Exam 3

Crossing over occurs during:

meiosis.

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

red cell alloantibodies.

What is meant by the term autosomal?

A trait that is not carried on the sex chromosomes

In a family study, it was determined that all four siblings in the family had a different blood type: A, B, O, and AB. The parents were most likely ____________.

AO and BO

Which of the following blood products requires a crossmatch to be performed before issuing?

Granulocyte concentrates that have more than 2 mL of red blood cells

What reagents are derived from plant extracts?

Lectins

To what does the abbreviation "MSBOS" refer?

Maximum blood order schedule

If an emergency exists and there is not enough time to perform a crossmatch for red cells, what is the correct procedure?

Release group O, D-negative red blood cells.

A patient's serum reacted weakly with all panel cells tested at the antiglobulin phase using LISS and were not enhanced using PEG. The autocontrol was negative. Ficin-treated panel cells were nonreactive. What is the most likely specificity of the antibody?

Anti-Ch

A patient phenotypes as D+C+E-c-e+. The most likely genotype is:

R1R1.

Hematopoietic progenitor cell engraftment evaluation following a transplant evaluates which specific markers in the recipient?

Similarities and differences of short tandem repeats of DNA

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.

Red cells that phenotype as S-s- are also:

U-Negative

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

Unable to determine without further testing

If all red cells tested at room temperature are positive with a patient's serum except for cord cells, the probable antibody identity is:

anti-I.

What antibodies are present in polyspecific AHG reagent?

anti-IgG and anti-C3

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.

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

15%

What is the approximate probability of finding a compatible unit of blood for a D-positive patient with antibodies to C, E, and K, if the frequency of C is 70%, E, 30%, and K is 10%?

2 out of 10 units

The indirect antihuman globulin test is incubated at what temperature?

37° C

In a random population, 16% of the population is homozygous for a particular trait. What percentage of the same population is heterozygous for that particular trait?

48%

How long following transfusion must the recipient's sample be stored?

7 Days

Why is the determination of the D antigen important for women during pregnancy?

A D-negative mother should be given Rh immune globulin to prevent potential formation of anti-D during delivery of a D-positive infant.

An antibody to Jsb was identified in a patient scheduled for elective surgery at a later date. What is the best approach to finding compatible blood?

A and B are correct. Contact the rare donor registry since Jsb negative units are rare. Request that family members be tested to determine if they share the same phenotype.

A 29-year-old female was admitted to the emergency room with severe bleeding. The blood type was tested and determined to be AB, D negative. Six units of RBCs are ordered STAT. Of the following types available in the blood bank, which would be the most preferable for crossmatch?

A, D negative

An infant less than 4 months old requires which procedures for compatibility testing?

ABO and D typing and antibody screen initially only; units released without additional testing if the screen is negative

Which of the following statements is true regarding high-protein anti-D reagents?

All of the above are true * They have been largely replaced with low-protein monoclonal reagents. *They contain approximately 20% bovine albumin. *They may increase the possibility of a false-positive reaction, requiring the use of a control.

When using the Hardy-Weinberg equation to calculate genetic frequencies, which of the following must be true?

All of the above are true The population statistics must be large. Mutations cannot occur. Mating must be random.

How is RNA different from DNA?

All of the above are true. RNA usually exists as a single strand. The sugar ribose is substituted for deoxyribose. The base uracil exists only in RNA.

DTT (dithiothreitol) would be useful in the identification of which of the following antibodies?

Anti-Kpb

An example of a cold alloantibody includes:

Anti-M

Antibodies to low-incidence antigens include all of the following except:

Anti-Vel

An anti-E was identified in a patient who recently received a transfusion. What other Rh system antibody should be investigated?

Anti-c

Which of the following is responsible for the activation of the classic pathway of complement?

Antibody bound to antigen

If all the panel cells were reactive at the same strength at the antihuman globulin phase, no negative reactions were observed, and the autocontrol was negative, what should be suspected?

Antibody to a high-frequency antigen

A donor unit with a positive DAT would cause reactions at what phase of the crossmatch?

Antiglobulin

Select the test that uses IgG-sensitized red cells (check cells).

Antiglobulin test

The mixed lymphocyte culture (MLC) is a procedure that has been used in HLA testing to determine:

B and D Class II HLA antigen determination. compatibility testing for tissue typing.

Select the cell involved in humoral immunity.

B lymphocytes

How is it genetically possible for a child to phenotype as D-negative?

Both parents are heterozygous D-positive.

In the complement cascade, lysis of the target cell is mediated by which of the following components?

C5 to C9

Hemolysis was observed at room temperature when testing a patient's serum with reagent red cells used for screening. When this test was repeated using the patient's plasma, no hemolysis was observed. What was the most likely explanation for the different reactions?

Complement activation was inhibited by calcium in the plasma sample.

Select the portion of the antibody molecule that imparts the antibody's unique class function.

