Seroprevalence of anti-SARS-CoV-2 antibodies in Japanese COVID-19 patients

• Published in: PloS one 2021-04, Vol.16 (4), p.e0249449-e0249449
• Main Authors: Hiki, Makoto, Tabe, Yoko, Ai, Tomohiko, Matsue, Yuya, Harada, Norihiro, Sugimoto, Kiichi, Matsushita, Yasushi, Matsushita, Masakazu, Wakita, Mitsuru, Misawa, Shigeki, Idei, Mayumi, Miida, Takashi, Tamura, Naoto, Takahashi, Kazuhisa, Naito, Toshio
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Antibodies; Antibodies, Viral - blood; Biology; Biology and life sciences; Chemiluminescence; Coronaviruses; COVID-19; COVID-19 - blood; COVID-19 - diagnosis; COVID-19 - epidemiology; COVID-19 Serological Testing; Diagnosis; Editing; Emergency medical care; Emergency medical services; Epidemics; Female; Genetic aspects; Hospitals; Humans; IgG antibody; Immunoassay; Immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin M; Immunoglobulin M - blood; Infections; Internal medicine; Japan; Japan - epidemiology; Male; Measurement; Medical innovations; Medical laboratories; Medical technology; Medicine; Medicine and health sciences; Methodology; Microparticles; Middle Aged; Monoclonal antibodies; Mutation; Olfaction; Pandemics; Patients; Proteins; Respiratory distress syndrome; Rheumatology; SARS-CoV-2 - metabolism; Serological tests; Serology; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Supervision; Surgery; Thromboembolism; University faculty; Viral diseases; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0249449

To determine the seroprevalence of anti-SARS-CoV-2 IgG and IgM antibodies in symptomatic Japanese COVID-19 patients. Serum samples (n = 114) from 34 COVID-19 patients with mild to critical clinical manifestations were examined. The presence and titers of IgG antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were determined by a chemiluminescent microparticle immunoassay (CMIA) using Alinity i SARS-CoV-2 IgG and by an immunochromatographic (IC) IgM/IgG antibody assay using the Anti-SARS-CoV-2 Rapid Test. IgG was detected by the CMIA in 40%, 88%, and 100% of samples collected within 1 week, 1-2 weeks, and 2 weeks after symptom onset in severe and critical cases, and 0%, 38%, and 100% in mild/moderate cases, respectively. In severe and critical cases, the positive IgG detection rate with the IC assay was 60% within one week and 63% between one and two weeks. In mild/moderate cases, the positive IgG rate was 17% within one week and 63% between one and two weeks; IgM was positive in 80% and 75% of severe and critical cases, and 42% and 88% of mild/moderate cases, respectively. On the CMIA, no anti-SARS-CoV-2 IgG antibodies were detected in COVID-19 outpatients with mild symptoms within 10 days from onset, whereas 50% of samples from severe inpatients were IgG-positive in the same period. The IC assay detected higher IgM positivity earlier from symptom onset in severe and critical cases than in mild/moderate cases. A serologic anti-SARS-CoV-2 antibody analysis can complement PCR for diagnosing COVID-19 14 days after symptom onset.