Unit 2 Questions Flashcards
1
Q
An individual from Bombay who has inherited the Le gene will have a phenotype of:
A
Le(a+b-)
2
Q
Individuals who are Le(a-b-) and can develop lewi antibodies without exposure to Lewis antigens are called:
A
Naturally occurring
3
Q
Which of the following may be a possible cause for the lack of expression of Lewis antigens during pregnancy?
A
Increased ratio of plasma lipoproteins to RBC mass
4
Q
A patient was phenotypes for the presence of Lewis antigens (Lea and Leb). A 3+ reaction was observed when patient cells were incubated with anti-Lea. No reaction was observed with anti-Leb. Based on these results, the patients phenotype is_________ and the patient is a ________ of ABH substances
A
- Le(a+b-)/nonsecretor
5
Q
What percentage of the white population inherits the Le gene?
A
90%
6
Q
Approximately what percentage of the black population is [Le(a-b-)]?
A
22%
7
Q
In order for an individual to express Leb antigen on their RBCs, the must have inherited which gene?
A
- All of the above
- Le
- Se
- H
8
Q
Pregnant women usually express which phenotype?
A
Le(a-b-)
9
Q
Why is anti-LebL the antibody of choice when phenotyping RBCs?
A
It recognizes any Leb antigen independent of ABO types
10
Q
Persons who inherit the Se and Le genes will have ______ A or B glycolipids in plasma than persons who are Se Le
A
Fewer
11
Q
All of the following statements are representative of Lewis antibodies except:
A
They are destroyed by enzymes
12
Q
Anti-Lea, which is reactive a the Coombs phase, may cause what kind of hemolysis?
A
In vivo
13
Q
RBCs that phenotypes as [Le(a-b-)] are inherited with plasma containing Lea substance. The RBCs convert to the phenotype [Le(a+b-)]. Whereas the same RBCs incubated with saliva containing Lea substance do not convert. Why?
A
Glycoprotein are not absorbed onto RBC membranes
14
Q
What does the type 1 chain refer to?
A
- beta-linkage of the number 1 carbon of galactose to the number. 3 carbon of N-acetylglucosamine residue of precursor structure
15
Q
Lewis cell-bound antigens absorbed from plasma onto the RBC membranes are:
A
Glycolipids
16
Q
Lewis antibodies are of what immunoglobulin class?
A
IgM
17
Q
What enzyme is responsible for Lewis Specificity?
A
L-fucosyltransferase
18
Q
Where are Lewis antigens found?
A
*all of the above
- plasma
- saliva
- milk
19
Q
What substances would be present in the saliva of a person with the LeLe HH SeSe AA genotype?
A
A
H
Lea
Leb
20
Q
How is Leb susbstance formed?
A
L-fructose is added to subterminal N-acetylglucosamine of type 1 H substance
21
Q
Which of the following statments is false?
A
- Lewis antibodies do not bind complement
22
Q
What would be the probable genotype of a patient who phenotypes as ABLe(a-b-)?
A
- lele sese HH AB
23
Q
What is found in secretions of Le(a-b-) individuals?
A
None of the above
24
Q
At which phase are Lewis antibodies usually detected?
A
Immediate spin
25
How does anti-Lea differ from anti- Leb?
Anti-Lea can bind complement more efficiently
26
Why are Lewis antibodies not generally implicated in HDN?
Lewis antibodies are IgM and cannot cross the placenta
27
Which blood group system is not based on carbohydrates?
Rh
28
How is Le(y) formed?
- Fucose A(1-3) G1cNac is added to type 2H precursor substance
29
It was discovered that a patient who was to receive two units of packs RBCs had an anti-Lea circulating in his system. What would be the proper procedure?
- the two units do not necessarily need to be Lea-negative but should be crossmatched through atleast 37 degrees and crossmatch compatible before given
30
The true Lewis phenotype will normally be detected at what age?
- not necessarily ever, as circumstances such as pregnancy may alter or mask an individual’s true Lewis phenotype
31
Which of the following statements about the Lewis system in not true?
Secretion of Lewis substance is controlled by the Se gene
32
P1 antigens:
Take up to 6-7 years to develop
33
I and i antigens are found in plasma, serum, and what other possible source?
*all of the above
- Breast milk
- urine
- saliva
34
Persons with the Kidd-null phenotype have been found in:
New Zealand
35
Lutheran antibodies are rarely associated with causing HDN for which of the following reasons?
*all of the above
- Lutheran antigens are poorly developed at birth
- Maternal Lutheran antibodies are absorbed onto glycoprotein on the placenta, decreasing the likelihood of HDN
- Luther antibodies are generally IgM class and normally do not cross the placenta
36
Which of the following is not involved in the Kell blood group system?
- Jka
37
Where are Duffy antigens found?
