TOPIC 3 - P1

Question 1

Antihuman Globulin Test AKA ________

Answer 1

Coombs’ test

Question 2

Principle: antihuman globulins (AHGs) obtained from immunized nonhuman species bind to human globulins such as IgG or complement, either free in serum or attached to antigens on RBCs

Answer 2

Coombs’ test

Question 3

2 major types of blood group antibodies

Answer 3

IgM and IgG

Question 4

• large pentamer structure
• directly agglutinate RBCs suspended in saline

Answer 4

IgM

Question 5

• termed nonagglutinating, or incomplete antibodies,
• monomer structure is too small to directly agglutinate sensitized RBCs

Answer 5

IgG

Question 6

AHG that contains _____ to RBCs sensitized with IgG antibodies allows for ______ of these sensitized cells

Answer 6

anti-IgG ; hemagglutination

Question 7

_____ detect IgG or complement-sensitized RBCs

Answer 7

Antiglobulin tests

Question 8

(HISTORY OF THE ANTIGLOBULIN TEST)

Before, only _______ were detected. AGT permitted the detection of nonagglutinating IgG antibodies and led to the discovery and characterization of many new blood group systems.

Answer 8

IgM antibodies

Question 9

(HISTORY OF THE ANTIGLOBULIN TEST)

_____, Coombs and associates described the use of the _______ for the detection of weak and nonagglutinating Rh antibodies in serum

Answer 9

1945 ; antiglobulin test

Question 10

(HISTORY OF THE ANTIGLOBULIN TEST)

_____, Coombs and coworkers described the use of _____ to detect in vivo sensitization of the RBCs (later AKA direct antiglobulin test [DAT]) of babies suffering from __________

Although the test was initially of great value in the investigation of _____, its versatility for detecting other IgG blood group antibodies soon became evident.

Answer 10

1946 ; AHG ; hemolytic disease of the newborn (HDN)

Rh HDN

Question 11

(HISTORY OF THE ANTIGLOBULIN TEST)

weeks after Coombs had described the test, _________ antibodies and the associated antigen were reported

Answer 11

Kell blood group system

Question 12

(HISTORY OF THE ANTIGLOBULIN TEST)

Although Coombs and associates were instrumental in introducing the antiglobulin test to blood group serology, the principle of the test had in fact been described by ____ in ____

Answer 12

Moreschi ; 1908

Question 13

(HISTORY OF THE ANTIGLOBULIN TEST)

1908: Moreschi’s studies used ________ serum to agglutinate rabbit RBCs that were sensitized with low nonagglutinating doses of _________

Answer 13

rabbit antigoat ; goat antirabbit RBC serum

Question 14

(HISTORY OF THE ANTIGLOBULIN TEST)

Early AHG reagents: prepared using a -___________ as the immunogen

Answer 14

Crude globulin fraction

Question 15

(HISTORY OF THE ANTIGLOBULIN TEST)

______: _______ demonstrated that the antibody activity that detected Rh antibodies was associated with the ________ fraction in the reagent

Answer 15

1947 ; Coombs and Mourant ; anti–gamma globulin

Question 16

(HISTORY OF THE ANTIGLOBULIN TEST)

______: _____ presented the first indication that there might be another antibody activity present that influenced the final reaction

Answer 16

1951 ; Dacie

Question 17

(HISTORY OF THE ANTIGLOBULIN TEST)

observed that different ________ were obtained when dilutions of AHG were used to test cells sensitized with _____ as compared with cold antibodies

Answer 17

reaction patterns ; warm

Question 18

(HISTORY OF THE ANTIGLOBULIN TEST)

_____: Dacie and coworkers published data showing that the reactivity of AHG to cells sensitized with warm antibodies resulted from _________ & ________ was responsible for the activity of cells sensitized by cold antibodies

Answer 18

1957 ; anti–gamma globulin activity ; anti–nongamma globulin activity

Question 19

____________ was shown to be beta globulin and had specificity for complement

Answer 19

nongamma globulin component

Question 20

Sensitization can occur either _____ OR ______

Answer 20

in vivo or in vitro

Question 21

• two-stage technique (With Incubation)
• use of AHG to detect in vitro sensitization
  of RBCs

Answer 21

Indirect Antiglobulin Test (IAT)

Question 22

• one-stage procedure (Without Incubation)
• use of AHG to detect in vivo sensitization of RBCs

Answer 22

Direct Antiglobulin Test (Dat)

Question 23

Antihuman Globulin Reagents can be:

Answer 23

can be polyspecific or monospecific

Question 24

• contain antibody to human IgG and to the C3d component of human complement
• can facilitate agglutination when RBCs have been sensitized with IgG or C3d or both.

