Diseases of the Immune System (Lecture 14) Flashcards
What is immunopathology?
Immunopathology studies how immune system dysfunction leads to diseases.
Disease states caused by the over or under reactivity of the immune system
Define allergy.
Exaggerated immune response that is manifested by inflammation
Allergies can lead to symptoms ranging from mild to severe.
What are allergens?
Antigens that induce allergy in sensitive individuals
Common allergens include pollen, certain foods, and medications.
What are autoimmune diseases?
Individuals actually develop hypersensitivity to themselves
Examples include rheumatoid arthritis and lupus.
What characterizes Type I hypersensitivity?
Immediate hypersensitivity; IgE-mediated; involves mast cells, basophils, and allergic mediators
Common examples are anaphylaxis and asthma.
What is atopy?
Hayfever, asthma
Atopy refers to a genetic predisposition to develop allergic diseases.
What is anaphylaxis?
Systemic; airway obstruction
Anaphylaxis is a severe, potentially life-threatening allergic reaction.
List the portals of entry for allergies.
- Atopic dermatitis
- Drug allergy
These are common ways allergens can enter the body and trigger an immune response.
What is the purpose of an allergy skin test?
This test helps identify specific allergens that trigger allergic reactions.
What are Type II hypersensitivities?
IgG- and IgM-mediated cell damage
These can lead to conditions like blood group incompatibility.
What is the significance of blood type in Type II hypersensitivities?
ABO hypersensitivities
Blood type matters in type II hypersensitivity because if someone gets the wrong blood, their immune system sees the foreign blood cell antigens as threats and attacks them. This causes the body to destroy those cells, leading to serious reactions like hemolysis.
What is Type III hypersensitivity?
Immune complex-mediated; antibody-mediated inflammation
Conditions include systemic lupus erythematosus and rheumatoid arthritis.
What is Type IV hypersensitivity?
T-cell-mediated; delayed hypersensitivity and cytotoxic reactions in tissues
Examples include contact dermatitis and graft rejection.
Which immune components are involved in Type I hypersensitivity?
IgE, mast cells, basophils, allergic mediators
These components play crucial roles in allergic reactions.
What types of diseases can Type II hypersensitivity include?
- Blood group incompatibility
- Pernicious anemia
- Myasthenia gravis
These diseases involve immune responses against the body’s own cells.
What characterizes Type III hypersensitivity?
Circulating IgG complexes deposited in basement membranes of target organs
• Mediated by: Immune complex deposition (antigen-antibody clumps) • Examples: Lupus, serum sickness, rheumatoid arthritis • Timing: Hours to days
This can lead to tissue damage and inflammation.
What are some examples of autoimmune diseases in Type III hypersensitivity?
- Systemic lupus erythematosus
- Rheumatoid arthritis
- Serum sickness
- Rheumatic fever
These diseases involve immune complexes causing damage to various organs.
