Chronic Inflammation Flashcards
(102 cards)
1
Q
What is chronic inflammation?
A
Inflammation of prolonged duration
2
Q
What are the origins of chronic inflammation?
A
- Progression from irresolved acute inflammation
- Recurrent episodes of acute inflammation
- Denovo process without acute phase (different mechanism)
3
Q
What is tissue damage caused by if not pathogenic cells?
A
Inflammatory cells
4
Q
What are the signs of chronic inflammation like in comparison to acute?
A
More attentuated, less obvious
5
Q
What are the cells involved in chronic inflammation? (4)
A
- Macrophages
- Sometimes lymphocytes
- Mast cells
- Plasma cells
6
Q
What type of cell is involved in chronic inflammation?
A
Mononuclear
7
Q
What differentiates chronic inflammation from acute inflammation?
A
No neutrophilic response, just mononuclear/lymphocytic response
8
Q
Give an example of a persistent infection turning from acute response to chronic process
A
Focus of infection cannot be reached by antibiotics in chronic osteomyelitis
9
Q
How is osteomyelitis often insiduous?
A
In acute osteomyelitis the central area of necrosis = surrounded by:
- Possible fibrosis
- Thickened bone formation
Can’t isolate pathogen for effective treatment
10
Q
What is primary chronic inflammation characterised by? (2)
A
- All the histological features of a chronic process with mononuclear cells
- Skips neutrophilic response
11
Q
What are the causes of primary chronic inflammation? (3)
A
- Persistent infection by organisms with low toxicity
- Prolonged exposure to non degradable toxic agents
- Autoimmune disease
12
Q
How does persistent infection by organisms with low toxicity trigger primary chronic inflammation?
A
Immunoresponse called delayed hypersensitivity triggered
13
Q
What type of response is delayed hypersensitivity?
A
Intracellular
14
Q
W hat does delayed hypersensitivity mostly occur in response to?
A
- Viruses
- Microbacteria e.g TB
15
Q
What are the 2 types of non degradable toxic agents that prolonged exposure to causes primary chronic inflammation?
A
- Exogenous
- Endogenous
16
Q
Give 3 examples of exogenous non degradable toxic agents
A
- Asbestos
- Silica
- Wood dust
17
Q
Give an example of endogenous non degradable toxic agents
A
Plasma lipids found in atherosclerosis
18
Q
What is autoimmune disease a response to?
A
Self antigens
19
Q
Give 2 types of autoimmune disease
A
- SLE
- Thyroiditis
20
Q
What are the first cells to populate a site of injury in chronic inflammation (which are progressions of each other)? (3)
A
- Monocytes
- Macrophages
- Multinucleated giant cells
21
Q
How long does it take for monocytes, macrophages and multinucleated giant cells to populate a site of injury after damage?
A
24-48 hours
22
Q
What are monocytes?
A
Precursors of macrophages circulating in blood
23
Q
How long do circulating monocytes survive?
A
2 days
24
Q
What are macrophages?
A
Monocytes that have migrated from the bloodstream into any extravascular tissue
25
What can macrophages do that monocytes cannot?
- Phagocytise
| - When activated: eliminate internalised microorganisms
26
What property of macrophages allows them to eliminate internalised microorganisms?
Increased lysosomal content
27
In what ways do macrophages contribute to chronic inflammation? (2)
- Release active products = tissue damage and fibrosis
| - Proliferation
28
How can the presence of cells in inflammation be used to judge the length of time from insult? (3)
- Within 4 hrs: seeing neutrophils
- Longer than 4 hrs: neutrophils and macrophages
- In repair=fibrosis
29
What accumulation persists in chronic inflammation?
Macrophage accumulation
30
What are the 3 reasons chronic inflammation macrophage accumulation persists?
- Continuous recruitment from circulation
- Local proliferation
- Peripheral macrophage immobilisation
31
What are the 2 types of peripheral macrophages that are immobilised?
- Epithelioid histiocytes
| - Giant cells
32
What are the 3 types of giant cell?
- Foreign bodies
- Langhan's giant cells
- Touton giant cells
33
What property of a giant cell differentiates it from monocytes/macrophages?
They are multinucleated
34
Identify the histological pics of different types of giant cells
See notes
35
What is a giant cell?
A collection of fused macrophages
36
What type of immune cell is found in chronic inflammation but not acute?
Lymphocytes
37
What are the 3 types of lymphocyte?
- B lymphocytes
- T lymphocytes
- Natural killer cells/null cell type
38
What is the purpose of B lymphocytes in chronic inflammation upon activation?
- Increase plasma cells
| - Increase IG production
39
What are the two types of T lymphocytes?
- CD4+ helper T cells
| - CD8+ cytotoxic T cells
40
What is the purpose of CD4+ helper T cells?
Secrete cytokines in immediate cell vicinity regulating other immune cells (e.g B cells/macrophages)
41
What is the purpose of CD8+ cytotoxic T cells?
Cell mediated immunity
42
What is the purpose of natural killer cells/null cell type? (2)
- Lyse tumour cells
| - Lyse infected cells
43
What is formed following chronic inflammation and what is it made up of? (3)
Inflammatory infiltrate
- Macrophages
- Lymphocytes
- Plasma cells
44
What are the possible consequences of chronic inflammation? (4)
- Tissue destruction/necrosis
- Healing due to fibrous tissue replacement
- Chronic non specific inflammation (granulation tissue)
- Chronic granulomatous inflammation
45
What are the 3 parts of fibrous tissue replacement healing in chronic inflammation? (3)
- Angiogenesis
- Fibroblastic proliferation
- Fibrosis
46
What is granulation tissue?
