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Good to study for final blood bank exam

The Du test is performed by incubating a patient's red cells with:

anti-D serum following by washing and antihuman globulin (AHG) reagent

A direct antiglobulin test is performed using polyspecific antisera. The result is 3+ DAT using only anti-IgG is performed next. The result is negative which of the following substances is most likely causing the positive reaction

anti-C3

A donor is tested with Rh antisera, with the following results:
Anti-D +
Anti-C+
Anti-E+
anti-c+
anti-e +
Rh control 0
What is the probable Rh genotype

R1R2

AABB requires that patients samples for compatibility testing be stored for at least:

7 days after transfusion

Most "naturally occurring" ABO system antibodies fall into which class

IgM

The immediate spin testing on a unit of donor blood with anti-D is negative. A weak D tst is performed on the unit of donor blood and exhibits a 2+ reaction. The donor blood unit is labeled as

D positive

Mixing patient serum and donor red cells together and observing for direct cell lysis or agglutination is known as

Major crossmatch

The d antigen is

non-existent

A patient's antibody screen is positive with Cell #2 the autocontrol is negative, is the antibody responsible for the positive screen most likely an alloantibody or an autoantibody

alloantibody

An individual lacking all antigens of the Rh blood group system is classified as

Rh null

A mother is Rh-negative and the father Rh-positve their baby is Rh-negative It may be concluded that

The father is heterozygous Rh-positve

Forward: Anti-A 2+mf, anti-B: 0
Reverse: A1 cells: 0, B cells: 3+
What could be a plausible explanation for this discrepancy

group O blood products given to group A

Which ABO phenotype selection contains the most H antigen and the least H antigen, respectively on the red cell's surface

O (most), A1B (least)

ABH soluble antigens are determined by the presence of the :

Se gene

Using Wiener nomenclature, a patien is r' what Rh antigens does this patient possess

Ce

The terminal sugar responsible for the A antigen is

N-acetylgalactosamine

In the ABO system, the O gene is considered

amorphic

Using Rosenfield terminology a patient has Dce/dCe how would this be written

1,2, -3, 4, 5

Interpret this patient's ABO and D type using the following results
Red Cells
Anti-A: 0
Anti-B: 4+
Anti-D 4+
Serum
A1: 3+
B: 0
O cells: 0

B positive

ABO/Rh blood type
forward:
Anti-A: 0/Anti-B: 0
Reverse:
A1: 4+/ B: 3+
Anti D 3+ Rh control 0

O positive

A recipient with group A phenotype requires a transfusion of 2 units of frozen plasma what types are appropriate to select for transfusion

AB and A

Patient cells with anti-A 4+, Patient with anti-B neg and patient cells with A1 cells 1+

cold autoantibody

Cell suspensions used is blood banking procedures are typically

3- 5%

Compatibility procedure will address what issues

prevent life threatening transfusion reactions
Maximize in vivo survival rate of red cells
check ABO compatibility
BUT NOT prevent antibody formation

When are Coombs control cells added

After the AHG reactions have been

Antibodies to Rh, MNS, Kell, or Duffy antigens may cause:

Acute hemolytic transfusion reaction

The Rh antisera that requires a parallel control is

High protein polyclonal

what antibody is present in the serum of a person who is group A

anti-B

What are resolutions for an ABO discrepancy

Review patient history
repeat ABO testing with longer incubation at room temp.
repeat ABO testing with incubation at 4C

The most common cause of false-negative results in the antiglobulin test is

Inadequately washed red cells

The most serious transfusion reactions are due to incompatibility to which blood group system

ABO

What is the potential effect in a tube agglutination test if a red cell suspension with a concentration greater than 5% is used

false negatives

Regarding the gel technique, which step is not performed

immediate spin

It would not be unusual for pregnant women to express which Lewis phenotype

Le (a-,b-)

What is source of antigen in routine blood bank procedures

Screening cells, Panel cells, and A1 and B cells

Rh system antibodies characteristically give

reactions that are enhanced with enzymes
reactions at 37 degrees

Unacceptable quality control results for the antiglobulin test performed in test tube may not be noticed if

the reagents used were improperly stored
the tech performing the test was never trained
preventive maintenance has not been performed on the cell washer

The expression of the gene that can be observed is called

Phenotype

A bombay individual would have which of the following ABO phenotypes

O

The test that uses IgG-sensitized red cells (check cells)

antiglobulin test

In an antibody identification panel only one red cell was negative at the antihuman globulin phase, on ruling out and matching the pattern an anti-k was identified what further testing is necessary to confirm the antibody

two more k-negative cells should be tested

The saliva of an adult whose red cells are shown to be group A Le(a-, b+) is expected to have

A, H, Lea and Leb substances

A antibody screen and computer crossmatch were peerfomed on a patient being admitted to the ICU with renal failure, The antibody screen is negative at AHG the blood bank tech calls, the hospital were teh patient had been transferred from and finds out the patient has a history of anti-E that was found about ten years ago, the blood bank tech who performed the computer crossmatch should now

proceed with a crossmatch at AHG phase and provide E negative units to this patient

