Hypersensitivity Flashcards
A severe, immediate and system wide harmful immune response to a non-pathogenic antigen is called what?
Anaphylaxis
An immediate or delayed immune response to innocuous antigen often resulting in healthy tissue damage is called what?
Hypersensitivity reaction
What are the four types of hypersensitivity reactions?
1-Type I (Degranulation)
2-Type II (Complement ADCC)
3-Type III (Antibody complex deposition)
4-Type IV (T cell sensitization)
Which three hypersensitivity reaction types are humorally mediated?
Type I, II, III
*Type IV is cell-mediated
Non-pathogenic antigens that illicit a type I hypersensitivity reaction are called what?
Allergen
*proteins or glycoproteins that interact with PRRs with enzymatic activity.
What are three Allergen-IgE activation granulocytes?
1-Mast cells
2-Basophils
3-Eosinophils
What are 4 examples of localized allergen response (type I hypersensitivity)?
1-Allergic rhinitis (hay fever)
2-Allergic asthma
3-Eczema
4-Food allergies
What cells typically respond to a helminth infection?
CD4 Th2 cells (sensitize eosinophils, basophils and mast cells)
TNF-a, histamine, heparin, Tryptase, chymase, cathepsin T and carboxypeptidase are all released by what?
Mast Cells
What three systems are affected by mast cell activation/degranulation?
1-Gastrointestinal tract (expulsion by diarrhea/vomiting)
2-Airways (expulsion via coughing, sneezing, phlegm)
3-Blood vessels (Edema and inflammation, increase flow of antigen to lymph nodes)
What cells are activated by mast cells and Th2 cytokines, express FCe receptors once activated and have highly toxic granules that promote further inflammation?
Eosinophils
What is the hygiene hypothesis?
Reduced early developmental immune pressure causes poor immune education and an inappropriate pathogen identification, leading to allergy and autoimmune disorders
Common allergens are related to what antigens?
Helminth specie antigens
What are the two phases of allergic reactions?
1-Acute phase (mast cells)
2-Late phase (Eosinophils, main destructive phase)
IgE coated mast cells are activated by antigen in the bloodstream entering tissue causing what rapid, systemic and deadly allergic reaction?
Anaphylactic shock
*Epinephrine halts this
Repeated exposure to escalating dosages of allergies to reduce type I responses is called what?
Hyposensitization
*most effective allergy treatment
What are 4 type I treatments?
1-Antihistamines
2-Leukotriene antagonists
3-Corticosteroids
4-Immunotherapeutics
Antibodies against self antigen or complement and antibody directed cellular cytotoxicity are typical of what type of hypersensitization?
Type II
*Drug allergies, graft rejection, autoimmunity
What is an example of Type II hypersensitivity that effect newborns?
Rh factor (if mother is Rh-, has Rh+ baby, she builds immune response. If she has another Rh+ baby, her IgGs will attack fetal blood)
*Rhogam is the drug that prevents B-cell activation and memory cell formation
Inefficient immune complex clearance such as antigen-antibody lattices, antigens with high affinity for tissue surfaces, highly charged antigens or compromised phagocytosis are what type of hypersensitivity?
Type III
*complexes deposited in blood vessels and tissues. Innate inflammatory response.
CD4 T cells and macrophages play a major role in what two phase Hypersensitivity type?
Type IV (cell-mediated delayed type)
*cell mediated, not humoral. Contact material acts as adjuvant
Obesity, tissue damage, heart disease, unresolved infection, periodontitis and intestinal microbes can all cause what?
Chronic systemic inflammation