Vascularised fibrous tissue replacing fibrin clot
47
What does granulation tissue contain? (5)
- Loose connective tissue
- Lots of fluid
- Lots of blood vessels (angiogenesis)
- Fibroblasts
- Macrophages
48
Why does granulation tissue contain macrophages?
To clear debris
49
What is granulation tissue normally part of?
The repair process for existing defects
50
When can granulation tissue cause issues? (2)
- Too large
| - Issues with healing process
51
What is a granuloma?
Mass collection of mononuclear macrophages/granulation tissue
52
What is a granuloma a type of?
Inflammation
53
What are the two types of granuloma?
- Necrotising (caseating)
| - Non necrotising
54
Name a condition with non necrotising granulomas
Sarcoidosis
55
Name a condition with necrotising granulomas
TB
56
What is a useful purpose of a granuloma?
Destroying/isolating pathogens/foreign material
57
What negative effects can a granuloma have?
Tissue destruction
58
Why do necrotising granulomas cause problems?
Tissue necrosis means macrophage can't access granulomas
59
What pathogen is TB caused by?
Mycobacterium tuberculosis (MT)
60
What are the two types of Mycobacterium tuberculosis?
- MT Hominis
| - MT Bovis
61
How many individuals are affected by TB in the world?
1.7 billion
62
How many new cases of TB are there every year?
8 million
63
How many TB deaths are there every year?
1.6 million
64
What is the only disease that causes more deaths than TB every year?
HIV
65
What disease is TB often associated with in epidemics?
HIV
66
What defines a TB infection?
Presence of mycobacterium
67
Does TB necessarily lead to clinical manifestation?
No
68
What is the 1st stage of TB pathogenesis?
Primary tuberculosis
69
How long does the 1st stage of primary tuberculosis last?
0-3 weeks
70
What occurs in the 1st stage of primary tuberculosis?
MT enters macrophages by endocytosis mediated by macrophage receptors
71
What are the features of the 1st stage of primary tuberculosis? (4)
- Asymptomatic initially
- Fever
- Malaise
- Primary complex
72
What is there a delayed hypersensitivity to in primary tuberculosis?
MT antigens
73
What test detects the delayed hypersensitivity to MT antigens in primary tuberculosis?
Tuberculin - Mantoux skin test
74
What is the primary complex at the TB infection site caused by?
Local lymph node that has become fibrotic and calcified
75
How long does the second stage of primary tuberculosis last?
4-6 weeks
76
What occurs in the second stage of primary tuberculosis?
- T helpers 1 response activates macrophages to become bactericidal
- Phagolysome complex contains infection
- Granuloma formation
77
What type of T helper is involved in primary tuberculosis?
T helper 1
78
What forms a phagolysosome complex in the second stage of primary tuberculosis?
T helpers 1 releasing IFN-gamma stimulating macrophages to form it
79
How do T helpers 1 stimulate granuloma formation in the second stage of primary tuberculosis?
Conversion of macrophages into epithelioid histiocytes/giant cells
80
What are epithelioid histiocytes?
Activated macrophages resembling epithelial cells
81
What are the first 2 steps of TB?
- Primary infection
| - Primary complex
82
What 3 ways can a primary complex progress in TB?
- Healed lesion (scar)
- Progressive primary TB
- Latent lesions (dormant)
83
What is a TB primary complex? (2)
- Localised caesation
| - Tiny granuloma fibroclacific nodule at infection site
84
What type of TB can progressive primary TB become?
Milary TB
85
What is milary TB?
Potentially fatal TB form from massive lymphohematogenous dissemination of MT
86
What can latent dormant lesions progress to if reactivated?
Secondary TB
87
What occurs in secondary TB? (4)
- Initial lesions starts regrowing again
- Small nodule progresses to caverna (large cystic lesion)
- Leads to widespread caviating granulomatous inflammations
- Localised caseating destructive lesions
88
What can secondary TB progress to? (2)
- Progressive secondary tubculosis
| - Then malary TB
89
What do patients with unhealed primary TB have?
Widespread multiple small granuloma scabs
90
List the 3 markers of inflammation
- ESR blood test
- CRP blood test (C-reactive protein)
- Plasma viscosity (PV)
91
What needs to be disposed after TB and why? (2)
- Myobacterium
- Macrophages
=indigestable
92
What can be used to tell the stage of inflammation?
The type of WBC present
93
What does ESR blood test stand for?
Erythrocyte sedimentation rate
94
What does the ESR blood test measure?
The rate at which red blood cells separate from plasma and fall to bottom of test tube
95
What causes an increased ESR? (3)
- Increased proteins e.g fibrinogen covering red cells due to more inflammation
- Proteins stick to each other
- Cause RBCs to fall more quickly
96
What is the disadvantage of the ESR blood test?
Not specific for acute inflammation
97
What is a CRP blood test also known as?
Acute phase protein
98
What is the advantage of a CRP blood test compared to an ESR blood test and why?
Very specific - measures level of 1 specific protein, ESR = many proteins
99
What does CRP increase in response to?
When IL6 is released and activates complement cascade
100
Why does increased plasma viscosity indicate inflammation?
Loss of fluid in inflammation
101
What are the disadvantages to the PV test? (2)
- More difficult to perform
| - Not widely used
102
PV is more specific and sensitive than ESR or CRP when monitoring the activity of which condition?
Rhuematoid arthritis
