Viruses . SARS-CoV-2 Antigenemia as a Confounding Factor in Immunodiagnostic Assays: A Case Study

[tetano]

Viruses


. 2021 Jun 14;13(6):1143.
doi: 10.3390/v13061143.
SARS-CoV-2 Antigenemia as a Confounding Factor in Immunodiagnostic Assays: A Case Study


Konstantinos Belogiannis ¹ , Venetia A Florou ¹ , Paraskevi C Fragkou ² , Stefanos Ferous ³ , Loukas Chatzis ⁴ , Aikaterini Polyzou ¹ , Nefeli Lagopati ^{1 5} , Demetrios Vassilakos ¹ , Christos Kittas ¹ , Athanasios G Tzioufas ⁴ , Sotirios Tsiodras ² , George Sourvinos ⁶ , Vassilis G Gorgoulis ^{1 5 7 8}



Affiliations

• PMID: 34198719
• DOI: 10.3390/v13061143

Abstract

Humoral immunity has emerged as a vital immune component against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nevertheless, a subset of recovered Coronavirus Disease-2019 (COVID-19) paucisymptomatic/asymptomatic individuals do not generate an antibody response, constituting a paradox. We assumed that immunodiagnostic assays may operate under a competitive format within the context of antigenemia, potentially explaining this phenomenon. We present a case where persistent antigenemia/viremia was documented for at least 73 days post-symptom onset using 'in-house' methodology, and as it progressively declined, seroconversion took place late, around day 55, supporting our hypothesis. Thus, prolonged SARS-CoV-2 antigenemia/viremia could mask humoral responses, rendering, in certain cases, the phenomenon of 'non-responders' a misnomer.

Keywords: COVID-19; ELISA; SARS-CoV-2; antibody; antigenemia; immunodiagnostics; immunoprevalence; non-responders; seroconversion; viremia.