Lab Exam Flashcards
What is performed if the auto control is positive?
DAT
DAT stands for Direct Antiglobulin Test.
What types of monospecific antibodies are mentioned?
- anti-lgG
- anti-lgM
- anti-lgA
- anti-C3d
- anti-C3c
These antibodies are used in the context of transfusion and immunology.
What are the two types of adsorptions used to remove autoantibodies?
- Autoadsorptions: ZZAP-treated own cells
- Alloadsorptions: paired reagent cells
Alloadsorptions are done in IBTS (Irish Blood Transfusion Service).
What may elutions be used to ascertain?
Specificity of antibody coating red cells
Elutions are used in the context of transfusion reactions and hemolytic disease.
What can nuisance antibodies be inhibited or neutralised to reveal?
Underlying alloantibodies
Nuisance antibodies may interfere with the detection of clinically significant antibodies.
What do Chido-Rogers antibodies target?
C4 complement proteins
These antibodies can be neutralised by adding excess complement (AB serum).
What do Knops-McCoy antibodies target?
CR1 molecule on red cells
These antibodies can be neutralised by the addition of recombinant KNIR reagent.
Fill in the blank: The addition of excess complement can neutralise _______.
Chido-Rogers antibodies
True or False: Elutions are only used in transfusion reactions.
False
Elutions are also used in the context of hemolytic disease of the fetus and newborn.
What is autoadsorption in the context of autoantibodies?
A method using ZZAP-treated own cells to remove autoantibodies
Autoadsorption is a technique employed in immunohematology to isolate and identify specific antibodies present in a patient’s serum.
What is alloadsorption?
A method using paired reagent cells to remove autoantibodies
Alloadsorption is done in institutions like the IBTS to help identify and characterize antibodies.
What is the purpose of elutions in transfusion medicine?
To ascertain the specificity of antibody coating red cells
Elutions help in identifying the specific antibodies that may be present on the surface of red blood cells.
What are nuisance antibodies?
Antibodies that can be inhibited or neutralised to reveal underlying alloantibodies
Nuisance antibodies may complicate serological testing and their neutralization can provide clearer results.
What do Chido-Rogers antibodies target?
C4 complement proteins
These antibodies can interfere with immune responses and are important in transfusion reactions.
How can Chido-Rogers antibodies be neutralised?
By the addition of excess complement (AB serum)
This method helps in reducing the interference caused by these antibodies during testing.
What do Knops-McCoy antibodies target?
CR1 molecule on red cells
These antibodies are significant in the context of transfusion immunology and can affect compatibility.
How can Knops-McCoy antibodies be neutralised?
By the addition of recombinant KNIR reagent (Knops Inhibition Reagent)
The use of recombinant proteins srCR1-LHR-C and srCR1-LHR-D is part of this neutralisation process.
What is the difference between phenotyping and genotyping?
Phenotyping involves serological testing; genotyping involves genetic analysis
These methods are used to identify blood group antigens and genetic polymorphisms associated with blood groups.
Fill in the blank: __________ is used to determine whether an antibody is allo or auto.
[Phenotyping]
Phenotyping helps distinguish between antibodies arising from the individual (autoantibodies) and those from another individual (alloantibodies).
What are High Frequency Antigens (HFAs)?
Antigens with an incidence of >90%, mostly >99%
HFAs are also called ‘high incidence’, ‘high prevalence’, and ‘public’ antigens.
What is the significance of lacking High Frequency Antigens?
Indicates a rare phenotype
The absence of HFAs can be clinically significant in blood transfusion.
How many red blood cell antigens are classified as HFAs by the lISBT?
189 red blood cell antigens
These antigens have varying ethnic exclusivity.
Why are routine laboratories often unable to investigate HFAs?
They are referred to a Reference laboratory
This is due to the complexity and rarity of some HFAs.
What is the purpose of antibody identification in the context of HFAs?
