Xiongyan Xue1, Changlin Zhu1, Shaozhen Huang1, Lianhua Pan1, Jianhua Xu2, Weixuan Li1. 1. Clinical Laboratory, Foshan First People's Hospital, Foshan 528000, China. 2. Medical Laboratory Center, Shunde Hospital of Guangzhou University of Chinese Medicine, Foshan 528333, China.
Abstract
OBJECTIVE: To evaluate the effects of heat inactivation of blood samples at 56℃ for 30 min on the results of SARS-CoV-2 antibody detection using different methods. METHODS: This retrospective study was conducted in 11 patients with established diagnosis of COVID-19 and 10 patients with diseases other than COVID- 19 in our hospital. We collected samples of serum, plasma and whole blood from each patient between February, 12 and 18, 2020, and with a double- blind design, the samples were examined for SARS-CoV-2 antibodies before and after heat inactivation at 56 ℃ for 30 min. In all the samples, the total SARS-CoV-2 antibodies were detected using immunochromatography, and the IgM antibodies were detected using fluorescence immunochromatography; the IgM and IgG antibodies in the serum and plasma samples detected with chemiluminescence immunoassay. We compared the detection results and analyzed the correlation of semi-quantitative detection results of IgM and IgG antibodies before and after heat inactivation of the samples. RESULTS: With immuno-chromatography, the coincidence rate of the total SARS-CoV-2 antibody detection before and after heat inactivation of the serum and plasma samples was 90.0% in COVID-19 cases and 100.0% in the negative cases, resulting in a total coincidence rate 95.2%; for the whole blood samples, the total coincidence rates of the total SARS-CoV-2 antibodies were 100.0%. For detection of IgM antibodies in the serum, plasma and whole blood samples using fluorescence immunochromatography, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were 100.0%, 0 and 47.6%, respectively. For detection of serum IgM and IgG antibodies and plasma IgG antibodies with chemiluminescence immunoassay, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were all 100.0%, and the total coincidence rate of plasma IgM antibodies was 95.2%. Pearson correlation analysis of the semi-quantitative results of IgM and IgG detection in the serum and plasma samples showed a correlation coefficient of 0.9999 (95%CI: 0.9998-1.000, P < 0.001) between the results before and after sample inactivation. CONCLUSIONS: Heat inactivation of blood samples at 56 ℃ for 30 min does not obviously affect the results of immunochromatography and chemiluminescent immunoassay for detection of SARS-COV-2 antibodies but can reduce the risk of infection for the operators. Heat-inactivated samples can not be used in fluorescence immunochromatography for SARS-CoV-2 antibody detection.
OBJECTIVE: To evaluate the effects of heat inactivation of blood samples at 56℃ for 30 min on the results of SARS-CoV-2 antibody detection using different methods. METHODS: This retrospective study was conducted in 11 patients with established diagnosis of COVID-19 and 10 patients with diseases other than COVID- 19 in our hospital. We collected samples of serum, plasma and whole blood from each patient between February, 12 and 18, 2020, and with a double- blind design, the samples were examined for SARS-CoV-2 antibodies before and after heat inactivation at 56 ℃ for 30 min. In all the samples, the total SARS-CoV-2 antibodies were detected using immunochromatography, and the IgM antibodies were detected using fluorescence immunochromatography; the IgM and IgG antibodies in the serum and plasma samples detected with chemiluminescence immunoassay. We compared the detection results and analyzed the correlation of semi-quantitative detection results of IgM and IgG antibodies before and after heat inactivation of the samples. RESULTS: With immuno-chromatography, the coincidence rate of the total SARS-CoV-2 antibody detection before and after heat inactivation of the serum and plasma samples was 90.0% in COVID-19 cases and 100.0% in the negative cases, resulting in a total coincidence rate 95.2%; for the whole blood samples, the total coincidence rates of the total SARS-CoV-2 antibodies were 100.0%. For detection of IgM antibodies in the serum, plasma and whole blood samples using fluorescence immunochromatography, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were 100.0%, 0 and 47.6%, respectively. For detection of serum IgM and IgG antibodies and plasma IgG antibodies with chemiluminescence immunoassay, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were all 100.0%, and the total coincidence rate of plasma IgM antibodies was 95.2%. Pearson correlation analysis of the semi-quantitative results of IgM and IgG detection in the serum and plasma samples showed a correlation coefficient of 0.9999 (95%CI: 0.9998-1.000, P < 0.001) between the results before and after sample inactivation. CONCLUSIONS: Heat inactivation of blood samples at 56 ℃ for 30 min does not obviously affect the results of immunochromatography and chemiluminescent immunoassay for detection of SARS-COV-2 antibodies but can reduce the risk of infection for the operators. Heat-inactivated samples can not be used in fluorescence immunochromatography for SARS-CoV-2 antibody detection.
Authors: Daniel K W Chu; Yang Pan; Samuel M S Cheng; Kenrie P Y Hui; Pavithra Krishnan; Yingzhi Liu; Daisy Y M Ng; Carrie K C Wan; Peng Yang; Quanyi Wang; Malik Peiris; Leo L M Poon Journal: Clin Chem Date: 2020-04-01 Impact factor: 8.327
Authors: Victor M Corman; Olfert Landt; Marco Kaiser; Richard Molenkamp; Adam Meijer; Daniel Kw Chu; Tobias Bleicker; Sebastian Brünink; Julia Schneider; Marie Luisa Schmidt; Daphne Gjc Mulders; Bart L Haagmans; Bas van der Veer; Sharon van den Brink; Lisa Wijsman; Gabriel Goderski; Jean-Louis Romette; Joanna Ellis; Maria Zambon; Malik Peiris; Herman Goossens; Chantal Reusken; Marion Pg Koopmans; Christian Drosten Journal: Euro Surveill Date: 2020-01
Authors: John Mair-Jenkins; Maria Saavedra-Campos; J Kenneth Baillie; Paul Cleary; Fu-Meng Khaw; Wei Shen Lim; Sophia Makki; Kevin D Rooney; Jonathan S Nguyen-Van-Tam; Charles R Beck Journal: J Infect Dis Date: 2014-07-16 Impact factor: 5.226
Authors: David S Hui; Esam I Azhar; Tariq A Madani; Francine Ntoumi; Richard Kock; Osman Dar; Giuseppe Ippolito; Timothy D Mchugh; Ziad A Memish; Christian Drosten; Alimuddin Zumla; Eskild Petersen Journal: Int J Infect Dis Date: 2020-01-14 Impact factor: 3.623