Yong Chong1, Hideyuki Ikematsu2, Naoki Tani1, Yoko Arimizu3, Haruka Watanabe1, Yukako Fukamachi1, Akiko Yonekawa1, Sho Iwasaka1,4, Ruriko Nishida1,5, Yoshihiro Eriguchi1, Noriko Miyake1, Shinji Shimoda1, Yoji Nagasaki3, Nobuyuki Shimono1,6, Koichi Akashi1. 1. Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences (The First Department of Internal Medicine), Fukuoka, Japan. 2. Japan Physicians Association, Tokyo, Japan. 3. Department of Infectious Disease, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan. 4. Emergency and Critical Care Center, Kyushu University Hospital, Fukuoka, Japan. 5. Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, Fukuoka, Japan. 6. Center for the Study of Global Infection, Kyushu University Hospital, Fukuoka, Japan.
Abstract
BACKGROUND: The longitudinal observation of the detection of antibody responses to SARS-CoV-2 using antibody kits during the clinical course of COVID-19 is not yet fully investigated. OBJECTIVES: To understand the significance of the detection of anti-SARS-CoV-2 antibodies, particularly IgG, using a rapid antibody kit, during the clinical course of COVID-19 patients with different severities. METHODS: Sixty-three serum samples from 18 patients (5 asymptomatic and 13 symptomatic patients) were retrospectively examined using a commercial SARS-CoV-2 IgM/IgG antibody kit. PCR positivity of patient samples was also examined as a marker of current SARS-CoV-2 infection. RESULTS: IgG antibodies were detected in all cases in this study. The IgG detection rates reached 100.0% in samples collected on day 13 or later. IgG seropositivity after an initial negative status was observed in 13 patients (3/5 asymptomatic and 10/13 symptomatic cases). Interestingly, the persistence of both PCR and IgG positivity was detected in seven cases, of which three were asymptomatic. The longest overlap duration of the PCR and IgG positivity was 17 days in asymptomatic status. CONCLUSIONS: SARS-CoV-2-specific IgG production can be detected in all infected individuals, using a rapid antibody kit, irrespective of clinical status. However, these findings suggest that, in some infected individuals, particularly those with asymptomatic status, the presence of virus-specific IgG antibodies does not imply prompt viral clearance.
BACKGROUND: The longitudinal observation of the detection of antibody responses to SARS-CoV-2 using antibody kits during the clinical course of COVID-19 is not yet fully investigated. OBJECTIVES: To understand the significance of the detection of anti-SARS-CoV-2 antibodies, particularly IgG, using a rapid antibody kit, during the clinical course of COVID-19patients with different severities. METHODS: Sixty-three serum samples from 18 patients (5 asymptomatic and 13 symptomatic patients) were retrospectively examined using a commercial SARS-CoV-2 IgM/IgG antibody kit. PCR positivity of patient samples was also examined as a marker of current SARS-CoV-2 infection. RESULTS: IgG antibodies were detected in all cases in this study. The IgG detection rates reached 100.0% in samples collected on day 13 or later. IgG seropositivity after an initial negative status was observed in 13 patients (3/5 asymptomatic and 10/13 symptomatic cases). Interestingly, the persistence of both PCR and IgG positivity was detected in seven cases, of which three were asymptomatic. The longest overlap duration of the PCR and IgG positivity was 17 days in asymptomatic status. CONCLUSIONS:SARS-CoV-2-specific IgG production can be detected in all infected individuals, using a rapid antibody kit, irrespective of clinical status. However, these findings suggest that, in some infected individuals, particularly those with asymptomatic status, the presence of virus-specific IgG antibodies does not imply prompt viral clearance.
Authors: Robin Patel; Esther Babady; Elitza S Theel; Gregory A Storch; Benjamin A Pinsky; Kirsten St George; Tara C Smith; Stefano Bertuzzi Journal: mBio Date: 2020-03-26 Impact factor: 7.867