Front Matter

Are there Examples of Such an Immune Mechanism? 237

ABO Incompatibility

In this type of hemolytic disease of newborns, the ABO blood type is incom­

patible. This occurs when the mother’s blood type of A, B, or O carries a unique

antigen similar to the Rh antigen (i.e., Kell, Duffy, Kidd, Lutheran, Diego, Xg, P,

Ee, Cc, MNSs) that is not found on the mother’s red blood cell surfaces but is

on the fetus’s red blood cells. This condition is considerably less harmful, very

uncommon, and generally not life threatening [4–6].

It is not difficult to imagine that if a fetus is exposed to neurotoxic chemical(s)

that have killed a significant number of neurons, the “unique antigens” that

have leaked into the maternal circulation could lead the mother to produce

antibodies to these antigens which could enter the fetus’s system and further

damage the fetus’s brain development. Here, there is a perpetual double jeop­

ardy for the future offspring! The neural antibodies produced during the first

(or previous) pregnancy can harm the subsequent fetuses of these “exposed”

mothers. In Figure 8.1, we have illustrated the mechanism of this terrible double

whammy  –  the synthetic chemicals (or occasionally an infection) could kill

certain progenitor neurons that lead to specific types of antigens released from

Release of fetal brain antigens

Early stage fetus

Environmental factors enter

pregnant mother’s circulatory

systems at early stages of

gestation and damage

certain brain progenitor

neurons.

Neuronal antigens from the damaged

neurons leak out into mother’s

circulation and adaptive

immune system develop

antibodies to the fetal

neuronal antigens.

Mother’s lgG enters the

fetal brain and interferes

in the normal development

of fetal brain, resulting in

ASD.

(^123)

• Figure 8.1 Illustration of neuroantigens released from the fetal brain and role of maternal
  neuroantibodies that can damage a developing fetal brain and may cause autism spectral
  disorder (ASD). (See insert for color representation of this figure.)