RBCs
38
What is the most common Kidd phenotype in the black population?
- Jk(a+b-)
39
Why is dosage inconsistent in the Duffy blood group?
- the genotype could be inherited as FyaFya or FyaFy for for Fy(a+b-) RBCs
40
Why is it relatively easy to find compatible unit for a patient with anti-K?
Kell is a low-frequency antigen
41
RBCs were treated with FI in to help rule in anti-M from a panel study. Cells not treated reacted at 2+at immediate spin and 1+ at 37C. There was no reactivity in the Coombs phase. FI in-treated cells demonstrated a ______ reaction with patient serum containing anti-M
Negative
42
The Fy5 antigen has not been shown to be the result of an interaction between Duffy genes and:
Rh
43
A blood bank technologist needed to confirm the presence of anti-P1 in a patient specimen. Fresh cells were not available for use, so an old panel that contained cells positive for P1 was used. No cells positive for the antigen reacted at any phase of the antiglobulin test, whereas cells from the screening cells showed specificity for the presence of anti-P1. What is a possible explanation for this?
- P1 antigen deteriorates rapidly upon storage
44
What will happen to I antigen expression when ABH sugars are removed from the RBCs?
Increased expression
45
What is the International society of Blood Transfusion (ISBT) assignment for the antigen P2?
003001
46
What is the definition of a blood group system?
A group of antigens produced by alleles at a single gene locus
47
Where are the Kell blood group antigens found?
RBCs
48
Anti-M was detected in a 27-year old man before surgery. Unit negative for M antigen were not available; however, the units were approved for transfusion when major crossmatch using M+N+ donor cells and patient serum resulted in:
IS - 1+, 37= 0, AHG = 0
49
Which of the following is known to enhance K antigen expression in the antihuman globulin test?
Polyethylene glycol
50
Anti-Lea reacts at what temperatures?
Room temperature
51
At what phase of the antihuman globulin test will anti-Kell be detected?
AHG
52
What is the function of a GPB-GPA hybrid (anti-Lepore type)?
Encodes normal GPA
53
Persons who phenotype negative for U antigen lack Ss-SGP because of a partial or complete deletion of ________
GPB
54
What sample requirement is essential for ID of a Kidd antibody?
Fresh serum or plasma
55
What does the U in U antigen stand for?
Universal
56
Infection with which organism is associated with naturally occurring IgM anti-K
*All of the above
- escheriachia coli
- campylobacter coli
- mycobacterium species
57
The M and N antigens are found in which glycoprotein?
Glycophorin A
58
How can pathological anti-I be differentiated from benign anti-I?
- broad thermal range of reactivity
59
Which of the following distinguishes the recessive LuLu gene from the dominant In(Lu) gene?
Normal expression P1
60
All of the following are characteristics of of Kidd antibodies except:
Naturally occurring
61
When RBCs are placed in a solution of 2M urea, the RBCs will lyse. However, it has been shown for that which RBCs are resistant to lysis?
Jk(a-b-)
62
What MN phenotype is found in highest frequency in the white population?
M+N+
63
The M and N antigens exhibit dosage. Therefore, if a person inherits the Homozygous genotype MM, their RBCs will react________ with anti-M than/as those of a person with a heterozygous genotype of MN
Stronger
64
Anti-M will react strongest with which cells?
M+N-
65
The Lu gene shares chromosomes 19 with what other blood group gene?
* All of the above
- H
-Le
-LW
66
The homozygous phenotype Fy(a+b-) has ________ antigenic Fy sites than heterozygous cells, Fy(a+b+)
More
67
What is the source of anti-M lectin?
Iberia Amara
68
All of the following are grouped with the para-Kell antigen except:
K11
69
What anemia will result in an increased expression of i antigen, which exceeds that found on control cord cells?
CDA type II
70
The Kell gene is located on the long arm of which chromosome?
7
71
At what are does I antigen become detectable on infant cells?
18 month
72
What RBC antigens do McLeod individuals express?
TracekKpbJsbK11
73
What characteristics differentiates Ss antigens from MN antigens?
Enzyme degradation
74
A person who inherits alleles Fya and Fyb will carry which antigens on their RBCs ?
Both Fya and Fyba antigen
75
What is the ISBT designation for the li blood groups?
207
76
On which malaria receptor site is Duffy antigen dependent?
Junction receptor
77
The structures that carry the P antigen also carry which determinants?
* All of the above
- A
- B
- I
78
A patient who has a pathologic autoanti-I must be transfused with:
A blood warmer
79
What is the etiology of dialysis- associated anti-N?
- Formaldehyde alters the N antigen so that it is recognized as foreign
80
The genes that code for GPA and GPB are closely linked on the long arm of which chromosome?
