What class of antibody is referred to as AntiRh?

• A. IgE
• B. IgM
• C. IgG
• D. IgA

Answer: (C)

AntiRh antibodies belong to the IgG class of antibodies. IgG is the most abundant type of antibody found in the blood circulation and plays a crucial role in the immune response. Specifically, AntiRh antibodies are produced in response to the presence of RhD antigens, typically when an Rh-negative individual is exposed to Rh-positive red blood cells. This response is particularly important during pregnancy or blood transfusions, where the incompatibility can lead to hemolytic disease of the newborn (HDN) if the mother has developed these antibodies.

IgG antibodies can cross the placenta, providing passive immunity to the fetus in certain situations, and their presence indicates a sensitization to the Rh factor. Understanding the role of IgG, especially in the context of blood types and pregnancy, is vital for managing potential complications arising from Rh incompatibility. The other classes of antibodies, while important in various immune responses, do not specifically relate to the AntiRh context as IgG does.