Answer 24

Polyspecific AHG reagent

Question 25

the disadvantage of this reagent is that, it may contain antibody activity to kappa and lambda light chains common to all immunoglobulin classes, thus reacting with IgA or IgM molecules

Answer 25

Polyspecific AHG reagent

Question 26

- contain only one antibody specificity: either anti-IgG or antibody to specific complement components [C3b or C3d (i.e., anticomplement)] - Anti-IgG: contain no anticomplement activity - contain antibodies specific for the FC fragment of the gamma heavy chain of the IgG molecule - Anticomplement: reactive against only the designated complement components - contain no activity against human immunoglobulins - often a blend of monoclonal anti-C3b and monoclonal anti-C3d

Answer 26

Monospecific

Question 27

(Preparation of AHG) classic method of AHG production involves injecting ______ or _______ into laboratory animals such as rabbits human globulin behaves as _______ the rabbit’s immune response is triggered, and an antibody to human globulin is produced

Answer 27

human serum ; purified globulin foreign antigen

Question 28

(Preparation of AHG) _______: mixture of antibodies from different plasma cell clones recognize different _________ (epitopes), or the same portion of the antigen but with different affinities

Answer 28

Polyclonal antibodies ; antigenic determinants

Question 29

(Preparation of AHG) ________: derived from one clone of plasma cells and recognize a single epitope Uses ________

Answer 29

Monoclonal antibodies ; hybridoma technology

Question 30

- one that contains both anti-IgG and anticomplement activity at the correct potency for immediate use - made using polyclonal or monoclonal antibodies

Answer 30

Polyspecific AHG

Question 31

Contains only one antibody specificity

Answer 31

Monospecific AHG

Question 32

immunizing 1 colony of rabbits with human immunoglobulin (IgG) antigen & another colony with human C3 antigen

Answer 32

Polyclonal AHG Production

Question 33

using serum from many donors to prepare the pooled IgG antigen to immunize the rabbits and the pooling of anti-IgG from many immunized rabbits ->essential in producing polyclonal reagents

Answer 33

Polyclonal AHG Production

Question 34

Polyclonal AHG Production process (1) colonies of animals are ______ to produce high-titer, high-avidity IgG antibodies

Answer 34

hyperimmunized

Question 35

Polyclonal AHG Production process (2) if the antibody ______ and _____ meet predetermined specifications, the animals are bled for a production batch of reagent

Answer 35

potency and specificity

Question 36

Polyclonal AHG Production process (3) Separate blends of the ______ and _______ antibodies are made

Answer 36

anti-IgG and anticomplement

Question 37

Polyclonal AHG Production process (4) each pool is then absorbed with ____, ____, and ____ cells to remove _______ antibodies

Answer 37

A1, B, and O ; heterospecific

Question 38

Polyclonal AHG Production process (5) Total Ab content of each pool is determined, and potency of the pools is analyzed to calculate the _______ for use.

Answer 38

optimum Ab dilution

Question 39

Polyclonal AHG Production process (6) Block titrations for anti-IgG pools are performed by reacting dilutions of each antibody against cells ___________ --> critical step in the manufacturing process because excess antibody may lead to _____ hence, false-negative test results

Answer 39

; sensitized with different amounts of IgG ; prozoning

Question 40

Polyclonal AHG Production process (7) potency of anti-C3 pools is measured using at least two examples each of a _____ and ______

Answer 40

C3b- and C3d-coated cell

Question 41

(Polyclonal AHG Production) advantage of using anti-IgG of polyclonal origin: ____________

Answer 41

capable of detecting the many different IgG Ab

Question 42

Immunization of laboratory animals, usually mice.

Answer 42

Monoclonal AHG Production

Question 43

using with purified human globulin

Answer 43

Monoclonal AHG Production

Question 44

Monoclonal AHG Production Process (1) Immunization of laboratory animals, usually ____, with purified human globulin

Answer 44

mice

Question 45

Monoclonal AHG Production Process (2) Mouse spleen cells containing antibody-secreting lymphocytes + myeloma cells=“_______”

Answer 45

hybridomas

Question 46

Monoclonal AHG Production Process (3) Hybridomas screened for antibodies with the required ______ and _______

Answer 46

specificity and affinity

Question 47

Monoclonal AHG Production Process (4) antibody-secreting clones may be ______ in tissue culture or by ______ into mice (antibody is collected as ______)

Answer 47

propagated ; inoculation ; ascites

Question 48

Monoclonal AHG Production Process (5) no need for _____ to remove heterospecific antibodies

