CERTIFIED HISTOCOMPATIBILITY SPECIALIST (CHS) ULTIMATE REGISTRY
REVIEW & PRACTICE EXAMINATION
1. What is the primary function of the HLA system?
A. Regulate blood glucose
B. Assist immune recognition of self and non-self
C. Produce red blood cells
D. Regulate calcium levels
Correct Answer: B. Assist immune recognition of self and non-self
Rationale:
The human leukocyte antigen (HLA) system helps the immune system distinguish self from
foreign tissue, which is critical in transplantation.
2. HLA genes are located on which chromosome?
A. Chromosome 3
B. Chromosome 6
C. Chromosome 12
D. Chromosome 18
Correct Answer: B. Chromosome 6
Rationale:
The major histocompatibility complex (MHC), including HLA genes, is located on
chromosome 6.
3. Which HLA class is primarily involved in presenting antigens to CD8+ T cells?
A. Class I
B. Class II
C. Class III
D. Class IV
Correct Answer: A. Class I
Rationale:
HLA Class I molecules present intracellular antigens to CD8+ cytotoxic T lymphocytes.
4. Which cells normally express HLA Class II molecules?
A. Red blood cells
B. Antigen-presenting cells
C. Platelets only
D. Skeletal muscle cells
, Correct Answer: B. Antigen-presenting cells
Rationale:
B cells, macrophages, and dendritic cells express HLA Class II molecules.
5. What is the primary purpose of tissue typing in transplantation?
A. Determine blood sugar levels
B. Match donor and recipient compatibility
C. Measure calcium balance
D. Assess liver function
Correct Answer: B. Match donor and recipient compatibility
Rationale:
Tissue typing minimizes graft rejection risk by identifying compatible HLA antigens.
6. Which test detects preformed antibodies against donor lymphocytes?
A. CBC
B. Crossmatch test
C. PT/INR
D. Blood culture
Correct Answer: B. Crossmatch test
Rationale:
Crossmatching identifies recipient antibodies that may react against donor tissues.
7. What is the MOST polymorphic HLA locus?
A. HLA-A
B. HLA-B
C. HLA-C
D. HLA-DP
Correct Answer: B. HLA-B
Rationale:
HLA-B has the highest degree of genetic variability.
8. Which transplant complication occurs when donor immune cells attack the
recipient?
A. Hyperacute rejection
B. Graft-versus-host disease
C. Acute renal failure
D. Anaphylaxis
, Correct Answer: B. Graft-versus-host disease
Rationale:
GVHD commonly occurs in bone marrow transplantation when donor T cells attack
recipient tissues.
9. What is PRA an abbreviation for?
A. Platelet response assay
B. Panel reactive antibody
C. Primary renal analysis
D. Plasma rejection antigen
Correct Answer: B. Panel reactive antibody
Rationale:
PRA estimates the percentage of the population to which a recipient has antibodies.
10. Which method is commonly used for molecular HLA typing?
A. Gram stain
B. PCR
C. ELISA only
D. Hematocrit testing
Correct Answer: B. PCR
Rationale:
Polymerase chain reaction (PCR) is widely used for DNA-based HLA typing.
11. Hyperacute rejection is primarily caused by:
A. Viral infection
B. Preformed recipient antibodies
C. Low hemoglobin
D. Electrolyte imbalance
Correct Answer: B. Preformed recipient antibodies
Rationale:
Preexisting antibodies attack donor tissue immediately after transplantation.
12. Which organ transplant is MOST dependent on HLA matching?
A. Cornea
B. Kidney
C. Liver
D. Skin graft only
REVIEW & PRACTICE EXAMINATION
1. What is the primary function of the HLA system?
A. Regulate blood glucose
B. Assist immune recognition of self and non-self
C. Produce red blood cells
D. Regulate calcium levels
Correct Answer: B. Assist immune recognition of self and non-self
Rationale:
The human leukocyte antigen (HLA) system helps the immune system distinguish self from
foreign tissue, which is critical in transplantation.
2. HLA genes are located on which chromosome?
A. Chromosome 3
B. Chromosome 6
C. Chromosome 12
D. Chromosome 18
Correct Answer: B. Chromosome 6
Rationale:
The major histocompatibility complex (MHC), including HLA genes, is located on
chromosome 6.
3. Which HLA class is primarily involved in presenting antigens to CD8+ T cells?
A. Class I
B. Class II
C. Class III
D. Class IV
Correct Answer: A. Class I
Rationale:
HLA Class I molecules present intracellular antigens to CD8+ cytotoxic T lymphocytes.
4. Which cells normally express HLA Class II molecules?
A. Red blood cells
B. Antigen-presenting cells
C. Platelets only
D. Skeletal muscle cells
, Correct Answer: B. Antigen-presenting cells
Rationale:
B cells, macrophages, and dendritic cells express HLA Class II molecules.
5. What is the primary purpose of tissue typing in transplantation?
A. Determine blood sugar levels
B. Match donor and recipient compatibility
C. Measure calcium balance
D. Assess liver function
Correct Answer: B. Match donor and recipient compatibility
Rationale:
Tissue typing minimizes graft rejection risk by identifying compatible HLA antigens.
6. Which test detects preformed antibodies against donor lymphocytes?
A. CBC
B. Crossmatch test
C. PT/INR
D. Blood culture
Correct Answer: B. Crossmatch test
Rationale:
Crossmatching identifies recipient antibodies that may react against donor tissues.
7. What is the MOST polymorphic HLA locus?
A. HLA-A
B. HLA-B
C. HLA-C
D. HLA-DP
Correct Answer: B. HLA-B
Rationale:
HLA-B has the highest degree of genetic variability.
8. Which transplant complication occurs when donor immune cells attack the
recipient?
A. Hyperacute rejection
B. Graft-versus-host disease
C. Acute renal failure
D. Anaphylaxis
, Correct Answer: B. Graft-versus-host disease
Rationale:
GVHD commonly occurs in bone marrow transplantation when donor T cells attack
recipient tissues.
9. What is PRA an abbreviation for?
A. Platelet response assay
B. Panel reactive antibody
C. Primary renal analysis
D. Plasma rejection antigen
Correct Answer: B. Panel reactive antibody
Rationale:
PRA estimates the percentage of the population to which a recipient has antibodies.
10. Which method is commonly used for molecular HLA typing?
A. Gram stain
B. PCR
C. ELISA only
D. Hematocrit testing
Correct Answer: B. PCR
Rationale:
Polymerase chain reaction (PCR) is widely used for DNA-based HLA typing.
11. Hyperacute rejection is primarily caused by:
A. Viral infection
B. Preformed recipient antibodies
C. Low hemoglobin
D. Electrolyte imbalance
Correct Answer: B. Preformed recipient antibodies
Rationale:
Preexisting antibodies attack donor tissue immediately after transplantation.
12. Which organ transplant is MOST dependent on HLA matching?
A. Cornea
B. Kidney
C. Liver
D. Skin graft only
