immun Flashcards
(32 cards)
type 1 hypersens examples
anaphylaxis
atopic (asthma, allergic rhinitis)
food allergies
type 1 hypersens pathophys
- Preformed IgE antibodies coating mast cells and basophils are crosslinked by contact with free antigen
- Cell degranulation results in the release of histamine and other inflammatory mediators.
Th2 immunity, IgE, mast cell degranulation, eosinophilic influx
Type 1 Hypersensitivity: Immediate
in type 1 hypersens the role of IL-5 is
Promotes eosinophil activation
in type 1 hypersens the role of IL-4 and IL-13 is
- Promotes smooth muscle contraction, intestinal permeability, mucus secretion, sensitivity of cells to the mast cell mediators
- Achieve resistance against helminths.
- “Weep and sweep response”- parasite resistance and expulsion
The asthmatic response comes from the lungs trying to
expel helminths
type 2 hypersens pathophys
- IgM or IgG antibodies bind to antigens on the cells of particular tissue types.
- Complement system activation and lysis or phagocytosis of cells
- Antibody-dependent cell-mediated cytotoxicity (e.g., by natural killer cells)
- Antibody interference with normal cell function
type 2 hypersens examples
Grave’s disease, Myasthenia Gravis, Vasculitis, AIHA (autoimmune haemolytic anaemia), pernicious anemia, Blood transfusion, Rheumatic fever
type 3 hypersens pathophys
Pathophysiology
- IgG antibodies bind to circulating antigens.
- Immune complex formation and deposition in particular tissues
- Deposits in tissue activate the complement system and attract neutrophils
- Neutrophilic lysis or phagocytosis of cells
type 3 hypersens examples
Glomerulonephritis, SLE, drug allergies, serum sickness
type 4 hypersens pathophys
Pathophysiology
- Contact of antigen with pre-sensitized T lymphocytes
- Presensitized CD4+ T cells recognize antigens on antigen-presenting cells → release of inflammatory cytokines → activation of macrophages
- Presensitized CD8+ T cells recognize antigens on somatic cells → cell-mediated cytotoxicity
type 4 hypersens examples
Contact Dermatitis (poison ivy), hashimoto’s thyroiditis, type 1 Diabetes, MS, crohns
T-cell mediated (delayed): which T cells
Th1 or Th17 cells activate and recruit macrophages, CTLs
Ms Singh, a 19 year old plumbing apprentice complained of feeling hot and fatigued. He complained of feeling his heart beat faster and harder in his chest.
After doing a thyroid panel (T3/T4, TSH) and an autoimmune panel, he was diagnosed with Grave’s disease, in which antibodies are directed towards the cell surface receptors of thyroid cells to enhance hormone secretion.
What type of sensitivity is this?
Type II hypersensitivity: cytotoxic
Ms Z, a 27 year old astronaut has been diagnosed with SLE
In Systemic Lupus Erythematosus, Autoantigens complexed with their cognate autoantibodies directly contribute to the activation of the immune system via the FcR (Fc receptor) and cause mediated update of these complexes.
Which of the types of sensitivity is this?
Type III Hypersensitivity: Immune complex
Ms K, a 45 year old gynaecologist has been diagnosed with a watermelon allergy.
In the anaphylaxis against watermelon, the mast cells degranulate, releasing histamine and pro-inflammatory factors as a result of repeated exposure to a particular antigen.
What type of hypersensitivity is this?
Type I hypersensitivity: immediate
A/Prof Sins, a 25 year old University lecturer has been diagnosed with late onset T1DM.
In T1DM, CD8 T cells target cells within the pancreas and kill them, preventing the production of insulin and glucose homeostasis within the body.
Which type of hypersensitivity is this?
Type IV: delayed (T-cell mediated)
T1DM
autoantibodies?
destruction of?
deficiency?
→ autoimmune response with production of autoantibodies, e.g., anti-glutamic acid decarboxylase antibody (anti-GAD), anti-islet cell cytoplasmic antibody (anti-ICA)
→ progressive destruction of β cells in the pancreatic islets
→ absolute insulin deficiency
→ decreased glucose uptake in the tissues
Mx: insulin
SLE most commonly affects?
affects women of childbearing age and is the most common form of lupus.
SLE pts have ?
Patients have a characteristic butterfly rash
medication for SLE
Mx: Corticosteroids, immunosuppressants, biologics
myasthenia gravis characterised by ?
An autoimmune neuromuscular disease characterized by generalized muscle weakness. It most commonly affects adults
myasthenia gravis pathophys
The pathophysiology involves autoantibodies directed against postsynaptic acetylcholine receptors (AchR), which induce T-cell mediated destruction of those receptors.
Myasthenia gravis medication
Mx: Pyridostigmine (acetylcholinesterase inhibitor), Immunosuppressants, plasmapheresis, IVIG
