Deck 15: Histocompatibility Laboratory Techniques and Applications

Question 1

For CLIA compliance, HLA testing labs can be inspected by

A)College of American Pathologists (CAP).
B)American Association of Blood Banks (AABB).
C)Centers for Medicare and Medicaid Services.
D)American Society of Histocompatibility and Immunogenetics (ASHI).
E)All of the above.

Answer 1

All of the above.

Question 2

In which situation below is transplant contraindicated?

A)Heart transplant recipient with negative T cell cross- match and positive B cell cross- match with donor cells.
B)Kidney transplant recipient with positive T cell cross- match and negative B cell cross- match with donor cells.
C)Liver transplant recipient with negative T cell cross- match and positive B cell cross- match with donor cells.
D)All of the above.

Answer 2

Kidney transplant recipient with positive T cell cross- match and negative B cell cross- match with donor cells.

Question 3

What is an important advantage of HLA testing by molecular methods?

A)Molecular methods are inexpensive.
B)Many alleles thought to be different based on serological methods have actually been shown by molecular methods to be the same.
C)There is more lot- to- lot variability in antisera than there is in molecular oligonucleotide primers.
D)Although cells used for typing must still be viable, fewer cells are required to get an accurate typing.

Answer 3

There is more lot- to- lot variability in antisera than there is in molecular oligonucleotide primers.

Question 4

Class II HLA antigens are best determined from

A)monocytes.
B)T lymphocytes.
C)B lymphocytes.
D)neutrophils.

Question 5

How can transplant recipients acquire HLA antibodies?

A)Blood transfusion
B)Prior organ transplant
C)Pregnancy
D)All of the above

Question 6

Observe the flow cytometry cross- match protocol in the table and interpret it. FITC is fluoroscein isothiocyanate which fluoresces green, and PE stands for phycoerythrin which fluoresces red.

A)This is a positive B cell cross- match.
B)This procedure must be repeated because it was performed incorrectly.
C)This procedure must be repeated because no fluorescence was detected in tube 1.
D)This procedure must be repeated because both fluorochromes were detected in tube 2.
E)This is a positive T cell cross- match.

Question 7

If a unrelated donor is being considered for progenitor cell transplant, which molecular HLA typing method below is required before final transplant can occur?

A)Low- resolution PCR sequence specific oligonucleotide primer typing
B)High- resolution PCR sequence specific oligonucleotide primer typing
C)Sequence- based typing
D)High- resolution PCR sequence specific probe typing
E)Low- resolution PCR sequence specific probe typing

Question 8

Can sodium oxalate and EDTA be used for HLA typing, antibody identification, and cross- matching by conventional serologic methods?

A)Yes, as long as the specimen is kept at room temperature.
B)Yes, as long as the specimen is kept at 2-6° C.
C)No, because EDTA and oxalate chelate Mg++ and Ca++.
D)No, because EDTA and oxalate are toxic to white blood cells.

Question 9

The complement dependent cytotoxicity method of HLA testing can be used for

A)cross- matching recipient plasma with donor cells.
B)HLA typing of Class I antigens.
C)identifying recipient HLA antibodies.
D)HLA typing of Class II antigens.
E)All of the above.

Question 10

An advantage of performing HLA cross- matches using flow cytometry is that

A)flow cytometers are considerably less expensive than fluorescent microscopes.
B)Both T and B cell cross- matches can be performed in one tube.
C)the completed cross- match tubes can be stored for about a week until analysis is convenient.
D)viable cells are not required.

Question 11

Panel reactive antibody testing for preexisting HLA antibodies is not done on recipient's

A)liver.
B)progenitor (stem)cell.
C)heart.
D)kidney.

Question 12

Which of the following is (are)TRUE regarding acceptable specimens for HLA typing by serological methods?

A)Lithium heparin is the anticoagulant of choice for HLA typing.
B)Peripheral blood, spleen tissue, and lymph node tissue can all be used for HLA typing.
C)Specimens should be stored at 2-6° C after collection.
D)Specimens preserved in sodium heparin or acid citrate dextrose are acceptable for up to one week after collection.
E)All of the above.

Question 13

How can monocytes be removed from lymphocyte preparations?

A)Washing Ficoll- Hypaque density separation with 5% ethanol
B)Specific monocyte destruction with monoclonal antibodies
C)Adding iron filings for monocyte phagocytosis
D)A and B
E)B and C

Question 14

The regulatory body for HLA testing for transplant programs is

A)College of American Pathologists.
B)Foundation for the Accreditation of Cellular Therapy.
C)American Society of Histocompatibility and Immunogenetics.
D)United Network for Organ Sharing.

Question 15

Under the Clinical Laboratory Improvement Amendments (CLIA)regulations, HLA testing is considered

A)low complexity.
B)high complexity.
C)waived.
D)moderate complexity.

Question 16

Which of the following is not acceptable for specimens to be used for HLA typing?

