Chronic Inflammation

Question 1

What is chronic inflammation associated with?

Answer 1

greater tissue destruction

Question 2

What is inflammatory infiltrate a mixture of?

Answer 2

macrophages and B cells/ T cells

Question 3

Why are neutrophils not as present in chronic inflammation?

Answer 3

Neutrophils are short-lived cells that can undergo apoptosis and be cleared by macrophages

Question 4

What is the time period for chronic inflammation?

Answer 4

occurs over months, years and possibly forever

Question 5

What are the 3 main classes of chronic inflammation?

Answer 5

non-specific
specific (primary)
chronic granulomatous

Question 6

What are the characteristics of non-specific inflammation?

Answer 6

usually arises from acute inflammation when immune system does not eradicate infection

infiltrate dominated by tissue macrophages, T cells and B cells

characterised by a dynamic balance between tissue destruction and repair

Question 7

What is an example of non-specific chronic inflammation?

Answer 7

periodontitis

Question 8

What are characteristics of specific chronic inflammation?

Answer 8

can be non-granulomatous or granulomatous

excessively activated macrophages

no acute phase

Question 9

What are the causes of specific chronic inflammation?

Answer 9

non immunological agents (foreign body, inert noxious material like silica and asbestos)

immunological agents (infective organisms that grow in cells, hypersensitivity, autoimmune, infection by fungi protozoa or parasites)

Question 10

What is an autoimmune disease?

Answer 10

unwanted response to body’s own cells

loss (breach of tolerance to self antigens

chronic inflammation generates cells and molecules that destroy tissues

Question 11

What cells attack what in RA?

Answer 11

auto reactive T cells against antigens of joint synovium

Question 12

What bacteria can RA arise from?

Answer 12

porphyromonas gingivalis

Question 13

What enzyme does P gingivalis create?

Answer 13

PAD and proteases (gingipain)

Question 14

Why does P gingivalis cause an autoimmune reaction?

Answer 14

production of enzymes that cause peptide citrullination which causes a breach of tolerance and production of antibodies that attack citrullinated proteins

Question 15

What are the characteristics of chronic granulomatous inflammation?

Answer 15

Differs from normal chronic inflammation as the predominant cell types are modified activated macrophages;
– Known as epithelioid macrophages
– Giant cells (multi-nucleated: formed from fused epithelioid macrophages)
– B and T cells present in tissue.

Question 16

What are the causes of chronic granulomatous inflammation?

Answer 16

– Immunological (delayed hypersensitivity type reaction or invading pathogens)
– Non-immunological (Foreign body in tissue e.g. asbestos particles)

Question 17

What are the subsets of macrophages?

Answer 17

M1 - pro inflammatory
M2 - anti inflammatory

Question 18

What do macrophages release to cause tissue injury?

Answer 18

– Toxic oxygen metabolites
– Proteases
– Neutrophil chemotactic factors
– Coagulation factors
– AA metabolites
– Nitric oxide

Question 19

What do macrophages release to cause tissue repair?

Answer 19

– Process of fibrosis
– Growth factors (PDGF,FGF,TGF beta)
– Fibrogenic cytokines
– Angiogenesis factors (FGF)
– Remodelling collagenases

Question 20

What cells are in and around a granuloma?

Answer 20

macrophages
epitheloid macrophages
T cells producing IL-12, IL-2, IFN-Y

Question 21

What is an example of chronic granulomatous inflammation?

Answer 21

Orofacial Granulomatosis

Question 22

What is intestinal crohns granulomatosis called?

Answer 22

oral crohns

Question 23

Where are the granulomas in the oral cavity?

Answer 23

soft tissue

Question 24

What cells produce matrix metalloproteinases (MMPs)?

Answer 24

fibroblasts, dendritic cells, lymphocyte, neutrophil, macrophages, endothelial

Question 25

What is ECM?

Answer 25

complex structure that supports cells made of protein fibres (mostly collagen)

Question 26

What remodels the ECM in soft tissues?

Answer 26

MMPs

Question 27

What do MMPs do?

Answer 27

clear pathway for cell migration and angiogenesis

Question 28

What is bone formation?

Answer 28

osteoblastogenesis

Question 29

What is bone resorption?

Answer 29

osteoclastogenesis

Question 30

When is the skeleton remodelled?

Answer 30

every 10 years

Question 31

What do osteoclasts differentiate from?

Answer 31

macrophages

Question 32

What do osteoblasts produce?

Answer 32

Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL)
osteoprotogerin (OPG)

Question 33

What does RANKL activate?

Answer 33

RANK (the receptor) on osteoclasts

Question 34

If RANKL production is controlled, what is prevented?

Answer 34

bone resorption

Question 35

What does osteoprotogerin (OPG) do?

Answer 35

OPG inhibits RANKL function – therefore controlling bone resorption

Question 36

What ratio is important in preventing bone resorption?

Answer 36

RANKL/OPG ratio

Question 37

What is an excessive immune response concerning bone loss associated with?

Answer 37

increase in the RANKL/OPG ratio and ‘tips the balance’ toward bone loss/resorption

Question 38

What is the action of RANKL?

Answer 38

binds to RANK receptor on the surface of osteoclast precursor cells, stimulating their differentiation into osteoclasts and activating them.