4. Acute phase reaction

Question 1

Acute inflammation

Answer 1

A healthy reaction by the body to virtually any trauma

Question 2

Acute phase reaction

Answer 2

= sysinflammation
It’s a protective response of connective tissue to injury
Aim: eliminate injury + start repair process

Question 3

Classification of inflammation

Answer 3

1) Local
- Acute
- Chronic
2) Systemic
- Acute phase reaction

Question 4

Steps of local inflammation

Answer 4

1) Vasodilation (minutes)
2) Increased capillary permeability (plasma exudation) (minutes)
3) Inflammatory cells (hours)

Question 5

Components of local immune response

Answer 5

• Dendritic cell w/TLR
• Macrophage
• Neutrophil granulocyte
• Mast cell
• Platelets
• Cytokines
• Complement system
• Coagulation system

Question 6

Vascular changes in inflammation

Answer 6

• Blood stasis

- Increased vascular permeability

Question 7

Innate immunity characteristics

Answer 7

• Non-antigen-specific
• Immediate action
• No memory
• Linear amplification

Question 8

Adaptive immunity characteristics

Answer 8

• Antigen-specific
• Latency
• Memory
• Exponential amplification

Question 9

Causes of acute phase reaction

Answer 9

Exogenous:
- Infection
- Chemical
- Radioactive irradiation, active radicals
- Necrosis
Endogenous
- Tumor
- Intense local immune reaction
- Major metabolic disturbance

Question 10

Components in blood clotting

Answer 10

• PAF (platelet activating factor)
• TXA2
• MCP (macrophage chemoattractant protein)
• TGF (transforming growth factor)
• IL

Question 11

Initiation of acute phase reaction

Answer 11

• Bleeding and blood clotting -> platelet activation-> IL-1
• Infectious agent -> complement activation-> C5a + C3a
• Immune complex -> same as above

Question 12

Small complement fragments and their role

Answer 12

C3a, C4a, C5a (“anaphylatoxins”)

• Mast cell degranulation
• Chemotaxis
• Leukocyte recruitment

Question 13

Anaphylatoxins

Answer 13

C3a, C4a, C5a

Question 14

Middle stage of acute phase reaction (“alarm”)

Answer 14

Increased levels of IL-6, IL-1, TNFα and IFNγ throughout the body, caused by:

• Macrophage
• Endothel cells
• Fibroblasts
• Keratinocytes
• T cells

Question 15

The two “fire departments” (anti-inflammatory)

Answer 15

1) Hypothalamic-pituitary-adrenal axis
- Activated by IL-6
- Cortisol anti-inflammatory effector
2) Liver
- Activated by IL-6, IL-1 and TNF
- Effector molecules:
- > Serum amyloid protein
- > C reactive protein
- > Mannose binding protein
- > Fibrinogen

Question 16

Acute phase proteins: protease inhibitors

Answer 16

α2-macroglobulin and α1-antitrypsin

Question 17

Acute phase proteins: complement

Answer 17

C3, factor B and C1 inhibitor

Question 18

Acute phase proteins: coagulation

Answer 18

Fibrinogen

Question 19

Acute phase proteins: opsonins

Answer 19

C3, CRP, SAA, SAP, mannose binding lectin

Question 20

Acute phase proteins: immune response modifiers

Answer 20

C3, SAP, protein inhibitor

Question 21

Acute phase proteins: radical-cathing

Answer 21

Albumin, SAA, coeruloplasmine

Question 22

Acute phase proteins that increase

Answer 22

1,5-2X: C3, Bf, coeruloplasmine
2-4X: α1-antitrypsin, haptoglobulin, fibrinogen
6-8X: C1 inhibitor
100-1000X: CRP, SAA !!

Question 23

Acute phase proteins that decrease

Answer 23

0,4-0,6X: transferrin, albumin, fibronectin

Question 24

Function of acute phase proteins

Answer 24

• Coagulation
• Opsonisation
• Protease inhibitors
• Radical cathing
• Immuno modulation
• Carrier proteins

Question 25

CRP

Answer 25

Opsonization APP

• Bind to phosphocholine on surface of dead cells and pathogens
• Enhances phagocytosis of particularily bacteria and autoantigens