A)ACD anticoagulant
B)Refrigerator storage up to 14 days
C)Room temperature storage up to five days
D)EDTA anticoagulant
E)Heparin anticoagulant

Question 17

A high resolution HLA sequence- specific primer PCR reaction was done in a 96 well microtiter plate. Each well contains primers to a different HLA allele and the same primers to a sequence of DNA to be used as an internal control. A negative control consists of distilled water left in an open tube during the specimen processing. After PCR, the contents of each well were electrophoresed and visualized on gel. Which finding automatically indicates a potentially invalid reaction that requires repeat analysis?

A)In the well that an HLA- A gene amplified, the control sequence also amplified (i.e., two bands were visible).
B)Two different alleles for the HLA- A locus were amplified.
C)An allele determined by PCR does not match the allele determined by classic serology.
D)No bands were visualized in the negative control.
E)An allele identified by the high resolution procedure does not match the allele identified by the low- resolution procedure.

Question 18

In a complement dependent cytotoxicity assay used for HLA antigen typing, which dye can be used to identify cells that have been lysed by corresponding antibody?

A)Ethidium bromide
B)Fluorescein isothiocyanate
C)Acridinium chloride
D)Carbonylmethyl fluorescein diacetate

Question 19

The Ficoll Hypaque technique isolates mononuclear cells by

A)cell surface marker affinity.
B)cellular adherence.
C)cell membrane solubility.
D)cell density.

Question 20

When DNA has been extracted from a sample for HLA molecular typing

A)it must be amplified immediately to insure accuracy of the process.
B)it can be stored one month at -20° C.
C)it can be stored in the refrigerator no more than 24 hours prior to amplification.
D)it can be stored indefinitely at -70° C.

Question 21

Which process below includes all the controls utilized to make sure that a particular laboratory analysis is performing properly?

A)Continuous quality improvement (CQI)
B)Quality assurance (QA)
C)Quality control (QC)
D)Total quality management (TQM)

Question 22

HLA typing is acceptable on lymphocyte preparations in which >95% of the cells can ingest the dye .

Question 23

A lymphocyte preparations in which < 95% of the cells have ingested trypan blue must be discarded and not used for HLA typing.

Question 24

When DNA is extracted from a sample for HLA typing, the purity of the sample is best determined by the ratio of the sample's absorbance at 260 and 280 nm.

Question 25

An advantage of flow cytometry cross- matching is that B cells and T cells do not have to be separated in lymphocyte preparations prior to analysis.

Question 26

HLA labs that support transplant programs can be accredited by

A)Centers for Medicare and Medicaid Services.
B)American Society of Histocompatibility and Immunogenetics (ASHI).
C)College of American Pathologists (CAP).
D)American Association of Blood Banks (AABB).
E)All of the above

Question 27

Traditional HLA typing always requires viable cells.

Question 28

After progenitor cell transplant, if STR DNA regions from both donor and recipient are detected, this is called a genetic .

Question 29

Personnel who work in HLA laboratories earn certification from the

A)National Credentialing Agency for Laboratory Personnel.
B)American Society of Clinical Pathologists.
C)American Board of Histocompatibility and Immunogenetics.
D)American Association of Blood Banks.
E)All of the above.

Question 30

One of the most frequent reasons for death after a progenitor cell transplant is graft versus host disease.

Question 31

The specimen required from a transplant recipient to do panel reactive HLA antibody testing and crossmatching with donor cells is .

Question 32

If ethidium bromide is used as the supravital dye in a complement dependent cytotoxicity assay, then cells injured by HLA antibody will appear orange.

Question 33

For HLA typing, the cell of choice is the .

Question 34

On- site laboratory inspection for accreditation of HLA testing laboratories must occur a minimum of every

A)2 years.
B)1 year.
C)5 years.
D)6 months.

Question 35

Gels for HLA typing by PCR should be interpreted by at least (how many?)people.

Question 36

If a transplant is going to fail due to immune attack, it will be because of recipient production of antibodies or cytotoxic T cells.

Question 37

PCR sequence specific oligonucleotide probe methods are usually preferred for large volumes of specimens over PCR sequence specific primer methods.

Question 38

It is still normal a year after progenitor cell transplant to perform STR analysis and find both donor and recipient DNA in peripheral blood white cells.

Question 39

For quality control purposes, which reagent below must be tested against the antibody screening panel to insure that it lacks HLA antibodies?

A)Trypan blue
B)Complement
C)Protein supplement
D)Antiglobulin

Question 40

Although flow cytometry donor:recipient cross- matching is not as sensitive as the traditional complement dependent cytotoxicity assays, it is widely used because it is automated and significantly reduces turnaround time.

Question 41

List three ways that T and B cells can be separated from each other using mononuclear cell preparations.

Question 42

What is a short tandem repeat (STR), and how can it be used to determine progenitor cell engraftment?

Question 43

How can the sensitivity of the cross- match between the recipient's serum and the donor's cells be enhanced?

Question 44

Describe the technique of the mixed lymphocyte culture reaction (MLC).

Question 45

List the steps in a complement dependent cytotoxicity assay used for HLA antigen typing.