Fichas
Hypersensitivity and allergy 12&17
Fichas del conjunto (59)
- 1What is hypersensitvity?An individual who has been sensitised to a particular antigen by repeated exposure over time is susceptible to developing an excessive immune response (hypersensitivity reaction) on subsequent exposure to the antigen
- 2What causes hypersensitivity?Antigens (allergens) involved are generally ubiquitous environmental substances to which only genetically susceptible individuals react inappropriately
- 3Is there only one cause for allergy?No - multifactorial
- 4What does the hypersensitivity response result in?Cellular and tissue changes and clinical signs of allergic disease
- 5Is the same hypersensitivity mechanism used for useful purpose and for foreign antigen?Yes
- 6What is another name for 'hypersensitivity mechanisms'?Immunopathological mechanisms
- 7What are the 4 classifications of hypersensitivity?1. Type I - immediate
2. Type II (antibody dependent: - cytotoxic type, - anti-receptor type)
3. Type III- immune complex
4. Type IV - cell mediated/ delayed type hypersensitivity (DTH) - 8What are the 2 stages of a hypersensitivity reaction?1. Sensitisation
2. Hypersensitivity - 9What is the process of sensitisation in type 1 hypersensitivity?1. Allergen is recognised by dendritic cell
2. Allergen grabbed and internalised by DC which then migrates to lymph tissue
3. Th2 produce specific cytokines
4. Cytokines act on allergen specific B cells
5. B cell produce allergen specific IgE - 10What is the hypersensitivity stage of type I?1. The allergen is recognised by the IgE which coats mast cells
2. Cross-linking of allergen by IgE causes degranulation of mast cell
3. Cuasing bronchoconstriction, vasodilation, pruritus within 5-60 mins (usually 15) - 11What is related to mast cell degranulation between 4-24 hours after?Late phase recruitment of eosinophils and macrophages - inflammatory cells
- 12What does the allergen cross link?IgE bound to FCER
- 13What leads to the degranulation of the mast cells?Intracellular signalling pathway
- 14What may also coat mast cells (reagenic antibody)?IgG (of a particular subclass)
- 15Give 3 other substances that can degranulate mast cells.1. C3a
2. C5a
3. Neuropeptide - 16Give 3 localised type 1 hypersensitivity disease.1. Cutaneous (eg flea allergy)
2. Respiratory (eg asthma)
3. Intestinal (eg food allergy) - 17Give 3 systemic type 1 hypersensitivity disease.1. Anaphylaxis (eg bee sting, penicillin reaction)
2. Severe and life threatening
3. Bronchoconstriction, laryngeal oedema, vasodilation - 18How is type 1 hypersensitivity regulated?The lack of Tregulatory activity causes there to be an increase in Th2
- 19What does an increase in Th2 cause?- IgE production
- Eosinophil attraction (IL-5, eotaxin)
- Mast cell attraction (IL-4) - 20What 2 cell types will be found in a histological section of a canine asthma-like disease?1. Bronchial mast cells
2. Bronchial CD4+ T cells - 21Give 7 factors that cause allergy.1. Age
2. Parasitism?
3. Microbial infection
4. Stress
5. Immune dysregulation
6. Allergen exposure
7. Genetic - 22What are the 2 things that have influenced the cause of the hygiene hypothesis?The way we live
How we bring up kids - 23Give 7 factors that influence the hygiene hypothesis.1. Isolation
2. Cleanliness
3. Processes foods
4. Vaccination
5. Antibiotic usage
6. Allergy
7. Autoimmunity - 24Is the allergic incidence increasing or decreasing?Increasing
- 25What does repeated infection cause with relation to the hygiene hypothesis?- Induces Tregulatory cells
- Causing 'bystander suppression' and non microbe-specific
- No Th1 or Th2 induced
- Controls autoimmunity/ allergy - 26What does lack of microbial exposure cause with relation to the hygiene hypothesis?- Reduces expansion
- Increases autoimmunity and allergy
- Th1 and Th2 produced - 27What are the 3 ways an antibody can kill a target cell?1. Opsonisation
2. Complement mediated lysis
3. ADCC through the binding of FcR of a natural killer cell to target cell - 28Give 3 examples of when there is type II hypersensitivity.1. Blood transfusion reactions
2. Antibody-mediated autoimmune diseases
3. Graft rejection - 29Why might a type II hypersensitivity reaction occur in dogs with transfusion reactions?DEA1- dog given DEA1+ blood on two occasions (induced alloantibody)
