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84 Cards in this Set
- Front
- Back
Which antibodies have the most significance for blood banking? |
IgM, IgG, and IgA. |
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What is the most clinically significant antibody that reacts at body temp? (37 degrees) |
IgG. |
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Which Ig is the most common cold agglutinin and what temp does it react at? |
IgM, 22 degrees Celsius. |
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Most common naturally occurring antibody |
IgM. |
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Most abundant Ig in serum and why is it most significant? |
IgG because it reacts at body temp. |
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Which Ig is in pentomere form and how is it dissociated? |
IgM. Through cleavage of covalent bonds interconnecting mononeric subunits and J chain by chemical treatment with 2ME. |
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Largest Ig |
IgM. |
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Largest Ig |
IgM. |
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Which Ig comes first in immune response? |
IgM, then IgG. |
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Which Ig crosses placenta? |
IgG. |
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When do infants begin to produce antibodies? |
6 months. |
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Rh is primarily _____ and _____ subclasses. |
IgG1 and IgG3. |
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Why don't rh antigens bind with complement? |
Low level of rh on RBC surfaces. |
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Antibodies to the Lewis blood group system are generally ___. |
IgM. |
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Antibodies to the Lewis blood group system are generally ___. |
IgM. |
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Activation of complement by Lewis blood group system. |
Can activate complement, but rarely cause hemolytic transfusion reactions due to their low optimal reactivity temp. |
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Complement activation by IgG |
Less effective than IgM due to less binding sites. |
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When complement in serum attacks donor cells, what is seen? |
Instead of agglutination, hemolysis is seen. |
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What is the immune response initiated by? |
Presentation of an antigen or immunogen. |
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Antigen |
Initiates formation of and reactions to antibodies. |
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Antigen |
Initiates formation of and reactions to antibodies. |
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Antigen characteristics influencing immune response |
Size, complexity, confirmation, charge, accessibility, solubility, digestibility, chemical composition, and molecular weight. |
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How do different blood group antigens differ in their immunogenicity? |
They have different characteristics. |
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Antisera |
Reagent antibodies. |
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Polyclonal antibodies |
Aka serum antibodies. Produced in response to a single antigen with more than 1 epitope. |
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Polyclonal antibodies |
Aka serum antibodies. Produced in response to a single antigen with more than 1 epitope. |
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Monoclonal antibodies |
Produced by isolating individual B cells from a polyclonal population with hybirdoma technology. |
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Why are monoclonal antibodies preferred in testing? |
Highly specific and well characterized. |
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Naturally occurring antibody |
Antibody formed with prior exposure to antigen such as grain, pollen, and bacteria. |
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IgM: naturally occuring |
React best at room temp, activate complement, and may be hemolytic when active at 37 degrees Celsius. |
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The most common occurring antibodies react with antigens of what blood group systems? |
ABH, Hh, Ii, Lewis, Mn, and P. |
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Most common immune antibodies encountered in testing: |
Rh, Kell, Duffy, Kidd, and Ss. |
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Immune antibodies |
Found in serum of individuals who have been transfused or who are pregnant. |
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Most immune RBC antibodies are ___ , react best at _____, and require ___ for detection. |
IgG, 37 degrees, AHG (incubate). |
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Naturally occurring anti-A and anti-B antibodies are routinely detected in ____________ and dependent on __________. |
Human serum, blood type. |
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Naturally occurring anti-A and anti-B antibodies are routinely detected in ____________ and dependent on __________. |
Human serum, blood type. |
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What antibody does blood group a have? |
Anti B. |
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Naturally occurring anti-A and anti-B antibodies are routinely detected in ____________ and dependent on __________. |
Human serum, blood type. |
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What antibody does blood group a have? |
Anti B. |
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What antibody does blood group B have? |
Anti A. |
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Naturally occurring anti-A and anti-B antibodies are routinely detected in ____________ and dependent on __________. |
Human serum, blood type. |
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What antibody does blood group a have? |
Anti B. |
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What antibody does blood group B have? |
Anti A. |
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What antibodies does blood group O have? |
Anti a and b. |
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What antibodies does blood group AB have? |
Neither antibody. |
