Block 4 W3 Flashcards

1
Q

Give examples of immune driven inflammation.

A
Allergies
Graft vs. Host disease
Autoimmune disease
Contact dermatitis 
Celiac disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is arachidonate acid formed from?

A

Cellular phospholipid bilayer by phospholipase A2.

Metabolised by cyclooxygenase into prostaglandins and prostacyclin, thromboxane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the role of prostacyclin, PGI2?

A

Vasodilator, hyperalgesic, stops platelet aggregation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the role of thromboxane, TXA2?

A

Thrombotic, vasoconstrictor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of prostaglandin, PGF2a?

A

Bronchoconstrictor, myometrial contraction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the role of prostaglandin, PGD2?

A

Inhibits platelet aggregation and vasodilator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the role of prostaglandin, PGE2?

A

Vasodilator and hyperalgesic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define NSAIDs and give examples.

A

Non-steroidal anti-inflammatory drugs
e.g. aspirin, ibuprofen, diclofenac
Prescribed for pain and chronic inflammation - minor aches and pains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 major effects of NSAIDs?

A
  1. Anti-inflammatory - blocks COX from making prostaglandins which regulate inflammation due to vasodilation and increased vessel permeability.
  2. Analgesic - prostaglandins sensitises spinal neurones to pain.
  3. Antipyretic - prostaglandin synthesis inhibited in hypothalamus so reduces firing rate that control thermoregulation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the mech of action of aspirin.

A

Irreversibly inactivates both isoforms of COX (1 and 2) by acetylating the catalytic serine residue in position 529.
Affects COX2 expression at both transcriptional and post-t level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does low dose aspirin do?

A

Preferentially affects thromboxane pathway -> reduced platelet aggregation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does high dose aspirin do?

A

Affects both pathways -> risk of bleeding as inhibits prostacyclin, required for inhibition of platelet aggregation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does ibuprofen interact with aspirin?

A

Block the anti-platelet effects.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the side effects of aspirin?

A

Deaf, swelling of eyes, face, lips, tongue, wheezing, cold clammy hands, hives, nausea, tachycardia, bloody stools, and vomit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do 2nd generation NSAIDs target?

A

Selective COX2 inhibitors
e.g. Coxibs
Minimised gastric problems but targeted prostacyclin which increased risk CVD.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define NO-NSAIDs?

A

Nitric oxide - donating NSAID

have gastro-protective effect and increased anti-inflammatory activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the adverse events of NSAIDs caused by?

A

Inhibition of COX1 - useful as a housekeeping role.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the adverse side effects of NSAIDs?

A
  1. Abdominal discomfort, dyspepsia - reduced PG synthesis in GI -> increased gastric acid secretion, diminished mucus secretion so acid irritates GI lining.
  2. Stomach/duodenal ulceration - PG normally causes mucus release so NSAIDs blocks this.
  3. MI - COX1 expressed in endothelium -> pre-disposes to blood clots and high BP.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Define SAIDs.

A

Steroidal anti-inflammatory drugs -> glucocorticoids
e.g. hydrocortisone, prednisone, dexamethasone
Synthesised from cholesterol.
Used in inflammatory diseases.
Reduces phospholipase A, COX2 thus reducing prostaglandins.

20
Q

What are the side effects of SAIDs?

A

Occurs with prolonged systemic use.

  • suppresses IR
  • suppresses endogenous glucocorticoid synthesis
  • iatrogenic Cushing’s syndrome
  • osteoporosis.
21
Q

How does histamine produce the Lewis Triple response?

A
  1. reddening - vasodilation
  2. wheal - increased permeability
  3. flare - antidromic stimulation of local nerves
22
Q

What is the effect of histamine systemically?

A
  • stimulation of gastric secretion
  • contraction of smooth muscle
  • cardiac stimulation
  • vasodilation
  • increased vascular permeability
23
Q

Give examples of sedating anti-histamines.

A

Chlorphenamine and promethazine

24
Q

Give examples of non-sedating anti-histamines.

A

Cetrizine and fexofenadine.

25
Q

Give examples of immunosuppressive drugs.

A

Cyclosporine
Tacrolimus - prevents transcription of IL-2
Rapamycin - inhibits mTOR and so cell cycle progression.

26
Q

Describe the mech of action of basiliximab.

A

Monoclonal antibody.

Acts via cytokine or binds receptors directly to limit proliferation of IL-2.

