CD40LG and COVID-19: In this study we compared the performance of an in-house-developed quantitative FCI12,13 with the SARS-CoV-2 trimericS-IgG CLIA from Diasorin and Roche RBD-specific IgG/IgM antibody ECLIA for serological diagnosis of SARS-CoV-2 infection in patients with either acute or convalescent COVID-19.