An adult individual has a genotype of lele, Sese, HH what is the red cell phenotype

Le (a-,b-)

ABO blood group antigens are expresses at _____traits

codominant

When group O blood is not available for transfusion, what is the next alternative

None

An individual has the genotype AO, HH, what antigens would be present on the red cells of this individual

A and H

The antigens of the Cartwright blood group system are

Yta, Ytb

Most adults have strong ___antigen expression and weak___expression (hint: cord cells are the opposite)

I and i

A technologist identifies and anti-c the only antibody not yet ruled out is anti-E what is the next step for the technologist to take

test the patients serum against additional cells that are c- and E+

What is the most likely to account for a false-negative antigen-antibody reaction

excess antibody or antigen levels

Lele sese hh

Le(a+.b-) Bombay

Given the following results, determine the MOST likely cause(s) of the following ABO discrepancy
anti-a: 0/anti-b: 3+/anti-a,b: 3+
a cells:3+/B cells:4+/ O cells: 3+

room temperature reactive alloantibody

an individual who secretes A and H substances in his saliva must possess the following genes

A, H and Se

lele Sese

Le(a-,b-)

Lele Sese H

Le(a-,b+)

A patient who is phenotypically group B has which antibody in his/her serum

anti-A

A patient in the ICU has had many blood transfusions over the past few days
anti-A: 1+mf/anti-B: 0/A1 cells: 0 A2 cells: 0/B cells: 4+/ Auto: 0/ DAT: 0
what is the MOST probable explanation for these results

group A patient transfused with group O blood

Le (a+,b-)

LeLe sese H

Le (a-,b-) Bombay

lele sese hh

A group O patient was crossmatched with group B red blood cells what phase of the crossmatch will first detect this incompatibility

Immediate spin (IS)

The weak D test detects

weak D antigen

anti H lectin

Ulex europeaus

pretransfusion testing begins with

proper identification of the patient

Infants do not require crossmatching if they are less than

4 months old

The indirect antihuman globulin test is incubated at what temp

37C

the antiglobulin test was preformed using gel technology A button of cells was observed at the bottom of the microtube following centrifugation this result indicates a

negative reaction

mycoplasma pneumoniae infections can sometimes be associated with

anti-I antibodies

Using wiener nomenclature a patient has D, C,e how would this be written

R1

Which procedure tests donor cells against the recipients serum and primarily functions to determine the ABO compatibility of the donor cells

major crossmatch

a positive antibody screen, negative autocontrol, and positive major crossmatch may be caused by

recipient alloantibody to donor cell antigens

Lewis antibodies are an example of

IgM antibodies that react on IS

When using low protein anti-D reagents an Rh control is indicated

when sample/donor unit types as AB positive

Persons who phenotype as Fy(a-b-) are resistant to infection by what organism

Plasmodium malariae

A patient needing a transfusion has a negative antibody screen in all phases of testing One out of four units crossmatched shows 2+ incompatibility at the AHG phase The most likely cause of this compatibility is

positive DAT in the donor

What reagent contains antibodies to multiple antigenic epitopes

Polyclonal-based

the Donath-Landsteiner antibody is

an IgG auto anti-P

The frequency of the D-negative phenotype in the population is

15%

High-titer,, low avidity antibodies typically

react with antigens of high frequency in the population

the phase of the agglutination reaction is important in the interpreation of the antibody screen or antibody identification panel because

indicates the class of antibody

when an individual is said to be group A it refers to the individuals

phenotype

red cells that phenotype as S- s- are also

U-negative

a group AB patient requires plasma the blood bank inventory indicates that no units of AB plasma are available for transfusion which of the following plasma ABO types is an acceptable substitute

No other ABO type is acceptable

antibody screening of the recipient is performed as a a component of compatibility testing to detect

red cell alloantibodies

High protein anti-D reagents

they contain approx 20% bovine albumin
increase the possibility of a false-positive reaction, requiring the use of a control
have been largely replaced with low protein monoclonal reagents

An agglutination reaction described as "many medium sized clumps, clear supernantant would be graded as

2+

HTLA antibodies

are usually clinically insignificant

Group O cells are used as a source for commerial screening cells because

ABO antibodies do not react with group O cells

The antibody screen

detects most clinically significant antibodies

proteolytic enzymes should not be used to screen for antibodies because

some antigens are destroyed by enzymes, which would cause the antibodies to be missed

examination of a tube with an optical aid agglutination viewer shows one large clump with a clear background this should be graded as

4+

which of the following blood group systems has been implicated in transfusion reactions on the first exposure to incompatible red blood cells

ABO

why is incubation omitted in the direct antihuman globulin test

the antigen antibody complex has already formed in vivo

antibodies deteced in the Immediate spin crossmatch are usually of which of the following classes of immunoglobulin classes

