Hemolytic Disease of the Newborn

Question

Hemolytic disease of the newborn
A)may not manifest itself fully until after birth.
B)is due to the action of IgM.
C)is due to the action of IgE.
D)is a Type I hypersensitivity reaction.
E)may not manifest itself fully until after birth AND is due to the action of IgE.

Accepted Answer

Hemolytic disease of the newborn may not fully manifest itself until after birth, as the maternal antibodies that cause the disease may not cross the placenta and affect the fetus until later in pregnancy or during delivery.

Answer: D 
 Hemolytic disease of the newborn is a Type II hypersensitivity reaction, in which maternal antibodies (often of the IgG class) target and attack fetal red blood cells. It is not caused by IgM or IgE antibodies.