4
81
Persons who express the phenotype P2 are at risk for developing anti-P1 when handling what animal species?
Pigeons
82
Persons who inherit the In(Lu) gene will exhibit:
Jk(a-b-) RBCs that can absorb anti-Jka
83
Persons who are negative for Duffy antigen are less likely to contract which of the following disease?
Malaria
84
What abnormal blood cell morphology is associated with McLeod Phenotype?
Acanthocytes
85
What organism is capable of converting Jk(b-) RBCs to Jk(b+)?
Micrococcus species
86
What is the ISBT designation for the Lutheran blood group system?
LU
87
How are lipids dissociated from the RBC membrane for biochemical studies?
Organic solvents
88
What type of hemolytic transfusion reaction (HTR) occur more frequently in patients with Jk antibodies?
Delayed
89
Anti-I is found in association with what microorganism?
Mycoplasma pneumoniae
90
Autoantibodies to Jka have been found in patients taking:
Methyldopa
91
What adult phenotype is rich in i antigen and common to the white population?
- i1
92
Units that were positive for P2 antigen gad to be crossmatched with serum of a patient containing the corresponding antibody because of a short supply of blood. Which of the following crossmatch results would be considered acceptable for transfusion?
IS = 1+, 37 = 0, AHG = 0
93
Most blood group alleles are:
Codominant
94
What Kidd antibody will react with all panel cells and phenotype are Jk(a-b-)?
Anti-Jk3
95
What is the most common genetic combination in the Kell blood group system?
- kKpbJsbK11
96
All of the following are characteristics of Duffy antibodies except:
- they are not implicated in HDN
97
Anti-Jka was identified in a previously transfused patient. Five cells that were homozygous for Jka yielded 2+ reactions in the AHG phase. The same cells were treated with ficin and yielded 3+ reactions in AHG. Therefore, Jka is _________ by enzyme treatment
Enhanced
98
All of the following are characteristics of the Ena antigen except:
It is a low-frequency antigen
99
What sequence of antigens coincides with strongest immunogen to weakest immunogen?
D, K, Fya, Fyb
100
Anti-N will react stronger with which phenotype?
M-N+
101
The Ii antigens are found on the membranes of which structures?
* All of the above
- platelets
- RBCs
- Leukocytes
102
Where are the Kidd antigens found?
RBCs
103
Why do En(a-) individuals have a reduced chance of infection with plasmodium falciparum?
- there is a reduction in N-acetylneuraminic acid
104
How is the Ena antigen related to the Wr(a-b-) phenotype?
En(a-) RBCs are all Wr(a-b-)
105
Anti-N is know to occur in _______ patients undergoing dialysis with equipment sterilized by formaldehyde?
Renal
106
Anti-Anton recognizes the same specificity as:
Anti-Wj
107
Approximately what percentage of the black population are s-?
3%
108
What can be done to rule in anti-M when only M+N+ RBCs are available?
Decrease the serum-to- cell ratio
109
What fatal disease is associated with the McLeod phenotype?
Chronic granulomatous disease
110
Which of the following statements regarding individuals who are Fy(a-b-) is true?
The presence of Fya in the tissue of individuals who are black who are Fy(a-b-) prevents those individuals from forming Anti-Fyb
111
Why is it strongly recommended that only homozygous cells be used when ruling out Kidd antibodies?
Anti-Jka may appear compatible with heterozygous cells [Jk(a+b+)]
112
A woman undergoing a hysterectomy requires two units of blood. The antibody screen was negative. One unit was incompatible in the Coombs phase (2+), the other unit was compatible. Give a reason why this antibody was not detected in the antibody screen
Existence of a low-frequency antigens
113
What is the etiology of chronic granulomatous disease (CGD)?
Phagocytes are unable to generate hydrogen peroxide, which is used to kill invading bacteria
114
What are the antibody characteristics of Fy3, Fy4, and Fy5?
* All of the above
- Reactive at AHG
- Immunogenic
- IgG
115
What finding may protect individuals from making alloanti-Lub in dominant In(Lu) genotypes?
The ability to absorb and elute anti-Lub
116
Persons who are genetically P1 may serologically type as P2 because of:
Inheritance of the In(Lu) gene
117
What biochemical observations signify a protein composition to the Kell antigens?
Inactivation at 56 C
118
Most Kell autoantibodies are directed against which antigens that are usually undefined?
High-frequency
119
Black persons who genotype as Fy4Fy4 will phenotype as:
Fy(a-b-)
120
What is the ISBT designation for the Kell system?
006
121
The Duffy antigens have mobility characteristics similar to what other antigenic structure?
MN-SGP
122
What Kell phenotype is found in highest frequency in the white population?
K-k+
123
All of the following are characteristics of anti-M except:
The reacts tronger with enzyme-treated cells
124
Anti-i is found in association with what disease?