- make antibody on the first occasion and then will hypersensitivity on second time due to antibody attacking 'foreign' antigen - 30Why might a type II hypersensitivity reaction occur in cats with transfusion reactions?Transfuse type B cat with type A or AB blood (naturally occurring alloantibody against type A)
- 31Give 2 outcomes of blood transfusion reactions.1. Acute angioedema
2. Chronic haemolytic - 32Give an autoimmune disease which is a type II hypersensitivity reaction to the antibody.Autoimmune haemolytic anaemia (AIHA)
- 33What happens in AIHA?Attack own red blood cells due to marcophages with FcR and C3bR
- 34What is the anti-receptor antibodies (subtype of type II hypersensitivity) also referred to as?Type V hypersensitivity
- 35Give an example of a receptor stimulating antibody disease in type II hypersensitivity.Grave's disease
- 36How does Grave's disease work?Anti-TSHR (thyroid stimulating hormone receptor) antibody binds to TSHR to cause prolonged stimulation of the pituitary and therefore excess hormone is produced
- 37Give a disease that involves receptor blocking antibodies in type II hypersensitivity.Myasthenia Gravis
- 38What happens in Myasthenia Gravis?The antibody blocks the Ach receptor and therefore Ach can't bind resulting in the muscle motor end plate not working due to no stimulation (neuromuscular junction)
- 39What are the clinical signs of Myasthenia Gravis?Episodic walking and collapsing due to the AchR being blocked/destroyed
- 40What are the 2 sub types of type III hypersensitivity?1. Antibody
2. Antigen - 41What happens in type III when there is antibody in excess?- Sensitisation leads to IgG response
- Local exposure to antigen
- Local immune complex formation
- Local inflammation
- The 'Arthus Reaction' - 42What can the antigen entering where the antibody is in excess cause?1. Complement activation ( causes neutrophil degranulation, mast cell degranulation, platelet aggregation microthrombi- inflammation)
2. Macrophage activation ( IL-1, TNF - Inflammation) - 43Give 3 human arthus reactions (occupational diseases).1. Farmer's lung (fungal spores)
2. Pigeon Fancier's lung
3. Cheesemaker's lung - 44What happens in type III when there is antigen in excess?- Sensitisation leads to circulating antibody
- Exposure to high concentration antigen
- Small soluble immune complexes in antigen excess
- Circulating immune complexes
- Systemic disease - 45What is the effect of antibody-antigen complex sitting in the wall of a blood vessel when there is excess antigen?- Complement activation
- Neutrophil degranulation
- Basophils
- Platelet aggregation microthrombi
- Vasodilation
- Vasculitis
- Inflammation - 46Why do immune complexes fall out of blood vessels?Turbulent blood flow
- 47Give 4 places where it is common to get localisation of circulating immune complexes.1. Renal glomerulus
2. Eye
3. Skin between epidermis and dermis
4. Synovium of joints - 48Give 6 factors that determine the immune complex deposition.1. Size of complex
2. Overwhelmed IC clearance mechanisms
3. Nature of antigen
4. Nature of antibody
5. High blood pressure and turbulent flow
6. Endothelial lesions - 49What is another term used to describe type IV hypersensitivity?Delayed type hypersensitivity (DTH)
- 50What is involved in type IV hypersensitivity?Mononuclear cells and cytokines due to contacting the allergen
- 51How long does it take for the DTH to occur?24-72 hours
- 52What is stimulated in a DTH?Sensitised memory Th1 which release IFN-gamma which recruits other cells to the tissue and producing a localised immune tissue response
- 53What cells are recruited by the IFN-gamma?Macrophae (IL-1, TNF, IL-6)
Th1
CD8
NK - 54What is an example of a DTH in human medicine?Heaves test for the BCG injection against TB
- larger response means the body is more sensitised and therefore higher level exposure has been had - 55What everyday compounds can cause a DHT?Sensitization by metal
- 56How has veterinary medicine been seen to cause a DTH?Reaction to neomycin containing topical
- use of an ear infection cream as topical to an infection on the snout - 57What was the initial purpose of hypersensitivity reactions?Defend the body from infection
- 58What does a type 1 hypersensitivity reaction help to protect against?Anti-parasitic
- 59What does a type IV hypersensitivity reaction help to protect against?Tuberculosis
Información
- Descripción
- (Immunology MD) 2. Disease mechanisms and host responses AD1 Fichas sobre Hypersensitivity and allergy 12&17, creado por Rachael Jones el 16/11/2016.
- Creado por
- Rachael Jones
- Visitas
- 34
- Valoración