clinical immunology

Question 1

Result of inappropriate activation of immune system?

Answer 1

Autoimmunity

Question 2

Result of failure to switch off immune system?

Answer 2

Chronic inflammatory diseases

Question 3

Result of failure of response of immune system?

Answer 3

Immunodeficiency

Question 4

How else can the immune system be dysregulated?

Answer 4

Transplant rejection

Wrong kind of response is generated

Question 5

What diseases and treatment can affect the immune system?

Answer 5

1. immunosuppressant drugs (for organ transplantation)
2. Chemotherapy for cancer (e.g neutropenia)
3. Poor diet/stress

Question 6

What can antibodies and other immune components be used for? (e.g in drugs)

Answer 6

To suppress/detect/eliminate things

Question 7

What are monoclonal antibodies?

Answer 7

When antibodies are generated in the labs and used to treat disease (made by cloning a unique WBC)
Bind to antigen in body to try kill cancer cells for example
Used in drugs and clinical tests

Question 8

What can immune cells do in drugs?

Answer 8

Kill cancers

Modulate inflammatory disease

Question 9

Stages of allergic response

Answer 9

1. Dendritic cells take up antigen= APC MHC II
2. Dentritic APC activates naive T cell
3. Naive T cell differentiates into Th2 cell (made when APC produces IL-4,IL-5,IL-13)
4. Th2 cell activates B cell and releases more IL-4, IL-5 which induces class switching to IgE production of plasma cell
5. Plasma cell releases IgE
6. IgE binds to Fc receptor on mast cell
7. When antigen(allergen) binds to IgE= cross links receptors
8. This triggers mast cell degranulation= histamine is released

Question 10

Which cytokines released from APC when in contact with naive T cell favour Th2 production?

Answer 10

IL-4,IL-5,IL-9,IL-13

Question 11

Which cytokines released from APC when in contact with naive T cell favour Th1 production?

Answer 11

IL-12, IFN-Gamma, IL-23, IL-27

Question 12

How are allergies diagnosed?

Answer 12

Antibodies (IgE) are looked for in serum of blood (liquid part of blood)

Question 13

What happens in autoimmunity?

Answer 13

Tissues are chronically inflamed (can lead to systemic inflammation)
As a result immune system damages its cells and biomolecules

Question 14

Examples of autoimmune diseases

Answer 14

Multiple sclerosis
Diabetes
Arthritis

Question 15

How are autoimmune diseases diagnosed?

Answer 15

Look for antibodies in serum

The under microscope see if antibodies damage normal body tissue

Question 16

3 types of immunodeficiency and what they mean

Answer 16

1. Primary immunodeficiency (inherited from birth)
2. Secondary immunodeficiency (induced by drugs e.g immunosuppressants)
3. Acquired Immunodeficiency- AIDS - result of HIV A

Question 17

How is immunodeficiency diagnosed?

Answer 17

1. Under microscope look at number of cells- e,g count number of infected T cells= indicate how sick patient is
2. Flow cytometer

Question 18

What is flow cytometry

Answer 18

Cells are tagged with fluorescently labelled antibodies
These will bind to different CD markers on cell surfaces
Each cell has different CD marker
Shows deficiency of certain cells
e.g can show no. of neutrophils, macrophages, dendritic cells

Question 19

What are ‘bubble babies’?

Answer 19

They have NO B/T cells= no specific adaptive immunity

As they lack a gene in BCR and TCR rearrangement

Question 20

How can bubble babies be treated?

Answer 20

Bone marrow transplant

Question 21

How can immunodeficient patients be used?

Answer 21

To discover how small components of immune system work

Question 22

What are examples of innate immunity/inflammation in the clinic?

Answer 22

1. Failure of PRR- NOD like receptors-defects- leads to susceptibility of Crohn’s disease
2. Failure of early complement system- leads to systemic lupus, erythematosus, glomerulonephritis

Question 23

Treatment involving innate immunity/inflammation in the clinic

Answer 23

Type 1 interferon- used to treat Hepatitis C infection

Treatment of blocking TNF-Alpha used to treat patients with rheumatoid arthritis and inflammatory bowel disease

Question 24

What is neutropenia?

Answer 24

Abnormally low concentration of neutrophils - immunodeficiency

Question 25

What causes neutropenia?

Answer 25

Bone marrow disease Chemotherapy Radiation means more susceptible to infection due to low neutrophil numbers

Question 26

What are neutrophils like?

Answer 26

Made in bone marrow require high cell turnover- to maintain numbers They are constantly replaced- as they are short lived

Question 27

Clinical presentations of neutropenia

Answer 27

1. Rapid onset of Fever and sepsis (medical emergency) 2. Abscesses 3. Dental and perianal infections 4. Tonsillitis/pharyngitis 5. Sinusitis 6. Pneumonia 7. Fewer signs of inflammation (milder fever)- as less neutrophils are recruited to site of infection

Question 28

What organisms cause infection when a patient has neutropenia? (Immunodeficiency-weakened)

Answer 28

Opportunistic Commensal Organisms

Question 29

Which opportunistic commensal organisms cause infections in patients with neutropenia

Answer 29

1. Staphylococcus 2. E.coli 3. Pseudomonas 4. Fungal disease e.g aspergillus

Question 30

How is neutropenia managed?

Answer 30

1. Good barrier care e.g dental hygiene and wound care 2. Look for infection by culturing blood 3. Antibiotics- e.g antifungals 4. GCS-F- stimulate neutrophil production

Question 31

Clinical scenarios linked to dendritic-T cell interaction

Answer 31

1. HIV infection- failure of T helper cell 2. Failure of Th1 response= susceptibility to mycobacterium 3. Failure of self tolerance= thyroid autoimmunity (T cells attack own body)

Question 32

How does HIV invade the body?

Answer 32

hijacks adaptive immune system HIV infects host cell via CD4 and CCR5 (chemokine) in tissues Infected tissue containing T helper and dendritic cells then migrate to lymph node = further viral replication occurs

Question 33

What is the tropism for HIV? (Binds to)

Answer 33

CD4 receptor on T helper cell CCR5 on dendritic cell infects these cells

Question 34

What organisms cause opportunistic infections?

Answer 34

Cryptococcus Pneumocystis pneumoniae toxoplasmosis

Question 35

What infection occurs as a result of loss of B cell function?

Answer 35

Salmonella | Pneumoniae

Question 36

What infections occurs as a result of Th1 loss of fucntion?

Answer 36

susceptible to mycobacterium

Question 37

What does loss of Th1 mean?

Answer 37

Less activation of macrophages= less phagocytosis

Question 38

What diseases occur as a result of loss of T cell antitumour function

Answer 38

Non-Hodgkin's Lymphoma | Kaposi's sarcoma

Question 39

What diseases occur as a result of loss of T regulatory cell function

Answer 39

Autoimmune diseases e.g ITP= blood doesn't clot properly= excessive bleeding High immunoglobulin levels

Question 40

Examples of clinical scenarios linked to B cell

Answer 40

1. Antibody fails to recognise new antigen(e.g influenza vaccine- diff strains) 2. Failure of B cell antibody class switching (e.g IgE in allergy) 3. T cell help for wrong B cells- molecular mimicry