Evaluation of S-RBD and high specificity ACE-2-binding antibodies on SARS-CoV-2 patients after six months from infection

Flaminia Tomassetti; Marzia Nuccetelli; Serena Sarubbi; Francesca Gisone; Marco Ciotti; Francesco Spinazzola; Cristina Ricotta; Monica Cagnoli; Monica Borgatti; Marco Iannetta; Massimo Andreoni; Graziella Calugi; Massimo Pieri; Sergio Bernardini

doi:10.1016/j.intimp.2021.108013

Evaluation of S-RBD and high specificity ACE-2-binding antibodies on SARS-CoV-2 patients after six months from infection

Int Immunopharmacol. 2021 Oct:99:108013. doi: 10.1016/j.intimp.2021.108013. Epub 2021 Jul 27.

Authors

Affiliations

¹ Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy; Lifebrain srl, Viale Roma 190/A, Guidonia Montecelio, Rome, Italy.
² Department of Laboratory Medicine, Tor Vergata University Hospital, Rome, Italy.
³ Department of Experimental Medicine, University of Tor Vergata, Rome, Italy.
⁴ Department of Laboratory Medicine, Virology Unit, Tor Vergata University Hospital, Rome, Italy.
⁵ Lifebrain srl, Viale Roma 190/A, Guidonia Montecelio, Rome, Italy.
⁶ Lifebrain Liguria, Via G.B. Monti, 109 R, Genoa, Italy.
⁷ Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
⁸ Department of Functional Area of Integrated Care Services, Infectious Diseases Clinic, Tor Vergata University Hospital, Rome, Italy; Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
⁹ Lifebrain srl, Viale Roma 190/A, Guidonia Montecelio, Rome, Italy; Department of Laboratory Medicine, Tor Vergata University Hospital, Rome, Italy; Department of Experimental Medicine, University of Tor Vergata, Rome, Italy. Electronic address: massimo.pieri@uniroma2.it.
¹⁰ Department of Laboratory Medicine, Tor Vergata University Hospital, Rome, Italy; Department of Experimental Medicine, University of Tor Vergata, Rome, Italy.

Abstract

The antibody response to SARS-CoV-2 has not yet fully defined, but the availability of sensitive and specific serological assays is crucial to observe the presence of specific antibodies against the human receptor binding domain (S-RBD) and high specificity ACE-2-binding antibodies or neutralizing antibodies (NT) in response to vaccines. Indeed, these peculiar antibodies should prevent viral interaction between RBD and Angiotensin-Converting Enzyme 2 (ACE2) receptor, located on surface of host cells. In this study, 72 samples from 37 hospitalized COVID-19 patients and 35 not-hospitalized patients were analyzed longitudinally. The detection of S-RBD and NT antibodies was carried out using CLIA tests. Hospitalized patients showed elevated serum levels of S-RBD (97.22%) and NT (77.78%) antibodies, differently, not-hospitalized, who were paucisymptomatic or asymptomatic patients, showed lower serum levels of S-RBD (65.71%) and NT (38.14%) antibodies. The results suggest that the NT serum level is strongly related to disease severity (p < 0.001) and to the serum level of S-RBD antibodies (p < 0.0001).

Keywords: Neutralizing antibodies; S-RBD antibodies; SARS-CoV-2; Serological tests; Vaccines.

MeSH terms

Adult
Aged
Aged, 80 and over
Angiotensin-Converting Enzyme 2 / immunology*
Antibodies, Neutralizing / blood
Antibodies, Neutralizing / immunology*
Antibodies, Viral / immunology*
COVID-19 / immunology*
Female
Humans
Immunity
Longitudinal Studies
Male
Middle Aged
SARS-CoV-2 / immunology
Serologic Tests

Substances

Antibodies, Neutralizing
Antibodies, Viral
Angiotensin-Converting Enzyme 2