IM
125
What is the ISBT designation for the Kidd blood group system?
009
126
What biochemical substitute is responsible for the i determinant?
Two repeating N-acetyllactosamine units on H2 structures
127
What serologic factor distinguishes anti-Fy3 from anti-Fya or anti-Fyb?
It is not destroyed by enzymes
128
What portion of GPA reacts with anti-EnaFR?
Ficin resistant
129
Persons who phenotype as Fy(a-b-) are resistant to infection by which organism?
Plasmodium vivax
130
Alloanti-Lub will react ______ with Lu(a+b+) cells than/as with Lu(a-b+) cells
Weaker
131
How is the Luke (LKE) system related to the P blood group system?
Anti-LKE reacts with all P1 and P2 individuals
132
At birth, infant cells are rich in ______, and is nearly undetectable
- i/I
133
Why is HDN not a consideration when the mother possess anti-P1 in her serum?
P1 antigen is poorly expressed at birth
134
All of the following characteristics regarding the Kell antigen are true except:
It is destroyed by ficin treatment
135
What is the biochemical structure of the P system antigens?
Glycosphingolipids
136
Which of the following is TRUE concerning the I and I antigens?
I and i antigens have a reciprocal relationship
137
Anti-Lu3 will be compatible with donor blood from individuals with which of the following phenotypes?
Lu(a-b-)
138
Where are the P antigens found?
* all of the above
- RBCs
- platelets
- Tissue fibroblasts
139
What amino acid is specific for S antigen?
Methionine
140
Why does anti-Lua go undetected in routine testing?
Most reagent cells are Lu(a-)
141
Why was U antigen included n the MNSs blood group system?
All U-negative RBCs were also S-s
142
Duffy antigens are destroyed by:
Ficin
143
A person who inherits the In(Lu) gene will not express which antigens?
Lua
144
Dithiothreitol (DTT), when used alone, can destroy antigens in which blood group system?
Kell
145
The gene that codes for P1 is located on which chromosome?`
22
146
What class of immunoglobulin makes up anti-Lua?
* All of the above
- IgG
- IgA
- IgM
147
Which population has the greatest frequency of the Fy(a-b-) phenotype?
Black
148
Anti-Fs is more likely to react with which cells?
Fy(a-b-)
149
The Miltenberger subsystem is related to what major blood group system?
MNSs
150
How were Aua and Aub initially linked to the Lutheran system?
Suppression by In(Lu) gene
151
Patient diagnosed with________, where the autoantibody is directed against the K antigen, may exhibit a diminished expression of antigen?
Autoimmune hemolytic anemia
152
What is the most common Lutheran phenotype in the white population?
Lu(a-b+)
153
How do MN antigens differ in their biochemical protein structure?
N contains glutamic acid at position 5 and M contains glycine
154
Anti-Lua is destroyed by what enzymes?
Trypsin
155
Which organ removes cells coated with Jk antibodies from circulation?
Liver
156
All of the following are characteristics of anti-P1 except:
The antibody is not neutralized by soluble P1 substance
157
What is Kell’s antithetical partner
?
Cellano
158
Autoantibodies to U antigen may be found in patients with:
Warm autoimmune hemolytic anemia
159
What name is attached to the Ena antigen?
Envelope
160
Which has been shown to define the Duffy receptor that plasmodium vivax uses to penetrate RBCs?
Anti-Fy6
161
What is unique about the Kpa antigen?
It suppresses the espresso on of k and Jsb
162
All of the following characteristics are consistent with benign anti-I except:
It does not bind to complement
163
Why are the M and N antigens important for paternity testing?
Antigens are well developed at birth
164
Hemolysis associated with ficin-treated cells is more common with which RBCs?
Jk(a+b-)
165
Why are P1 individuals susceptible to urinary tract infections by Escherichia coli?
E. Coli attach to antigen glycolipids on uroepithelial cells
166
Serologic tests determine a persons:
Phenotype
167
What effect do enzyme-treated cells have on anti-I detection?
Enhances reactivity
168
A cold antibody panel was performed to help identify an antibody that reacted at room temperature. The results of the panel are as follows: A1-cell = 0, A2 cells = 2+, B cells = 3+, O adult ells = 4+, cord O cells = 1+. This is consistent with which antibody?
Anti-IH
169
A patient who had a viral infection suspected to be IM may develop which antibody?
Anti-i
170
A woman came in for a cesarean section. The antibody screen was positive with a 3+ reaction in the AHG phase using screening cell I. Screening cells II and III were negative in all phases. A 8-cell panel was performed that paralleled the antibody identified was anti-Kell. What procedure might be helpful in predicting the infants susceptibility for HDN?
Determination of the fathers phenotype
171
Type I H antigen in secretions is a product of which of the following genes?
