Immunologic Principles Flashcards
What is the study of the immune system?
Immunology
WHat is the study of blood group specific Ags and Abs?
Immunohematology
What is the definition of blood banking?
It is the collection, processing, storage, preservation & proper disposal of blood for donation
What is the other term for antigen?
Immunogen
What is the substance that binds w/ Ab?
Antigen or Immunogen
What are the factors affecting immunogenicity?
Foreignness Chemical complexity High molecular weight Digestibility Dosage and route of administration Accessibility of reactive sites
This is the portion of the Ags that bind to Ab or TCR?
Epitope
This is the low molecular weight molecule that is too small to stimulate immune response but can combine w/ another molecule to induce response?
Hapten
What are adjuvants?
These are compounds that enhance immune response.
What is the difference between auto and alloantigens?
Autoantigens belong to the host, while alloantigens are from other members of the host’s species
What is the relationship of antigens called when antigens are from other species?
Heteroantigens
These antigens are unrelated plants or animals but identically related in structure?
Heterophile Ags
TRUE OR FLASE:
RBC Ags dictates the blood type/group of an individual
TRUE - it is detected through DIrect Hemagglutination reaction
What are the three methods of agglutination reaction?
Slide, Tube, and Gel method
Which among the three methods qualitatively test for reaction?
Slide method
Which method is the LEAST SENSITIVE?
Slide method
A 2+ grade in tube method has _______ clumps and _____ supernatant
medium sized clumps and turbid, red supernatant
Who discovered the gel method?
Dr. Yves Lapierre in Lyon France
This method is known as an immunological technique in which either an Ag or Ab is immobilized onto a solid medium?
Solid phase red cell adherence (SPRCA)
This Ag is found in the short arm of chromosome no. 6
HLA (Human leukocyte Ag)
TRUE OR FALSE:
Antibodies are also known as immunoglobulins
TRUE
Monomer
basic functional and structural unit of Ab
These are produced in response to antigenic stimulation
Antibodies
TRUE OR FLASE:
Antibodies are carbohydrates
FALSE - they are glycoproteins
TRUE OR FALSE:
All immunogens are not antigens, but all antigens are all immunogens
FALSE
All immunogens are antigens, but not all antigens are immunogens
This factor that affects immunogenicity where in it is considered as non-self
Foreigness
TRUE OR FALSE:
the more complex the Ag, the more immunogenic
TRUE
TRUE OR FALSE:
Not all parts of the immunogen are recognized
TRUE
Which cells present substances to the immune system?
APCs
What is the fastest route of administration to be able to have an immune response?
IV or intravenous
What is the counterpart of an epitope that is found on the Ab?
Paratope
Using the gel method, what is the gel used for ABO or Rh typing?
Polyacrylamide gel
Using the gel method, what is the gel used for crossmatching?
Neutral gel cards (has NO anti-sera)
What are the advantages of gel method?
There is standard reading, small sample size, results stable for 3days
What are the disadvantages of gel method?
Costly because of reagents, need special centrifuge
How many RCS is needed for gel method?
25-50uL or 1-2 drops
What is the most sensitive method of agglutination reaction?
Gel method
TRUE OR FALSE:
Bigger agglutinates settle at the bottom
FALSE
Big agglutinates cannot pass through, and will settle at the top resulting to a 4+ grading
Using the SPRCA, if you want to detect Ag, you will immobilize _______________
Antibody
Who discovered SPRCA?
Plapp and coworkers in 1984
TRUE OR FALSE:
SPRCA is used to improve sensitivity and specificity?
TRUE
TRUE OR FALSE:
MHC/HLA plays a major role in innate immunity only
FALSE:
It also plays a major role in humoral immunity
This is defined as the unresponsiveness to platelet transfusion
Platelet refractoriness
What cells produce antibodies?
Plasma cells differentiated from B-cells
Antibody is made up of 4 chain polypeptide that is held together by ____________
noncovalent forces and disulfide bond/linkage
The two light chains are: ________________________
kappa and lambda, found in chromosome 2 and 22 respectively
Which region of the heavy chain is Ag binding site found?
Variable region
This chain dictates the type of Ab produced?
Heavy chain
Positively charged Ab is found in the __________ terminal end
Amino terminal end
Negatively charged Ab is found in the ___________ terminal end
Carboxy terminal end
What are the most commonly encountered Abs in blood bank?
IgM, IgG, and IgA
Which fragment of the variable region binds with Ag?
Fab
Which fragment of the constant region binds with host’s cell?
Fc/ crystallizable fragment
What substance is responsible to bend and reach Ag?
Proline
What are the fragments formed in papain digestion?
2 Fab, 1 Fc
Which enzyme cleave IgG at the carboxyterminal end?
Pepsin
What are the fragments form in pepsin digestion?
1 Fab, 1 Fc
Which immunoglobulin has J-chain?
IgM
TRUE OR FALSE:
IgG is capable of crossing the placenta which can lead to HDN
TRUE
Where does clearance of red cell with IgM?
Intravascular
IgM is detected in what phase?
