CD40LG and COVID-19: a. Test specificity ranged from 84.3-100.0% in pre-COVID-19 specimens. b. Specificity was higher when weak LFA bands were considered negative, but this decreased sensitivity. c. IgM detection was more variable than IgG, and detection was highest when IgM and IgG results were combined. c. Agreement between ELISAs and POCTs ranged from 75.7-94.8%. d. No consistent cross-reactivity was observed.