Blood Banking Flashcards
(127 cards)
1
Q
Identified as antigens capable of initiating an immune response, which can affect RBC compatibility
A
Surface markers
2
Q
T/F: surface markers are identified as antigens capable of initiating an immune response, which can affect RBC compatibility
A
True
3
Q
Antigens are either __ or __
A
Sugars
Proteins
4
Q
T/F: antigens are either sugars or proteins
A
True
5
Q
Blood group describe by Karl Landsteiner in 1900
A
ABO blood group
6
Q
Who discovered ABO blood group
A
Karl Landsteiner
7
Q
Year ABO blood group was discovered
A
1900
8
Q
Most important blood group system
A
ABO blood group
9
Q
Principle of ABO blood group
A
Individuals possess antibodies against antigens they lack
10
Q
T/F: in ABO blood group, individuals possess antibodies against antigens they lack
A
True
11
Q
Char of antibodies in ABO blood group (4)
A
Production initiated at birth, but titer low until 3-6 mos of age
If A or B Ag is absent, person will make antibodies against missing antigens
Naturally-occurring
Complementary relationship enables ABO testing of Px sera and RBCs
12
Q
ABO antigens exhibit this kind of inheritance
A
Autosomal codominance
13
Q
T/F: ABO Ags exhibit autosomal codominant inheritance
A
True
14
Q
Location of ABO
A
Chromosome 9
15
Q
ABO: One locus in chromosome 9 is occupied by one of 3 alleles: (3)
A
A, B, O
16
Q
T/F: ABO: One locus in chromosome 9 is occupied by one of 3 alleles: A, B, O
A
True
17
Q
T/F: ABO: Each person has a pair of chromosomes that carry one allele
A
True
18
Q
Group O is a
A
Silent allele
19
Q
Silent allele
A
Group O
20
Q
Allele wherein gene product not detectable
A
Silent allele or amorph
21
Q
Secretor genes: location
A
Chromosome 19
22
Q
Secretor genes (2) -describe each
A
Hh- H antigen on RBC
Se- H antigen in secretions
23
Q
T/F: Hh and Se are on chromosome 19 and are closely linked
A
True
24
Q
T/F: H and Se genes: each locus has 2 recognized alleles, 1 allele is an amorph
A
True
25
Produces a glycosyltransferwse that acts on type 2 chains- H Ag on RBCs
H gene
26
H gene produces a glycosyltransferwse that acts on type __ chains- H Ag on RBCs
2
27
Produces a glycosyltransferwse that acts on type 2 chains- H Ag on __
RBCS
28
T/F: H gene produces a glycosyltransferwse that acts on type 2 chains- H Ag on RBCs
True
29
Non-secretors (3)
h gene
| se gene
30
Produces a glycosyltransferwse that acts on type 1 chains- H Ag in secretions
Se gene
31
Se gene produces a glycosyltransferase that acts on type __ chains- H Ag in __
1, secretions
32
Bombay phenotype
Genotype hh
33
Genotype hh
Bombay phenotype
34
Very rare, doesn't make transferase to form H Ag
Genotype hh or Bombay phenotype
35
T/F: hh is very rare, doesn't make transferase to form H Ag
True
36
Char of Bombay phenotype (3)
Bombay RBCs fail to react with anti-A, anti-B, or anti-H lectin
Only blood from other Bombay phenotype scan be transfused
Bombay serum contains anti-A, anti-B, anti-A,B, and anti-H (potent, reacts strongly at 37。C
37
Genotype hh Se
Para-Bombay phenotype
38
Normal amount of H ag is detectable in saliva because these are secretors but may produce a weak anti-H
Para-Bombay phenotype
39
T/F: para-Bombay phenotype: Normal amount of H ag is detectable in saliva because these are secretors but may produce a weak anti-H
True
40
A subgroups:
__% A1
__% A2 or weaker
80%
| 20%
41
Inheritance of A2 gene:
Small amount of H Ag conversion
42
T/F: Inheritance of A2 gene: Small amount of H Ag conversion
True
43
T/F: A subgroups have same immunodominant sugars
True
44
Differentiation of A1 and A2 subgroups based on:
Reactivity with anti-A1 (lectin [Dolichos biflorus] or human-based)
-A1 cells react with anti-A1 while A2 cells don't
45
T/F: Genes at 3 separate loci control the presence and location of the A, B, and H antigens: ABO, Hh, and Se
True
46
H gene
Gene product/enz:
Antigen:
Immunodominant sugar:
H gene
Gene product: L-fucosylytransferase
