Rationale
Point-of-care (POC) antibody screening for SARS-CoV-2 infection has yielded varied results. We analyzed two POC antibody testing devices to study whether these are comparable to ELISA testing done in a high complexity CLIA facility employed as a standard.
Methods
We enrolled 146 individuals, with 41 individuals having had a history of positive PCR for COVID-19. After informed consent, we obtained serum and at the same time performed a finger stick for whole blood. Autobio and MEDsan rapid IgG/IgM tests that use SARS-CoV-2 spike protein to detect antibody were performed with serum and compared to Roche’s SARS-CoV-2 immunoassay, which uses nucleocapsid protein to detect antibody. The Autobio test was also evaluated using whole blood obtained by finger stick.
Results
Serum testing using the Autobio kit versus the Roche immunoassay (used as the standard for comparison) revealed a sensitivity of 93.2% and a specificity of 96.1%; whole blood testing using the Autobio kit vs. the Roche immunoassay revealed a sensitivity of 90.5% and a specificity of 97.9%. Whole blood compared to serum testing using the Autobio POC kit revealed a sensitivity of 90.7% and a specificity of 99.0%. Serum testing using the MEDsan kit vs. the Roche immunoassay revealed a sensitivity of 100% and a specificity of 96.1%.
Conclusions
Despite using different antigens, both the POC devices showed comparable results to the high complexity ELISA. POC testing for antibodies to SARS-CoV-2 is easier, requires fewer resources than high-complexity lab testing and provides rapid results regarding individual antibody status to SARS-CoV-2. However, the specific test characteristics for each kit must be rigorously evaluated, as they vary substantially.
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