Studied by 14 peopleGenetically encoded antigen system on the Erythrocytes, Leukocytes, Thrombocytes & Plasma
Blood group antigens
Enumerate the characteristics of Blood group antigens
Glycolipids (ABO)
Glycoproteins (Lewis Antigen)
Term for macromolecules capable of triggering an adaptive immune response by inducing the formation of antibodies
Immunogen
Term for small molecules that stimulate an immune response & is a partial antigen
Hapten
Enumerate the parts of an Immunogen
Hapten
Carrier
Enumerate the adaptive responses of Immunogens
Induce formation of antibodies
Sensitize T cells in an immunocompetent host
What complex determines the Human Leukocyte Antigen (HLA)?
Major Histocompatibility Complex (MHC)
Most Immunogenic Blood Group
A, B
2nd most Immunogenic Blood Group
Rh, D
If you have D antigen = ?
Rh positive (+)
If you DON'T have D antigen = ?
Rh negative = (-)
Enumerate the Immunogenicity of Blood Antigens
A, B
Rh, D
Kell (K)
Duffy (Fya)
Common Rh antigens
A foreign substance that reacts with antibody
Antigen
How long before a Transfusion reaction occurs with an incorrect blood type?
10-15 minutes
Antigenic property; Exact binding site of antigen to antibody
Epitope
Where can Epitopes be found?
Antigen
Exact binding site of antibody to antigen
Paratope
Where can Paratopes be found?
Antibody
Enumerate the Traits of an Immunogen
Macromolecular size
Chemical composition and molecular complexity
Foreigness
Ability to be processed and presented with MHC molecules (Antigen presentation)
Type of Epitope that consists of sequential amino acids on a single polypeptide chain
Linear Epitope
Type of Epitope that results from the folding of 1 or more polypeptide chains
Conformation Epitope
Term for an antigen that occurs in less than 1% of the population
Low incidence
Term when an antigen occurs in 99% of the population
High incidence
Products of antigenic stimulation and that demonstrate specific antibody activity
Antibodies/Immunoglobulins
AKA Gamma globulins
Antibodies/Immunoglobulins
What bond is present between chains in the antibody?
Disulfide bond
Blood Group Immunoglobulin that reacts with an antigen on the patient's own cells
Autoantibody
Blood Group Immunoglobulin that reacts with foreign antigen not present on the patient's own erythrocytes
Alloantibody
Enumerate the 2 types of Alloantibodies
Natural
Product of Immunization
What is the product of immunization to foreign erythrocyte by exposure through transfusion or pregnancy?
Immune antibodies
Enumerate Immunoglobulin classes from most predominant to least? (GAMDE)
IgG
IgA
IgM
IgD
IgE
Enumerate the 2 types of monomeric antibodies that can be produced from a polymeric antibody
2-mercapthoethanol (2-ME)
Dithiothreitol (DTT)
Effect of Papain in a monomer
Cut monomer exactly at the hinge region and into 3 parts
Effect of Pepsin in a monomer
Cut monomer below the
Enumerate the factors that influence Antigen-Antibody reaction
Antigen-Antibody Ratio
pH
Temperature
Immunoglobulin type
Centrifugation
Effect to Ab-Ag ratio if it is a Homozygous concentration
Strong Ab-Ag reaction
Effect to Ab-Ag ratio if it is a Heterozygous concentration
Weak Ab-Ag reaction
Optimal pH level for Ag-Ab reaction
6.5-7.5
Temperature used to detect IgG
37C
Temperature used to detect IG
Room temperature
Reagents that enhance the detection of IgG antibodies by increasing their reactivity
Enhancement medium/ Potentiator
Substance that increases dielectric constant which reduces zeta potential of RBC
Protein media
Most commonly used protein media
22%/33% Bovine Serum
Polyethylene Glycol (PEG)
Potentiator that removes water molecules in the environment
Polyethylene glycol (PEG)
Incubation time of PEG
15-30 minutes
Most commonly used Potentiator
Low Ionic Strength Solution (LISS)
Incubation time for LISS
5-15 minutes
Potentiator that targets the sialic component
Proteolytic enzymes
Test that detects antibodies and complement proteins that have attached to the RBC
Antihuman Globulin test
What animal is used to inject human serum into to produce antihuman serum?
Rabbits
Enumerate the types of Antiglobulin Tests
Direct Antihuman Globulin (DAT)
Indirect Antihuman Globulin (IAT)
Antiglobulin test that detects in vivo sensitization of RBC with complement components
Direct Antihuman Globulin (DAT)
Antiglobulin test that detects in vitro sensitization of RBC
Indirect Antihuman Globulin (IAT)
Enumerate the factors that affects AHG Test
Cell : Serum ratio (1:30)
Reaction medium
Temperature
Incubation time
Washing
Centrifugation (1,000 RCF for 20 mins)
Enumerate AHG Test Reagents
Polyspecific AHG, Monospecific AHG
Causes of False-Positive AHG Test results
Over centrifugation
Direct agglutination by strong cold agglutinins
Over incubation with enzyme treated cells
Improper use of PEG or polycation enhancement reagents
Inadequate resuspension of cell button
Rouleaux formation
Dirty glassware
Small fibrin clots may traps cells and mimic agglutination
Cells with a positive DAT will yield false-positive results in any indirect antiglobulin test
Causes of False-Negative AHG Test results
AHG reagent failure
Failure to add AHG reagents
Improper or inadequate washing
Delayed washing
Cell : Serum ratio too low
Failure to add test serum or enhancement reagents
Under centrifugation
Resuspension of cell button too vigorous
Enumerate & differentiate the 3 positive reactions in Blood Bank
Agglutination
Hemolysis
Precipitation
Agglutination
Antibody-mediated clumping of particles that express antigen on the surface
Hemolysis
Rupture of Red cells with release of intercellular hemoglobin
Precipitation
Formation of insoluble complex from soluble antigen-antibody reaction
Appearance of RBC like a stack of coins
Rouleaux
Note
Flashcard