Autoimmunity

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Questions and Answers

What is autoimmunity?

An immune response to foreign antigens
Immune reactivity against the body’s own components, either antibody-mediated or cell mediated (correct)
The inability to respond to pathogens
Immune tolerance to self antigens

Discuss the general features of autoimmune disorders

They result from loss of tolerance to self antigens, may be systemic or organ-specific, and are chronic and progressive (correct)
They are acute and self limiting
They are cause solely by genetic mutations
They involve only B cells

What is organ specific autoimmunity?

Autoimmune reactions targeting a single organ due to inappropriate immune response against its autogens (correct)
Autoimmune reactions limited to skin tissues
A type of autoimmunity that does not involve antibodies
A systemic reaction affecting multiple organs

Outline the causes of autoimmunity in animals

Genetic predisposition, abnormal antigen display, inflammation, or cross-reactivity due to infection (C) Signup and view all the answers

In which situation can autoimmunity be physiological?

When RBC lose CD47 during aging, allowing phagocytosis by macrophages (B) Signup and view all the answers

Can hidden antigens cause autoimmunity, and if so, how?

Yes, hidden antigens released after tissue damage can lead to autoantibody production (D) Signup and view all the answers

What role does AIRE play in autoimmunity?

Regulates tolerance by controlling the expression of self-antigens in the thymus; defects lead to autoimmunity (B) Signup and view all the answers

What is rheumatoid factor (RF)?

An autoantibody against the Fc region of IgG (A) Signup and view all the answers

Give an example of a disease in which RF is produced

Systemic Lupus Erythematosus (SLE) (C) Signup and view all the answers

What is molecular mimicry?

A shared epitope between a pathogen and a host that induces autoimmunity (D) Signup and view all the answers

In what circumstances does molecular mimicry participate in autoimmunity?

When pathogens carry antigens that resemble host proteins, triggering an immune response against both (A) Signup and view all the answers

What is the difference between molecular mimicry and bystander activation ?

Molecular mimicry is caused by cross-reactivity between pathogen and host antigens, while bystander activation is the stimulation of non-specific lymphocytes by cytokines during infection (B) Signup and view all the answers

Which mechanisms are the basis for the pathology observed in autoimmune disorders?

Hypersensitivity types I, II, III and IV (C) Signup and view all the answers

How does autoimmune lymphocytic thyroiditis develop in dogs?

By production of autoantibodies against thyroglobulin or thyroid peroxidase, blocking hormone production and infiltrating thyroid tissue with lymphocytes (C) Signup and view all the answers

What is the dominating tissue damage mechanism in canine type 1 diabetes mellitus?

T cell mediated destruction of B cells through type IV hypersensitivity (A) Signup and view all the answers

What is the mechanism of tissue damage in dogs with Type 1 diabetes?

ADCC Signup and view all the answers

What is the target protein in autoimmune equine polyneuritis?

Myelin P2 protein (B) Signup and view all the answers

What is the cause of alopecia areata?

Autoantibodies against trichohyalin, a protein in hair follicles, leading to hair loss (D) Signup and view all the answers

Explain the autoimmune basis of Myasthenia gravis in jack russels

Autoantibodies against acetylcholine receptors block nerve impulse transmission and destroy receptors via complement fixation (B) Signup and view all the answers

Name at least three autoimmune disorders

Pemphigus foliaceus, pemphigus vulgaris, alopecia areata Signup and view all the answers

In which skin autoimmune disease is collagen type XVII a target molecule?

Bulbous pemphigoid (C) Signup and view all the answers

What is Bullous pemphigoid?

An autoimmune disease targeting type XVII collagen in the skin basal membrane, leading to subepidermal blisters (A) Signup and view all the answers

In which part of the skin is Pemphigus vulgaris located?

The epidermis, specifically targeting desmoglein 3 (C) Signup and view all the answers

Flashcards

Autoimmunity

Immune response against the body's own tissues, either antibody-mediated or cell-mediated.

Autoimmune disorders feature

Loss of tolerance to self-antigens, can be systemic or organ-specific, and are chronic and progressive.

Organ-specific autoimmunity

Immune response targeting a specific organ due to abnormal immune response against its own components.

Causes of autoimmunity (animals)

Genetic predisposition, abnormal antigen display, inflammation, or cross-reactivity with infections.