Determinazione di anticorpi anti SARS-CoV-2 in matrice salivare in individui vaccinati e in pazienti COVID-19.

Determination of anti-sars-cov-2 antibodies in salivary samples from vaccinated individuals and COVID-19 patients.

Introduction: Saliva is a promising biological fluid to be used for measuring a number of analytes. Aim of this ppaper is to verify if salivary anti-SARS-CoV-2 antibodies determination could be suitable for monitoring the viral spread and vaccination efficacy during the COVID-19 epidemic. Methods: a total of 69 subjects were enrolled at the Padova University Hospital: 39 COVID-19 patients and 30 health care workers (HCW), who underwent a complete vaccination cycle with BNT162b2. All subjects collected a salivary sample, using Salivette, (SARSTEDT AG & Co, Nümbrecht, Germany). For 9 HCW, salivary samples were collected at three different times within the same day. A serum sample was also obtained for all individuals. Salivary COVID-19 N/S1 RBD (sal-IgG) and serum anti-SARS-CoV-2 S-RBD IgG Ab (ser-IgG) were used for determining anti SARS-CoV-2 antibodies. Results: positive sal-IgG were found in 67/69 (97.1%) samples; in serum samples, the positivity for ser-IgG was found in 68/69 (98.6%). The sal-IgG median levels differed from COVID-19 to vaccinated HCW, being 0,21 kAU/L in patients samples and 0,8 kAU/L in vaccinated HCV samples (p =0.030). Median levels for ser-IgG in COVID-19 and patients vaccinated HCW were 121 kBAU/L and 940 kBAU/L (p <0.001) respectively. A statistically significant correlation was found between ser-IgG levels and time post-vaccination in HCW (rho =-0.6292, p <0.001). Sal-IgG levels were not influenced by the daytime of collection (rho =0.148, p=0.373). Passing-Bablok regressions showed that sal-IgG and ser-IgG comparability was assessable only when ser-IgG values were divided by 1000, showing slope and intercept values of 0.016 (95%CI: 0.016-0.078) and 0,221 (95%CI:-0.097 to 0.786), respectively. Conclusions: sal-IgG are detectable both in COVID-19 and in vaccinated individuals and the values are not influenced by the daytime of collection. As expected sal-IgG were much lower than ser-IgG. [ABSTRACT FROM AUTHOR]

Copyright of Biochimica Clinica is the property of SIBioC - Laboratory Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)