Avaliação comparativa do desempenho de um teste rápido na detecção de anticorpos IgG e IgM contra o SARS-CoV-2

Abstract

Initiated in 2019, COVID-19 is a disease whose etiological agent is the SARS-CoV-2 coronavirus, which has in its constitution, two main structural proteins, Spike (S) and Nucleoprotein (N) that involves ribonucleic acid (RNA) viral genomics. Thus, antibodies produced during infection usually target these viral proteins. The gold standard technique for detecting the disease is reverse transcription followed by quantitative polymerase chain reaction (RT-qPCR). However, other faster and less expensive methodologies, such as rapid tests, are being used in Brazil. Evaluating and ensuring the quality of these tests is important for the correct laboratory diagnosis to be applied. Thus, the objective of this work was to evaluate the performance of a rapid test for the detection of antibodies against SARS-CoV-2 by a comparability method with ELISA, RT-PCR and immunofluorescence methodologies. Using 42 positive samples, 30 negative samples for anti-SARS-CoV-2 antibodies and 28 samples from Coronavac vaccinated individuals. Kit performance was determined by the parameters of sensitivity, specificity, PPV, NPV, repeatability, reproducibility and temperature variation. Statistical tests such as kappa index, McNemar test, Mann-Whitney test were applied to point out significant differences, demonstrate similar or different proportions between the results and determine the level of test reliability and the graphs were generated by the GraphPad PRISM 9 software. The kit evaluated showed a sensitivity of 95.23% and a specificity of 100%. The PPV for the test was 100% and the NPV was 93.75%. In addition to a good correlation when compared to the results of immunofluorescence for samples of vaccinated by Coronavac (X² p= 0.125) and (k = 0.510 p = 0.004). The study demonstrated a good performance of the kit for detecting antibodies during SARS-CoV-2 infection, which was against other similar studies, mainly related to the specificity of the test. The data obtained from samples of vaccinates indicate that there is a need to evaluate the use of these kits in populations highly vaccinated against SARS-CoV-2.