Path Mechanisms I 2: Models of PD

Question 1

What was the early model of PD Pathogenesis?

Answer 1

Simply that the bacteria in plaque directly caused PD

Technically correct but too simple

Question 2

What questions did the research from the 1980’s ask?

Answer 2

How do bacteria cause PD?
Why doesn’t everyone get PD?
Why does PD cause bone loss and AL?

Question 3

After the 1980s research what “middle man” was added to the early model?

Answer 3

the host immuno-inflammatory response

Question 4

What are the 4 stages of the currently accepted PD model?

Answer 4

1. Specific Pathogenic Bacteria
2. Host Immuno-inflammatory response
3. CT and Bone Metabolism
4. Clinical Expression of Disease Initiation and Progression

Question 5

What factors into Specific Bacteria inducing a host response (1 –> 2)?

Answer 5

Antigens
LPS
Other Virulence Factors

Question 6

What factors into Host Response Causing CT/Bone Metabolism (2 –> 3)?

Answer 6

Matrixmatalloproteinases (MMP)
Cytokines (IL-1B)
Prostaglandins (PGE2)

Question 7

What Factors into to Host Response repelling bacterial insult (2 –> 1)?

Answer 7

Antibodies

PMNs

Question 8

How is the immune response a double edged sword?

Answer 8

It intends to be protective (antibodies/PMNs) but in some patients it is destructive.

Question 9

What causes the inflammatory response to be destructive?

Answer 9

Too much:

Destructive enzymes
Inflammatory mediators
Immunopathology