Distribution of TAS2R38 bitter taste receptor phenotype and haplotypes among COVID-19 patients.

Bitter taste receptor TAS2R38 is expressed in the respiratory tract and can respond to quorum-sensing molecules produced by pathogens, stimulating the release of nitric oxide, with biocidal activity. TAS2R38 presents two main high-frequency haplotypes: the "taster" PAV and the "non-taster" AVI. Individuals carrying the AVI allele could be at greater risk of infections, including SARS-CoV-2. The aim of this study was to assess the frequency of PAV and AVI alleles in COVID-19 patients with severe or non-severe symptoms compared to healthy subjects to further corroborate, or not, the hypothesis that the PAV allele may act as a protecting factor towards SARS-CoV-2 infection while the AVI one may represent a risk factor. After careful selection, 54 individuals were included in the study and underwent genetic analysis and PROP phenotype assessment. Our investigation could not point out at a significant relationship between single nucleotide polymorphisms responsible for PROP bitterness and presence/severity of SARS-CoV-2 infection, as previous studies suggested. Our results uncouple the direct genetic contribution of rs10246939, rs1726866 and rs713598 on COVID-19, calling for caution when proposing a treatment based on TAS2R38 phenotypes.

Diagnostic testing for SARS-CoV-2: state of the art and perspectives of molecular salivary testing

OBJECTIVES Closing commercial, recreational and educational activities is one of the most frequently adopted measures worldwide, to respond to the COVID-19 pandemic. Beyond their positive effect, however, such measures present negative economic, educational, and psychological aspects on the population. To reduce these disadvantages, together with vaccines and therapies, it is crucial to develop efficient tools for early diagnosis and to rapidly interrupt the infective chain. especially in particularly susceptible communities. This dossier aims to provide an overview of the currently available diagnostic tests for SARS-CoV-2, with an insight in salivary molecular tests. MATERIALS AND METHODS The present dossier reviews the currently available diagnostic tests for SARS-CoV-2 with a focus on salivary molecular tests, used within an experimental protocol by the UNIMI SAL research group of University degli Studi of Milan. The dossier includes an overview of COVID-19. a narrative review of the literature and a paradigmatic case report that highlights the characteristics and potential use of the different available tests. RESULTS The diagnostic SARS-CoV-2 tests can be classified according to the target they aim to detect, that is viral RNA, antigens or antibodies. The currently official diagnostic tool is the naso-pharyngeal molecular swab, due to its high sensibility (>98%) and specificity (>99%). A farther tool is the antigenic swab, that, despite the advantage of a rapid result, is less accurate and whose positive result needs therefore to be confirmed by a naso-pharyngeal molecular swab. Serological tests find their optimal application in epidemiological screenings concerning the anti- body status of individuals but are not strictly diagnostic. reason why a positive outcome requires to be followed by a naso-pharyngeal molecular swab. Serological tests find their optimal application in epidemiological screenings concerning the anti- body status of individuals but are not strictly diagnostic. reason why a positive outcome requires to be followed by a naso-pharyngeal molecular swab. Salivary molecular tests is under validation. It is a non-invasive tool that can be self-performed and shows a high concordance with naso-pharyngeal molecular swabs. Salivary molecular tests will be described in the context of an experimental protocol by the UNIMI SAL research group of University degli Studi of Milan. Saliva. collected by means of a dental cotton roll, was obtained in different settings. both from adults and children, and its analysis provided promising results thanks to its high concordance with naso-pharyngeal molecular swabs and its ability to early detect positive asymptomatic and pre-symptomatic. CONCLUSIONS The COVID-19 pandemic has prompted an increased request for new diagnostic and therapeutic possibilities in short times. To implement research towards new and innovative tools useful to overcome the difficulties connected to closures and stay-at-home measures, is crucial. In this context, salivary molecular tests seem to provide the adequate characteristics for active surveillance and early detection of positive cases. CLINICAL SIGNIFICANCE Knowledge of different diagnostic tests and their applicability is fundamental for all health workers. The comprehension of the different available devices and methods on the market for rapid and not rapid detection of SARS-CoV-2, is useful in the management of their daily clinical activity.