27
Q

Define atopy.

A

Predisposition for IgE mediated IR.

28
Q

In type I hypersensitivity, describe the immediate reaction caused by the release of mast cells.

A

Histamine usual effects and chemoattractant for neutrophils and eosinophils.
Leukotrienes - bronchial spasms/constrictions, mucus secretion.
Prostaglandins effects
Th2 cytokines - activates Th2 cells and eosinophils activation.

29
Q

In type I hypersensitivity, describe the late reaction caused by the release of mast cells.

A

Migration of eosinophils - release peroxidase causing further tissue damage.

30
Q

Describe allergic rhinitis and treatments.

A

Type I
Hay fever due to grass or pollen.
Signs - red itchy watery eyes, runny nose.
Treatment - reduce exposure, anti-histamines, intranasal corticosteroids.

31
Q

Describe asthma and treatments.

A

Type I
Contraction of bronchial smooth muscle -> SOB.
Treatment - reliever inhaler-salbutamol (B2 agonist), preventative inhaler-corticosteroids.

32
Q

Describe allergic eczema and treatments.

A

Type I
Skin breached by allergens, scratching + microbial toxins influx due to unresolved skin -> release of cytokines and chemokine.
Chronic disease - Th1 cells and eosinophils.
Treatment - reduce itching, emollients, topical corticosteroids.

33
Q

Describe urticaria and treatments.

A

Type I
Release of histamine within skin - leads to angio-oedema.
Treatment - anti-histamines, corticosteroids.

34
Q

Describe anaphylaxis and treatments.

A

Type I
Systemic response to allergen -> rapid synthesis of prostaglandins and leukotriene:
- systemic vasodilation, increased vascular permeability
- fall in BP
- severe bronchial constriction, oedema and shock.
Treatment - norepinephrine pen -> vasoconstrictor.

35
Q

Describe rhesus disease and treatments.

A

Type II
HDN
Treatment - routine antenatal anti-D prophylaxis (RAADP) prevents sensitisation. Anti-D antibodies neutralises any D+ RBC mother is exposed to.

36
Q

Describe antibiotic allergies and treatment.

A

Type II
Drug binds RBC - Abs produced -> destruction of RBCs, drug acts as immunological hapten.
Treatment - removal of drug, steroids.

37
Q

Describe Good-pasture syndrome and treatment.

A

Type II
IgG Ab recognise collagen within kidney basement membrane so binding -> complement activation.
Treatment - oral immunosuppressants and plasmapheresis.

38
Q

Describe myasthenia gravis and treatment.

A

Type II
Abs block acetylcholine receptors at NMJ - muscle weakness of eyes and face.
Treatment - pyridostigmine, immunosuppressants biologics, thymectomy.

39
Q

Describe Graves disease and treatment.

A

Type II
Abs bind thyroid hormone receptor causing activation -> increased thyroid hormone production.
Treatment - thionamides, radioactive iodine therapy, surgery.

40
Q

Describe the mechanism of type III hypersensitivity.

A

Complexes are deposited in organs (kidney, vessels, synovial joints) - constant activation of complement -> tissue damage.
Vasculitis, glomerular nephritis, arthritis.

41
Q

Describe systemic lupus erythematous and treatment.

A

Type III
Autoantigens is DNA - anti-DNA antibodies result in systemic damage to tissues i.e. kidney, skin, heart and joints.
Treatment - alkylating agent (cyclophosphamide suppressing DNA synthesis), immunosuppressants, rituximab and belimumab.

42
Q

Describe rheumatoid arthritis.

A

Type IV
Cell-mediated joint tissue destruction due to inflammation and cartilage damage.
Treatment - NSAIDs, corticosteroids.

43
Q

Describe the mechanism of type IV hypersensitivity.

A

Sensitisation - haptens cross epidermis -> creates neo-antigens -> presented to APCs = development of memory response.
Secondary exposure - memory Th1 cells activates inflammation, macrophages and tissue destruction.

44
Q

Describe contact dermatitis and treatment.

A

Type IV
Nickel, poison ivy
1st contact sensitises, 2nd contact elicits dermatitis.
Treatment - trigger avoidance.

45
Q

Describe multiple sclerosis and treatment.

A

Type IV
T cells destroy myelin sheath -> paralysis.
Treatment - immunosuppressants, biologic therapy i.e. anti-cytokine and monoclonal Abs.