CD40LG and cytomegalovirus infection: Serologic diagnosis of hCMV infection (hCMV-specific IgM, IgG, and IgG avidity determination) is recommended primarily for pregnant women with abnormalities found in follow-up imaging studies (magnetic resonance imaging (MRI), ultrasound) and who have experienced flu-like symptoms (fatigue, headache, fever) without any other identifiable cause [41].