Longitudinal characterization of the IgM and IgG humoral response in symptomatic COVID-19 patients using the Abbott Architect. (Special Issue: Coronavirus.)

Background: Antibody testing has recently emerged as an option to assist with determining exposure to SARS-CoV-2, the causative agent of COVID-19 Elucidation of the kinetics and duration of the humoral response is important for clinical management and interpreting results from serological surveys Objectives: Here we evaluated the clinical performance of Abbott SARS-CoV-2 IgM and IgG assays, as well as the longitudinal dynamics of the antibody response in symptomatic COVID-19 patients Study design and results: The diagnostic specificity was 100% for IgM and 99 67% for IgG using 300 pre-COVID-19 serum specimens Using 1349 sequential serum samples collected up to 168 days post symptom onset from 427 PCR-confirmed individuals, clinical test sensitivity of the SARS-CoV-2 IgM assay was 24 6% at 3 months The diagnostic sensitivity for the SARS-CoV-2 IgG assay post symptom onset was 23 2% at 100 days Despite that decline, 92 3% of the patient cohort remained IgG positive 3-6 months following symptom onset Conclusions: This study demonstrates the Abbott IgM assay against SARS-CoV-2 is detected slightly earlier compared to IgG, with both tests exhibiting excellent overall sensitivity and specificity In symptomatic patients who test negative by PCR for a SARS-CoV-2 infection, assessing IgM and IgG antibodies can aid in supporting a diagnosis of COVID-19