Answer 48

absorption

Question 49

Monoclonal AHG Production Process (6) All antibody molecules produced identical in terms of ________ and _______

Answer 49

antibody structure and antigen specificity

Question 50

advantage of using anti-IgG of monoclonal origin: once an antibody-secreting clone of cells has been established, antibody with the same _______ and _____ will be available indefinitely ->allows the production of a consistently pure and uncontaminated _____

Answer 50

- specificity and reaction characteristics - AHG reagent

Question 51

disadvantage of monoclonal ahg production is that all antibodies produced by a clone of cells recognize a _______ present on an antigen

Answer 51

single epitope

Question 52

Antibodies Required in AHG

Answer 52

(1) Anti-IgG (2) Anticomplement

Question 53

(Anti-IgG) majority of these antibodies: mixture of ____ and ______

Answer 53

IgG1 and IgG3 subclass

Question 54

(Anti-IgG) Rarely: _________ antibodies may be found shown to fix ______ and may be detected by _______

Answer 54

nonagglutinating IgM ; complement , anticomplement

Question 55

(Anti-IgG) only RBC alloantibodies as solely IgA have been examples of _____

Answer 55

anti-Pr

Question 56

(Anticomplement) Some antibodies “fix” _______ to the RBC membrane after complexing of the antibody with its corresponding antigen

Answer 56

complement components

Question 57

(Anticomplement) ____. _____ and ____ in the table refer to antibodies that bind complement the vast majority of the time, that show variability in their ability to bind complement, and that rarely bind complement, respectively

Answer 57

most, some, and rare

Question 58

ANTIBODIES CAPABLE OF BINDING COMPLEMENT (MOST)

Answer 58

ABO Le(a) Le(b) Jk(a) Jk(b) Sc1 Co3 Ge2 Ge3 Li P PP1Pk Vel

Question 59

ANTIBODIES CAPABLE OF BINDING COMPLEMENT (SOME)

Answer 59

Xg(a) LKE Lan

Question 60

ANTIBODIES CAPABLE OF BINDING COMPLEMENT (RARE)

Answer 60

D P(1) Lu(a) Lu(b) Kell Fy(a) Fy(b) Co(a) Co(b) Di(a) S S Yt(a)

Question 61

(Anticomplement) Presence of anticomplement activity would enhance the reactions of ________ (e.g., anti-Fya and anti-K)

Answer 61

clinically significant antibodies

Question 62

(Anticomplement) Further degradation of membrane-bound C3b and C4b occurs by removing ____ and ____ to leave C3d and C4d firmly attached to the RBC membrane

Answer 62

C3c and C4c

Question 63

(Use of Polyspecific Versus Monospecific AHG in the IAT) most important function of polyspecific AHG is the __________

Answer 63

detection of IgG antibodies

Question 64

(Use of Polyspecific Versus Monospecific AHG in the IAT) associated with __________ that are not caused by clinically significant antibodies

Answer 64

unwanted positive reactions

Question 65

(Use of Polyspecific Versus Monospecific AHG in the IAT) - __________: compared monospecific anti-IgG with polyspecific AHG - concluded that some clinically significant antibodies are detected with the _________ but not with anti-IgG - This is especially true for _____, a complement-binding IgG antibody often associated with ___________

Answer 65

- Petz and coworkers - anticomplement component of AHG - anti-Jka ; delayed hemolytic transfusion reactions

Question 66

(Use of Polyspecific Versus Monospecific AHG in the IAT) _________: concluded that they would continue to use polyspecific AHG reagent for routine compatibility testing

Answer 66

Howard and associates

Question 67

(Use of Polyspecific Versus Monospecific AHG in the IAT) - ______:when using monospecific anti-IgG to screen for unexpected antibodies and to test for blood group compatibility, it offers reliability without interference from common and clinically insignificant IgM-complement fixing antibodies - numerous reports of clinically significant RBC alloantibodies that were undetectable with ________

Answer 67

- Milam - monospecific anti-IgG

Question 68

(Principles of the Antiglobulin Test) Antibody molecules and complement components are _______

Answer 68

globulins (proteins)

Question 69

(Principles of the Antiglobulin Test) Injecting an animal with human globulin stimulates the animal to produce ________ (i.e.,AHG)

Answer 69

antibody to the foreign protein

Question 70

(Principles of the Antiglobulin Test ______ employ a variety of AHG reagents reactive with various human globulins, including anti-IgG antibody to the C3d component of human complement, and polyspecific reagents that contain both anti-IgG and anti-C3d activity

Answer 70

Serologic tests