Advanced Molecular and Immunological Diagnostic Methods to Detect SARS-CoV-2 Infection

John Charles Rotondo; Fernanda Martini; Martina Maritati; Elisabetta Caselli; Carla Enrica Gallenga; Matteo Guarino; Roberto De Giorgio; Chiara Mazziotta; Maria Letizia Tramarin; Giada Badiale; Mauro Tognon; Carlo Contini

doi:10.3390/microorganisms10061193

Advanced Molecular and Immunological Diagnostic Methods to Detect SARS-CoV-2 Infection

Microorganisms. 2022 Jun 10;10(6):1193. doi: 10.3390/microorganisms10061193.

Authors

John Charles Rotondo^{1

2}, Fernanda Martini^{1

2

3}, Martina Maritati^{1

4}, Elisabetta Caselli⁵, Carla Enrica Gallenga¹, Matteo Guarino⁶, Roberto De Giorgio⁶, Chiara Mazziotta^{1

2}, Maria Letizia Tramarin¹, Giada Badiale¹, Mauro Tognon¹, Carlo Contini¹

Affiliations

¹ Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy.
² Center for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy.
³ Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy.
⁴ Orthopaedic Ward, Casa di Cura Santa Maria Maddalena, 45030 Occhiobello, Italy.
⁵ Section of Microbiology, CIAS Research Center and LTTA, Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy.
⁶ Department of Translational Medicine, St. Anna University Hospital of Ferrara, University of Ferrara, 44124 Ferrara, Italy.

Abstract

COVID-19 emerged in late 2019 in China and quickly spread across the globe, causing over 521 million cases of infection and 6.26 million deaths to date. After 2 years, numerous advances have been made. First of all, the preventive vaccine, which has been implemented in record time, is effective in more than 95% of cases. Additionally, in the diagnostic field, there are numerous molecular and antigenic diagnostic kits that are equipped with high sensitivity and specificity. Real Time-PCR-based assays for the detection of viral RNA are currently considered the gold-standard method for SARS-CoV-2 diagnosis and can be used efficiently on pooled nasopharyngeal, or oropharyngeal samples for widespread screening. Moreover, additional, and more advanced molecular methods such as droplet-digital PCR (ddPCR), clustered regularly interspaced short palindromic repeats (CRISPR) and next-generation sequencing (NGS), are currently under development to detect the SARS-CoV-2 RNA. However, as the number of subjects infected with SARS-CoV-2 continuously increases globally, health care systems are being placed under increased stress. Thus, the clinical laboratory plays an important role, helping to select especially asymptomatic individuals who are actively carrying the live replicating virus, with fast and non-invasive molecular technologies. Recent diagnostic strategies, other than molecular methods, have been adopted to either detect viral antigens, i.e., antigen-based immunoassays, or human anti-SARS-CoV-2 antibodies, i.e., antibody-based immunoassays, in nasal or oropharyngeal swabs, as well as in blood or saliva samples. However, the role of mucosal sIgAs, which are essential in the control of viruses entering the body through mucosal surfaces, remains to be elucidated, and in particular the role of the immune response in counteracting SARS-CoV-2 infection, primarily at the site(s) of virus entry that appears to be promising.

Keywords: COVID-19; ELISA; RT-PCR; SARS-CoV-2; anti-SARS-CoV-2 antibodies; antigen-based immunoassays; secretory IgA; spike protein.

Publication types

Review

Grants and funding

This work was supported by the University of Ferrara, Fondo di Ateneo per la Ricerca (FAR) grants. John Charles Rotondo and Chiara Mazziotta were supported by the CHEST Foundation and Carlo Erba Foundation, respectively.