IgM

Polyspecific AHG contains which of the following components

Anti-IgG and C3

A person whose red cells type as M+ N+ with antisera would be

heterozygote

The genotype of two parents areas follows:
Mother: dd
Fater: Dd
D is dominant and d is recessive. which of the following probability of genotypes is possible in this offspring

50% Dd; 50% dd

In the process of identifying an antibody the tech observed 2+ reactions with 9 of the 10 cells in a panel at the IS phase these reactions disappeared following incubation at 37C and the antihuman globulin phase of testing the antibody most likely to be responsible is

anti-I

The D antigen of the fisher-race nomenclature corresponds to which of the following antigens ofteh Wiener nomenclature

Rh0

Characteristics of IgM antibodies include

reacts best at room temp or lower
does not cross the placenta
has the potential to bind 10 separate antigen sites

Check cells are used to determine the validity of testing at the AHG phase and check for what errors

omission of AHG sera from the test
inadequate washing of cells
contaminated saline

DTT destroys antigens off which blood group

Kell

What immunofominant sugar is responsible for H specificity

L-fucose

Anti L-W reacts strongest with which cell

D positive

The immunoglobulin class of anti-M antibodies is

Frequently a mixture of IgG and IgM

ABO reverse grouping consists of

cells of known antigen and serum of unknown antibody

A person with the phenotype Cc is

C single dose, c single dose or heterozygous

clinically significant antibodies occur in approx

3% of the population

Cold autoantibodies are typically of which specificity

I

ABO forward grouping consists of

Cells of unknown antigen and serum of known antibody

a tech encounters a cold-reacting antibody that reacts at room temp IS with all of teh antibody identification panels testing with cord cells shows a negative result the antibody is most likey

anti-I

if the autocontrol and all antibody pane cells agglutinate at room temp but react less strongly at 37C in the AHG phase you might suspect

cold reacting autoantibodies

the AABB standards require that all insitiutions issung blood to recipients for transfusion retest the donor blood what is required to be retested

ABO typing on all units; D typing on Rh neg units

MOST likely ABO discrepancy

anti-a:4+/anti-B 0/Anti-AB 4+/A1 2+ A2 0/B 4+

group A2 with anti-A1

A patient was transfused two weeks before his current testing results indicates a positive DAT and a positive antibody screen with screening cell 1 and 2 at IAT the autoantibody may be removed from the serum using

allogenic adsorption

The Du antigen

is a weakened form of the D antigen

Characteristics of Kidd antibodies:except

IgG immunoglobulin ability to bind complement show delayed HTR

what is the action of AHG reagent

cross links RBCs that have become sensitized with antibody or complement

A gene that produces no detectable product is referred to as

an amorph

characteristics of the ABO blood group antibodies include

they are naturally occuring and are mostly IgM

which autoantibody specificity is found in patients with paraoxsmal cold hemoglobiniuria

P

antibodies to Rh, MNS, Kell or Duffy antigens may cause

Acute hemolytic transfusion reactions

which reagent would you use to preform reverse typing to identify the presence of ABO antibodies in the patient's serum

A1 and B cells

Most clinically significant antibodies against blood groups are

IgG

Most likely ABO discrepency
anti-a: 4+/anti-b 0/anti-ab 4+/A1: 0 A2 0/ B: 0

Elderly or immunocompromised patient

which antigens are not destroyed by enzymes

MNSs and Duffy

which of the following phenotypes will react with anti-f

rr

a patients phenotype consists of the following typing results D+, C+, E-, c-, e+, S-, s+
which alloantibodies is the patient capable of forming

anti E, c, S

what is the name of the procedure in which the antibody is removed from the surface of a red cell destroying the cell

elution

the two A main subgroups A1 and A2 can be differentiated by using reagent made from

Dolichos biflorus

an antibody that is typically enhanced by treatment with proteolytic enzymes is

Kidd and Rh

when beginning the antibody exclusion process after testing a panel of RBCs the tech should first

start ruling out the first non-reactive cell on the panel

the immunogominant sugar that confers B blood group specificity is

d-galactose

compatibilty testing for neonates can be performed using plasma from

biological mother

which antibodies can either be IgM or IgG and is often detected by incompatible crossmatch

anti-Lua

how would you interpret the results if both the anti-D reagent and the Rh control were 2+ agglutination reactions

invalid, unable to determine without further testing

which red cell antigens are found on glycophorin-A

M,N

Serum ABO grouping is not routinely performed on newborns because

infants lack ABO antibodies until about 4 mths of age

most causes of autoimmune heolytic anemias (AIHA) are

warm AIhA

prozone occurs when

antibody molecules are in excess of antigen

which red cell typing would most commonly be found in the black donor population

Fy (a-b-)
Js (a+b+)
Le(a-b-)

anti-I will react routinely with

all adult red cells

which antibodies is typically IgG shows dosage and shows no reactivity with enzyme treated cells

Duffy (Fya and Fyb)

give examples of conditions that would exhibit a positive DAT

HTR, HDFN, WAIHA

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