EXAM #2: BLOOD GROUPS & COMPATIBILITY TESTING

Question 1

In transfusion medicine, where are antigens?

Answer 1

These are proteins on the RBC

Question 2

In transfusion medicine, where are antibodies located?

Answer 2

Serum

Question 3

What classes make-up the majority of antibodies that we are concerned with in transfusion medicine?

Answer 3

IgG and IgM

Question 4

What is the difference between an allo and an autoantibody?

Answer 4

Allo= non-self 
Auto= self

Question 5

What class of antibodies causes severe intravascular hemolysis?

Answer 5

IgM

Question 6

What class of antibodies causes delayed extravascular hemolysis?

Answer 6

IgG

Question 7

Which class of antibodies crosses the placenta?

Answer 7

IgG

Question 8

What blood groups are the most important consideration in transfusion?

Answer 8

ABO

*****ABO mismatch causes intravascular hemolytic transfusion reaction.

Question 9

What is the Bombay phenotype?

Answer 9

Patients who lack the H-antigen, which is normally present on 99.9% of RBCs

Question 10

What is group A antigen?

Answer 10

N-Acetyoglactosamine added to H antigen

Question 11

What is group B antigen?

Answer 11

Galactosamine added to the H antigen

Question 12

What is AB group antigen?

Answer 12

BOTH N-Acetylgalatosamine and Galactosamine

Question 13

What is O antigen?

Answer 13

ONLY H antigen

Question 14

If a patient gets an A gene from Mom, and an O gene from Dad, what is the phenotype?

Answer 14

A

Question 15

When is the adult level of ABO antigen reached?

Answer 15

3 years

Question 16

What class are the ABO antibodies?

Answer 16

IgM

Question 17

What type of antibodies are generated against group O?

Answer 17

Anti-A and Anti-B

Question 18

What type of antibodies are formed against AB?

Answer 18

Neither

Question 19

What is the antigens in the Rh system that are of concern?

Answer 19

• “Big D”
• C
• E

Question 20

What is the typical phenotype of a Caucasian in the Rh system?

Answer 20

DCe

Question 21

What is the typical phenotype of Black patients in the Rh system?

Answer 21

Dce

Question 22

What is the Rh negative phenotype?

Answer 22

dce

Question 23

What is Rh positive and negative referring to?

Answer 23

Presence or absence of D antigen

Question 24

What class of antibodies is generated against Rh?

Answer 24

IgG

Question 25

What is HDFN?

Answer 25

Hemolytic Disease of the Fetus and Newborn

• Rh- Mom
• Rh+ baby x2

In the second pregnancy there is an issue.*

Question 26

What is RhoGAM?

Answer 26

• Synthetic Anti-D is given to a Rh- mother

- Intent is for the Anti-D to attach to baby Rh factor and “conceal” them from the Mom’s immune system

Question 27

What are the two parts of blood typing?

Answer 27

1) Front-type
2) Back-type

Needs to be agreement on both of these to determine the blood type

Question 28

What is the DAT looking for?

Answer 28

Antibody or complement attached to RBCs
- IgG class

This is looking at the RBCs*

Question 29

What is the IAT looking for?

Answer 29

In vitro antibody sensitization

Question 30

What is compatibility testing?

Answer 30

Test donor plasma and patient blood