Schein - Blood Typing

Question 1

Plasma

Answer 1

Albumin, antibodies, complement, clotting factors, acute-phase proteins

Question 2

Serum

Answer 2

Plasma - clotting factors

Question 3

Are the ABO antigens protein or carbohydrates?

Answer 3

Carbohydrates

Question 4

Structure of a blood group antigen

Answer 4

Core glycan + terminal sugar

Question 5

Glycosyltransferase

Answer 5

• found on chromosome 9

- adds terminal sugars

Question 6

What sugar will Glycosyltransferase add if it is an A allele? B? O?

Answer 6

A - N-acetylgalactosamine
B - galactose
O - no activity

Question 7

What sugar molecule is added to transform the antigen from h–>H?

Answer 7

Fucose

Question 8

How is It that when we are born we already have anti-A and Anti-B antibodies?

Answer 8

We have these antibodies made in the gut microbiota. Eventually the ones we don’t need will get destroyed.

Question 9

Bombay-O

Answer 9

The Fucose molecule is never added so we never make H from h. In routine blood typing they will look like type O blood. However, this patient will have anti-O, anti-A, and anti-B antibodies so they need blood only from another Bombay-O person.
- you will be able to see anti-H agglutinations in a patient with type O blood.

Question 10

Whole blood transfusion

Answer 10

You donate the RBCs as well as the plasma, so you have to be cognizant of what types of antibodies are in the plasma as well as what types of antigens are on the RBCs.

Question 11

Transfusion reaction

Answer 11

Intravascular lysis - the antibodies will be coated with RBCs, you will have complement lysis

• the macrophages in the liver and spleen will phagocytose Abs and complement coated RBCs
• Hb is liberated in amounts toxic for the kidneys
• large release of cytokines
• DIC - disseminated intravascular coagulation - is possible, which is clotting in circulation, cut off of blood supply to organs, and clotting factor will be used up so you can bleed out easily.

Question 12

WHA Type of molecule is Rh?

Answer 12

Protein

Question 13

What antibody binds to Rh? ABO?

Answer 13

Rh - IgG

ABO - IGM

Question 14

Rhogam

Answer 14

Drug given to mothers who are in their 3rd trimester. It is essentially just exogenous IgG against the Rh+ so that the mother will not produce its own when the blood mixes and a memory will not be generated.

• it could destroy the fetal RBCs before an immune response can be generated
• it could cause feedback to occur where no Abs will be made.
• cytokines interrupt antigen specific B cells from turning into plasma cells
• ABO incompatibility can have a somewhat protective affect

Question 15

What is the difference in hemolysis in ABO vs Rh?

Answer 15

The IgM that reacts to the ABO will be able to activate complement well and therefore they can be destroyed in the blood stream In intravascular hemolysis. The IgG that reacts to Rh is small and does not activate complement well so they travel to the liver and spleen and undergo extra vascular hemolysis.

Question 16

WHat antibody did most minor blood groups use?

Answer 16

IgG

Question 17

Why is it so hard to agglutinate with IgGs detecting Rh?

Answer 17

• IgG is small whereas RBCs are much larger so they can’t bind multiple RBCs at the same time.
• The RBCs have a net negative charge so they repel each other.

Question 18

Direct Coomb’s Test

Answer 18

We want to see if the person already has antibodies on their RBCs, which would indicate some sort of autoimmunity against their RBCs. So we take their RBCs and add anti-IgG antibodies and see if their is agglutination. If the bottom of the test tube is all read there is agglutination, if it is just a dot there is no agglutination.

Question 19

Indirect Coomb’s Test

Answer 19

We want to see if the mother has anti-Rh antibodies in her serum. So, we take some normal Rh+ RBCs and we mix it with her serum and add anti-IgG antibodies. If there is agglutination then she has anti-Rh antibodies and we have to worry about the baby.

Question 20

Multiple Myeloma

Answer 20

Malignancy of antibody-producing cells

- tumors form in the bone marrow, which is where the B cells reside. That it why it is called “myeloma”

Question 21

In what band of the serum electrophoresis spectrum are most of the antibodies found?

Answer 21

The gamma band on the end

Question 22

Monoclonal gammopathy

Answer 22

Multiple myeloma is a monoclonal gammopathy because it is gamma band that is being affected. It basically means that there is an increased number of a protein in the gamma region in the blood.

Question 23

Paraprotein/M protein

Answer 23

It is the name of the protein that is being over expressed and causing the “M” like pattern that we see.

Question 24

Waldenstrom’s macroglobulinemia

Answer 24

Less mature B cells so they are only able to secrete IgM. The blood will be very viscous due to the increased amount of IgM in the blood.

Question 25

Bence-Jones Proteins

Answer 25

Light chain disease that will cause there to be light chains in the urine.

Question 26

What type of info can you get from a serum electrophoresis? Immunofixation?

Answer 26

Serum electrophoresis- you can see that something is elevated but not which Ig
Immunofixation - seperate proteins on cellulose acetate strips, flood strip with antibodies to a specific isotype. It can tell you which heavy and light chains are elevated.

Question 27

Formed Elements

Answer 27

WBCs, RBCs, Platelets