Evaluation of the Feasibility and Efficacy of Point-of-Care Antibody Tests for Biomarker-Guided Management of Coronavirus Disease 2019

Background. Biomarker-guided therapy could improve management of inpatients with coronavirus disease 2019 (COVID-19). Although some results indicate that antibody tests are prognostic, little is known about patient management using point-of-care (POC) antibody tests. Methods. COVID-19 inpatients were recruited to evaluate 2 POC tests: LumiraDx and RightSign. Ease of use data were collected. Blood was also collected for centralized testing using an established antibody assay (GenScript cPass). A nested case-control study assessed if POC tests conducted on stored specimens were predictive of time to sustained recovery, mortality, and a composite safety outcome. Results. While both POC tests exhibited moderate agreement with the GenScript assay (both agreeing with 89% of antibody determinations), they were significantly different from the GenScript assay. Treating the GenScript assay as the gold standard, the LumiraDx assay had 99.5% sensitivity and 58.1% specificity whereas the RightSign assay had 89.5% sensitivity and 84.0% specificity. The LumiraDx assay frequently gave indeterminant results. Both tests were significantly associated with clinical outcomes. Conclusions. Although both POC tests deviated moderately from the GenScript assay, they predicted outcomes of interest. The RightSign test was easier to use and was more likely to detect those lacking antibody compared to the LumiraDx test treating GenScript as the gold standard.