Se
172
A patient who recently recovered from a Mycoplasma pneumoniae infection may develop which antibody?
Anti-I
173
Antibodies to the blood groups below exhibit dosage except:
Kell
174
RBC antigens are written using which of these conventions?
Genders are written in italics
175
Which of the following techniques/reagents may be useful in increasing the reactivity of anti-M?
Acidified serum techniques
176
Name the substance used to neutralize antibodies to P1
Hydatid cyst fluid
177
You have a patient with Anti-P1. Theoretically, how many units would be compatible if you set up 10 unit of blood?
2
178
Enzymes destroy the antigens of which of the following blood groups?
*All of the above
- N
- M
- Fya
179
Which antigen(s) is/are antithetical partners to s?
MN
180
What antibody gives a 1+ reaction in undiluted and diluted samples?
High titer, low avidity
181
Which group of antigens below best represents the definition of high- frequency antigens?
Jsb, Kpb
182
A patient presented in the emergency room needing to be transfused ASAP. According to the computer, the patient has a Kell antibody 5 years ago. The antibody screen is negative now. Of the following, the best procedure to obtain suitable blood for transfusion is:
To antigens type the units for Kell and completely crossmatch the negative ones
183
Which of the following blood groups in inherited from the parents but absent at birth?
Fya
184
Which of the following are written in the order of allele, antigen and phenotype?
A^1, A1, Av1
185
Which of the follow lists of phenotypes is written correctly?
S+s+; K- ; Fy(a+b-)
186
RBCs from an adult are suspected of having a rare i-antigen. Which of the following reactions is expected with these cells?
- Anti-I weak; Anti-I strong; Anti-I^T-weak
187
Cord blood cells and adults cells that have the rare i phenotype will both demonstrate which reaction?
Weak with anti-I and strong with anti-i
188
All of the following antigens are found on reagent screening cells except:
Jsa
189
Which of the following statements concerning acid equates is false?
The pH of the eluate remains at 3 before testing against a panel
190
What screening cells are used primarily for testing donor units for unexpected antibodies?
Pooled
191
When performing the elution procedure, the solution containing the recovered antibody is called:
Eluate
192
What is the purpose of Coombs control cells?
* All of the above
- to ensure that AHG tests with negative results are not false-negatives
- to ensure that washing removed all unbound antibody
- to ensure that AHG was not omitted or inactivated
193
In what test might rouleaux cause an interference?
Reverse ABO grouping
194
What is elution?
A technique used to dissociate IgG antibodies from sensitized RBCs
195
A patient with a warm autoantibody has a positive DAT. The antibody screen was negative, but the eluate reacted uniformly with all normal cells and patient cells What was the antibody screen negative?
The warm autoantibody has bound to patient RBCs in circulation
196
The process of removing antibody from serum by combining a serum sample with appropriate RBCs under optimal conditions is called:
Absorption
197
How does LISS enhance antibody detection in the antibody screen’?
Increases the rate at which antibody bind to RBC antigens
198
Which cells are employed to removed autoantibody from patient serum without removing any alloantibody from serum?
Patient RBCs
199
What would be a realistic source of finding compatible units for a person with an antibody to a high-frequency antigen?
Siblings
200
Why is it important to match the lot number on the panel sheet with the lot number on the panel cells?
Pattern of reactions will change from lot to lot
201
Which of the following high-frequency antigens do not abuse in vivo RBC destruction when completed with corresponding antibody?
Cha
202
A person has developed an antibody to the LISS reagent. What test will not be affected by this circumstance?
- DAT
203
Which of the following statements is correct concerning cold antibody screens?
Patient serum is incubated with group O adult and cord RBCs at 4C
204
Routine pretransfusion testing consists of all of the following except:
A DAT
205
A positive auto control in antibody detection procedures is usually indicative of:
Positive DAT
206
In the interpreting an antibody screen, which of the following questions might be asked to decipher the class of antibody?
In what phase did the reaction occur?
207
Why is an enzyme treatment used in antibody ID?
- Enzymes aid in the seperation and ID of multiple antibodies and the absorption of autoantibody from patient serum
208
Which of the following is a mechanism of an elution procedure?
Disruption of structural complementarity of antigen and antibody
209
Neutralization of antibody is applicable to all of the following blood groups except:
Rh
210
What determines if a RBC antibody is clinically significant?
Shortened RBC survival
211
Why are screening cells group O?
To prevent interference with anti-A and anti-B in patient serum
212
Cold reactive autoantibodies can be selectively removed from patient serum by adsorption with autologous RBCs. What other cell cans be used?
Rabbit RBCs
213
Why is rouleaux not usually found in the AHG phase of antibody screens?
- patient serum is washed away before adding AHG
214
What is the most common use of adsorption?
