L2 - Immunodeficiency and Autoimmunity

Question 1

Features of the innate immune system

Answer 1

Rapid
Non-specific
Works immediately
No memory

Question 2

What makes up the innate immune system?

Answer 2

Physical barriers
Chemical barriers
Resistance to pathogens (dendritic cells, macrophages, neutrophils)

Question 3

What makes up the adaptive immune system?

Answer 3

Humoral - antibodies
Specialised cells
- B cells (produce antibodies)
- T cells (helper and killer)

Question 4

Features of adaptive immunity?

Answer 4

Delayed response 
Specific 
Self/non self recognition 
Diversity in types of response 
Memory 

• protects against reinfection of specific antigens

Question 5

Where are B cells made/matured?

Answer 5

Made and matured in the bone marrow

Question 6

Where are T cells made and matured?

Answer 6

Made in the bone marrow but mature in the thymus

Question 7

Which cell type can be described as a gatekeeper of the immune system?

Answer 7

T helper cells CD4

Question 8

What activates t helper cells CD4?

Answer 8

Activated by binding of MHCII

Question 9

What to t helper cells CD4 do?

Answer 9

Presents antigen to cytoxic T cells CD8+ and naive B cells and undergo clonal expansion

Question 10

What do cytoxic T cells CD8+ do?

Answer 10

Bind MHCI

defects damaged MHC from infected/diseased cell, or non-self MHC directly

Question 11

When is IgM antibody used?

Answer 11

Primary response

Question 12

When is IgG antibody used?

Answer 12

Secondary response

Question 13

When is IgA antibody used?

Answer 13

Protects mucosal surfaces

Question 14

When is IgD antibody used?

Answer 14

B cell receptor

Question 15

When is IgE antibody used?

Answer 15

Antibody of allergy found on mast cells

Question 16

What is immunosuppression and what is it’s uses?

Answer 16

Natural or artificial process which can turn off the immune response either partially or fully

Uses: transplant rejection, autoimmune diseases, lymphoproliferative diseases

Question 17

What is immune deficiency?

Answer 17

Lack of an efficient immune system - susceptible to infection

NB: X-linked/autosomal recessive traits

Question 18

What is primary/secondary immunodeficiency?

Answer 18

Primary: very rare, often diagnosed in early childhood (recurrent infection often suggests immunological problems)

Secondary: acquired immunodeficiency, causes; stress, cancer, surgery, malnutrition, irradiation, AIDS, infection

NB can also be acquired due to immunosuppressive effects of drugs eg chemotherapy

Question 19

What is organ specific autoimmunity?

Answer 19

• affects single organ
• autoimmunity restricted to auto antigens of that organ
• overlap with other organ specific diseases
• autoimmune thyroid disease is typical (hasimotos and grave’s)

Question 20

What is hashimotos thyroiditis?

Answer 20

Destruction of thyroid follicles

• associated with autoantibodies to thyroglobulin and thyroid peroxidase
• leads to hyperthyroidism

Question 21

What is Graves’ disease?

Answer 21

Inappropriate stimulation of thyroid gland by anti-TSH-autoantibodies
- leads to hyperthyroidism

Question 22

Why does autoimmunity occur?

Answer 22

Autoreactive B cells
Autoreactive T cells
Defects in T cells

Question 23

which type of precursor cell will give rise to dendritic, macrophage and neutrophils?

Answer 23

myeloid precursor cells

Question 24

which type of precursor cell will give rise to B and T cells?

Answer 24

Lymphoid precursor cells

Question 25

what type of cell is CD4?

Answer 25

T helper cell

Question 26

what type of cell is CD8?

Answer 26

T cytotoxic cell

Question 27

Cells from innate immune system (macrophage, dendritic, NK cells and mast cells) are armed with Pattern Recognition Receptors (PRRs) - what do PRRs do?

Answer 27

recognise foreign material but they are not specific activate cytokines and surface molecules which will instruct the T cells to recognise the microorganism for the right immune response

Question 28

what is autoimmunity?

Answer 28

- theoretical concept | - genetically determined

Question 29

what is an autoimmune disease?

Answer 29

- breakdown of self-tolerance | - environmental factors acting on a favourable genetic background

Question 30

are autoimmune disease more common in women or men?

Answer 30

women (hormonal influence)

Question 31

what are some environmental triggers of autoimmunity?

Answer 31

infection trauma tissue damage smoking

Question 32

what is the most common autoimmune disease?

Answer 32

Rheumatoid Arthritis

Question 33

which autoimmune disease ischaracterised by inflammatory joint pathology associated with synovial joint inflammation and tissue destruction?

Answer 33

Rheumatoid Arthritis

Question 34

Susceptibility of what autoimmune disease is associated with defined HLA-DRB1 alleles?

Answer 34

Rheumatoid Arthritis

Question 35

What is systemic specific autoimmunity?

Answer 35

- affect several organs simultaneously - autoimmunity associated with auto antigens found in most cells of body - overlap with other non-organ specific diseases - connective tissue diseases are typical (SLE, scleroderma, polymyositis, sjogrens syndrome)

Question 36

is using inflammatory markers as a diagnostic test disease specific or non specific?

Answer 36

non specific

Question 37

is using autoantibody testing as a diagnostic test disease specific or non specific?

Answer 37

disease specific

Question 38

is using HLA typing as a diagnostic test disease specific or non specific?

Answer 38

disease specific

Question 39

why do we measure antibodies?

Answer 39

- diagnostic/early diagnosis/exclusion of diagnosis - sub typing of patients - monitoring of exacerbation or remission - cost effective

Question 40

what is HLA?

Answer 40

human leukocyte antigens HLA are antigens on most cells in your body. Your immune system uses HLA to recognize which cells belong in your body and which do not.

Question 41

which cells are used in antinuclear antibody testing? (ANA)

Answer 41

HEP 2000 cells large nuclei and most autoimmune conditions target DNA

Question 42

when would we carry out ANA tests?

Answer 42

when we suspect an autoimmune disorder

Question 43

which test would you carry out if you suspect an autoimmune disorder?

Answer 43

Antinuclear antibody (ANA) testing

Question 44

in a positive ANA test, what will you see under a microscope?

Answer 44

patterns of florescent markers - Immunofluorescence matters are disease specific

Question 45

what is immunosuppression?

Answer 45

a natural or artificial process which turns off the immune | response, partially or fully, accidentally or on purpose.

Question 46

when would we use immunosuppressive treatments?

Answer 46

- transplant rejection - autoimmune diseases - lymphoproliferative diseases

Question 47

what are causes of secondary/acquired immunodeficiencies?

Answer 47

- stress - surgery/burns - malnutrition - cancer - immunosuppressive drugs - irradiation - AIDS - infection