CHT EXAM PRACTICE TEST

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CHT EXAM PRACTICE TEST

Actual Qs and Ans - Expert-Verified Explanation -Guaranteed passing score -100 Questions and Answers

-Format: Multiple-choice / Flashcard

Question 1: A patient with an anti-HLA-B8 CREG antibody might be expected to have a positive T cell crossmatches with all of the following donors except?

• A1, A3, B8, B35, DR4, DR17
• A1, A24, B7, B8, DR1, DR17
• A24, A68, B7, B64, DR1, DR7
• A11, A29, B38, B62, DR4, DR7
• A1, A3, B35, B55, DR1, DR4

Answer:

• A1, A3, B35, B55, DR1, DR4

Question 2: Primers and probes bind to their DNA targets through a process known as

a) High stringency

b) Hydrogen bonding

c) Covalent bonding

d) Primer dimerism

e) Low Stringency

Answer:

b) Hydrogen bonding

Question 3: A positive MLC between a brother and sister who are both typed as HLA-DR4,- is most likely due to

• The siblings not being HLA-identical
• A meiotic crossover between HLA-DR4 alleles
• A proliferative response to HLA class I alleles
• High background in the MLC
• Somatic hypermutation

Answer:

• The siblings not being HLA-identical

Question 4: A bone marrow patient is A1,A11,B62,B64,DRB1

0103,DRB1

• Which of the following potential donors is the best match?

a) A1,Blank,B62,B64,DRB1

0103,DRB1

1503

b) A1,A11,B7,B8,DR5,DR6

c) A1,A11,B

1401,B

15,DRB1

0103,DRB1

1501

d) A1,A9,B14,B15,DR1,DR15

e) A1,A11,B14,B15,DRB1

0102,DRB1

1502

Answer:

c) A1,A11,B

1401,B

15,DRB1

0103,DRB1

1501

Question 5: A sample typed by SSP in 1996 was determined to be DRB1

0101,DRB1

• When the same sample was retyped in 1998 by SSP the typing was DRB1

0101,DRB1

04(01,34). What is the best explanation of these results?

a) New alleles sometimes have the same primer reactivity patterns as old alleles

b) Long term DNA storage at -80oC affects primer reactivity

c) IUB codes require reinterpretation with time

d) As new DQB1 alleles are discovered the DRB1 typings should be revised for unusual linkages

e) DRB1*0434 was thought to be a rare allele in 1996 but by 1998 was appreciated as a common

allele

Answer:

a) New alleles sometimes have the same primer reactivity patterns as old alleles

Question 6: Multiplexing of PCR-SSP reactions involves

a) Adding multiple DNA's to the same PCR-SSP reaction

b) Amplifying the DNA with a two-stage PCR amplification profile

c) Using multiple 5' and/or 3' primers in the same reaction

d) Computer analysis of SSP reaction patterns to look for multiple valid results

e) Keeping the HLA field complex enough to deter new applicants to the field

Answer:

c) Using multiple 5' and/or 3' primers in the same reaction

Question 7: 31. All of the following techniques are useful in distinguishing autoantibodies from high PRA alloantibodies except

• Platelet absorption
• NIH-CDC analysis on frozen cell trays

• DTT treatment
• Flow cytometry
• Autocrossmatch

Answer:

• NIH-CDC analysis on frozen cell trays

Question 8: Which of the following statements is false?

a) Class II proteins have polymorphism in only one of the two polypeptide chains

b) Class I proteins have polymorphism in only one of the two polypeptide chains

c) Class III proteins are on chromosome 6

• beta2-microglobulin subtyping is not critical for bone marrow transplantation

e) DRB4 alleles are not always present

Answer:

a) Class II proteins have polymorphism in only one of the two polypeptide chains

Question 9: The wipe (swipe) test assays for contamination of pre-PCR regions with...

a) Amplified DNA

b) Degraded DNA

c) Taq inhibitors

d) HLA proteins

Answer:

a) Amplified DNA

Question 10: The antigen-binding site of an antibody is comprised of which of the following?

• The variable region of the light and heavy chains
• The variable region of the light chain only
• The entire light chain