Removal autoantibody from patient serum
215
What is a positive DAT?
In vivo sensitization of RBC with antibody
216
Which is the second phase of a hemagglutination reaction?
Agglutination
217
What test is used to confirm the efficacy of chloroquine treatment?
DAT
218
What antibody is associated with a mixed-Field reaction?
Sda
219
Why is it important for screening cells to be from individuals who have a homozygous expression of antigens?
Weakly reacting antibodies may not agglutinate heterozygous cells
220
How is an antibody ruled in?
Three RBC samples positive for antigen show reactivity; three RBC samples negative for the antigen show no reactivity
221
What can be concluded in a patient who has anti-K identified in his serum but phenotypes positive for K antigen?
Patient was recently transfused with K-positive blood and anti-K was misidentified
222
What is tested is an antibody screen?
Patient serum is tested against group O reagent screening cells
223
What effects does ZZAP reagent have on sensitized RBCs?
*All of the above
- removes antibody from RBCs
- enzyme treats RBCs
- increase adsorption capability of RBCs
224
What is a possible explanation for nonreactive eluate?
- positive DAT due to drugs
225
Why are antibodies to high frequency antigens, such as cellano (k), rarely seen in patient samples?
Most persons are not anti genially stimulated to produce the antibody, because their RBCs are positive for the antigen
226
What might a positive antibody screen and a negative auto control indicate?
An alloantibody has been detected
227
When might you suspect multiple antibodies in a patients serum?
* All of the above
- pattern of reactivity not fitting a single antibody
- variations in phase of reactivity
- variation in antibody reactivity strength
228
In what circumstances would be an alloadsorption be performed?
Multiple antbodies in serum
229
One drop of Coombs control cells was added to a negative antibody screen. No agglutination was observed after centrifugation. What course of action is taken?
Repeat the test
230
What are antibody titration studies warranted?>
During pregnancy
231
What is the simplest way of reducing the inference from benign cold autoantibodies in antibody screening procedures?
Use monospecific IgG
232
A 2-unit crossmatch was ordered on a patient in the emergency room. The patients antibody screen was negative. One unit was compatible and the other was incompatible at AHG. If the patients antibody screen was negative and the donor has no history of antibodies, what outdo be the reasons for this reaction?
* Options A and B
- the patients serum has an antibody to a low-frequency antigen not present on screening cells
- the donor has a positive DAT
233
What test must be performed on a patient with a warm autoantibody in their serum before transfusing?
Warm autoadsorption
234
During an antibody ID, there was 1+ reaction at AHG with donor cells with the antigen profile Fya(+), Fyb(+). Given these results, what might the conclusion?
Single antibody (showing dosage)
235
What is the purpose of treating serum containing cold autoantibodies with dithiothreitol (DTT) or 2-mercapthoethanol (2-ME)?
To denature IgM cold autoantibody and test serum for presence of IgG allantibody
236
What is the first step in reading hemagglutination reactions?
Checking supernatant for hemolysis
237
How many units would you likely have to screen to find two compatible units for someone with the following antibodies: anti-C, anti-Lea, anti-Jkb ?
32
238
Why might some blood banking facilities prefer the use of monospecific IgG over polyspecific antihuman globulin (AHG) in their antibody screens??
- interference from naturally occurring cold antibodies in patient serum in reduced
239
What is the purpose of saline washing in the antibody screen procedure?
Removal of unbound IgG that would neutralize the AHG reagent
240
Why can’t autoadsorption be performed on a patient who was transfused 1 month before?
Donor cells might adsorb out alloantibody in serum
241
All of the following antigens are interacted by poroteolyti enzymes except:
C
242
When should multiple antibodies be suspected in a positive antibody screen?
Cells react at different phases and strengths
243
How is chloroquine diphosphate used in blood banking ?
To accurately phenotype patient cells when the DAT is positive
244
Tests itch which AHG reagents can determine if IgG, complement or both are coating RBCs?
Polyspecific
245
Which of the following is known as the “sensitization phase” in the antibody screen?
37C incubation
246
What is an antigen profile sheet
?
An insert listing the antigenic makeup of each vial of screening cells
247
What makes up an autologous control?
Patient serum and patient cells
248
Why should only homozygous cells be used to rule out an antibody?
Weakly reacting antibody may not react with heterozygous cells
249
In the autoabsorption procedure for the removal of cold autoagglutininins from serum, pretreatment of the patients RBCs with which of the following reagents is helpful:
Ficin
250
In which scenario can an antibody be ruled out?
patient serum does not react with a cell known to carry the corresponding antigen
251
What is done with a patients serum after an autoadsorption technique has been performed?
Alloantibody ex are identified, and the serum can be used for compatibility testing
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What is the final step in antibody ID?
