CD40LG and infectious mononucleosis: The results confirmed infectious mononucleosis in the seroconversion phase, with positive antibodies anti-EBV (viral capsid antigen-VCA) immunoglobulin M (IgM): 29.7 AU/mL; anti-EBV (VCA) immunoglobulin G (IgG): 696 AU/mL; and anti-EBV (EBNA): >600 AU/mL.