5 - Chronic Inflammation Flashcards

1
Q

What is chronic inflammation?

A

Chronic response to injury with associated fibrosis. Destruction and repair occuring at same time

  1. De novo e.g autoimmune and TB
  2. Take over from acute inflammation if damage too severe
  3. Alongside acute in repeated irritation
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2
Q

What are the main cells involved in chronic inflammation?

A

- Macrophages: phagocytosis, presentation of antigens, synthesis of proteins and enzymes and cytokines and free radicals, control other cells

- Lymphocytes: B make antibodies, T in control and cytotoxic

- Eosinophils: allergies and parasites

- Fibroblasts/Myofibroblasts: make collagen

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3
Q

How do monocytes get from blood to tissue?

A

Same process as with neutrophils. Once in tissue they differentiate into macrophage and they can live for weeks/months

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4
Q

How do you spot a macrophage histologically?

A

Foamy cytoplasm with slipper nuclei

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5
Q

Why are lymphocytes involved in chronic inflammation and what do they look like?

A
  • Macrophages release cytokines, e.g TNF, IL-1 to recruit lymphocytes
  • They can secrete cytokines for more recruitment of inflammatory cells
  • Hyperchromatic, larger nucleus than cytoplasm, 1-2 times the size of RBC
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6
Q

What do plasma cells look like histologically?

A
  • Usually nucleus with tail of cytoplasm
  • Clock face nucleus as chromatin around the outside
  • From B-cells and produce antibodies against persistent antigens
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7
Q

What do eosinophils look like histologically and when are they seen?

A
  • Tomato with sunglasses
  • Recruited by eotoxin as they contain proteins that are toxic to parasites but toxins damage human
  • Seen in parasitic infections and allergies with mast cells
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8
Q

What makes the macrophage different to neutrophils

A
  • They are involved in chronic inflammation
  • They can live for months and replicate
  • Can stimulate fibrosis, angiogenesis, fever, acute phase reaction
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9
Q

Why are fibroblasts involved in chronic inflammation?

A
  • They respond to chemokines and move to where they are needed where they secrete GAG’s, collagen and elastin
  • They can differentiate into myofibroblasts for wound healing
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10
Q

What are giant cells?

A
  • Fused macrophages with lots of nuclei
  • Occur when certain foreign bodies and bacteria are present
  • Involved in granulomatous inflammation
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11
Q

What are Langhans giant cells?

A

Nuclei arrange around periphery of cell in horse-shoe shape.

Seen mainly in TB

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12
Q

What are foreign body type giant cells?

A
  • Nuclei arranged randomly
  • Seen with foreign bodies
  • If small body then giant cell will have phagocytosed it, if large the body will stick to it’s surface
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13
Q

What are touton giant cells?

A

- Nuclei in ring towards centre of the circle

- Form in lesions where there is high lipid content, e.g xanthomas

  • Foam cells
  • Occurs in breast tissue and associated with fat necrosis
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14
Q

What are some situations where chronic inflammation occurs?

A
  • Autoimmune
  • Chronic persistent infections
  • After or alongside acute inflammations
  • Prolonged exposure to toxic tissues
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15
Q

What sre some of the possible complications of chronic inflammation?

A

- Atropy e.g gastric mucosa

- Impaired function e.g chronic IBS

- Excessive fibrosis e.g chronic cholecystitis, chronic peptide ulcers

- Tissue destruction

- Stimulation of immune response

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16
Q

Why can fibrosis during chronic inflammation lead to impaired function?

A
  • Excess collagen production and scar tissue can replace normal parenchymal tissue and impair function of organ
  • Myofibroblasts can cause contraction and limit blood flow further, e.g in cirrhotic liver the contraction will impair flow of portal blood flow so ascites
17
Q

What are some clinical examples of chronic inflammation?

A
  • Rheumatoid arthritis
  • Ulcerative colitis
  • Crohn’s disease
  • Chronic cholecystitis
  • Chronic gastritis
  • Cirrhosis
18
Q

What is chronic cholecystitis?

A
  • Repeated obstruction by gall stones in gall bladder
  • Repeated bouts of acute cholecystitis leads to chronic inflammation
  • Fibrosis of gall bladder wall
19
Q

What is chronic gastritis?

A

Acute: alcohol, taking NSAID’s like aspirin, stressful event,

Chronic: Helicobacter Pylori (spirilli bacilli) so use urea breath test

Signs: vomiting blood due to erosion of blood vessels at base, indigestion, pains, fullness, stomach ulcer

20
Q

What is the difference between ulcerative collitis and Crohn’s disease?

A
  • Ulcerative will have crypt abscess but Crohn’s wont. Crohns will have granulomas but ulcerative won’t
  • Ulcerative is continuous from rectum but Crohn’s can come at random intervals from mouth to anus
  • Will present with diarrhoea, rectal bleeding, especially with ulcerative as this is superficial
21
Q

What is a crypt abscess?

A
22
Q

What does cirrhosis look like histologically?

A
  • Nodules surrounded by circles of fibrosis (collagen)
  • Only cirrhosis if in whole liver
  • Chronic inflammation with fibrosis leading to disorganisation of architecture attempted regeneration
23
Q

What is a granuloma?

A
  • Form in chronic inflammation when body needs to deal with particles that are poorly soluble or difficult to erradicate e.g TB, splinter
  • Mass of granulation tissue
24
Q

What are the two types of granulomas?

A

Foreign body:

  • Contain macrophages, foreign body giant cells, epithelioid cells, few fibroblasts and few lymphocytes.
  • Aroun non-antigenic material e.g thread, no immune reaction

Hypersensitivity/Immune Type:

  • Macrophages, giant cells, more epithelioid cells, some fibroblasts and lymphocytes
  • Central necrosis (mainly TB)
  • Around insoluble but antigenic material that cause cell-mediated immunity e.g leprosy, fungi
  • Sarcoidosis, Wegener’s granulomatosis and Crohn’s
  • Can be harmful as occupy parenchymal space in organ
25
Q

What are the main causes of granulomas?

A
  • Foreign material
  • Infections (TB, leprosy, syphilis, aspergillosis)
  • Unknown (sarcoidosis and Crohn’s)
26
Q

What does a granuloma look like in TB?

A
  • Central necrosis
27
Q

What does granuloma look like in sarcoidosis?

A
  • Uknown reason for abnormal clumps of inflammatory cells forming granulomas, mainly in skin, lungs, lymph nodes
28
Q

What does a foreign body granuloma look like?

A
29
Q

What is Wegener’s granulomatosis? (Granulomatosis with polyangitis) ?

A

Autoimmune disease with necrosis in blood vessels and granulomotous inflammation