Evaluation of a Serological Assay to Determine the Immunoglobulin Status in SARS-CoV-2 Infected Patients Reveals a Low Performance

Abstract

Introduction: Emergence of SARS‐CoV‐2 has promoted the development of several serological tests for antibody detection. The external evaluation of their performance is needed before use. This study aims at assessing the performance of a Commercial lateral flow device for IgM/IgG Antibody SARS-CoV-2 detection. Methods: One‐hundred twenty-two samples SARS-CoV-2 positive by RT-PCR were used. A serological test (Ichroma2 COVID-19 Ab kit) was used as gold standard. All these samples were tested > 14 day post symptoms onset. Among the 122 samples used after testing with gold standard: 41 were IgM / IgG positive, 43 IgM positive / IgG negative and 38 IgM negative / igG positive. Results: The commercial test evaluated shows a sensitivity and specificity of 2.4% (95% confidence interval [CI]: 0.0%-5.7%) and 100% for IgM and 10.1% (95% confidence interval [CI]: 3.5%-16.8%) and 100% for IgG. Conclusion: Our findings demonstrate the crucial importance to evaluate performance of an assay before implementing. Key words: [Serological methods, Immunochromatography, performance, SARS-CoV-2, COVID-19]