Constant region of the heavy chain

Genes located far apart on the same chromosome are more likely to:

Cross over

How would a donor who tested negative with anti-D reagent in the immediate spin test but tested positive at antihuman globulin with anti-D reagent be labeled?

D-Positive

The LW antigen expression is typically stronger on __________ cells.

D-positive red

Rz ry r' R0

DCE CE Ce Dce

Sections of single-stranded DNA used to identify certain sections of complementary DNA are called:

DNA probes

What is the most important concern when trying to identify antibodies in a patient with a warm autoantibody?

Determining whether there are underlying alloantibodies

Which of the following tests is not included in routine compatibility testing?

Direct antiglobulin test

Incubation step is not necessary Requires washing the cells several times before the addition of antihuman globulin reagent Tests for certain clinical conditions such as hemolytic disease of the newborn and autoimmune hemolytic anemia Detects IgG or complement-coated red cells

Direct antiglobulin test Both the direct and indirect antiglobulin test Direct antiglobulin test Both the direct and indirect antiglobulin test

What are the two components of the major crossmatch?

Donor red cells and recipient serum

Antibodies to which of the following blood group system show dosage (i.e., are stronger with homozygous expression of the antigen)?

Duffy

Parents who are both phenotyped as group A cannot have a group O child.

False

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

What portion of the antibody molecule binds to receptors on macrophages and assists in the removal of antibody bound to red cells?

Fc fragment

What regulatory agency provides licensure for blood banking reagents?

Food and Drug Administration

Select the method that uses a dextran-acrylamide matrix.

Gel technology

When two genes are close together on the same chromosome and are inherited as a group or bundle, they are inherited as this A gene that does not express a detectable product Equal expression of two different inherited genes as in most blood group systems Having two or more alleles at a given gene locus When a gene product is expressed only when it is inherited by both parents

Haplotypes Amorphic genes Codominant genes Polymorphic Recessive

Of the following markers that can be used to test for paternity, which marker provides the most useful statistical value?

Human leukocyte antigen typing

Select the term that is associated with the B-cell response to antigens

Humoral immunity

Cold autoantibodies are typically of which specificity?

I

Variable region of an immunoglobulin Imparts flexibility to the immunoglobulin molecule Part of the antigen that the immunoglobulin binds to The type of immunoglobulins determined by the heavy chain One of the two types of light chains

Idiotype Hinge region Epitope Isotype Kappa

Found in secretions, such as breast milk Able to cross the placenta Associated with intravascular cell destruction Associated with allergic reactions and mast cell activation Efficient in activation of the complement cascade Has the highest serum concentration Associated with immediate-spin in vitro reactions Has the highest number of antigen binding sites

IgA IgG IgM IgE IgM IgG IgM IgM

Most Rh system antibodies are of which immunoglobulin class?

IgG

What immunoglobulin class is capable of crossing the placenta?

IgG

Antibodies detected in the immediate spin crossmatch are usually of which of the following immunoglobulin classes?

IgM

What immunoglobulin class reacts best at room temperature at immediate spin?

IgM

In which of the following situations can the crossmatch test be omitted?

In a patient who has received a massive transfusion within a 24-hour period

In order to enhance the reaction of an antibody in vitro, it may be necessary to adjust which of the following?

Increase the incubation time in the incubator

All the following antigens are commonly found on screening cells except:

Kpa

Reagent derived from plants used to distinguish group A1 from group A2 red cells Reagent used to determine the ABO antigenic composition of a patient s red cells Reagent to detect the presence of red cell antibodies and B cells Reagent to identify the specificity of a red cell antibody antisera Reagent used in the identification of ABO antibodies

Lectins ABO antisera Screening cells Panel cells A1 and B cells

Which of the following facts is not a characteristic of Kell system antibodies?

Lose reactivity with proteolytic enzyme reagents

Antibodies to Lub antigen are not commonly detected because:

Lub antigen is of high incidence.

Which condition is often associated with the presence of anti-I?

Mycoplasma pneumoniae infection

The antiglobulin test was performed using gel technology. A button of cells was observed at the bottom of the microtube following centrifugation. This result indicates a:

Negative reaction

The children of an AB mother and a B father could phenotype as all of the following except:

O

After the addition of monoclonal-based anti-D to a patient's red blood cel! suspension, agglutination was observed. What is the interpretation of this result?

Patient is D-positive

What reagent contains antibodies to multiple antigenic epitopes?

Polyclonal-based

QUIZ 5 ch. 1-4

QUIZ 5 ch. 1-4

QUIZ 6 ch. 5-8

QUIZ 6 ch. 5-8

Current theory regarding the genetics of the Rh system suggests that:

Rh system antigens are coded by two closely linked genes.

Which of the following will cause an antigen to elicit a greater immune response?

Size greater than 10,000 daltons

Extravascular destruction of blood cells occurs in the:

Spleen

Select the correct statement regarding the collection of a blood sample for compatibility testing.

The sample must be labeled at the bedside.

Which of the following statements is true regarding IgG-sensitized red cells?

They must be used to confirm a negative antiglobulin tube test.

