Transfusions

Question 1

What are four differences between IgG and IgM?

Answer 1

(1) IgG warm agglutination, IgM cold agglutination
(2) IgG does not lyse RBCs, IgM binds complement and lyses RBCs
(3) IgG crosses placenta, IgM does not cross placenta
(4) IgG binds protein-rich antigens, IgM binds carbohydrate-rich antigens

Question 2

What are two differences between type 1 and type 2 blood group chains?

Answer 2

Type 1 has a β1→3 linkage and chains are secreted

Type 2 has a β1→4 linkage and chains are membrane-associated

Question 3

What is the structure of antigens in the O, A, and B blood groups?

Answer 3

O - H antigen
A - H antigen + Gal-NAc
B - H antigen + Gal

Question 4

What is the Bombay phenotype and what are its consequences?

Answer 4

Oh genotype, no H antigen on RBCs

Appear as type O but cannot receive type O blood donations; donors must also have Bombay phenotype

Question 5

Which populations have i and I antigens?

Answer 5

i = children
I = adults

Question 6

What is anti-I antibody associated with?

Answer 6

Cold hemagglutinin disease (CHAD) and Mycoplasma pneumoniae

Question 7

What is anti-i antibody associated with?

Answer 7

Infectious mononucleosis

Question 8

How can hydrops fetalis due to Rh- mother and Rh+ fetus be prevented?

Answer 8

Give mother anti-D Ab (Rhogam) at 28 weeks and delivery, which will bind Rh+ fetal blood cells and mark them for destruction, preventing maternal production of anti-D alloantibody

Question 9

What microbes bind Leb antigen?

Answer 9

H. pylori and Norwalk virus

Question 10

What is anti-P1 antibody associated with?

Answer 10

Paroxysmal cold hemoglobinuria (aka Donath-Landsteiner syndrome) - biphasic hemolysin due to binding of antibody in cold temperatures and hemolysis in warm temperatures
Seen in bird handlers

Question 11

What do anti-Kell antibodies cause?

Answer 11

Anti-Kell (anti-K) antibodies cause hemolysis and bone marrow suppression