Immediate spin phase
IgG is detected in what phase?
AHG Phase
TRUE OR FALSE:
Both IgG and IgM activates the classical pathway
TRUE
What is the term that defines the number of binding sites?
Valence
Which immunoglobulin has the highest concentration?
IgG
Which immunoglobulin has the highest half-life?
IgG
Which immunoglobulin has the largest molecular weight?
IgM
What are the opsonins in complement activation?
C3b (most of the time) C4b, C5b for phagocytosis
What is the chemotaxin in complement system?
C5a
What is the anaphylatoxin in complement system?
C3a, C4a, C5a
What is the MAC formed that promotes cell lysis?
C5b6789
What is the requirement to activate antibody dependent pathway?
1 IgM molecule or 2 IgG molecules
What are the 3 pathways of complement system?
Classical, Properdin or alternative, and lectin or mannose-binding lectin pathway
What is the common goal of the three complement pathways?
Cell lysis or create membrane attack complex
where does the three complement pathway meet?
C3
If there is a complete hemolysis, the supernatant is ______________________ with ________ cell button
Clear to red with NO cell button
If there is a partial hemolysis, the supernatant is ______________________ with ________ cell button
Pink to red, presence
If there is no hemolysis, the supernatant is ______________________ with ________ cell button
Clear, presence
TRUE OR FALSE:
All antigen-antibody reactions are governed by Law of Mass of Action
TRUE
TRUE OR FALSE:
Law of mass of action states that Ag-Ab reaxn are IRREVERSIBLE
FALSE
It is reversible
What is the definition of affinity?
it is the initial force of attraction between single binding sites
What is avidity?
it is the sum of all forces of attraction between multivalent Ags and Abs
this is defined as the antibody’s characteristic where it will only react to the Ag that caused its production
Specificity
This intermolecular forces bind in 2 polar substances?
Hydrogen bonds
Antibodies are __________ charged
Positive
Antigens are ________ charged
Negative
Ionic bonds exist between _____________________
oppositely charged particles (Neg/Pos)
Hydrophobic bonds exist between ___________________
2 non-polar substances
Hydrogen bonds are weaker than _________________ but stronger than __________________
Ionic bonds, Van der Waals Forces
Van der Waals Forces exist between __________
electron clouds
Define agglutination
It is the aggregation of particles caused by the binding of Ag and Ab
What are the antibodies called that cause agglutination?
Agglutinins
What are examples of particles that participate in agglutination reaction?
RBC, bacteria, latex particles (inert carriers)
what are the two steps of agglutination?
Sensitization and lattice formation
TRUE OR FALSE:
Sensitization is REVERSIBLE
TRUE
Agglutination becomes visible when it is done with _______________
lattice formation
Lattice formation is _______________
the formation of larger aggregates of the Ag-Ab complex
Sensitization is ____________
the initial binding of antibodies to antigens
What is the ideal serum to cell ratio?
40:1
How to achieve the ideal serum to cell ratio?
Add 2 drops of Ab and 1 drop of Ag
What is zone of equivalence?
It is where the concentration Ab and Ag is equal
TRUE OR FALSE:
INC in concentration of Ab will DEC the probability of collision of events
FALSE
There will also be a INC of the probability of collision of events
What is the incubation time for albumin?
30 mins
What is the incubation time for LISS?
15 mins
TRUE OR FALSE:
Incubation time must be followed to avoid zone of equivalence
FALSE
Zone of equivalence must be achieved
Which immunoglobulin reacts at room temperature?
IgM
Which immunoglobulin reacts at warm temperature or 37 deg C?
IgG
What is the ideal pH?
6.7 to 7.2 (7.0)
TRUE OR FALSE:
DEC ionic strength DEC zeta potential
TRUE
What is the medium used to decrease ionic strength?
LISS (low ionic strength saline)
If the zeta potential is INC this may lead to ____________
easier agglutination = intravascular hemolysis
What are the factors affecting lattice formation?
Zeta potential, Ab-Ag concentration, centrifugation
What is the action of 22% bovine serum albumin?
It neutralizes the negative charge on RBC
What is the action of PEG or polyethylene glycol?
removes water and hydrophilic bonds
Which enhancement media is the best?
PEG or polyethylene glycol
Which enhancement media decreases incubation time?
LISS
This enhancement media enhance or destroy RBC Ags
Enzymes
What are the examples of enzyme enhancement media?
Papain, Ficin, Bromelin
What substance make negative charge for zeta potential?
Sialic Acid
Post-zone is ___________
Ag excess
Pro-zone is __________
Ab excess
If there is a prozone or postzone, what could be the result?
False NEGATIVE
What is the most commonly used sample in blood bank?
Red cell suspension (2-5%)
What is the formula for %RCS?
= (Amount of washed RBC/total volume)x100
What is the effect of centrifugation?
it decreases reaction time by promoting cell-to-cell contact
Lattice formation only occurs if Ab-Ag concentration is ____________
equal
What is the most effective method to enhance reaction?
Centrifugation