/
Immunohematology Overview
Save to my account
Sign up
Immunohematology Overview
Immunohematology Essentials
Study
1
Question
What are the key components of Immunohematology as discussed in Chapter 4?
Answer
1. Genetics and Immunology of Blood Groups 2. ABO Blood Group System 3. Rh Blood Group System 4. Testing for Antibodies 5. Compatibility Testing 6. Transfusion Reactions 7. Components of Blood 8. Donors 9. Hemolytic Disease of the Newborn (HDN) 10. Serological Testing of Blood Products 11. Immunohematology Problem Solving
2
Question
What is the definition of 'phenotyping' in the context of Immunohematology?
Answer
Phenotyping refers to the physical expression of a genotype. For example, an individual with the AO genotype may phenotypically express as blood group A.
3
Question
What is the concept of 'dosage' in antibody testing?
Answer
Dosage is defined as the phenomenon where an antibody reacts more strongly with homozygous cells (e.g., KK) than with heterozygous cells (e.g., Kk). This effect is especially noted with antigens such as Kell, M, N, S, s, Fya, Fyb, Jka, Jkb, and the antigens of the Rh system.
4
Question
How do the frequencies of Duffy antigens Fya and Fyb differ among populations?
Answer
The frequencies of Duffy antigens Fya and Fyb vary significantly with race, indicating genetic diversity among different ethnic groups.
5
Question
What are the components involved in compatibility testing for blood transfusions?
Answer
Compatibility testing involves determining whether the donor's blood will react adversely with the recipient's blood. This includes: 1. ABO and Rh typing 2. Antibody screening 3. Crossmatching of donor and recipient blood samples to ensure compatibility.
6
Question
What are potential repercussions of transfusion reactions?
Answer
Transfusion reactions can lead to a variety of complications, including: - Febrile non-hemolytic reaction - Allergic reactions - Hemolytic transfusion reactions - Transfusion-related acute lung injury (TRALI) - Graft-versus-host disease (GVHD)
7
Question
What is the Fyab phenotype and its prevalence among different ethnic groups?
Answer
The Fyab phenotype occurs in almost 70% of African Americans and is very rare in whites.
8
Question
What is the Xga antigen and how is it inherited?
Answer
The Xga antigen is X-linked and is expressed more frequently in women who can inherit the antigen from either parent compared to men.
9
Question
What does it mean for an individual to have the BB genotype?
Answer
An individual with the BB genotype has inherited the B gene from both parents and is therefore homozygous for the B antigen.
10
Question
What does the genotype DCedce signify in terms of heterozygosity?
Answer
The genotype DCedce contains one C and one c gene and is heterozygous for the C and c antigens.
11
Question
Which genotype is heterozygous for C?
Answer
The heterozygous genotype for C is A. DCedce.
12
Question
What types of serological testing does a blood bank technologist perform to determine a patient's blood group?
Answer
The blood bank technologist performs phenotyping to determine the blood group of a patient.
13
Question
What is phenotyping in the context of blood typing?
Answer
Phenotyping refers to the determination of an individual’s blood group based on the antigens present on the surface of red blood cells.
14
Question
What is genotyping, and how is it different from phenotyping?
Answer
Genotyping is the process of determining the genetic makeup of an individual, particularly in relation to specific alleles, whereas phenotyping is the assessment of observable characteristics based on that genetic makeup.
15
Question
What occurs if anti-K reacts with a KK donor cell with a score of 3 and a Kk cell with a score of 2?
Answer
The antibody is demonstrating a stronger reaction to the KK cells than to Kk cells, indicating its specificity for the K antigen.
16
Question
What does a stronger reaction in serological testing indicate about the antibody?
Answer
A stronger reaction indicates higher specificity or affinity of the antibody for the particular antigen present on the cells.
17
Question
What other techniques besides phenotyping and genotyping might a blood bank technologist use?
Answer
A blood bank technologist might also use Polymerase Chain Reaction (PCR) for analyzing genetic material, particularly when genotyping is needed.
18
Question
What are the implications of being homozygous for a particular antigen?
Answer
Being homozygous for a particular antigen means having identical alleles for that antigen, which can affect blood compatibility, transfusion reactions, and the inheritance of certain traits.
19
Question
In the context of blood groups, what does the expression of antigens rely on?
Answer
The expression of blood group antigens relies on the genetic makeup of the individual, determining which antigens are present on the surface of their red blood cells.
20
Question
Why is it that women may inherit the Xga antigen more frequently than men?
Answer
Women may inherit the Xga antigen more frequently than men because they have two X chromosomes, allowing them to inherit the antigen from either parent, while men have only one X chromosome.
21
Question
What role does the Rh factor play in blood transfusions?
Answer
The Rh factor is important in blood transfusions because it can lead to immune reactions if an Rh-negative individual receives Rh-positive blood.
22
Question
What is the importance of categorizing blood types in blood banks?
Answer
Categorizing blood types in blood banks is crucial for ensuring compatibility for blood transfusions, organ transplants, and pregnancy to prevent potential adverse immune reactions.
23
Question
What is linkage disequilibrium?
Answer
Linkage disequilibrium refers to the non-random association of alleles at different loci in a given population. It occurs when the presence of one allele at a locus influences the presence of another allele at a different locus, often due to physical proximity on a chromosome and limited recombination during meiosis.
24
Question
Define homozygosity.
Answer
Homozygosity is the condition of possessing two identical alleles for a particular gene at a locus on homologous chromosomes. This means that an individual inherits the same allele from both parents for that specific gene.
25
Question
Define heterozygosity.
Answer
Heterozygosity refers to the condition of having two different alleles for a specific gene at a locus on homologous chromosomes. An individual is heterozygous when one allele is inherited from one parent and a different allele is inherited from the other parent.
26
Question
In the context of blood groups, what antigens does Carla express?
Answer
Carla expresses the blood group antigens Fya, Fyb, and Xga, which are part of the immunological system that determines blood types and compatibility.
27
Question
Why might James not express the same blood group antigens as Carla?
Answer
James may not express the same blood group antigens as Carla due to factors such as genetic variations, gender, race, or possibly medication that affects antigen expression.
28
Question
Which of the following statements is true regarding blood group genotypes? A. An individual with the O genotype is homozygous for B antigen. B. An individual with the genotype is homozygous for B antigen. C. An individual with the OO genotype is heterozygous for O antigen. D. An individual with the phenotype is homozygous for A and B antigens.
Answer
None of the statements are correct regarding blood group genotypes. Specifically: A. An individual with the O genotype is actually homozygous for O alleles (not A or B). B. An individual with the B genotype can be either homozygous (BB) or heterozygous (BO). C. An individual with the OO genotype is homozygous for O antigen, not heterozygous. D. An individual cannot be homozygous for both A and B antigens at the same time.
29
Question
What is the Bombay phenotype?
Answer
The Bombay phenotype is a rare blood type characterized by the genetic inability to produce the H antigen, which is a precursor to the A and B blood group antigens. It occurs in individuals with the genotype hh, which means they can appear to have type O blood but will not express A or B antigens.
30
Question
What genotypes will give rise to the Bombay phenotype?
Answer
The only genotype that will give rise to the Bombay phenotype is HH (homozygous for the H gene) or hh (homozygous for the non-functional allele that prevents the formation of H antigen), but individuals with hh will not express A, B, or H antigens.