Chapter 18 - Practical Applications of Immunology Flashcards
(45 cards)
What are some comon practical applications (uses) of immunology?
- Vaccination: inject Ag to trigger immune repsonse (make Ab)
- Serological Testing: test PT blood (serum) and look for Ag OR Ab (IgM) = timely and accurate diagnosis
Briefly describe how Vaccination works in regards to primary and secondary immune responses
- Injection of Ag will provoke a primary immune reponse -> formation of memory B cells and Ab (after clonal sel and exp)
- Will produce rapid, intense secondary immune response
A substance (Ag) that stimulates the immune system is known as a…
immunogen
This is described as protection for most of the population
Herd Immunity
Name 5 desirable characteristics for an ideal vaccine. Describe each
SEOOA
1. Vaccine Safety
- Vaccine must never be pathogenic/toxigenic
2. Vaccine Effectiveness
- Vaccine must be a strong immunogen (ex. protein) and stimulate immune system
3. Vaccine with Oral Administration
- Orally (painless) > injectable (painful)
4. Vaccine Require One Injection
- One injection/combination vaccine preferred (PT less likely to come back if req. multiple injection)
5. Vaccine is Affordable/Easily Accessible
- Availiable to most people @ resonable cost
Name the different Types of Vaccines (6)
- Live, attenuated vaccine
- Inactivated, killed vaccine
- Toxoid vaccines
- Conjugated vaccines
- Subunit vaccine
- mRNA (nucleic acid) vaccine
Compare these Types of Vaccines: Live, attenuated vaccine vs. Inactivated, killed vaccine
Include examples of DZ that use these types of vaccine
Live, attenuated vaccine
- Weakened pathogen
- Closely mimic actual infection (bc inj. Ag is still alive)
- Ex: MMR, Smallpox
Inactivated, killed vaccine
- Killed pathogen
- Safer (compared to live vaccines)
- Ex: Influenza, Polio
Describe: Toxoid vaccines, Conjugated vaccines, Subunit vaccines, mRNA (nucleic acid) vaccines
Toxoid vaccines
- inactivated toxin (make Ab against toxoid = antitoxin)
- immune response will target toxin
- Ex: Td vaccine
Conjugated vaccines
- main vaccine component is combined with a strong immunogen (protein)
- Ex: Pneumonia vaccine
Subunit vaccines
- Use antigenic fragments (piece of pathogen CW) to stimulate immune response
- Ex: Petussis vaccine; Hep. B vaccine
mRNA vaccines
- inject only bacterial/viral nucleic acid (NOT live pathogen)
-> inject mRNA into host cell -> make protein Ags -> stimulate immune response to make Ab - Ex: Covid vaccine
What part of the blood sample is being tested?
serum (no CF; top part)
YOU ARE NOT SAMPLING THE PLASMA (has CF)
When using serological testing, what are we looking for? (Hint: Theres two things we could look for)
Antigen or Antibody (IgM)
This is the study or diagnositc examination of blood serum (to see how the immune system response to pathogens or substances introduced into the body)
Serology
Name 5 desirable criteria for an ideal serological test
- High specificity/accuracy
- High sensitivity
- East set-up & interpretation
- High Throughput
- Affordable cost and Easy Access
Describe the criteria for an ideal serological test
High specificity/accuracy
- Unambigious (one interpretation)
- Reliable (100% accuracy)
- Ex: Pregnancy test; HIV test; athlete drug doping test
High sensitivity
- Uses small sample size = detect small quantities Ag or Ab
East set-up & interpretation
- test construction simple
- results easy to read (ex: color change; + or - symbol)
High Throughput
- Many tests carried out at once (bc machine automation) = fast results
Affordable cost and Easy Access
- Avalibale to most people @ reasonable cost
Define: Throughput
ability to stimultaneously test hundreds/thousands of samples
There are two types of serological tests. Name them and describe what you are looking for
Two Tests:
Direct Serological Test
- Look for Ag (pathogen)
Indirect Serological Test
- Look for Ab (IgM)
An antigen or antibody is provided either by the _____ sample or the ______ ______
patient
lab test
Understand what a serological test will have and what the PT serum sample would have to provide
If serological test has Ag, the PT serum sample will provide the Ab
If serological test has the Ab, the PT serum sample wil provide the Ag
Name (6) common examples of serological testing
- Precipitation Reactions
- Agglutination Reactions
- Neutralization Reactions
- Fluorescent-Antibody Technique
- Complement-Fixation Reactions
- ELISA
Describe this example of serological testing: Precipitation Reactions
Include: Types of testing avaliable, Component involved (Ag/Ab), Interpretation of Results (What does the PT/Lab provide, Know what a positive/negative test looks like), Clinical Applications
Types of Testing Avaliable
- Direct Tests
- Indirect Tests
Component involved (Ag/Ab)
- Ag: soluble antigens (not attached to pathogen)
- Ab: IgG/IgM
Interpretation of Results
POSITIVE Direct Test:
- PT (serum sample) provide: Ag
- Lab provide: Ab
- PT provide soluble Ag -> Ab (lab) binds to Ag (PT) -> immune complex forms -> precipitan ring at equivalence zone = PT HAS DZ
POSITIVE Indirect Test:
- PT (serum sample) provide: Ab
- Lab provide: Ag
- PT provide Ab -> Ab (PT) binds to Ag (lab) -> immune complex forms -> precipitan ring at equivalence zone = PT has DZ
Clinical Applications
- VDRL Test
-> Blood test for Syphilis only
-> Look for PT Ab (against T. pallidum) = Indirect test - Lancefield Classification of Streptococcal Species
-> Classifies streptococci into groups from A-K and H-U (ex: GAS, GBS, GCS)
-> Helps distinguish between different species of Genus Streptococcus
In regards to precipitation reactions, just by looking at a test tube, how would you tell a PT has a disease?
