Abstract: Objective To investigate the false positive results of serum IgG and IgM specific to the 2019 novel coronavirus,so as to give full play to the value of antibody detection in diagnosis and prevention and control of COVID-19. Methods The 2019-nCoV nucleic acid detection results, 2019-nCoV vaccine injection history and other relevant clinical information were collected from 9034 hospitalized patients from August 2020 to February 2021. Serum specimens were collected and the levels of IgG and IgM were detected by magnetic particle chemiluminescence. The false positive rate of IgG and IgM and its influencing factors were analyzed. Results ① The false positive rates of IgG and IgM were 0.75% and 0.34%, respectively. ② The false positive results of IgG（P=0.6098）and IgM（P=0.8288） were not correlated with gender. False positive result of IgG was not correlated with age（P=0.9130）, while the false positive result of IgM was affected by the age of the patients（P=0.0022）. The false positive rate of IgM was significantly increased in the patients with age older than 45. ③In IgG and IgM antibody false positive patients, infected patients accounted for the highest proportion. Conclusion The false positive rates of IgG and IgM detected by magnetic particle chemiluminescence are low. Age over than 45 years is an influencing factor to false positive results of IgM.

Key words: 2019 novel coronavirus, IgG/IgM antibody, Magnetic particle chemiluminescence, False positive reaction