In this study we primarily evaluated the time course of the antibody response to different antigens of SARS-CoV-2 (IgG, IgM, and IgA against S1, IgG against NP, and neutralizing antibodies) in COVID-19 patients admitted to hospital for interstitial pneumonia during the first epidemic wave in March and April 2020 in Italy. This evidence concerns the gene CD40LG and COVID-19.