CD40LG and congenital syphilis: Treponemal tests must not be used up to 18 months of age, as before, there is no correlation between the positivity of treponemal tests in the newborn and the mother, which can suggest congenital syphilis1,8,21.Tests detecting IgM treponemal antibodies (e.g., FTA-Abs IgM and IgM enzymatic immunoassays) are not recommended for congenital syphilis diagnosis because although they do not penetrate the placental barrier, such antibodies are not detected in every case of congenital syphilis, which may imply nontreatment of children with syphilis1,5,.6