immune complexes form at equivalence zone, where a precipitan ring is present.
precipital ring = cloudy line (immune complex present) where 1:1 ration of Ag to Ab
Describe this example of serological testing: Agglutination Reactions
Include: Types of testing avaliable, Component involved (Ag/Ab), Interpretation of Results (What does the PT/Lab provide, Know what a positive/negative test looks like), Clinical Applications
Types of Testing Avaliable
- Direct Tests
- Indirect Tests
Component involved (Ag/Ab)
- Ag: particulate antigens (attached to pathogen)
- Ab: IgM
Interpretation of Results
POSITIVE Direct Test:
- PT (serum sample) provide: Ag
- Lab provide: Ab (IgM)
- Ag and IgM present = immune complex = clumping = POSITIVE TEST
POSITIVE Indirect Test:
- PT (serum sample) provide: Ab
- Lab provide: Ag
- Ag cand IgM present = immune complex = clumping = POSITIVE TEST
Clinical Applications
- Hemaggulitnation
-> For blood typing; Agglutination of RBC surface Ag & complimentary Ab - Antibody Quantitation
-> measuring Ab titer
-> Differentiate bw primary (high IgM) & secondary (high IgG) exposure
Know how to tell what blood type you have in regards to hemagglutination.
Ex: If you have two wells, one with anti-A Ab and one with anti-B Ab, what would you observe you placed a PT serum sample who has Type A blood into these two wells (hint: which wells would clump)?
Type A:
- Anti-A well: clumping
- Anti-B well: x
Type B:
- Anti-A well: x
- Anti-B well: clumping
Type AB:
- Anti-A well: clumping
- Anti-B well: clumping
Type O:
- Anti-A well: x
- Anti-B well: x
Describe this example of serological testing: Neutralization Reactions
Include: Types of testing avaliable, Component involved (Ag/Ab), Interpretation of Results (What does the PT/Lab provide, Know what a positive/negative test looks like), Clinical Applications
Types of Testing Avaliable
- Indirect Tests
Component involved (Ag/Ab)
- Ag: Toxin/Virus
- Ab: Antitoxin/Antivirals
- Cell Indicator
Interpretation of Results
Toxin Neutralization Test: + Indirect Test:
- PT (serum sample) provide: Ab
- Lab provide: Ag (toxin) & cell indicator
- PT serum sample (has Ab) -> lab adds Ag and cell indicator -> PT Ab and Lab Ag form immune complex -> toxin is neutralized -> cell indicator is UNDAMAGED -> PT HAS DZ
- IF NEGATIVE: PT serum sample does NOT have Ab -> Lab adds Ag and cell indicator -> no Ab (PT) present -> toxin not neutralized -> toxin attack cell indicator -> cell indicator damage -> PT DOES NOT HAVE DZ
Viral Hemaggulitnation Inhibition Test: + Indirect Test:
- PT (serum sample) provide: Ab
- Lab provide: Ag (virus) & cell indicator (RBC)
- Pt serum sample (has Ab) -> lab adds Ag (virus) and cell indicator (RBC) -> PT Ab bind to lab Ag (virus) -> virus neutralized -> hemagglutinatoin inhibited -> NO CLUMPING -> PT HAS DZ
- IF NEGATIVE: PT serum sample (NO Ab) -> lab adds Ag (virus) and cell indicator (RBC) -> no Ab (PT) present-> virus not neutralized -> hemagglutinatoin of RBC ->YES CLUMPING -> PT DOES NOT HAVE DZ
Clinical Applications
- DX of bacterial disease (toxin production)
- DX of viral disease
Describe this example of serological testing: Fluorescent Antibody Reactions
Include: Types of testing avaliable, Component involved (Ag/Ab), Interpretation of Results (What does the PT/Lab provide, Know what a positive/negative test looks like), Clinical Applications
Types of Testing Avaliable
- Direct Tests
- Indirect Tests
Component involved (Ag/Ab)
- Ag: Streptococci or T. Pallidum
- Ab: Fluorescent Ab or Anti-human Ab
Interpretation of Results
POSITIVE Direct Florescent-Antibody (FA) Test:
- PT (clinical/throat sample) provides: Group A streptococci (Ag)
- Lab provides: Fluorescent-Dyed Ab
- PT sample (has Group A streptococci Ag) -> lab adds fluorescent-dyed Ab -> Immune complex forms -> Fluorescent Streptococci (chains)-> POSITIVE, PT has DZ
- IF NEGATIVE: No fluorescent streptococci (chains)
POSITIVE Indirect Florescent-Antibody (FA) Test:
- PT (serum sample) provides: Ab
- Lab provide: T. pallidum (Syphilis) & Fluorescent Antihuman Ab (Ab that binds to human Ab)
- PT sample (has Ab against T. Pallidum) -> Lab adds Ag (T. pallidum) and Fluorescent Anti-human Ab -> Immune complex forms -> Fluorescent Antihuman Ab binds to PT Ab of immune complex-> fluorescent T. pallidum (spiral) -> POSITIVE, PT has DZ
- IF NEGATIVE: No flourescent T. pallidum (spiral)
Clinical Applications
- Identify GAS from throat sample (direct FA test)
-> Ex: diagnose strep throat/scarlet fever by looking for streptococcus pyogenes - See if T. pallidum from PT blood is producing Ab (indirect FA test)
-> Used to diagnose Syphilis