ch 19 Disorders associated with Immune system Flashcards
What is hypersensitivity?
immune system is functioning and targeting normally but is giving an undesirable response (excessive)
What is autoimmunity?
Immune system is functioning normally but is targeting abnormally (ends up attacking “self” cells and tissues)
Is the immune system functioning normally during hypersensitivity?
Yes, but inducing an excessive response
Is the immune system functioning normally during autoimmunity?
No, self-cells are mistakenly being attacked
what are the four types of hypersensitivity?
Type 1: anaphylactic hypersensitivity
Type 2: cytotoxic hypersensitivity
Type 3: Immune complex hypersensitivity
Type 4: delayed hypersensitivity
What happens in the body when hypersensitivity Type 1 occurs?
What causes it?
How long does it take to occur?
anaphylactic hypersensitivity:
- anaphylactic shock
- Caused by insect stings / food
- less than 30 minutes after exposure
What happens in the body when hypersensitivity Type 2 occurs?
What causes it?
How long does it take to occur?
cytotoxic hypersensitivity:
- IgG and IgM cause MAC attack through complement
- Caused by Rh Factor , thrombocytopenic purpura
- 5-8 hours after exposure
What happens in the body when hypersensitivity Type 3 occurs?
What causes it?
How long does it take to occur?
Immune complex hypersensitivity:
- antibody-antigen complex
- Caused by serum sickness (such as a snake bite)
- 2-8 hours after exposure
What happens in the body when hypersensitivity Type 4 occurs?
What causes it?
How long does it take to occur?
delayed hypersensitivity:
- T cell response causing cell lysis
- Caused by poison oak, poison ivy, cheap metals in jewelry
- 1 - 3 days
What types of hypersensitivity requires B cell activity?
Type 1: anaphylactic hypersensitivity
Type 2: cytotoxic hypersensitivity
Type 3: Immune complex hypersensitivity
How does the body normally respond to an injected antigen (like a bee sting) during a type I hypersensitivity?
systemic anaphylaxis that can lead to anaphylactic shock
What were some examples of type II hypersensitivity given in class?
- Rh Factor
- thrombocytopenic purpura
Which types of hypersensitivity can be linked specifically to IgG?
Type 2: cytotoxic hypersensitivity
Type 3: Immune complex hypersensitivity
Which type of hypersensitivity is dependent only on T cell activation?
Type 4: delayed hypersensitivity
Which type of hypersensitivity has the shortest wait time for the onset of a reaction after exposure?
Type 1: anaphylactic hypersensitivity, responds in 30mins~
what are the four types of autoimmunity are there?
Type 1: cytotoxic reaction
Type 2: cytotoxic reaction
Type 3: immune complex autoimmunity
Type 4: cell-mediated autoimmunity
What happens in the body when autoimmunity Type 1 occurs?
Examples?
cytotoxic reaction:
- Antibodies cause cell death
- Ex: Hemolytic anemia causes hemolysis
What happens in the body when autoimmunity Type 2 occurs?
Examples?
cytotoxic reaction:
- antibodies alter cell function
- Graves’ disease
What happens in the body when autoimmunity Type 3 occurs?
Examples?
immune complex autoimmunity:
- self antigens cause complex deposits
- rheumatoid arthritis
What happens in the body when autoimmunity Type 4 occurs?
Examples?
cell-mediated autoimmunity:
- CD8+ T cells react to “self” cells
- type 1 diabetes, multiple sclerosis, psoriasis
How are TH17 CD 4+ T cells related to the autoimmunities?
Excessive inflammation
What are a few of the suspected causes of hypersensitivity and autoimmunity?
- Being too clean
- Presence of industrial pollutants
How does the hygiene hypothesis connect with hypersensitivity and autoimmunity?
Haven’t trained the immune system to fight off pathogens
Is the immune system functioning normally during immunodeficiency?
No, Some or all not working properly
What are the two most common immunodeficiencies?
Congenital: Inherited (genetic)
Aquired: Not inherited (cancer, virus)
What does the abbreviation SCID stand for?
Severe Combines Immunodeficiency Disease
How does SCID affect the immune system? Is SCID a serious condition?
SCID is congenital immunodeficiency disorder. A person is born without the ability to PRODUCE B AND T CELLS. YES THIS IS SERIOUS
What are the structural characteristics of HIV?
(shes going to test on this)
- contains gp41 (aids in fusion)
- contains gp120 (binds with CD4 T cell receptor CCR5 or CXCR4)
- contains reverse transcriptase (allows for reproduction of virus and mutations)
- Virion is enveloped.
- Virion has prominent glycoprotein spikes
- Virion contains 2 pieces of ssRNA genome
- Virion contains the enzyme reverse transcriptase
Which type of HIV is common in North America, for the United States and Mexico?
HIV 1: Clade B, Group M
What allows HIV to change over the course of an infection?
Enzyme reverse transcriptase: creastes stable cDNA
What are the human host cell receptor and coreceptors that allow HIV to infect?
CD4 and Coreceptor for attachment is either CCR5 or CXCR4
Which specific immune cell types are infected by HIV?
Macrophages, Dendritic cells, CD4+ T cells
How is the life cycle of HIV distinct from other viral families?
Retro virus using reverse transcriptase
Which body organ becomes infested with large amounts of HIV?
Lymph node become chronic reservoirs
How is HIV most likely to be transmitted?
Through contaminated body fluid: Intercourse, blood transfusion, sharing needles, open sores
What is Phase 1 of HIV?
Asymptomatic phase
What is Phase 2 of HIV?
Symptomatic phase
What is Phase 3 of HIV?
AIDS
How does T cell number relate to disease progression?
T cell count goes down as disease progresses
What is the normal value, before disease starts to affect the body?
Normal value: 800-1200
What does the abbreviation ARS stand for?
Acute Retroviral Syndrome
During which phase of HIV infection would
ARS occur?
During Phase 1
What is a noticeable indicator that HIV infection has progressed to phase 2?
Opportunistic pathogens become more common
What does the abbreviation HAART stand for?
Highly Active Antiviral Therapy
Why is treatment with HAART a
challenge in developing countries?
Its too expensive
Which state has the most new HIV infections?
Florida
Which state contains the greatest number of people living with HIV infections?
New York
In the US, who is most at risk for becoming infected with HIV?
Homosexual males
Globally, who is most at risk for becoming infected with HIV?
Women
Be able to explain the difference between a person that is HIV positive and a person who has AIDS
AIDS has no adaptive immune system and takes a while to develop
HIV positive could be latent and unpassable if viral load is low enoough
Even though AIDS is an infectious disease caused by a virus, why is it also considered an immunodeficiency disease?
- HIV infects helper T cells, denritic cells, and macrohpages.
- Over time, as HIV destroys these cells, this means it is destroying a large part of the immune system.
- This eventually leaves a person with part of their immune system absent and not able to fight off infection
How are hypersensitivity and autoimmunity disorders connected to the hygiene hypothesis?
H & A are connected to the hygiene hypothesis because the hygiene hypothese states that being too clean as a child (and not exposed to antigens) does not allow the immune system time to practice or train itself at targeting and functioning properly. If the immune system doesnt have good practice it will state to make mistakes more easily, leading to allergies and autoimmunities
True or False
In autoimmune disorders the immune system is functioning but targeting abnormally
True
