Reliability of antibody tests for COVID-19 diagnosis

Özet

Objective: The reverse transcription–polymerase chain reaction test (RT-PCR) is the gold standard for the diagnosis of coronavirusdisease 2019 (COVID-19), and antibody tests are useful as supplemental tools for diagnosis, for measuring the population’s immunitylevels, and for checking infection in asymptomatic contacts. This study aimed to evaluate the reliability of five commercial antibodydetection test kits.Materials and Methods: The reliability of the Colloidal Gold COVID-19 IgG/IgM Rapid Test Kit, Antibody Rapid Test Hotgen,Beijing Hotgen Biotech Co., Ltd., China), Abbott Chemiluminescent Microparticle Immunoassay (Illinois, USA), RocheElectrochemiluminescence Immunoassay (Roche Diagnostics, Switzerland), Siemens Chemiluminescence (Munich, Germany), andEuroimmun ELISA (Lübeck, Germany) for COVID-19 diagnosis was studied. The antibody-negative group included 50 sera from2018, and the antibody-positive group included 98 patients with positive RT-PCR results from whom blood samples had been collected3–9 weeks after hospital discharge. Statistical analysis was performed using SPSS version 23.0 (IBM Corporation, Armonk, NY, USA).The antibody tests’ validity and intra-assay reproducibility were examined, and the Cohen’s kappa coefficients were obtained. Thedisease prevalence was pegged at 10%.Results: The antibody tests’ sensitivity (69.12–72.46%) and positive predictive values (42.44–100.0%) were low, and their specificity(89.58–100%) and negative predictive values (96.31–97.03%) were high. Their accuracy rates varied from 87.54% to 97.25%, and theirintra-assay coefficients of variation varied from 1% to 10%.Conclusion: The agreement between the results of the antibody detection test kits was higher when the kits were classified according tothe targeted antigens. The time of blood sample collection, targeted antigens, and antibody types affected the results. Serological testswere found to be useful, and the commercial kits were found to be largely reliable, although, some parameters need to be improved.