Immunologic Principles Related to Blood Bank

Question 1

What is the ultimate role of immunohematology?

Answer 1

Successfully provide safe and effective blood components for treatment

Question 2

Intravascular hemolysis occurs when?

Answer 2

Cell membrane is destroyed by complement (not by antibody)

Question 3

Which causes immediate problems?
-Intravascular hemolysis
-Extravascular hemolysis

Answer 3

Intravascular hemolysis

Question 4

In immunohematology, what is the most common and most severe cause of intravascular hemolysis?

Answer 4

Wrong ABO type of blood given to a patient

Question 5

Extravascular hemolysis

Answer 5

Antibody is attached to red cell membrane

Question 6

What removes antibody coated red cells from circulation during extravascular hemolysis?

Answer 6

The spleen

Question 7

Examples of extravascular hemolysis (2)

Answer 7

-Delayed transfusion reactions
-Hemolytic Disease of the Newborn

Question 8

Which immune response does blood bank focus on:
-Humoral
-Cellular

Answer 8

Humoral

Question 9

Definition: Substance capable of inducing a specific immune response

Answer 9

Antigen

Question 10

Another name for antigen

Answer 10

Immunogen

Question 11

Portion of the antigen where the antibody combines

Answer 11

Epitope

Question 12

Another name for epitope

Answer 12

Antigenic determinant

Question 13

How can antigens be acquired? (3)

Answer 13

-Injection
-Inhalation
-Ingestion

Question 14

Definition:
Overall strength of reaction between several epitopes and antibodies

Answer 14

Avidity

Question 15

Avidity is dependent on what 3 factors?

Answer 15

-Affinity of the antibody
-Valency
-Noncovalent attractive forces

Question 16

Protein synthesized by plasma cells

Answer 16

Antibody

Question 17

Another name for antibody

Answer 17

Immunoglobulin

Question 18

Antibody to a foreign substance

Answer 18

Alloantibody

Question 19

Antibody to self

Answer 19

Autoantibody

Question 20

What are classes of antibodies based on?

Answer 20

Heavy chain composition

Question 21

What are the heavy chains of concern in blood bank?

Answer 21

IgM (Mu) and IgG (Gamma)

Question 22

What are the light chains found in immunoglobulins?

Answer 22

Kappa and Lambda

Question 23

Immunoglobulin structure:
This portion binds to the antigenic determinant (epitope)

Answer 23

Fragment antigen binding portion (Fab)

Question 24

Immunoglobulin structure:
This includes the binding site for complement and macrophage Fc receptors

Answer 24

Fragment crystallizable portion (Fc)

Question 25

Immunoglobulin structure: Disulfide bonding which holds the light chain and heavy chain together

Answer 25

Hinge region

Question 26

Immunoglobulin structure: Allows flexibility for immunoglobulin to attach to antigen

Answer 26

Hinge region

Question 27

What 2 enzymes can split the antibody molecule at the hinge region?

Answer 27

Papain and Pepsin

Question 28

Number of binding sites for IgG

Answer 28

2

Question 29

Number of binding sites for IgM

Answer 29

10

Question 30

IgM has how many monomers?

Answer 30

5

Question 31

IgG has how many monomers?

Answer 31

1

Question 32

IgG or IgM: Crosses the placenta

Answer 32

IgG

Question 33

IgG or IgM: Reacts at room temperature

Answer 33

IgM

Question 34

IgG or IgM: Reacts at 37C

Answer 34

IgG

Question 35

IgG or IgM: First antibody seen in primary immune response

Answer 35

IgM

Question 36

IgG or IgM: Is part of the anamnestic immune response

Answer 36

IgG

Question 37

IgG or IgM: Naturally occurring

Answer 37

IgM

Question 38

IgG or IgM: Must be previously exposed in order to create

Answer 38

IgG

Question 39

IgG or IgM: Requires enhancer to visualize lattice formation

Answer 39

IgG

Question 40

Where antibodies are located

Answer 40

Plasma or serum

Question 41

Where antigens are located

Answer 41

On the red blood cell membrane

Question 42

Strength of the binding between a single antibody and an epitope of an antigen

Answer 42

Affinity

Question 43

First stage of antigen-antibody reactions

Answer 43

Sensitization stage aka Recognition stage

Question 44

Second stage of antigen-antibody reactions

Answer 44

Agglutination stage

Question 45

Antigen-antibody stage in which the antibody is attached to antigen on the red cell membrane but a visible reaction is NOT observed

Answer 45

Sensitization Stage

Question 46

Antigen-antibody reactions: Random pairing determined largely by chance

Answer 46

Sensitization stage

Question 47

What is the serum-to-cell ratio? (#s)

Answer 47

2 drops of plasma/serum to 1 drop of red cells

Question 48

TRUE or FALSE: Increasing the serum/plasma amount increases the concentration of antibodies available to bind to red cell antigens but does NOT increase reaction probability

Answer 48

TRUE

Question 49

What environmental factors influence the sensitization stage of antigen-antibody reactions? (4)

Answer 49

-Incubation time (15-60 minutes) -Temperature (IgG 37C/IgM RT or lower) -pH (optimal ~7.0) -Ionic strength (physiologic saline)

Question 50

___________ forms when red cells are in close proximity to promote lattice formation between the antibody and antigenic sites on adjacent red cells

Answer 50

Agglutination

Question 51

What factors influence agglutination? (3)

Answer 51

-Distance between red blood cells (zeta potential) -Optimal concentrations of antigen and antibody (zone of equivalence) -Effect of centrifugation

Question 52

Definition: The force or repulsion between red cells in a physiologic saline solution

Answer 52

Zeta potential

Question 53

Red cells possess a net _______ charge on the cell surface in a saline suspension. ________ from the saline environment are attracted to these charges.

Answer 53

-negative -cations (+ charge)

Question 54

What is IgM able to facilitate agglutination better than IgG?

Answer 54

It is larger in size with more binding sites

Question 55

Excess antibody

Answer 55

Prozone

Question 56

Excess antigen

Answer 56

Postzone

Question 57

Maximum agglutination is observed when amount of antibodies = amount of antigens

Answer 57

Zone of equivalence

Question 58

Prozone and postzone can both cause what type of test results?

Answer 58

False negatives

Question 59

What helps facilitate the formation of a lattice network by forcing red cells closer together?

Answer 59

Centrifugation

Question 60

Why is hemolysis considered a positive reaction in blood bank?

Answer 60

Hemolysis can mean that complement was activated by the antibody (probable IgM)

Question 61

Primary response vs Secondary/anamnestic response: Takes 5-7 days

Answer 61

Primary

Question 62

Primary response vs Secondary/anamnestic response: Takes 24-48 hours

Answer 62

Secondary

Question 63

Primary response vs Secondary/anamnestic response: Total titer is higher

Answer 63

Secondary

Question 64

Primary response vs Secondary/anamnestic response: Titer lasts longer

Answer 64

Secondary

Question 65

Primary response vs Secondary/anamnestic response: More IgM

Answer 65

Primary

Question 66

Primary response vs Secondary/anamnestic response: Mostly IgG

Answer 66

Secondary

Question 67

Primary response vs Secondary/anamnestic response: Memory B cells

Answer 67

Secondary

Question 68

Primary response vs Secondary/anamnestic response: Needs more antigen to stimulate

Answer 68

Primary

Question 69

Primary response vs Secondary/anamnestic response: Delayed hemolytic transfusion reaction

Answer 69

Secondary

Question 70

White cells that synthesize antibodies

Answer 70

Plasma cells

Question 71

Zeta potential can be easily overcome by this immunoglobulin to produce agglutination

Answer 71

IgM