Phenotype patients RBCs for corresponding antigen
253
A doctor has ordered 4 units of RBCs for a patient with anti-E in his serum. How many units would have to be screened to yield 4 E-negative units?
6
254
How many neutralization aid in the ID of multiple antibodies?
Once antibody has been neutralized serum can be further tested in panel studies
255
What does a panel of reagent RBCs consist of?
11 to 20 group O RBC suspensions
256
If you suspect anti-C is present in a patients serum, and anti-Fya still has to be ruled out using other reagent cells, what would the phenotype of the rule out cell have to be?
Fy(a+), C-, Fy(b-)
257
Cells that have antibody attached to them but are still separated from one another are:
Sensitized
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What is the advantage of having a 3-cell panel screen versus a 2-cell panel screen?
* All of the above
- more cells in the homozygous state that show dosage
- you can narrow down the specificity of the AB better
- you might detect more rare antibodies
259
Name a disease in which your positive D control might be positive
Multiple myeloma
260
The electrical force that exists between RBCs is:
* all of the above
- called the zeta potential
- due to the net negative charge of the RBC membrane
- related to the voltage or potential that exists at the surface of the RBC and the other layer of the ionic cloud
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Pseudoagglutination:
* all of the above
- is frequently associated with alterations in serum proteins
- occurs when serum viscosity is increased
- an confused with panagglutination
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While performing an antibody screen, a test reaction is observed that is suspected to be rouleaux. A saline replacement test is done, and the reaction remains. What is the best interpretation?
- the original reaction was due to true agglutination
263
Of the antibodies listed below, which does NOT fit with the others in terms of the optimal temperature of reactivity?
Anti-E
264
Antibodies formed as the result of RBC stimulation in the patient are known as:
Immune
265
Antibodies resulting from exposure to pollen, fungus, or bacteria are known as:
Naturally occurring
266
A laboratory employee who previously tested negative in a donor antibody screen is now testing positive after having had an intravenous immunoglobulin treatment for needle-stick exposure. Which type of antibody has this person formed?
Passive
267
The AABB’s Standards for Blood Banks and Transfusion Services requires antibody screen of all populations listen below except:
Prenatal patients
268
In which section of the blood banks laboratory would blood be issued for transfusion?
- main laboratory
269
Electronic cross matching
Must be confirm current with historical recipients ABO group
270
What tests are involved when a physician orders a 4-unit crossmatch on a patient?
ABO, Rh, antibody screen, IS crossmatch
271
Which patient information is NOT acceptable as one of the two identifiers?
Hair and skin color
272
Which of the following might be used to investigate a cold autoantibody?
Rabbit erytrhocyte stroma
273
A positive DAT may be seen in:
* All of the above
- warm autoimmune hemolytic anemia
- cold agglutinins syndrome
-hemolytic transfusion reaction
274
Why are monoclonal anti-D reagents preferred over the slide test reagents?
They contain a low protein concentration and are not prone to false-positive reactions
275
If an intrauterine transfusion is indicated, which of the following is acceptable?
Only type O RBCs
276
Immediate spin resulting in agglutination may be caused by:
Cold reacting allo- or autoantibodies
277
Why is reviewing a potential recipient’s historical data important?
All of these are reasons to review patient historical data
278
Which cells are used for a donors antibody screen?
Pooled screening cells (2 donors)
279
Which of the following would prolong labeling of the packed RBC unit?
*none of the above
280
What one forward-typing reagent can be used to confirm O units collected from another facility?
Anti-A,B
281
All of the following procedures might be done in an investigation of an ABO discrepancy expect:
Neutralization studies with urine
282
The label on the recipients pretransfusion specimen
Must duplicate patient wristband information
283
Where can an ID band be placed on a double arm amputee?
* all of these
- ankle
- head
- torso
284
Blood is collected Saturday in the emergency room for possible transfusion. The patient is admitted to the hospital and on Wednesday it is determined that the transfusion is truly needed
The specimen must be recollected because more than 3 days have passed since
285
How are 8 units of cryoprecipitate usually issued?
As one pooled units
286
A three-cell antibody screening set provides _______ antigen expression in all major blood group systems expect Kell
Homozygous
287
A 40-year old male presented in the ER with acute bleeding. The technologist received a specimen but was unable to resolve a typing discrepancy between the forward and reverse typings. What blood type should the patient receive for emergency transfusion?
O-negative uncrossmatced packed RBCs
288
All of the following viral tests are required for donor processing except:
CMV
289
What is the main concern for obstetric patients in prenatal testing?
Antibody that causes HDN
290
In which department of the blood bank laboratory would an ABO discrepancy be resolved?
Reference laboratory
291
A proper blood ban specimen is good for how many days after it is drawn from a patient that has had a prior transfusion within 90 days?
3 days
292
Which of the following options are suitability requirements for product labeling?
