UAMS BLOOD BANK EXAM #2 UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Question:
1. What is the second most important blood bank system after ABO and what are the 5 principal antigens?
When Rh is referred to, what is most commonly being talked about?
Answer:
Rh blood group system. D, C, E, c, and e. The D antigen is typically called the Rh factor.
Question:
2. Who first recognized the Rh blood group in 1939 and how was it named?
Answer:
Landsteiner and Weiner; Rh was the name given because of the similarity of this ABY to one made by
rabbits and guinea pigs that reacted with rhesus monkeys cells. It agglutinated with 85% of human RBCs.
Question:
3. What is the most important Rh antigen? What is important to know about this one?
Answer:
D antigen, it is very antigenic. Antibodies will be produced with exposure to even the smallest amount of
D AGN. Antibodies to the D AGN are one of the most clinically significant in blood bank, because they
are a major concern for both blood transfusions and HDN because they are classified as IgG and can cross
the placenta.
Question:
4. When classifying ABO and Rh antibodies, what are the major comparison differences?
Answer:
ABO is classified as IgM, acquired by bacterial or pollen ingestion. ABO also reacts at RT and are
antibodies present under normal conditions. Rh is classified as IgG, acquired through immunization due to
pregnancy or transfusions. Rh reacts at 37 C and requires incubation and must have been formed by
previous exposure.
Question:
5. What is the most widely accepted theory that describes inheritance of Rh?
Answer:
Two closely linked genes (loci) on chromosome 1. RHD and RHCE.
Question:
6. What does RHD and RHCE do?
Answer:
RHD determines the D AGN expression on RBCs. RHCE determines the C, c, E, e expressions that can be
CE, Ce, cE, and ce.
Question:
7. Which alleles are co-dominant? What represents the D allele? What represents the absence of the D
allele?
,Answer:
C and c & E and e. D presence. d absence.
Question:
8. What is the frequency of the D AGN and the absence of the D AGN (d)?
Answer:
D - 85%. d - 15%
Question:
9. What is the Fisher-Race Rh terminology?
Answer:
It is the DCE terminology; it states that AGN production is controlled by 3 sets of closely linked (3 loci)
genes located on the same chromosome and that each gene produces an AGN. There is a gene that controls
D and d, a gene that controls C and c, and a gene that controls E and e.
Question:
10. What is the Wiener terminology? How many alleles exist at the Rh gene locus with this theory? What
are these alleles and how do they convert to the Fisher-Race terminology?
Answer:
It is the Rh-Hr terminology; it states that a single gene at the Rh locus codes for a series of factors or the
AGNs. Each parent contributes one Rh gene and can be inherited as homozygous or heterozygous. 8
alleles - R0, R1, R2, RZ, r, r', r'', and ry. R0 - Dce R1 - DCe R2 - DcE RZ - DCE r - dce r' - dCe r'' - dcE ry
- dCE
Question:
11. Which Rh inheritance theory does not address gene inheritance but instead reports only serological
findings or phenotype by numbering the AGNs? How are they numbered?
Answer:
Rosenfield terminology. D - 1 C - 2 E - 3 c - 4 e - 5
Question:
12. What is the actual genetic makeup of an individual? What is the outward expression of genes?
Answer:
Genotype. Phenotype.
Question:
13. What is used to determine Rh or phenotype?
Answer:
5 antisera - Anti-D, anti-C, anti-E, anti-c, and anti-e.
Question:
14. If a red cell is typed as D+, C+, E=, c+, and e+, what is the phenotype?
Answer:
DCce.
, Question:
15. What causes a weak expression of the Rh or D AGN? What happens if a patient has a weak D
expression and the typing sera is added?
Answer:
The D AGN is highly pleomorphic; the patient can have the D AGN but have it in a reduced amount or
have it with an altered structure that reduces its strength. The typing sera might attach or sensitize to RBCs
but will fail to agglutinate and will require additional testing.
Question:
16. What are the 3 most common causes of a weak D antigenic expression?
Answer:
Genetic causes - patient may inherit a weakened expression of the D AGN causing them to have fewer
AGNs on each red cell. This can happen is you are heterozygous for the Rh or D AGN, weakening its
expression. Cis/trans effect (position effect) - C inherited in the trans position opposite to D; C and D are
on opposite chromosomes. D mosaic (partial D) - there is a missing part of the typical antigenic structure
of the D complex; an alloantibody is made that appears to be anti-D after exposure to D-pos RBCs.
Question:
17. What is the strongest D AGN genotype?
Answer:
R2R2
Question:
18. What should be suspected if a D-pos individual makes anti-D that is non-reactive with his/her own
cells?
Answer:
Partial D phenotype is most likely but can be 2 different manufacturer's monoclonal anti-D reagents are
used on the interpretation as D pos or D neg; does not agree.
Question:
19. What type are weak D pos individuals? What type of blood do they receive? What must all Rh neg
blood have done to it? What do weak D mothers receive?
Answer:
They are Rh pos even though their expression is weak. They may receive Rh pos blood. If they were to
give blood, their blood would be labeled Rh pos; all Rh neg blood must have a weak D test performed to
confirm. Weak D mothers DO NOT receive RhIG.
Question:
20. What is the Rh system necessary for proper functioning of the RBC membrane? What is the
phenotype? What are the mechanisms that produce it? What do cells that are RhNull demonstrate?
