Chronic Inflammation

Question 1

What are the stimuli to arise chronic inflammation?

Answer 1

• Persistent infection
• Infection with viruses, mycobacteria, parasites and fungi
  _ Autoimmune disease
• Foreign material
• Some cancer

Question 2

Chronic inflammation is divided in what type of inflammations?

Answer 2

Granulomatous inflammation

Non granulomatous inflammation

Question 3

type of MCH that binds to T cells

Answer 3

CD4– MCH II

CD8- MCH I

Question 4

What does the T cells use for antigen surveillence

Answer 4

TCR complex

Question 5

Describe the development of T cells form their birth to activation.

Answer 5

1. Produced in bone marrow as PROGENITOR T CELLS
2. Develops in thymus
3. TCR undergoes rearrangement
4. Depending of type of activation progenitor cells become
5. 1 CD4 helper T cell
6. 2 CD8 cytotoxic T cell

Question 6

What are the requierments for T cell activation

Answer 6

Binding of antigen / MCH complex

Additional second signal

Question 7

Describe CD4 helper T cell activation

Answer 7

1. Extracellular antigen is phagocytosed, processed and presented via MCH class II by APC
2. B7 on APC binds to CD28 of CD4

Question 8

What are the subsets of CD4 helper T cell and their function

Answer 8

1. Th1 subset
   - Secretes IL 2 (t cell growth factor and CD8 T cell activator) and IFN gamma (MO activator)

Th2
- Secretes IL 4 and IL5 and IL 10

Question 9

What interleukin inhibits the Th1 phenotype and by what cells is secreted?

Answer 9

IL 10

By Th1 and Macrophages

Question 10

Describe CD8 cytotoxic T cell activation

Answer 10

1. Intracellular antigen is processed and presented on MCH I

2. IL 2 form CD4 Th1

Question 11

Describe the development of B cells form their birth to activation.

Answer 11

Immature B cells Produce in bone marrow

Undergo Ig rearrangement to become naive B cells that express surface IgM and IgD

Question 12

How are B cells activated

Answer 12

1. Antigen binding by surface IgM or IgD
2. B cell antigen presentation to CD4 helper T cell via Mch II
   and CD40 receptor of B cell binds to CD40L on helper T ccell

Question 13

What ILs needs to be secreted to have IgG, IgA, IgE

Answer 13

IL 4 and IL5

Secreted by Helper T cells

Question 14

What is the defying characteristic of a granuloma

Answer 14

Epitheloid histiocytes (MO with abundant pink cytoplasm)

Question 15

Difference between noncaseating and caseating granuloma

Answer 15

noncaseating Lack of central necrosis

caseating granuloma Central necrosis

Question 16

Causes of noncaseating granuloma

Answer 16

Reaction to foreign material 
Sarcoidosis
Beryllium exposure
Crohn Disease
Cat Scratch disease

Question 17

Cause of caseating granuloma

Answer 17

Tb and fungal infection

Question 18

In a patient with a caseating granuloma what are the stains that the pathologist needs to do to discard pathogens

Answer 18

GMS stain— fungla infection

AFB stain– TB

Question 19

Histological hallmark of ulcerative colitis?

Answer 19

Crypt abscesses

Question 20

Histological hallmark of Crohns disease?

Answer 20

Non caseating granulomas

Question 21

Describe granuloma formation

Answer 21

1. MO present antigen via MCH II to CD$ helper T cell
2. MO secretes IL 12— differentiate helper cell to Th1
3. Th1 secretes IFN gamma that convert MO to epitheloid histiocytes

Question 22

What does IL 12 does?

Answer 22

Induce CD4 helper T cell into Th1 subtype

Question 23

What molecule converts MO into epitheloid histiocytes?

Answer 23

IFN gamma