric S/N protein demonstrated 85 % sensitivity on the first week post symptoms onset, reaching 94 % in samples collected at the fourth week of disease. The agreement between LFIA and ELISA with the same antigen was 92.7 %, 0.827 kappa Cohen value (95 % CI [0.765-0.889]). Further improvements are needed to standardize the prototype for whole blood use. The inclusion of the novel chimeric S + N antigen in the COVID-19 IgG antibody LFIA demonstrated optimal agreement with results from a comparable ELISA, highlighting the prototype's potential for accurate large-scale serologic assessments in the field in a rapid and user-friendly format.