Ricerc@Sapienza

Infections with SARS-CoV2 cause the coronavirus disease 2019 (COVID-19), with different clinical manifestations. Most individuals mount an IgG and IgA serum response following SARS-CoV-2 infection. Neutralizing antibodies are key in protective immunity because they block viral entry by targeting the S protein receptor¿binding domain (RBD. Patients suffering from secondary immunodeficiencies (SID) patients have enhanced morbidity and mortality following SARS-CoV-2 infection than are more vulnerable than immunocompetent (IC), but it is not clear whether they may produce more inflammatory cytokines driving an improper immune response and/or an impaired IgG/IgA against SARS-CoV-2.
The general aim of this project is to study the humoral immune responses in adult IC individuals and in adult SID patients. To that end, we will measure the levels and kinetics of antibodies and serum cytokines produced in the two groups and compare them; their relationship with demographic data, the symptoms of SARSCoV 2-infection and clinical severity of COVID-19 in IC and SID will be analyzed. We have already collected more than one hundred sera in which anti-SARS-CoV-2 IgG were measured for diagnostic or screening purpose healthcare workers pre and post-vaccination, from hospitalized patients and from SID patients attending hematooncology clinics, Policlinico Umberto I. In this study we will measure IgA by commercial EIA kit and neutralizing antibodies specific to the S protein of SARS-CoV-2 by a laboratory-adapted pseudovirus test. Longitudinal samples will be obtained from IC and SID, tracking immunity over longer periods after infection or vaccination, to test durability and levels of Ig protective titers. A Secondary Outcome may be to observe the incidence rate of SARS-CoV-2 (re)infection after a previous infection or vaccination.
This research will give further understanding of the immunoregulatory events in disease progression and the immune response to SARS-CoV-2 infection.