Antigen: H antigen
Immunodominant sugar: L-fucose
47
A gene
Gene product/enz:
Antigen:
Immunodominant sugar:
A gene
Gene product: N-acetylgalactosaminyltransferase
Antigen: A antigen
Immunodominant sugar: N-acetylgalactosamine
48
B gene
Gene product/enz:
Antigen:
Immunodominant sugar:
B gene
Gene product: D-galatosyltransferase
Antigen: B antigen
Immunodominant sugar: D-galactose
49
Generally, A and B genes encode these that produce A and B antigens
Glycosyltransferases
50
T/F: genes do not directly encode for the antigen but encode for the ENZYME that transfers the immuno dominant sugar that confers the specificity
True
51
T/F: O gene does not encode a functional enzyme because it is an amorph gene
True
52
T/F: A and B genes are dominant genes while O gene is an amorph gene
True
53
T/F: weak a subgroups show weaker reactivity than A2
True
54
Weak A subgroups (2)
A3
| Ax
55
Weak A subgroup with mixed-field pattern of agglutination with anti-A
A3
56
Weak A subgroups make up __% of the population
1%
57
T/F: weak A subgroups make up 1% of the population
True
58
Weak A subgroup with stronger reaction with anti-A, B than anti-A
Ax
59
Weaker A subgroups are detected by
Elution and adsorption of anti-A
60
Very rare, little consistency in description, recognized by variations in strength of reaction with anti-B and anti-A,B
B subgroups
61
People typed as A and B generally produce this class of antibodies and small quantities of this class of antibodies
```
IgM class ABO antibodies
*and small quantities of IgG
```
62
People typed as O produce this class of antibodies
IgG class antibodies- anti-A,B
63
Readily crosses the placenta
IgG
64
Aka RBC typing
Forward typing
65
Aka forward typing
RBC typing
66
Reagents for forward typing (2)
Anti-A and anti-B
67
Anti-A and anti-B used for forward typing are generally __ this designed to give at least __ or stronger reactions
Monoclonal antibodies
| 3+
68
aka serum typing
Reverse typing
69
Aka reverse typing
Serum typing
70
ABO testing which uses anti-A and anti-B
Forward typing
71
ABO testing which uses A1 cells and B cells
Reverse typing
72
Reagents used for reverse typing
A1 cells and B cells
73
Reagent cells for ABO typing are Rh _
Rh negative
74
T/F: reagent cells for ABO typing are Rh neg
True
75
RBCs contain __ or __ on their __ or as __
RBCs contain surface markers or antigens on their surface or as part of their membranes
76
Expected reaction in reverse typing
| -anything weaker may indicate __
2+
| Serum problem
77
T/F: expected result in reverse typing is 2+ and anything weaker may indicate serum problem
True
78
Forward and reverse typing are both required in patients and donors to serve as __ for each other
Check
79
T/F: Forward and reverse typing are both required in patients and donors to serve as check for each other
True
80
Non-routine reagents (3)
| -and use/s or description of each
```
Anti-A,B
-used to aid in classification of subgroups
-confirm group O units (retype)
A2 cells
-discrepancy resolution
Lectins
a. Anti-A1: Dolichos biflorus
b. Anti-A2: Ulex europaeus
```
81
Uses of anti-A,B (2)
- used to aid in classification of subgroups
| - confirm group O units (retype)
82
Process of confirming group O units
Retype
83
Use of A2 cells
For discrepancy resolution
84
Lectins (2)
| -also describe
Anti-A1 from Dolichos biflorus
| Anti-H from Ulex europaeus
85
Source of anti-A1 and anti-H
Anti-A1 from Dolichos biflorus
| Anti-H from Ulex europaeus
86
Dolichos biflorus as source of this lectin
Anti-A1
87
Ulex europaeus as source of this lectin
Anti-H
88
Causes of ABO discrepancies: 4 groups
Weak or missing antigen reactivity
Extra antigen reactivity
Weak or missing antibody reactivity
Extra antibody reactivity
89
Weak or missing antigen reactivity (6)
| -describe each
```
Mixed cell populations and chimeras
-review transfusion and transplant history
Excessive blood group substance
-can neutralize reagents
Newborns