* All of the above
- absence of detectable antibodies
- No discrepancies in ABO and Rh testing
- Nonreactive viral marker tests
293
Why would an Rh type be ordered on a cord blood sample?
To determine mothers candidacy for RhIG if she is Rh-negative
294
Which of the following would lead to nonacceptance of a blood bank specimen?
* All of above
- initials of phlebotomist not on specimen
- A patient name spelled incorrectly
- an erroneous Social security number
295
The advantages of electronic crossmatching as compared to serologic crossmatch include
*all of these
- less specimen is required
- less time is required
- automatic alters of discrepancy
296
Why can the Rh-hr control be eliminated from donor processing?
- An Rh-negative unit of blood typed as an Rh-positive would only be transfused to an Rh-positive patient
297
Patient blood management programs:
Are based on patient evidence
298
Personalized medicine involves:
* All of these
- individualized treatment for patients
- prevention of alloimmunization
- the use of a national database
299
Which patient undergoing a bone marrow transplant?
- patient undergoing a bone marrow transplant
300
It is December 1, 2017, and you irradiate an O-negative packed RBC that you have in inventory, which outdates January 5, 2018. What will the new outdate be for that unit?
December 29, 2017
301
A STAT type and screen comes from surgery. Your institution uses a blood bank band ID bracelet system. The nurse who obtained specimens did not label them with the blood bank number before she handed them to transport to take to the laboratory. What would be the most appropriate action to take?
Reject the specimen and have it recollected
302
Possible reasons for incompatibilities after initial pain during a crossmatch include:
* all of these reasons
- new alloantibody in recipients plasma
- alloantibody to a low-incidence present is on the donor unit RBCs
- warm-reactive autoantibody is present in the recipients plasma
303
After completing an antibody screen using the gel testing method, results after centrifugation yield a pellet of unagglutinated cells at the bottom of the micro tube and a thin layer of cells at the top gel column. This situation commonly indicates:
That fibrin from serum that has not clotted completely
304
The indicator cells used to detect antibodies in a solid phase technology are:
AHG-coated RBCs
305
Which of the following factors are likely to cause false-positive results while using gel technology?
* All of the above
- Lipemia
- icteric sample
- rouleaux
306
Upon centrifugation of an antibody screen procedure done by the gel system, the RBC agglutinates are disguised throughout the gel Column with a few agglutinates at the bottom of the microtubes. This reaction should be graded as a:
2+ reaction
307
The FDA has approved the ________ for application of gel technology
ABO, Rh, DAT, antibody screen and ID, as well as crossmatching
308
When performing an antibody screen by gel technology, the following steps are eliminated:
The saline wash and control check cells
309
The gel system has all of the the following advantages over the traditional tube procedure except:
Different grading system
310
Which of the following tests is not available for both the gel testing method and solid phase technology?
DAT
311
If you had a lipemic and icteric sample that needed to have an antibody screen done, which of the following would obtain the best results?
SPRCA
312
In a gel-based technology, the solid band at the top of the gel indicates a_________, whereas formation of a pellet at the bottom of the microtubes indicates__________.
4+ reaction/a negative reaction
313
Using the affinity column techniques, a serologic reaction that forms a fine RBC band at the top of gel column and a RBC button at the bottom of the gel column is interpreted as:
Mixed-field
314
Low ionic strength saline (LISS) is added to antibody screening methods for which of the following test systems?
SPRCA
315
The washing procedure is applicable to which of the following serological methods?
Solid phase and tube system
316
A layer of RBCs agglutinates at the top of the gel media, and a pellet of unagglutinated RBCs forms at the bottom. These findings are comparable to which of the following reactions in the test tube?
Mixed-tube
317
In performing an antibody screen by the solid phase technique, a monolayer of RBCs is formed at the top of the micro plate wells following the addition of indicator cells. This result should be interpreted as:
Positive
318
Using the gel test system, the technologist used a 3% cell solution. What would be the probable outcome ?
Weaker results because of the increase in antigen/antibody ratio
319
Which of the following is a factor in possible false-positive results when using the gel system to screen for antibodies?
* All of the above
- bacterial contamination
- temperature
- time
320
Which of the following statements is the most accurate? A mixed-filed in the gel system:
Needs to have further testing performed
321
Which of the following substances may interfere with gel technology but not SPRCA technology?
* All of the above
- hemolysis
- lipemia
- icteric samples
322
SPRCA testing requires the use of all these specialized microplate equipment except:
Thermal cycler
323
Manufacturers Grifrols and Ortho both produce automated blood bank equipment that uses
Column agglutination technology
324
Special pipette are required for this method
Column agglutination technology
325
True or False: An anti-M detected by using gel AHG antibody screening cards is considered clinically insignificant
False
