Unit 1 Introductory Concepts

Question 1

What is the study of blood group antigens and antibodies called?

Answer 1

Immunohematology

Question 2

Who discovered the ABO blood groups in 1901?

Answer 2

Karl Landsteiner

Question 3

What improved preservative solution was introduced by Gibson?

Answer 3

Citrate-phosphate-dextrose (CPD)

Question 4

What are RBC antibodies in individuals without previous exposure to RBC antigens through transfusion, injection, or pregnancy called?

Answer 4

Naturally occurring antibodies

Question 5

What causes agglutination by adjusting zeta potential between RBCs?

Answer 5

Enhancement media

Question 6

What is an antigen?

Answer 6

A foreign molecule that binds specifically to an antibody or a T-cell receptor

Question 7

What is the immunodominant sugar of A antigen?

Answer 7

N-Acetyl-D-galactosamine

Question 8

What is the second most immunogenic blood group antigen?

Answer 8

Rh D (+)

Question 9

What is a hapten?

Answer 9

An incomplete antigen that reacts to antibodies but cannot induce antibody formation

Question 10

What is the ideal pH for antigen-antibody reactions?

Answer 10

7.0 (physiologic is ideal)

Question 11

What type of antibody is IgM?

Answer 11

Cold-reacting antibody

Question 12

What is the predominant antibody produced in the secondary immune response?

Answer 12

IgG

Question 13

Which IgG subclass best passes the placenta?

Answer 13

IgG1

Question 14

What antibody is most commonly encountered in the ABO system?

Answer 14

IgM

Question 15

What is the most common enhancement media used in laboratories?

Answer 15

Low Ionic Strength Solution (LISS)

Question 16

What enzyme is isolated from fig plants and used in blood banking?

Answer 16

Ficin

Question 17

What does anti-human globulin (AHG) reagent do?

Answer 17

Acts as a bridge between antibodies and determines if RBCs are coated with antibodies or complement

Question 18

What is the function of citrate in anticoagulants?

Answer 18

Chelates calcium and prevents coagulation

Question 19

What is the significance of the ABO blood group system?

Answer 19

It was the first blood group system discovered, essential for transfusions.

Question 20

What antibody is involved in mucosal immunity?

Answer 20

IgA

Question 21

What are naturally occurring antibodies also known as?

Answer 21

Non-RBC Stimulated Antibodies

Question 22

What does the term ‘alloantibodies’ refer to?

Answer 22

Antibodies targeting antigens absent in a patient’s RBCs

Question 23

What does the term ‘autoantibodies’ refer to?

Answer 23

Antibodies targeting antigens present in a patient’s RBCs

Question 24

What is the main purpose of the mononuclear phagocyte system?

Answer 24

Clears antigen-antibody complexes from the body

Question 25

What is the first successful animal-to-animal blood transfusion credited to?

Answer 25

Richard Lower

Question 26

What is the lock and key mechanism in antigen-antibody reactions?

Answer 26

The reciprocal relationship (fit) between the antigen and its binding site on the antibody

Question 27

What is the temperature range for IgM agglutination reactions?

Answer 27

22-24°C or 4-6°C

Question 28

What is the function of polyethylene glycol (PEG) in blood banking?

Answer 28

Removes excess water to enhance antigen-antibody reactions

Question 29

What are the properties that influence antigen immunogenicity?

Answer 29

Size, complexity, conformation, charge, accessibility, solubility, digestibility, chemical composition

Question 30

What are the two stages of hemagglutination?

Answer 30

Sensitization and lattice formation

Question 31

What factor influences the distance between RBCs during agglutination?

Answer 31

Zeta potential

Question 32

What causes hemolysis during antibody reactions?

Answer 32

Activation of complement proteins

Question 33

What is the primary significance of anti-D antibodies in Rh-negative mothers?

Answer 33

Prevent development of anti-D antibodies after delivering Rh-positive infants

Question 34

What is an epitope?

Answer 34

The exact antigen site recognized by an antibody

Question 35

What is a paratope?

Answer 35

The exact antibody site that binds to the antigen

Question 36

What is the role of the J chain in antibodies?

Answer 36

Joins antibody monomers, seen in pentameric IgM

Question 37

What is the effect of high avidity in antigen-antibody reactions?

Answer 37

Leads to low dissociation and stronger binding

Question 38

What does the classical complement pathway result in?

Answer 38

Cell lysis via antigen-antibody reaction

Question 39

What factors influence host immune responses?

Answer 39

Nutritional status, hormones, genetics, age, race, exercise level, disease, injury

Question 40

What are the subclasses of IgG antibodies?

Answer 40

IgG1, IgG2, IgG3, IgG4

Question 41

What does polyspecific AHG target?

Answer 41

Both IgG antibodies and complement proteins

Question 42

What is the main characteristic of monoclonal antibodies?

Answer 42

They are homogeneous and derived from a single ancestral cell

Question 43

What reaction occurs when antigen excess causes a false-negative result?

Answer 43

Post-zone reaction

Question 44

What reaction occurs when antibody excess causes a false-negative result?

Answer 44

Pro-zone reaction

Question 45

What is the incubation time for LISS in blood banking?

Answer 45

10-15 minutes

Question 46

What does the term 'chimera' refer to in immunology?

Answer 46

Presence of different populations of cells in a single individual

Question 47

What is the result of transfusing IgA into an IgA-deficient patient?

Answer 47

Severe anaphylaxis

Question 48

Who first introduced sodium citrate as an anticoagulant?

Answer 48

Hustin

Question 49

Who developed the acid-citrate-dextrose (ACD) formula?

Answer 49

Loutit and Mollison of England