MoD S4 - Chronic Inflammation Flashcards Preview

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Flashcards in MoD S4 - Chronic Inflammation Deck (32):
1

What is chronic inflammation?

Chronic response to injury with associated fibrosis

2

How does chronic inflammation arise?

Give examples for each 'mechanism'

May take over from acute inflammation:
- If damage is too severe to be resolved quickly

May arise de novo:
- Some autoimmune conditions (Rheumatoid arthritis)
- Some chronic infections (Viral hepatitis)
- Chronic low level irritation

May develop alongside acute inflammation:
- If severe persistent or repeated irritation

3

How is chronic inflammation characterised?

What is the most important characteristic?

Characterised by the microscopic appearance (which is much more variable then acute inflammation)

Most important characteristic is the cell type present

4

What cell types might be involved with chronic inflammation?

Macrophages
Lymphocytes
Plasma cells
Eosinophils
Fibroblasts/myofibroblasts

5

What is frustrated phagocytosis?

When macrophages encounter a large foreign body that they cannot internalise (E.g. an implant) they experience frustrated phagocytosis where they attach to the foreign body and secrete superoxides, free radicals and lysosomal contents to damage it.

Inability to internalise foreign body may also result in giant cell formation

6

What is a giant cell?

A multinucleate cell made by fusion of macrophages

7

What types of giant cells are there?

Langhans
Foreign body type
Touton

8

Give a few examples of chronic inflammation and the major inflammatory cell type present in these conditions

Rheumatoid arthritis - Plasma cells

Chronic gastritis - Lymphocytes

Leishmaniasis - Macrophages

9

Langhans Giant cells appear in what conditions?

Granulomatous conditions (E.g. Tuberculosis)

10

Touton giant cells appear in what conditions?

Appear during fat necrosis

11

When do foreign body type giant cells appear?

When the body is exposed to foreign substances (E.g. Sutures, implants or bone fragments)

12

Why is looking at giant cell type useful?

Can aid diagnoses (Different types appear in different conditions)

13

List the major effects of chronic inflammation

Fibrosis
Impaired or increased function
Atrophy
Stimulation of immune response

14

What causes chronic cholecystitis?

What is the major effect of chronic inflammation on the gallbladder?

Repeated obstruction of the cystic duct by gall stones from the gall bladder

Repeated acute inflammation leads to chronic inflammation

Leads to fibrosis of the gallbladder wall

15

How does gastric ulceration occur?

What is the end result?

Acute gastritis - Alcohol, drugs

Chronic gastritis - Helicobacter pylori

Ulceration occurs due to the imbalance between acid production and mucosal defence that these condition result in

The affected gastric wall will become fibrotic

16

What is inflammatory bowel disease?

How does it present?

Idiopathic chronic inflammatory disease affecting large and small bowel, comes in two forms:

Ulcerative colitis:
- Superficial
- Diarrhoea, bleeding

Crohn's Disease:
- Transmural (across the entire wall)
- Diarrhoea, bleeding
- Strictures (narrowing of bowel)
- Fistulae (abnormal connection between the bowel and another epithelium lined organ)
- Cobblestone ulceration

Acute inflammation appears in the mucosa/crypts

17

What is the result of Inflammatory bowel disease?

Impaired function (causing diarrhoea)

18

What is cirrhosis?

What are the common causes of cirrhosis?

Chronic inflammatory process of the liver

Alcohol
Hepatitis A, B, C viruses
Immunological
Fatty liver disease (associated with diabetes and obesity)
Drugs and toxins

19

What does cirrhosis lead to?

Fibrosis causing increasingly disorganised architecture

Impairment of function

Normal liver tissue replaced with 'nodules'

Cholestasis (bile cannot flow out of the liver)

20

When can chronic inflammation cause increased function?

In Thyrotoxicosis (Grave's Disease)

21

When can chronic inflammation cause atrophy?

What are the consequences in this case?

Atrophic gastritis

Auto-antibodies destroy parietal cells (Secrete gastric acid) and cause atrophy of gastric mucosa and impairment of function

22

What is rheumatoid arthritis?

How is chronic inflammation involved?

Autoimmune disease that results in loalised and systemic immune response

Systemic immune response can affect organs apart from joints and can cause amyloidosis

Localised chronic inflammation leads to joint destruction

23

What is meant when you say 'There is overlap between chronic inflammation and the immune response'

Immune diseases can cause pathology by chronic inflammation

Also, chronic inflammatory processes can stimulate immune responses

24

What is granulomatous inflammation?

What is a granuloma?

Chronic inflammation with granulomas

An accumulation of epitheloid histiocytes (modified, immobile macrophages) surrounded by lymphocytes

25

How do granulomas arise?

Persistent, low grade antigenic stimulation

OR

Hypersensitivity

26

What are the main causes of granulomatous inflammation?

Mildly irritant foreign material

Infections:
- Mycobacteria (tuberculosis, leprosy)
- Other infections (Some fungi)

Unknown causes:
- Sarcoid
- Wegeners' granulomatosis
- Crohns' Disease

27

What causes tuberculosis and how does that cause disease?

Caused by mycobacterium (especially M. tuberculosis)

Causes disease by persistence and induction of cell mediated immunity (no toxins or lytic enzymes)

28

Describe a tuberculosis granuloma

Has the same general structure as a granuloma however:

- Area of caseous necrosis in the centre (surrounded by epitheloid histiocytes)

Giant cells (Langhans' type) present

29

What are the outcome of tuberculosis?

Arrest (stops the TB and localises it - Dormant TB)
Fibrosis

Scarring

Erodes into the bronchus and causes acute inflam.

Tuberculous empyema (collection of pus in the pleura)

Erosion into the bloodstream

30

What can happen if tuberculosis erodes into the bloodstream?

Many bugs:
- Miliary (systemic) tuberculosis

Few bugs:
- Single organ tuberculosis

31

What are the similarities in morphology between tuberculosis and BCG?

Both result in the formation of granulomas

32

List some granulomatous infections and idiopathic granulomatous diseases

Infections:
- Tuberculosis
- Syphilis
- Leprosy
- Chronic fungal infections
- Cat scratch disease

Idiopathic:
- Sarcoidosis
- Crohns'