Ethics approval and consent to participate: This study received appropriate ethical review committee approval, with a waiver of informed consent.
Consent for publication: Not applicable.
Availability of data and materials: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Competing interests: The authors declare that they have no competing interests.
Funding: The Reale Group and the Fondazione Valentino Garavani & Giancarlo Giammetti, to support the COVID-19 Research in our Institution, financed this work. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Authors' contributions: FDM and MS had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. FDM, BP, and MS conceived and designed the study. FDM, BP, FRP, and MS acquired, analyzed, and interpreted the data. FDM and FRP performed statistical analyses. AG and MS supervised the work. BP was the major contributor in writing the manuscript. PC, AG, and MS critically revised the manuscript for important intellectual concept. All authors read and approved the final manuscript.
Acknowledgements: We thank Franziska Lohmeyer, PhD (Scientific Direction of the Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy) for English revision of the manuscript, and clinical staff members in the Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy for collection of samples. None of these individuals received compensation for their contributions.