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Flashcards in MoD - Chronic Inflammation Deck (28):
1

What is the result of chronic inflammation?

What is the result of acute inflammation?

Repair and scarring

Resolution is possible

2

How does chronic inflammation arise?

May 'take over' from acute inflammation - if damage is too severe to be resolved within a few days

May arise de novo - some autoimmune conditions = RA
Chronic persistent infections - Viral hepatitis
Chronic low level irritation - reaction to foreign material

May develop alongside acute inflammation - in severe repeated or persistent irritation

Prolonged exposure to toxic agents

3

What does chronic inflammation look like?

Microscopic appearances are much more variable than acute inflammation

Most important characteristic = type of cell present

4

What types of cell are present in chronic inflammation?

Macrophages
Lymphocytes - B
(Plasma cell) and T type
Eosinophils
Fibroblasts/myofibroblasts

5

What are macrophages derived from?

What are their functions?

Blood monocytes

Phagocytosis and destruction of debris and bacteria
Processing and presentation of antigen to immune system
Synthesis of cytokines, complement components, blood clotting factors and proteases
Control of other cells by cytokine release
Stimulate angiogenesis - formation of new blood vessels
Induce fibrosis
Induce fever

6

What are the functions of lymphocytes?

What are the the two types and their functions?

Complex, mainly immunological
Process antigens
Secrete antibodies
Secreting cytokines
Killing cells

B lymphocytes = produce antibodies

T lymphocytes = control and some cytotoxic functions

7

What are plasma cells?

Differentiated antibody producing B lymphocytes

8

When are eosinophils present?

Allergic reactions
Parasite infestations
Some tumours e.g. Lymphomas

9

What is the function of fibroblasts/myofibroblasts?

Recruited by macrophages to make collagen

10

What are giant cells

What are the three types?

Where are they found?

Multinucleated cells made by fused macrophages

'Frustrated phagocytosis'

Langhans - TB

Foreign Body Type - Foreign material

Tout on - Fat necrosis

11

What are the cell types in..
Rheumatoid arthritis
Chronic gastritis
Leishmaniasis (protozoan infection)

Mainly plasma cells

Mainly lymphocytes

Mainly macrophages

12

What may the presence of a giant cell type help with?

Help to diagnose

13

What are four effects of chronic inflammation?

Excessive fibrosis - e.g. Gall bladder, cirrhosis, ulcers

Impaired function - e.g inflammatory bowel diseases (rarely increases function)

Atrophy - gastric mucosa (loose cells that produce gastric acid)

Stimulation of immune response - macrophage, lymphocytes interactions

14

What is an example of fibrosis?

What happens in this condition?

Chronic Cholecystitis

Repeated obstruction by gall stones.

Gall stones and thickened fibrotic wall

Repeated attacks of acute inflammation --> chronic inflammation

15

Why would gastic ulceration occur?

What are the two types and what causes them?

Imbalance of acid production and mucosal deference

Acute - alcohol, drugs

Chronic - helicobacter pylori

16

What disease result in impaired function?

What are the two types?

What are the symptoms of this disease

What causes these?

Inflammatory bowel disease - affecting small and large bowel

Ulcerative colitis and Crohn's

Rectal bleeding and diarrhoea

Idiopathic

17

What is the difference between ulcerative colitis and Crohn's?

What is a fistula?

Ulcerative colitis is superficial - diarrhoea and bleeding

Crohn's is trans mural - Strictures and fistula

Fistula - abnormal connection between two epithelium lined organs

18

What is the effect of chronic inflammation in cirrhosis?

What is the main cause of cirrhosis?

What shows on the histology?

Fibrosis and impaired function

Alcohol

Nodules - blue stained fibrous tissue, lots of collagen

Chronic inflammation with fibrosis --> cirrhosis

19

What is an example of increased function of chronic inflammation?

How does it increase the function?

Thyrotoxicosis - Graves' Disease


Antibodies reduced by plasma cells, stimulate TSH receptor, thyroid epithelia produced thyroxin

20

What is rheumatoid arthritis?

Autoimmune disease

Localised and systemic immune response

Localised chronic inflammation --> joint destruction

Systemic immune response can affect other organs and cause amyloidosis

21

What is a granuloma?

What is granulomatous inflammation?

What are the two general types of granuloma?

What is granulomas inflammation a characteristic of?

Cohesive group of macrophages and other inflammatory cells

Chronic inflammation with granulomas

Foreign body granuloma
Hypersensivity
/immune type granuloma

Crohn's disease

22

Why do granulomas arise?

Persistent, low grade antigenic stimulation

Hypersensitivity

23

What causes a granuloma?

Foreign material

Infections e.g. Mycobacteria - TB, lepropsy, syphilis

Unknown causes e.g. Sarcoidosis, Crohn's disease

24

What causes TB?

Why is it difficult of diagnosis?

How does it cause disease?

What is characteristic about a TB granuloma?

What are the outcomes?

Mycobacteria especially M.tuberculosis

Difficult and slow to culture - takes 6 weeks growth in a lab

By persistence and induction of cell-mediated immunity
Produces no toxins or lytic enzymes

Caseous necrosis in the middle

Arrest, fibrosis, scarring
Erosion into bronchus
TB empyema - formation of pus in pleural cavity
Erosion into blood stream --> effects multiple organs

25

Name 2 granulomatous diseases of unknown cause

Describe

Sarcoidosis - non case acting granuloma, giant cells, involves lymph nodes and lung. Young adult women. Variable clinical manifestations.

Crohn's disease - 'patchy' full thickness inflammation throughout bowel (regional enteritis)

26

Name Crohn's distinguishing factors from ulcerative colitis?

Crohn's
Discontinuous distribution
Affect any part of the GI tract
Deep inflammation
Cobble stone appearance to bowel mucosa
Granulomas often present
Anal lesions common
Bowel fistula more likely
Can't surgically remove anything for Crohn's as it affects who GI tract


Ulcerative colitis
Tends only to affect rectum
Superficial disease - Inflammation limited to mucus on and sub mucosa
Crypt abscesses common and distorted crypt architecture
Significant Increased risk of colon cancer - due to cell turnover
Most severe in distal colon
Colectomy often indicated

27

Why is it very important to distinguish between TB and sarcoidosis?

Sarcoidosis would treat with steroids to reduce immune response but would not want to give that to someone with TB

Both granuloma disorders

28

Define chronic inflammation

A chronic response to injury with associated fibrosis

It is NOT rapid, NOT immediate and NOT shortlived (acute inflammation)