Jan Van Elslande1, Matthijs Oyaert2, Scott Ailliet1, Marc Van Ranst3, Natalie Lorent4, Yannick Vande Weygaerde5, Emmanuel André3, Katrien Lagrou3, Stien Vandendriessche2, Pieter Vermeersch6. 1. Clinical Department of Laboratory Medicine and National Reference Center for Respiratory Pathogens, University Hospitals Leuven, Leuven, Belgium. 2. Clinical Department of Laboratory Medicine, Ghent University Hospital, Ghent, Belgium. 3. Clinical Department of Laboratory Medicine and National Reference Center for Respiratory Pathogens, University Hospitals Leuven, Leuven, Belgium; Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium. 4. Clinical Department of Pneumology, University Hospitals Leuven, Leuven, Belgium. 5. Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium. 6. Clinical Department of Laboratory Medicine and National Reference Center for Respiratory Pathogens, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium. Electronic address: pieter.vermeersch@uzleuven.be.
Abstract
BACKGROUND: Most SARS-CoV-2 infected patients develop IgG antibodies within 2-3 weeks after symptom onset. Antibody levels have been shown to gradually decrease in the first months after infection, but few data are available at six months or later. METHODS: A retrospective multi-center study was performed using 652 samples of 236 PCR-confirmed SARS-CoV-2 infected patients from 2 Belgian University hospitals. Patients were included if at least two samples were available (range 2-7 samples); including at least one sample collected 30 days or later after first positive PCR (range 0-240 days). Of those 236 patients, 19.1 % were classified as mild/asymptomatic (mild) and 80.9 % as moderate to critical (severe). IgG anti-nucleocapsid antibodies (anti-N) were measured using the Abbott Architect immunoassay. RESULTS: 22.2 % of mild and 2.6 % of severe COVID-19 cases never seroconverted (p < 0.001). Of the mild patients who seroconverted 0-59 days after PCR; 18.8 %, 40.0 % and 61.1 % were seronegative in the windows 60-119 days, 120-179 days and 180-240 days after PCR, respectively. In severe patients, these numbers were 1.9 %, 10.8 % and 29.4 % respectively (p < 0.05 each). Antibody levels were significantly higher in severe patients compared to mild patients in each 60 day window (p < 0.001 each). CONCLUSIONS: SARS-CoV-2 anti-N IgG antibody levels steadily decreased after 2 months up to 8 months post PCR. Of severe COVID-19 patients, 70.6 % remained positive up to eight months after infection. Antibody levels were significantly lower in mild SARS-CoV-2 infected patients and 61.1 % became seronegative within 6 months after the first positive PCR.
BACKGROUND: Most SARS-CoV-2 infectedpatients develop IgG antibodies within 2-3 weeks after symptom onset. Antibody levels have been shown to gradually decrease in the first months after infection, but few data are available at six months or later. METHODS: A retrospective multi-center study was performed using 652 samples of 236 PCR-confirmed SARS-CoV-2 infectedpatients from 2 Belgian University hospitals. Patients were included if at least two samples were available (range 2-7 samples); including at least one sample collected 30 days or later after first positive PCR (range 0-240 days). Of those 236 patients, 19.1 % were classified as mild/asymptomatic (mild) and 80.9 % as moderate to critical (severe). IgG anti-nucleocapsid antibodies (anti-N) were measured using the Abbott Architect immunoassay. RESULTS: 22.2 % of mild and 2.6 % of severe COVID-19 cases never seroconverted (p < 0.001). Of the mild patients who seroconverted 0-59 days after PCR; 18.8 %, 40.0 % and 61.1 % were seronegative in the windows 60-119 days, 120-179 days and 180-240 days after PCR, respectively. In severe patients, these numbers were 1.9 %, 10.8 % and 29.4 % respectively (p < 0.05 each). Antibody levels were significantly higher in severe patients compared to mild patients in each 60 day window (p < 0.001 each). CONCLUSIONS:SARS-CoV-2 anti-N IgG antibody levels steadily decreased after 2 months up to 8 months post PCR. Of severe COVID-19patients, 70.6 % remained positive up to eight months after infection. Antibody levels were significantly lower in mild SARS-CoV-2 infectedpatients and 61.1 % became seronegative within 6 months after the first positive PCR.
Authors: Sophia Hober; Cecilia Hellström; Jennie Olofsson; Eni Andersson; Sofia Bergström; August Jernbom Falk; Shaghayegh Bayati; Sara Mravinacova; Ronald Sjöberg; Jamil Yousef; Lovisa Skoglund; Sara Kanje; Anna Berling; Anne-Sophie Svensson; Gabriella Jensen; Henric Enstedt; Delaram Afshari; Lan Lan Xu; Martin Zwahlen; Kalle von Feilitzen; Leo Hanke; Ben Murrell; Gerald McInerney; Gunilla B Karlsson Hedestam; Christofer Lendel; Robert G Roth; Ingmar Skoog; Elisabet Svenungsson; Tomas Olsson; Anna Fogdell-Hahn; Ylva Lindroth; Maria Lundgren; Kimia T Maleki; Nina Lagerqvist; Jonas Klingström; Rui Da Silva Rodrigues; Sandra Muschiol; Gordana Bogdanovic; Laila Sara Arroyo Mühr; Carina Eklund; Camilla Lagheden; Joakim Dillner; Åsa Sivertsson; Sebastian Havervall; Charlotte Thålin; Hanna Tegel; Elisa Pin; Anna Månberg; My Hedhammar; Peter Nilsson Journal: Clin Transl Immunology Date: 2021-07-19