To assess clinical significance, exclude underlying alloantibodies, and guide transfusion decisions
Identifying antibodies helps ensure safe blood transfusions.
Fill in the blank: High Frequency Antigens are also referred to as _______.
high incidence, high prevalence, and public antigens
What are Ch/Rg?
Plasma antigens located on complement receptor C4
What is the purpose of coating cells with C4?
To increase amounts of Ch/Rg for testing
What indicates a strong reaction in coated cells?
A strong reaction is an instant indication of anti-Ch/Rg specificity
What does a comparison of coated vs uncoated cells show?
Shows the strength of the anti-Ch/Rg reaction
In the inhibition panel, if anti-Ch/Rg is inhibited, what can be inferred?
C4 in plasma can inhibit anti-Ch/Rg
What is the significance of soluble recombinant blood group proteins (sRGB)?
They determine if a suspected blood group protein is the culprit
How is the sRGB test conducted?
Incubate patient’s plasma with sRGB in parallel with a diluent control
What does diminished or eliminated reactivity in the presence of a positive diluent control indicate?
Indicates the antibody has been inhibited
What are the advantages of the MAIEA assay?
Monoclonal Antibody Immobilization of Erythrocyte Antigens
Fill in the blank: The anti-Ch/Rg can be inhibited by _______ in plasma.
C4
True or False: The MAIEA assay is used for testing erythrocyte antigens.
True
What can inhibit Anti-Ch/Rg antibodies in plasma?
C4
C4 is a component of the complement system that can inhibit certain antibodies.
What does sRGB stand for in the context of blood group testing?
Soluble recombinant blood group proteins
sRGB is used to determine if a suspected blood group protein is the cause of an antibody response.
What is the process for testing suspected blood group proteins using sRGB?
Incubate patient’s plasma with sRGB in parallel with a diluent control
This helps determine if the antibody is inhibited.
What indicates that an antibody has been inhibited during testing with sRGB?
Reactivity is diminished or eliminated in the presence of a positive diluent control
This suggests that the antibody has been inhibited by the sRGB.
What does MAIEA stand for?
Monoclonal Antibody Immobilization of Erythrocyte Antigens
MAIEA is an assay used to detect human antibodies binding to specific RBC proteins.
What is the purpose of using peroxidase-conjugated goat anti-human Ig in the MAIEA assay?
To detect human antibodies that have bound to targeted proteins
This helps confirm the presence of specific antibodies in the sample.
What type of antibodies are used in the MAIEA assay?
Monoclonal antibodies specific for suspected RBC membrane proteins
These antibodies are crucial for identifying the presence of specific antigens.
How can the MAIEA assay be used as a competitive binding assay?
To map epitopes
This allows researchers to identify specific binding sites on antigens.
True or False: The MAIEA assay can only be used for positive results.
False
The assay can also provide information about the binding characteristics of antibodies.
What does MAIEA stand for?
Monoclonal Antibody Immobilization of Erythrocyte Antigens
What is the purpose of the MAIEA assay?
To detect antibodies to high-frequency antigens in blood
Which antibodies are targeted by the MAIEA assay?
Knops, Cromer, Lutheran, Kell, Yt, and Indian System
What type of assay can MAIEA be used as for mapping epitopes?
Competitive binding assay
What does a positive result in the MAIEA assay indicate?
Human antibody has bound to the targeted protein
What is the economical benefit of using MAIEA?
Economical on plasma, achieving 83% efficiency
What additional method is mentioned for supplementary testing?
Genetic sequencing
What does serology provide clues for in genetic sequencing?
Indicates which gene to target
What type of antibodies can be identified effectively using MAIEA?
CR1-related antibodies
Fill in the blank: The MAIEA assay is particularly useful when a particular blood group system is suspected based on _______.
[enzyme studies]
What are Lu21, INFI, and INJA HEA’s in relation to MAIEA?
They were discovered with the help of MAIEA
