COMPARISON OF TWO METHODS FOR SARS-COV-2 ANTIBODY TESTING
Keywords:
enzyme-linked immunosorbent assay, COVID-19, chemiluminiscent immunoassayAbstract
Serologic testing became essential for assessing seroprevalence, vaccine efficiency and public health policy since the start of the COVID-19 pandemic. Many platforms are available on the market, but studies on their performance and limitations remain scarce. This study aimed to evaluate two commercial kits: a chemiluminescent immunoassay (CLIA) and an enzyme-linked immunosorbent assay (ELISA) and show their technical requirements and result concordance in the determination of anti-SARS-CoV-2 IgG antibodies.
The study included 268 samples from PCR positive patients referred to the Institute of Immunobiology and Human Genetics for anti-SARS-CoV-2 antibody testing. Two commercially available kits were used per manufacturers’ recommendations for all samples: SARS-CoV-2 RBD IgG CLIA kit from Snibe and ELISA SARS-CoV-2 IgG (RBD-S protein) from INEP. For our purposes, CLIA was chosen as the comparative method.
The positive, negative and overall percentage agreements for these two techniques were 90%, 82.7% and 87.3% respectively. Cohen’s kappa was 0.72, meaning there was a moderate agreement between the two methods. Most of the discrepancies occurred in the lower concentration category with a positive percentage agreement of only 50%.
Given the highly concordant results, CLIA remains advantageous as the more efficient and convenient method. Both are reliable serological assays for antibody determination in the SARS-CoV-2 pandemic response.
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