Select the region of the antibody molecule responsible for imparting unique antibody specificity.

Variable region

If anti-M was reacted with red cells that are M+N+, how would they compare with red cells that are M+N-?

Weaker

A father carries the Xga blood group trait and passes it on to all of his daughters but to none of his sons. What type of inheritance pattern does this demonstrate?

X-linked dominant

Antigen has a higher frequency in females Antigen of high incidence; antibody to it can cause hemolytic transfusion reactions Antibodies are sensitive to enzymes and have high-titer low-avidity characteristics System associated with McLeod phenotype Antigens Yta and Ytb are in this system System associated with glycophorin A and B Antibodies in this system often fall below detectable levels and are associated with delayed transfusion reactions Antibody to this antigen demonstrates weak mixed field reaction System associated with chronic granulomatous disease System associated with resistance to malaria

Xga Vel Chido/Rodgers Kell Cartwright MNSs Kidd Sda antigen Kell Duffy

In the solid-phase red cell adherence test, a negative test would appear as:

a button of cells on the bottom of the well.

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

a heterozygote.

You have added Coombs' control cells (check cells) after performing an IAT on a patient. You observe agglutination in the tube. What situation was NOT controlled for in testing by adding these check cells?

addition of patient serum

Lewis system antibodies have not been implicated in hemolytic disease of the fetus and newborn because:

all of the above are correct. the antigens are not fully developed at birth. Lewis system antibodies do not cross the placenta. the antibodies are not clinically significant.

Alternate forms of a gene at given genetic loci are called:

alleles

The Donath-Landsteiner antibody is:

an IgG auto anti-P.

A gene that produces no detectable product is referred to as:

an amorph

In a serologic test, the term prozone is also known as:

antibody excess.

Part of the daily quality control in the blood bank laboratory is the testing of reagent antisera with corresponding antigen-positive and antigen-negative red blood cells. What does this procedure ensure?

antibody specificity

In a lymphocytotoxicity test, cells that take on the dye:

are recognized by a specific antibody.

An antigen that originates from the individual is termed:

autologous

Most blood group systems are inherited as:

autosomal codominant

Antibody screening cells are positive at the antihuman globulin phase of testing. The first step of the investigation should be to:

check transfusion and pregnancy history.

The inheritance of the Rh antigens are:

codominant

To determine the presence of a red blood cell antigen in a patient sample, what source of antibody is selected?

commercial antisera

To determine the presence of a red blood cell antibody in a patient sample, what source of antigen is selected?

commercial reagent red blood cells

Monospecific AHG reagents:

contain either anti-IgG or anti-C3 antibody specificities

The best description of the elution technique is that it is a technique used to:

disassociate IgG antibodies from red cells for further identification.

The use of the electronic (computer) crossmatch is restricted to recipients who:

do not have a clinically significant antibody.

All the following statements are true regarding Lewis system antibodies except antibodies:

do not react following enzyme treatment of cells

Antibodies to Kidd, Kell, and Duffy blood group antigens share all the following characteristics except:

enhanced with enzyme treatment.

Select the method that uses the principle of sieving to separate larger agglutinates from smaller agglutinates in antigen-antibody reactions.

gel technology

The linked HLA genes on each chromosome are inherited as a:

haplotype.

Polyethylene glycol is a reagent that can be added to the screen or panel in order to:

increase the avidity of IgG antibodies.

The phase of the agglutination reaction is important in the interpretation of the antibody screen or antibody identification panel because it:

indicates the class of the antibody.

All of the following can cause the D antigen expression to be weaker except:

inheriting the G gene.

A patient's antibody history listed an anti-cellano. This antigen is also known as:

k in the kell system

The gel technology method uses a concentration of red cells that is:

lower than tube techniques.

The phosphate, sugar, and base that constitute DNA and RNA are called:

nucleotides

A gene inherited in a cis position to another gene is:

on the same chromosome

If an anti-I is suspected in a patient's sample that requires a transfusion, the most acceptable course of action is to:

perform the prewarm technique.

When an individual is said to be group A, it refers to the individual's:

phenotype.

Reagent antibodies prepared from human sources are:

polyclonal in specificity.

In relationship testing, a "direct exclusion" is established when a genetic marker is:

present in the child but absent in both the mother and alleged father.

Compatibility procedures will address all of the following except to:

prevent formation of all red cell antibodies.

Product limitations and technical considerations for each reagent can be found in the:

product insert.

High-titer, low-avidity antibodies typically:

react with antigens of high frequency in the population.

What reagent would be selected to detect the presence of unexpected red blood cell antibodies in a patient's serum sample?

screening cells

Anti-Sda should be suspected if:

the antibody reacts with most panel cells and are mixed field and refractile microscopically.

Solid-phase red cell adherence used for antibody detection has an advantage over tube testing because:

the endpoint is more clearly defined.

If two traits were found to occur higher in a population together than each occurs separately, they may be linked. This would suggest that:

the genes are close together on the same chromosome.