-lower number of A a/o B antigen sites
Subgroups of A and B
-A3, Ax, Ael
-B subgroups rare
Leukemia
-weak expression of A a/o B antigen
Cis-AB phenotype
-rare chromosome
```
90
MOST common cause of chimerism
Transfusions
91
T-F: transfusions are the most common cause of chimerism
True
92
Extra antigen reactivity (4)
DAT +
Acquired B
Contaminated cord blood samples
Unwashed cell suspensions
93
Patient types as AB, but serum contains anti-B
Acquired B
94
Transient condition associated with disorders of the gastrointestinal tract
Acquired B
95
Acquired B is a transient condition associated with disorders of the ___
Gastrointestinal tract
96
T/F: acquired B is a transient condition associated with disorders of the gastrointestinal tract
True
97
T/F: certain clones used to make monoclonal anti-B cause strong reactions with acquired B cells
True
98
T/F: Acquired B: strength of reactivity is weakened with reduced reagent pH
True
99
Strength of reactivity is weakened with reduced reagent pH
Acquired B
100
Strength of reactivity is weakened with __ reagent pH
Reduced
101
Associated with colonic bacterial infections
Acquired B
102
Test RBCs with human anti-B acidified to pH __
6.0
103
T/F: strongly reactive DAT cells can spontaneously agglutinate with cell grouping reagents
True
104
Most often seen with Rh typing reagents
Direct antiglobulin test +
105
T/F: DAT + can occur with ABO reagents if coating antibody is cold-reactive
True
106
Can occur with ABO reagents if coating antibody is cold-reactive
DAT +
107
DAT + can occur with ABO reagents if coating antibody is __
Cold-reactive
108
Resolution for DAT + (3)
Wash cells with 37•C
Incubate Px cell suspension at 37•C and wash with warm saline
Elute antibodies from RBCs with chloroquine diphosphate or dithiothreitol (DTT)
109
Used to elute antibodies from RBCs to resolve DAT + (2)
chloroquine diphosphate or dithiothreitol (DTT)
110
Main cause of contaminated cord blood samples
Wharton's jelly
111
How to resolve contaminated cord blood samples (2)
Wash w/ saline 3 or 4x, retest
| Request heel-stick sample
112
Sample requested to resolve contaminated cord blood samples
Heel-stick sample
113
Washing can dissipate problems caused by (2)
Px antibodies to reagent components
| Rouleaux formation
114
Resolves Px antibodies to reagent components and rouleaux formation
Washing
115
Weak or missing antibody reactivity (4)
| -describe also
```
Chimeras
-persistent chimeras develop a tolerance to both cell populations
Missing antibodies
-immunocompromised Px
Low antibody levels
-newborns and older Px
Subgroups
-cells from A subgroup Px's often typed as group O
```
116
T/F: persistent chimeras develop a tolerance to both cell populations
True
117
Low antibody levels usually seen in (2)
Newborns
| Older pop
118
Missing antibodies are usually in
Immunocompromised Px's
119
Cels from A subgroup Px's often typed as group __
O
120
T/F: titer of anti-A is usually higher than that of anti-B in most group O
True
121
T/F: subgroups may be due to anti-A1 or other allo antibodies and not by anti-A
True
122
Testing panel of (3) can help determine of subgroup discrepancy exists
A1, A2, and O cells
123
Rouleaux formation: resolution:
Saline replacement technique
124
How to resolve cold-reactive antibodies (allo antibody or autoantibody) (2)
Use of mini-cold panel
| Testing with A2, O, and autologous cells, in addition to tests with A- and B cells
125
How to resolve passively acquired antibodies (1)
Check Px transfusion history
126
Extra antibody reactivity (3)
Cold-reactive antibodies (autoantibody or alloantibody)
Passively acquired antibodies
Rouleaux
127
Suggested resolution process for ABO serologic problems (5)
Repeat testing on same sample
Wash Px cells
Obtain Px info
-diagnosis
-historical blood group
-history: transfusions, transplants, medications
Review results with group O RBCs and autocontrol
Obtain new sample if contamination suspected
