TY - JOUR
T1 - Circulating IgG levels in SARS-CoV-2 convalescent individuals in Cyprus
AU - Mamais, Ioannis
AU - Malatras, Apostolos
AU - Papagregoriou, Gregory
AU - Giallourou, Natasa
AU - Kakouri, Andrea C.
AU - Karayiannis, Peter
AU - Koliou, Maria
AU - Christaki, Eirini
AU - Nikolopoulos, Georgios K.
AU - Deltas, Constantinos
N1 - Funding Information:
Funding: The project is funded mainly by the EU’S HORIZON 2020 Research and Innovation Programme under Grant Agreement No 857122, the Republic of Cyprus, and the University of Cyprus, for supporting the Center of Excellence in Biobanking and Biomedical Research (the coordinator is CD). The project was also partly sponsored financially by the Chinese Embassy in Cyprus and the Volunteer Doctors Cyprus organization.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Long-term persistence and the heterogeneity of humoral response to SARS-CoV-2 have not yet been thoroughly investigated. The aim of this work is to study the production of circulating immunoglobulin class G (IgG) antibodies against SARS-CoV-2 in individuals with past infection in Cyprus. Individuals of the general population, with or without previous SARS-CoV-2 infection, were invited to visit the Biobank at the Center of Excellence in Biobanking and Biomedical Research of the University of Cyprus. Serum IgG antibodies were measured using the SARS-CoV-2 IgG and the SARS-CoV-2 IgG II Quant assays of Abbott Laboratories. Antibody responses to SARS-CoV-2 were also evaluated against participants’ demographic and clinical data. All statistical analyses were conducted in Stata 16. The median levels of receptor binding domain (RBD)-specific IgG in 969 unvaccinated individuals, who were reportedly infected between November 2020 and September 2021, were 432.1 arbitrary units (AI)/mL (interquartile range—IQR: 182.4–1147.3). Higher antibody levels were observed in older participants, males, and those who reportedly developed symptoms or were hospitalized. The RBD-specific IgG levels peaked at three months post symptom onset and subsequently decreased up to month six, with a slower decay thereafter. IgG response to the RBD of SARS-CoV-2 is bi-phasic with considerable titer variability. Levels of IgG are significantly associated with several parameters, including age, gender, and severity of symptoms.
AB - Long-term persistence and the heterogeneity of humoral response to SARS-CoV-2 have not yet been thoroughly investigated. The aim of this work is to study the production of circulating immunoglobulin class G (IgG) antibodies against SARS-CoV-2 in individuals with past infection in Cyprus. Individuals of the general population, with or without previous SARS-CoV-2 infection, were invited to visit the Biobank at the Center of Excellence in Biobanking and Biomedical Research of the University of Cyprus. Serum IgG antibodies were measured using the SARS-CoV-2 IgG and the SARS-CoV-2 IgG II Quant assays of Abbott Laboratories. Antibody responses to SARS-CoV-2 were also evaluated against participants’ demographic and clinical data. All statistical analyses were conducted in Stata 16. The median levels of receptor binding domain (RBD)-specific IgG in 969 unvaccinated individuals, who were reportedly infected between November 2020 and September 2021, were 432.1 arbitrary units (AI)/mL (interquartile range—IQR: 182.4–1147.3). Higher antibody levels were observed in older participants, males, and those who reportedly developed symptoms or were hospitalized. The RBD-specific IgG levels peaked at three months post symptom onset and subsequently decreased up to month six, with a slower decay thereafter. IgG response to the RBD of SARS-CoV-2 is bi-phasic with considerable titer variability. Levels of IgG are significantly associated with several parameters, including age, gender, and severity of symptoms.
KW - Antibodies
KW - COVID-19
KW - Cyprus
KW - IgG
KW - SARS-CoV-2
UR - http://www.scopus.com/inward/record.url?scp=85121111146&partnerID=8YFLogxK
U2 - 10.3390/jcm10245882
DO - 10.3390/jcm10245882
M3 - Article
AN - SCOPUS:85121111146
SN - 2077-0383
VL - 10
JO - Journal of Clinical Medicine
JF - Journal of Clinical Medicine
IS - 24
M1 - 5882
ER -