CD40LG and COVID-19: When our study was designed, the chosen serological assay was the only one available at our hospital laboratory, with manufacturer-claimed clinical sensitivities for IgM and IgG of 78.65% and 91.21%, respectively, and specificities for IgM and IgG of 97.50% and 97.3%, respectively; we found this to be a reliable immunoassay for the measurement of specific IgM and IgG in the sera of COVID-19 patients in a validation study [12].