Immuno Exam 3 - Dr. Thomason

What is developed from an inappropriate immune system response against cells and/or tissues normally present in the body?

autoimmunity

T/F Immune mediated disorder involve specific cells, organs, or body systems

TRUE

What are the two mechanisms of tissue damage that can be caused by immune-mediated diseases?

humoral and cellular mechanisms

T/F Immune-mediated diseases can easily be tested for

FALSE

What is the key to autoimmunity?

the loss of self-tolerance

What type of selection in the bone marrow and thymus can contribute to immunological self-tolerance?

negative selection

Where can the expression of tissue-specific proteins contribute to immunological self-tolerance?

thymus

What cells suppress the autoimmune responses?

treg

What can contribute to the immunological self-tolerance in auto-reactive B and T cells?

introduction of anergy

What is an immune reaction to a specific tissue antigen?

organ specific

What is an immune response to dispersed antigens that leads to systemic deposition of immune complexes?

non-organ specific

What is an example of a non-organ specific immune -mediated disease?

systemic lupus erythematosus

What type of immune-mediated disease is neutropenia, thrombocytopenia, and hemolytic anemia?

Organ specific

What type of immune-mediated disease is rheumatoid arthritis?

organ specific

What type of immune-mediated disease is discoid lupus erythematosus?

organ specfic

What type of immune-mediated disease is systemic lupus erythematosus?

non-organ specific

In what species are autoimmune diseases more common?

dogs

In what species are autoimmune diseases less common?

cats and horses

In what species are autoimmune diseases sporadic?

production animals

What are the predisposing factors of autoimmunity?

age, gender, lifestyle, and diet

What are environmental factors of autoimmunity?

UV irradiation and chemical

T/F Autoimmunity is multifactorial

TRUE

What type of autoimmunity is a true immune mediated disease and has no identifiable trigger factor?

primary

How are primary autoimmune disorders diagnosed?

exclusion

What type of autoimmunity has an underlying trigger factor?

secondary

What type of autoimmune disorder has an idiopathic cause?

primary

How are normal canine erythrocytes elmitaed.removed?

via the mononuclear phagocyte system

What does the mononuclear phagocyte system identify antibodies against?

membrane-bound antigens

What does immune-mediated hemolytic anemia destory?

premature erythrocytes

What does the immune system attack with immune-mediated hemolytic anemia?

RBC

In Immune-mediated hemolytic anemia, what bind to RBC membranes?

anti-RBC antibodies.

What do drugs and vaccines act as in an autoimmune response?

hapten

What binds to the membrane of a cell to form a target of an immune reponse?

hapten

What may drugs and vaccine modify that can cause autoimmune disorders?

the structure of a self-protein

What does immune-mediated thrombocytopenia destroy?

platelets

How can secondary immune mediated disease be treated?

Treat underlying condition, supportive care, immunosuppressive therapy

What is the auto-antigen of autoimmune disease?

acetylcholine receptor

What is teh consequence of myasthenia gravis?

progressive weakness

What autoimmune disease causes progressive weakness and uses nicotinic acetylcholine receptors?

myasthenia gravis

What is an autoantibody-mediated disease that destroys nicotinic acetylcholine receptors at the neuromuscular junction?

Myasthenia gravis

T/F Hypersensitivity reaction are always life-threatening

FALSE

What reaction is an excessive immune reponse?

hypersensitivity

What type of antigens lead to symptomatic reactions upon re-exposure to the antigen in hypersensitivity reactions?

innocuous

What is the inital exposure to an antigen in hypersensitivity reactions?

sensitization W

What does subsequent exposure to the antigen leads to an excessive immune response?

hypersensitivity reaction

What type of hypersensitivity develops 15-20 minutes after antigen ezposuree and can have mild to life-threatening signs?

type 1

What is immediate hypersensitivity also known as?

allergies or anaphylaxis

What type of hypersensitivity is immediate hypersensitivity?

type 1

What are the two phases of type 1 hypersensitivity?

sensitization and re-exposure

What antibody is produced during sensitization in hypersensitivity reactions?

IgE

T/F The first phase of hypersensitivity is often asymptomatic

TRUE

What does re-exposure activate?

mast cells

What cells are responsible for releasing substances that cause anaphylaxis/allergies?

mast cells

What antibodies are released during a normal reponse of sensitization?

IgG or IgA

What happens when you mount an exaggerated TH2 response during sensitization?

produce IgE leading to type 1 hypersensitivity

If both parents have an allergy, will the offspring have it?

yes

If one parent have an allergy, will the offspring have it?

maybe

What environment factor can make one less likely to develop allergies?

multiple infections when younger

What are the three origins of allergies?

genes, environmental factors, and DC capture antigens

What generate th2 cells?

Dendritic cells

What cytokines do dendritic cells produce?

IL4 and IL13

What do IL4 and IL13 (produced from dendritic cells) trigger in the sensitization reaction?

B-cell synthesis of IgE

What does binds to mast cells that primes them and makes the individual sensitized?

IgE

Where do the mast cells bound with IgE stay after sensitization?

tissues

What happens to IgE antibodies when re-exposure occurs?

cross linking

What does cross-linking of IgE antibodies initiate during re-exposure?

release or degranulation of mast cell granules

T/F Re-exposure is rapid

TRUE

What active substances do mast cells release?

histamines, heparin, and eosinophil chemotactic factor

What is released from mast cells that call in eosinophils and basophils?

eosinophils chemotactic factor

When does an immediate type 1 hypersensitive reaction occur?

10-20 minutes after exposure

What in the cell is going on during immediate type 1 hypersensitive reaction?

mast cell degranulation

When does a late-phase type 1 hypersensitive reaction occur?

4-24 hours after exposure

What in the cell is going on during late phase type 1 hypersensitive reaction?

recruitment of eosinophils

What is the hallmark of type 1 hypersensitivity?

eosinophils

What are the clinical consequences of a type 1 hypersensitivity reaction?

vasodilation, vascular permeability, interaction with local nerve endings, and contractions of smooth muscle

What symptoms will you see with type 1 hypersensitivity reaction?

redness, edema, pruritus, bronchoconstriction

What three things determine the severity and location of a hypersensitivity reaction?

degree of sensitization, amount of antigen, and route of administration

Where are the majority of type 1 hypersensitivity reactions localized to?

the tissues that contact the allergen

What are examples of type 1 hypersensitivity reactions of the skin?

atopic dermatitis and flea allergy dermatitis

What are examples of respiratory type 1 hypersensitivity reactions?

asthma and allergic rhinitis

What are examples of type 1 hypersensitivity reactions of the intestinal tract?

food allergy

What is feline asthma?

lower airway disease with limited airflow

What are the clinical signs of feline asthma?

wheezing, coughing, and respiratory distress

Airway inflammation, accumulating airway mucus, and bronchoconstriction are all from what problem?

feline asthma

What can cause the most extreme form of type 1 hypersensitivity?

generalized mast cell degranulation

In type 1 hypersensitivity disorder, what causes an anaphylactic reaction?

when released vasoactive molecules exceeds the ability to respond to the rapid changes in the vascular system

What is the shock organ of the dog?

GI tract and liver

What is the shock organ of cats?

lungs

What determines where anaphylaxis occurs?

shock organ

What causes smooth muscle contraction in anaphylaxis>

vasoactive molecules

What smooth muscles often contract in an anaphylaxis reponse?

bronchi,GI tract, and bladder

What is the most active substance of type 1 hypersensitivity?

histamine

What is the initial cellular component of type 1 hypersensitivity?

mast cells

What mediates type 1 hypersensitivity?

IgE