Hypersesnitivity Flashcards
Hypersensitivity reactions are caused by the immune system and can lead to ___ for the host.
Damage
_____ : prior exposure to an antigen that resulted in production of antibodies and/or immune cells creative to that antigen. It is required for a hypersensitivity reaction .
Pre-sensitization
There are four types of hypersensitivity. 1 through 3 are ____ and 4 is ___.
Humoral
Cellular
Type I hypersensitivity reactions involves antibody ____. The antigen must be ____. ___ cell activation is the main effector mechanism.
Type of reactions:
IgE
Soluble
Mast
Allergic rhinitis, allergic asthma, atopic eczema, systemic anaphylaxis, some drug allergies
Type II hypersensitivity reactions involves antibody ___. Two pathways:
1. Cell or matrix associated antigen activating ___, ___, and ___ cells.
2. Cell surface receptor (antigen), ____ alters the singling.
IgG
Complement
Phagocytes
NK
Antibody
Type III hypersensitivity reaction involves antibody ____. Antigen is ___. The effector mechanism is activating ___ and ____.
Examples of reactions:
IgG
Soluble
Complement
Phagocytes
Serum sickness, Arthus reaction
Type IV hyper sensitivity is ___ ___ hypersensitivity (DTH) and involves ___ cells.
Delayed type
T cells
Table of the four types of hypersensitivity:
Type I: allergic response:
___ antibodies produced in response to initial exposure bind to receptors on ___ cells. On second exposure, ___ attached to the mast cells recognized the ___ and binds. ____ of the cell is triggered by release of histamine, leading to allergy symptoms.
IgE
Mast
IgE
Allergen
Degranulation
Type I hypersensitivity:
Antigen presenting cell activates ___ cells which produce IL-4. This activates __ cells and they become a plasma cell that produces ____ antibody. This antibody binds to ___ cells.
TH2
B
IgE
Mast
Type I hypersensitivity reactions are traditional ____, such as:
Allergies
Urticaria (hives), hay fever, eczema, food allergies, allergic asthma, anaphylaxis
Type I hypersensitivity:
Immediate response within minutes caused by antigen _____ IgE on a presensitized mast cell, ____ and release of histamine leading to _____.
Delayed response takes hours when mast cells produce ____ that attract eosinophils and other cytokines leading to ____ and tissue damage
Cross-links
Degranulation
Vasodilation
Chemokines
Inflammation
What factors impact development of type I hypersensitivity reactions?
Genetics, environment-hygiene hypothesis, microbial and other environmental exposure
If you’re exposed to something your body either develops a ___ response or an ____ response
Tolerant
Inflammatory
Treatments of type I hypersensitivity are typically ____, not curative and include:
Palliative
Antihistamines, bronchodilators, epinephrine, desensitization therapy
We utilize ___ __ hypersensitivity reactions to perform allergy testing
Type I
Type II hypersensitivity is ____ mediated. IgG and IgM bind to ___ ___ antigens resulting in cell death of the antibody coated cell via ____, ____ activation, ____ ___ mediated Inflammation, or by antibody binding blocking ___.
Antibody
Cell surface
Phagocytosis, complement, Fc receptor, function
Type II hypersensitivity cell destruction examples:
1. ___ ___ ___: incompatible blood transfusions, need to test Rh compatibility and blood type
2. ___ ___ ___: antibodies against RBC membrane antigens
3. ___ ____: anti-platelet antibodies destroy platelets
4. ___ ___ of the newborn: due to blood type incompatibility of mom and baby
Blood transfusion reactions
Autoimmune hemolytic anemia
Immune thrombocytopenia
Hemolytic disease
Type II hypersensitivity inflammation examples:
1. ___ ___: autoimmune disease mediated by anti-glomerular basement membrane antibodies that target alpha-3 chain of type IV collagen
2. ___ ___ ___: following streptococcus pyogenes infection. Activation of lectin complement pathway
Goodpasture syndrome
Acute rheumatic fever
Type II hypersensitivity cellular dysfunction examples:
Type III hypersensitivity is mediated by ___ ___ of IgG antibody. They become deposited in various tissue. The site depends entirely on ____ the complex deposits, not antigen specific
Immune complexes
Where
___ ___ is the classic example of type III hypersensitivity. Antibodies to foreign antigens travel around the body and ___ in tissue. This activates ____ leading to ____ and tissue damage.
Serum sickness
Deposit
Complement
Inflammation
In serum sickness, the immune complexes form by ____ protein and ___ protein resulting in fever, rash, and poly arthritis. Most common these day with ___ vaccination, _____, and immune modulated agents (_____).
Human
Non-human
Rabies
Anti-venom
rituximab
Type III hypersensitivity also occurs in autoimmune disease (additional T cell involvement):
1. ___ ___ ___: autoantibodies to nucleoproteins, cytoplasmic antigens, leukocyte antigens, clotting factors, etc.
2. ___ ___: IgM form abnormal complexes with IgG
Systemic Lupus erythematosus
Rheumatoid arthritis
Two T cell mechanisms of Type IV hypersensitivity:
1. ___ ____: primarily TH1 and TH17. Antigen recognition and release of chemotactic factors and inflammatory mediators. Activation of macrophages and neutrophil recruitment leading to ROS
2. ____ ____: direct cell killing
CD4+ T helper cells
CD8+ cytotoxic T lymphocytes
CD8+ cytotoxic T lymphocytes (CTLs) use ____ and accumulation of macrophages in ___ __ to kill. ____ are a hallmark feature of type IV hypersensitivity.
Granulomas
Giant cells
Granulomas
Type IV hypersensitivity for TB test:
Mycobacteria derived proteins are injected, ____ cells recognize ____ MHC, release ____ cytokines and induce ___ causing a positive reaction
TH1
Class 2
Inflammatory
Vasodilation
Allergic contact ____ is a form of type IV hypersensitivity. Similar to reaction to injected Ag, but caused solely by skin contact. Antigens include highly reactive small molecules that penetrate the skin.
Dermatitis
Development of multiple sclerosis-CNS condition is due to ___ hypersensitivity. ___ or ____ become activated and cross the blood brain barrier. ___ ___ release Chemokines and attract B cells and macrophages. antigen presenting cells in the brain uptake ____ and present it. ___ ___ CD4 and CD8 cells cause direct damage to CNS. Plasma cells produce ___ ____ antibodies and activate complement leading to _____ ___.
Type IV
TH1 or TH17
T cells
Myelin
Auto-reactive
Auto-myelin
Demyelinated plaques
MS-CNS condition:
Type IV hypersensitivity conditions:
1. ___ __ ____: destruction of Beta cells in the pancreas leads to insulin deficiency
2. ___ ___ ___: ulcerative colitis and Crohn’s disease. Dysfunctional immune response to commensalism organisms leads to TH1 and TH17 mediated damage
3. ___ ___: anti-gliadin response leads to T cell, plasma cell, macrophage infiltration followed by villi destruction
Type I diabetes
Inflammatory bowel diseases
Celiac disease
Inflammatory bowel disease, barrier becomes ___.
Leaky
Celiac disease villi destruction:
In summary:
