IgG can be aquired from the mother by crossing the placenta, but IgM cannot. Thus, the presence of IgM indicates that the baby has encountered the infection in utero and generated its own antibodies to the infection. So the baby has congenital CMV. (See FA2020 p105 for information on immunoglobulin isotypes)
NOTE: IgM is the first antibody formed in response to infection and for most serologies IgM presence will be indicative of ongoing infection.
frijolesWhy is the IgG up then? Wouldn't that suggest a resolved infection? I get that kid is infected but I figured the IgG was a false result and that it would explain the labs.+9
nsingheyMother's IgG was transferred through placenta+1
305charlie94Shouldn't the mother also be positive for IgM? I get that the baby has congenital CMV but I figured the mother should be infected as well to transmit the disease +
pfeboHad the same question, I figured the infection was resolved in the mother. However the newborn has the infection at the moment and developed IgM and the IgG's in the are from the mother.+4
pfeboHad the same question, I figured the infection was resolved in the mother. However the newborn has the infection at the moment and developed IgM and the IgG's in the are from the mother.+
neoaminI got that wrong because I thought the baby could not create immunoglobulin at that point.+
nbmesucksCMV is a herpes virus which like most herpes virus can remain latent. CMV remains latent in mononuclear cells. Since the mother has had the infection before she makes IgG she would no longer need to make IgM to defend active infection. IgM is only present at the initial infection every time thereafter your memory B-cells would make IgG - they don't need to waste time making IgM (which is really only made to buy time for the B-cells to class switch and undergo affinity maturation to make IgG)+2
submitted by โcassdawg(1780)
IgG can be aquired from the mother by crossing the placenta, but IgM cannot. Thus, the presence of IgM indicates that the baby has encountered the infection in utero and generated its own antibodies to the infection. So the baby has congenital CMV. (See FA2020 p105 for information on immunoglobulin isotypes)
NOTE: IgM is the first antibody formed in response to infection and for most serologies IgM presence will be indicative of ongoing infection.