Clinical Study on the 2019 Novel Coronavirus (2019-nCoV) IgG/IgM Antibody Test Kit (Colloidal Gold Method)
Since December 2019, continuous surveillance on influenza and relevant diseases had been carried out in Wuhan City, Hubei Province, and several patients with viral pneumonia had been found and diagnosed with viral pneumonia/pulmonary infection. Relevant viruses were typed for detection. On January 7, 2020, the laboratory detected a novel coronavirus. The “2019 novel coronavirus (2019-nCoV)” was identified in the viral pneumonia cases that occurred in Wuhan, and then named by the World Health Organization (WHO) on January 12 2020. The 2019-nCoV infected cases typically have symptoms like fever, fatigue, dry cough as the main respiratory syndrome, and gradually develop dyspnea. Severe patients presented with acute respiratory distress syndrome, septic shock, refractory metabolic acidosis, and coagulation dysfunction. Some patients had mild onset symptoms, but no fever. Most patients had good prognosis, while a few patients were critically ill and even died.
Generally, human body can produce IgM and IgG antibodies after being infected with the virus. IgM antibodies generally began to rise within 1 week of initial infection, and reached a peak after 2~3 weeks. IgG antibodies appeared later than IgM antibodies, generally around 14 days after infection, and reached a peak in the fifth week, which could last for 6 months and even several years. The IgG antibody titer, higher or lower by 4 times or above in the recovery stage than in the acute stage, was of clinical diagnostic significance for virus infection.
To validate its clinical effectiveness, according to the requirements of the Technical Guidance for Clinical Trials of In Vitro Diagnostic Reagents and Key Points for Technical Review of the Registration of 2019-nCoV Antigen/Antibody Detection Reagents (Interim), a comparative study was carried out between the Vazyme reagent and the available clinical diagnostic results, and the relevant test data were obtained and statistically analyzed.
2. Clinical Trial Design
Following the Provisions for In Vitro Diagnostic Reagent Registration, Technical Guidance for Clinical Trials of In Vitro Diagnostic Reagents and Key Points for Technical Review of the Registration of 2019-nCoV Antigen/Antibody Detection Reagents (Interim), comparative analysis was performed for the data and results, to evaluate the clinical performance of the test reagent. Test results were analyzed, and statistical results were obtained. Finally, the clinical report was completed.
The enrolled population was the patients suspected with 2019-nCoV pneumonia, and included continuous samples from patients with 2019-nCoV pneumonia at different stages. Clinical samples were numbered in the principle of complete randomization. The test results of the test kit were compared with the clinical diagnosis results, so as to evaluate the clinical application performance of the kit to be tested.
In addition, the nucleic acid test results used for clinical diagnosis were referenced and compared for the consistency, so as to fully evaluate the clinical performance of the antibody test reagent.
3 Clinical Study Results and Analysis
3.1 Sample inclusion In this study, 570 cases were included, of which 201 cases were confirmed by clinical diagnosis and 369 cases were excluded. Continuous samples were collected from 15 patients at different time points.
3.2 Analysis of results
3.2.1 Comparative analysis of clinical diagnosis results with test reagent results According to the number of cases confirmed or excluded upon clinical diagnosis results, the statistical results are shown in the following table:
Clinical diagnostic results
Test reagent results