Open AccessDetection of Anti-SARS-CoV-2 Nucleocapsid and Spike Antibodies in Patients with Coronavirus Disease 2019 in Japan
Author(s) -
Hiroshi Furukawa,
Shomi Oka,
Takashi Higuchi,
Miho Yamaguchi,
Shota Uchiyama,
Tomohiro Koiwa,
Moriyuki Nakama,
Masaaki Minegishi,
Hirokazu Nagai,
Shigeto Tohma
Publication year - 2022
Publication title -
clinical medicine insights. circulatory, respiratory and pulmonary medicine
Language(s) - English
Resource type - Journals
ISSN - 1179-5484
DOI - 10.1177/11795484221075492
Subject(s) - serology , medicine , covid-19 , antibody , coronavirus , virology , rheumatoid arthritis , immunology , disease , infectious disease (medical specialty)
OBJECTIVES Coronavirus Disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Serological testing for anti-SARS-CoV-2 nucleocapsid (N) antibodies (Abs) and anti-SARS-CoV-2 spike (S) Abs is performed to detect prior COVID-19 infection. It is still controversial which antibodies are the most sensitive and specific, and which can be detected earliest after infection. Here, we evaluated the results of serological tests of anti-SARS-CoV-2 N and S Abs in Japan.METHODS Symptomatic COVID-19 patients (n = 84) and control patients with rheumatoid arthritis (n = 93) were recruited at Tokyo National Hospital. Anti-SARS-CoV-2 N and S Abs were measured by commercial electrochemiluminescence immunoassays.RESULTS The fraction of patients positive for anti-SARS-CoV-2 N and S Abs was highest >14 days after symptom onset. The frequency of anti-SARS-CoV-2 S Ab positivity at this time (80.4%) tended to be slightly but not significantly lower than anti-SARS-CoV-2 N Ab positivity (84.8%). Optimized cut-off levels for anti-SARS-CoV-2 N and S Ab positivity were lower than the manufacturer's recommended cut-off levels. Using multiple linear regression analyzes with anti-SARS-CoV-2 N and S Abs, we created an Ab-index with high sensitivity.CONCLUSION To increase the sensitivity of serological diagnostic tests for COVID-19, it is suggested that both anti-SARS-CoV-2 N and S Abs should be measured and cut-off levels decreased.