Comparison between chemiluminescence and colloidal gold method in the detection of 2019 novel coronavirus specific antibodies and the value in COVID-19 diagnosis and treatment

OBJECTIVE: To compare the chemiluminescence and colloidal gold method in the detection of 2019 novel Coronavirus (2019⁃nCoV, or SARS ⁃CoV ⁃2) specific antibody and to evaluate the impor⁃ tance in the diagnosis and treatment of COVID ⁃ 19. METHODS: A total of 191 cases of diagnosed and suspected COVID ⁃19 patients admitted in Febrary 2020 in Wuhan Leishenshan Hospital were includ⁃ ed. The patients were divided into 2019⁃nCoV continuous positive group, 2019⁃nCoV positive to neg⁃ ative group, and 2019 ⁃ nCoV suspect group according to the results of pharyngeal swab 2019 ⁃ nCoV nucleic acid detection. In addition, 27 patients without COVID ⁃ 19 were set as control group to test the specificity. The serum samples were collected, and colloidal gold and chemiluminescence method were used to detect total antibodies (IgM+IgG) and IgM. SPSS 24. 0 was used to compare the difference in antibody detection rates between the two methods. RESULTS: The specificity of total antibodies (IgM+IgG) and IgM detection was 100%. Two methods of total antibody detection had no signifi⁃ cant difference in continuous positive group (P=1. 00). In positive to negative group and suspect group, the positive detection rate of chemiluminescence method was significantly higher than colloidal gold method (95. 2% vs 76. 2% and 94. 9% vs 70. 5%, respectively, both P<0. 05). The chemiluminescence method showed no significant difference between the three groups in IgM detection (P> 0. 05). CONCLUSION: The detection of 2019⁃ nCoV specific antibody can be an important supplemental method to pharyngeal swab 2019 ⁃ nCoV nucleic acid detection during the diagnosis and treatment of COVID ⁃ 19. The chemiluminescence method is better than colloidal gold method in the detection of total antibody. The IgM detection using chemiluminescence method is suitable for all stages of the dis⁃ ease.