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Unexpected antibodies |
Anything other than a/b antibodies. |
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Alloantibodies |
Produced after exposure to genetically different, or nonself antigens such as different RBC antigens after transfusion. |
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Autoantibodies |
Produced in response to self antigens. |
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How can autoantibodies be removed? |
Special absorption and Elyria. Techniques and then tested against reagent RBCs. |
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Properties of host that influence immune response |
1. Age 2. Disease 3. Exercise level 4. Genetics 5. Hormones 6. Injury 7. Nutritional status 8. Race |
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A decrease in antibody levels in older individuals may result in: |
False negative reactions, especially in reverse ABO blood typing. |
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What sample is preferred for DAT? |
Plasma because it lacks fibrin strands, which can cause a false positive. |
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Secretors |
People who have blood group antibodies in their body fluids. |
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Traditional lab methods for detecting antigens or antibody |
Hemagglutination, precipitation, agglutination inhibition, hemolysis, and other techniques. |
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Major technique used in most transfusion lab testing |
Hemagglutination. |
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Sensitization |
Stage in which antigen binding to antibody occurs. |
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Lattice formation |
2nd stage agglutination is present. |
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Agglutination inhibition |
Method in which a positive reaction is the opposite of what is normally observed in agglutination. Antigen and antibody can't combine because another substrate had been added and blocks agglutinates. No agglutination is positive. |
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Prozone |
Excess antibody. |
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Prozone |
Excess antibody. |
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Postzone |
Excess antigen. |
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Factors influencing agglutination |
Centrifugation: enhances because it decreases reaction time. Zeta potential: under centrifugation, sensitized RBCs overcome natural repulsion for each other. Increases lattice formation. Antigen-antibody ratio: ideal reactive conditions. |
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Zone of equivalence |
State of equilibrium in antigen-antibody reactions. |
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Epitope |
Unique confirmation of the antigen that allows recognition by corresponding antibody. |
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Epitope |
Unique confirmation of the antigen that allows recognition by corresponding antibody. |
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Zeta potential |
Net negative charge surrounding RBCs. |
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Factors influencing agglutination reactions |
1. Ph 2. Temp (IgM or IgG) 3. Immunoglobulin type 4. Different techniques for IgG and IgM 5. Enhancement media, especially for IgG antibodies 6. Protein media |
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LISS |
Low ionic strength solutions: reduces incubation time from 30-60 minutes to 5-15 minutes. |
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AHG |
Test designed to determine if RBCs are coated with antibody or complement or both. |
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AHG |
Test designed to determine if RBCs are coated with antibody or complement or both. |
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Polyspecific AHG |
Can determine if RBCs have been sensitized with IgG or complement (components c3b or c3d) or both. |
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How does indirect antiglobulin test detect RBCs coated with antibody? (AHG) |
Cross links sensitized cells, resulting in visible agglutination. |
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What are polyclonal reagents directed against? |
Multiple epitopes found on the original antigen used to stimulate antibody production. |
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What are monoclonal antibodies directed against? |
Specific epitopes and therefore are a potential solution. Made by hybridoma technology. |
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Advantages of monoclonal reagents |
Highly specific and characterized. Uniformly reactive and produced by hybridoma technology. |
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Disadvantages of monoclonal technology |
Overspecificity, complement may not be fixed in antigen-antibody reaction, and oversensitivity could caused false positive reactions. |
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What can immunodeficiency diseases result from? |
Various defects at many different levels of immune function and may be congenital or acquired. From innate or adaptive immunity. |
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Diseases important in blood bank serological testing |
Immunodeficiency Hypersensitivity Monoclonal and polyclonal gammopathies Autoimmune disease Hemolytic disease of newborn (HDN) |
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Hypersensitivity |
Inflammatory response to a foreign antigen and can be cell or antibody mediated, or both. |
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DAT testing |
Used to see if coated with antibody or complement. |
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Autoimmune disease |
Autoantibodies are produced against the host's own cells and tissues. |
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What can HDN result from? |
When maternal IS produces an antibody directed at an antigen present on fetal cells, but absent from maternal cells. |
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What can HDN result from? |
When maternal IS produces an antibody directed at an antigen present on fetal cells, but absent from maternal cells. |
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Which antigens cause HDN? |
ABO, Rh, snd Kell. |