Immune System Diseases Flashcards
(54 cards)
Name the five major components of the innate immune system.
- Epithelial barriers
- Phayocytic cells (neutrophils, macrophages)
- Dendritic cells
- NK cells
- Plasma proteins (complement)
What are the four types of hypersensitivity reactions? Briefly describe each one.
Type 1 (allergic hypersensitivity - IgE) Type 2 (abnormal Abs) Type 3 (immune complex) Type 4 (delayed, T cell mediated)
Allergens activate TH2 CD4+ T cells, which secrete cytokines ______ and ______, activating plasma cells to secrete Ig__ and IgG4.
IL-4 and IL-13 activates plasma cells to make IgE and IgG4
Mast cells become _______ by binding Fc portions of IgE to their surface receptors.
sensitized
Describe the two phases of a Type 1 hypersensitivity reaction.
Initial rapid response (from 5 min to 60 min after exposure) results in vasodilation, increased vascular permeability, and smooth muscle spasm.
Late phase (delayed - from 2-8 hours after exposure) involves inflammation and tissue destruction with infiltration of neutrophils, eosinophils, and T cells with secretion of lipid mediators and cytokines.
Systemic anaphylaxis is an example of Type __ hypersensitivity that involves pruritus (itching), urticaria (hives), erythema, bronchoconstriction followed by laryngeal edema that may escalate to laryngeal obstruction and hypotensive shock. Can be fatal in minutes to hours.
Type 1 hypersensitivity
What causes Type 2 hypersensitivity reactions? Name the three mechanisms of tissue destruction.
Abnormal antibodies that bind to cellular antigens, causing one of three things:
- Opsonization and phagocytosis
- Inflammation
- Antibody-mediated cellular dysfunction
What causes inflammation during a Type 2 hypersensitivity reaction?
Complement activation products recruits polymorphs, monocytes, and phagocytic cells.
Myasthenia gravis and Grave’s disease are examples of what type of destructive mechanism of Type 2 hypersensitivity reactions?
Ab-mediated cellular dysfunction.
How do Type 3 hypersensitivity reactions cause inflammation?
Antibody-antigen complexes get trapped in small vessels of the body, bind complement, and cause vessel wall damage.
Which antibody subtypes are involved in Type 3 hypersensitivity reactions?
IgG and IgM
Name five symptoms of a Type 3 hypersensitivity reaction.
- Fever
- Urticaria
- Arthralgias (joint pain)
- Lymph node enlargement
- Proteinuria
What is an Arthus reaction?
A local immune complex (Type 3) reaction. Localized reaction with tissue vasculitis and necrosis that peaks at 4-10 hours after Ag exposure.
What causes Type 4 hypersensitivity reactions?
Overreaction of T cells
Type 1 diabetes mellitus, MS, RA, peripheral neuropathies like Guillan-Barre syndrome, IBD, and contact dermatitis are all examples of Type __ hypersensitivity.
4
Which T cell subtype is involved in cytokine secretion during a delayed-type hypersensitivity reaction?
Th1 CD4+ cells
Granuloma formation during a delayed hypersensitivity reaction occurs due to a ________ antigen. In this process, initial perivascular CD4+ T cells are progressively replaced by ________ over 2-3 weeks, which then turn into epitheloid cells and may later turn into multinucleated giant cells.
occurs due to a persistent antigen. T cells replaced by macrophages that can turn into epitheloid, then multinucleated giant cells
T-cell mediated cytotoxicity is a subtype of Type ___ hypersensitivity that involves the generation of ____ T cells in response to viral infections, tumor cells, or allografts.
subtype of Type 4, generates CD8+ killer T cells
How do CD8+ T cells inflict injury during T cell-mediated cytotoxicity?
Direct killing by perforin-granzyme or Fas-FasL
Are autoimmune diseases more common in women than in men?
Yeah
How do “susceptibility genes” relate to autoimmune diseases?
The susceptibility genes predispose people to generating self-reactive T cells involved in autoimmune diseases.
Name four non-organ specific autoimmune diseases.
- Systemic Lupus Erythematosus
- Progressive systemic sclerosis
- Polymyotosis and dermatomyotosis
- Rheumatoid disease
Name six organ-specific autoimmune diseases.
- Vitiligo - anti-tyrosine Abs
- Grave’s
- Hashimoto disease - anti-thyroid Abs
- Addison’s disease - anti-adrenal cortex Abs
- Type 1 DM - anti-islet cell Abs
- Myasthenia gravis
What plasma components are involved in Systemic Lupus Erythematosus?
Immune complexes and antibodies