Preliminary Data of a Quantitative Point of Care Test for SARS-CoV-2 Antibodies From Greece

Abstract

Background: Antibody testing is necessary to identify immune individuals in the post-initial wave of the COVID-19 pandemic.

Patients and methods: We prospectively evaluated the performance of a quantitative point-of-care test (POCT) for SARS-CoV-2 antibodies. The patient group (PG) comprised of hospitalized confirmed COVID-19 cases. Asymptomatic healthcare volunteers with negative rRT-PCR were included in the control group (CG). Measurement of IgM and IgG was obtained by dry fluorescence immunoassay.

Results: Twenty-six PG (65.9±15.4 years old, male 57.7%) and 18 CG (45.6±10.1 years old, male 33.3%) were included. By manufacturer's cut-off (≥0.04 mIU/ml), sensitivity and specificity were 73.08% and 88.89% for IgM and 88.46% and 33.33% for IgG, respectively. Estimated areas under the ROC curve were 0.907 and 0.848 for IgM and IgG, respectively. Results were improved using a cut-off of IgM ≥0.05 mIU/ml and IgG ≥0.10 mIU/ml.

Conclusion: Using stringent cut-off values, SARS-CoV-2 antibody POCT detects immune people and can be used during socioeconomic normalization of communities.

Keywords: COVID-19; IgG; IgM; SARS-CoV-2; antibodies; diagnostics; novel coronavirus; point-of-care testing.