Patients with severe COVID-19 both seroconvert earlier and develop higher concentrations of SARS- CoV-2-specific IgG than patients with mild symptoms. In this retrospective study we considered different categories of patients defined as "vulnerable" because affected by other pathologies, such as patients with genetic and cardiovascular diseases; patients with autoimmune dermatological dis- ease; kidney and lung transplant patients, and pregnant women because the prevalence of Covid-19 infection during pregnancy is not known. This study was performed at IRCCS San Matteo Hospital in Pavia, North Italy, a zone considered at high risk during the COVID-19 pandemic from June to December 2020. None of the positive screened patients had symptoms of COVID-19 infection at the time of inclusion in this study.
Keywords: IgG anti SARS-CoV-2 (S); nucleic capsid protein (NCP); tumor nerosis factor alpha (TNFα); Interleukin-17 (IL-17).