Abstract: Objective To analyze the novel coronavirus pneumonia convalescents' health status and antibody levels, and select suitable donors for convalescent plasma collection and treatment. Methods The relevant medical examination data of discharged patients diagnosed with novel coronavirus pneumonia in the First Hospital of Changsha from February 7 to March 8, 2020, and health status of those who were willing to participate in convalescent plasma donation were evaluated. ELISA was used to detect novel coronavirus IgM, IgG antibody and total antibody, solid phase red cell adherence assay was used to screen platelet antibody, agglutination was used to detect and irregular red cell antibodies. Results The average age of 15 donors was 32 years old, the average length of hospital stay was 16.5 days, and the average sample collection time was 17.9 days before discharge. 2019-nCoV RNA screening results of 15 donors were all negative and 1 HBsAg positive was not qualified for donation. All 15 donors were negative for direct antibody and irregular antibody screening, and nonspecific positive for platelet antibody screening. 20% (3/15) was IgM negative, 53.33% (8/15) IgG antibody titer was greater than 160, 60% (9/15) total antibody titer was greater than 320, 46.67% (7/15) met both IgG antibody titer greater than 160 and total antibody titer greater than 320. Conclusion 46.67%~60% of proposed donors was permitted to donate convalescent plasma. It is of great significance to conduct the novel coronavirus pneumonia convalescents' health assessment and antibody level screening before collection, in order to select suitable donors and ensure the convalescent plasma treatment effect.

Key words: COVID-19, CP, 2019-nCoV, antibody, Direct, antibody, Irregular, antibody, Platelet, antibody