QUESTIONS AND CORRECT ANSWERS
Question:
1. What is the second most important blood bank system after ABO and what are the 5 principal antigens?
When Rh is referred to, what is most commonly being talked about?
Answer:
Rh blood group system. D, C, E, c, and e. The D antigen is typically called the Rh factor.
Question:
2. Who first recognized the Rh blood group in 1939 and how was it named?
Answer:
Landsteiner and Weiner; Rh was the name given because of the similarity of this ABY to one made by
rabbits and guinea pigs that reacted with rhesus monkeys cells. It agglutinated with 85% of human RBCs.
Question:
3. What is the most important Rh antigen? What is important to know about this one?
Answer:
D antigen, it is very antigenic. Antibodies will be produced with exposure to even the smallest amount of
D AGN. Antibodies to the D AGN are one of the most clinically significant in blood bank, because they
are a major concern for both blood transfusions and HDN because they are classified as IgG and can cross
the placenta.
Question:
4. When classifying ABO and Rh antibodies, what are the major comparison differences?
Answer:
ABO is classified as IgM, acquired by bacterial or pollen ingestion. ABO also reacts at RT and are
antibodies present under normal conditions. Rh is classified as IgG, acquired through immunization due to
pregnancy or transfusions. Rh reacts at 37 C and requires incubation and must have been formed by
previous exposure.
Question:
5. What is the most widely accepted theory that describes inheritance of Rh?
Answer:
Two closely linked genes (loci) on chromosome 1. RHD and RHCE.
Question:
6. What does RHD and RHCE do?
Answer:
RHD determines the D AGN expression on RBCs. RHCE determines the C, c, E, e expressions that can be
CE, Ce, cE, and ce.
Question:
7. Which alleles are co-dominant? What represents the D allele? What represents the absence of the D
allele?
,Answer:
C and c & E and e. D presence. d absence.
Question:
8. What is the frequency of the D AGN and the absence of the D AGN (d)?
Answer:
D - 85%. d - 15%
Question:
9. What is the Fisher-Race Rh terminology?
Answer:
It is the DCE terminology; it states that AGN production is controlled by 3 sets of closely linked (3 loci)
genes located on the same chromosome and that each gene produces an AGN. There is a gene that controls
D and d, a gene that controls C and c, and a gene that controls E and e.
Question:
10. What is the Wiener terminology? How many alleles exist at the Rh gene locus with this theory? What
are these alleles and how do they convert to the Fisher-Race terminology?
Answer:
It is the Rh-Hr terminology; it states that a single gene at the Rh locus codes for a series of factors or the
AGNs. Each parent contributes one Rh gene and can be inherited as homozygous or heterozygous. 8
alleles - R0, R1, R2, RZ, r, r', r'', and ry. R0 - Dce R1 - DCe R2 - DcE RZ - DCE r - dce r' - dCe r'' - dcE ry
- dCE
Question:
11. Which Rh inheritance theory does not address gene inheritance but instead reports only serological
findings or phenotype by numbering the AGNs? How are they numbered?
Answer:
Rosenfield terminology. D - 1 C - 2 E - 3 c - 4 e - 5
Question:
12. What is the actual genetic makeup of an individual? What is the outward expression of genes?
Answer:
Genotype. Phenotype.
Question:
13. What is used to determine Rh or phenotype?
Answer:
5 antisera - Anti-D, anti-C, anti-E, anti-c, and anti-e.
Question:
14. If a red cell is typed as D+, C+, E=, c+, and e+, what is the phenotype?
Answer:
DCce.
, Question:
15. What causes a weak expression of the Rh or D AGN? What happens if a patient has a weak D
expression and the typing sera is added?
Answer:
The D AGN is highly pleomorphic; the patient can have the D AGN but have it in a reduced amount or
have it with an altered structure that reduces its strength. The typing sera might attach or sensitize to RBCs
but will fail to agglutinate and will require additional testing.
Question:
16. What are the 3 most common causes of a weak D antigenic expression?
Answer:
Genetic causes - patient may inherit a weakened expression of the D AGN causing them to have fewer
AGNs on each red cell. This can happen is you are heterozygous for the Rh or D AGN, weakening its
expression. Cis/trans effect (position effect) - C inherited in the trans position opposite to D; C and D are
on opposite chromosomes. D mosaic (partial D) - there is a missing part of the typical antigenic structure
of the D complex; an alloantibody is made that appears to be anti-D after exposure to D-pos RBCs.
Question:
17. What is the strongest D AGN genotype?
Answer:
R2R2
Question:
18. What should be suspected if a D-pos individual makes anti-D that is non-reactive with his/her own
cells?
Answer:
Partial D phenotype is most likely but can be 2 different manufacturer's monoclonal anti-D reagents are
used on the interpretation as D pos or D neg; does not agree.
Question:
19. What type are weak D pos individuals? What type of blood do they receive? What must all Rh neg
blood have done to it? What do weak D mothers receive?
Answer:
They are Rh pos even though their expression is weak. They may receive Rh pos blood. If they were to
give blood, their blood would be labeled Rh pos; all Rh neg blood must have a weak D test performed to
confirm. Weak D mothers DO NOT receive RhIG.
Question:
20. What is the Rh system necessary for proper functioning of the RBC membrane? What is the
phenotype? What are the mechanisms that produce it? What do cells that are RhNull demonstrate?
