The Journal of Applied Laboratory Medicine | July 1, 2021

Nilles EJ, Karlson EW, Norman M, Gilboa T, Fischinger S, Atyeo C, Zhou G, Bennett CL, Tolan NV, Oganezova K, Walt DR, Alter G, Simmons DP, Schur P, Jarolim P, Woolley A and Baden LR

J Appl Lab Med. 2021

DOI: https://doi.org/10.1093/jalm/jfab072

This study was performed using a Simoa Homebrew assay.

Abstract

Background

Serological testing provides a record of prior infection with SARS-CoV-2, but assay performance requires independent assessment.Methods

We evaluated three commercial (Roche Diagnostics pan-IG, Epitope Diagnostics IgM and IgG) and two non-commercial (Simoa, Ragon/MGH IgG) immunoassays against 1083 unique samples that included 251 PCR positive and 832 pre-pandemic samples.Results

The Roche assay registered the highest specificity 99.6% (3/832 false positives), the Ragon/MGH assay 99.5% (4/832), the primary Simoa assay model 99.0% (8/832), and the Epitope IgG and IgM 99.0 (8/830) and 99.5% (4/830) respectively. Overall sensitivities for the Simoa, Roche pan-IG, Epitope IgG, Ragon/MGH IgG, and Epitope IgM were 92.0%, 82.9%, 82.5%, 64.5% and 47.0% respectively. The Simoa immunoassay demonstrated the highest sensitivity among samples stratified by days post symptom onset (PSO), < 8 days PSO (57.69%) 8-14 days PSO (93.51%), 15-21 days PSO (100%), and > 21 days PSO (95.18%).Conclusions

All assays demonstrated high to very high specificities while sensitivities were variable across assays.