Immunology

Question 1

What are the 2 types of immunity

Answer 1

innate (non-specific)

adaptive (specific)

Question 2

What are the components of innate immunity

Answer 2

-physical barriers (skin)
-mechanical factors (cough/ cilia)
-secretions (tears/ saliva)
-cellular factors (phagocytic/ NK cells)

Question 3

What are the 2 types of acquired immunity

Answer 3

Cell mediated- T cells

Humoral -B cells/ antibodies

Question 4

What is an antigen

Answer 4

Anything that brings about an immune response

and

anything that binds specifically to antibodies/ T-cell antigen recpetors.

Question 5

What are the actions brought about by antibodies binding to antigens

Answer 5

-lysis of bacteria
-neutralization of toxins
-opsonization (mark antigen for other cells to come and destroy)
-antibody dependent cell mediated cytotoxicity

Question 6

What cells produce antibodies

Answer 6

B cells that differentiate into plasma cells

Question 7

Where are antibodies produced

Answer 7

lymph nodes
spleen
bone marrow

Question 8

What are the 5 different classes of immunoglobulins

Answer 8

IgG
IgA
IgM
IgE
IgD

Question 9

Which is the heaviest Ig/ has the most antibody binding sites

Answer 9

IgM

Question 10

Which Ig is the most abundant in the plasma AND can cross the placenta

Answer 10

IgG

Question 11

Which Ig are characteristic of the
primary immune response
secondary immune response

Answer 11

primary= IgM
secondary= IgG

Question 12

Which Ig is responsible for protection of mucosal surfaces and how

Answer 12

IgA

production of secretions- tears, saliva, sweat, mucus
present in respiratory and GI tract

Question 13

What are the functions of IgE

Answer 13

anaphylactic reactions
anti-parasitic

stimulates mast cells, basophils and recruits eosinophils

Question 14

Which Ig cause complement activation

Answer 14

IgG IgM

Question 15

Functions of IgD

Answer 15

help in B cell differentiation
acts as a lymphocytic membrane receptor

Question 16

Functions of IgG

Answer 16

Neutralises toxins
opsonizes bacteria
characteristic of secondary immune response

Question 17

Functions of IgM

Answer 17

opsonizes and agglutinates bacteria
characteristic of primary immune response

Question 18

What cells are responsible for cell-mediated immunity

Answer 18

T cells

Question 19

What are the different types of T-cells

Answer 19

CD4- T helper
CD8- cytotoxic T cells
CD25- activated cytotoxic T cells

Question 20

What is the function of T-helper cells

Answer 20

present antigens and activates CD8, B cells and macrophages

Question 21

Once activated what do cytotoxic T cells do?

Answer 21

destroy infected target cells

Question 22

What is MHC and what is their role in the immune response

Answer 22

Major histrocompatibility complex- are genes that code for glycoproteins on membrane surfaces

they present antigens to T cells

Question 23

Which MHC class presents endogenous/ viral antigens to signal CD8 T cells

Answer 23

Class 1

Question 24

Which MHC class presents exogenous antigens to signal CD4 T cells

Answer 24

Class 2

Question 25

HLA associated diseases : B27 DR 2 DR 3 DR4

Answer 25

HLA B27= ankylosing spondylitis/ reiters disease HLA DR2= Good pastures HLA DR3= Hashimotos, Addisons, Myaesthenia gravis HLA DR4= T1DM

Question 26

Where do all lymphoid tissue originate from pleuripotent cells

Answer 26

Bone marrow

Question 27

WHere do cells that are destined to become T and B cells go?

Answer 27

T cells- Thymus B cells- stay in bone marrow

Question 28

What are the primary and secondary lymphoid organs

Answer 28

Primary= Thymus + Bone marrow Secondary= Lymph nodes, spleen, Mucosa Associated Lymphoid tissue (MALT)

Question 29

What are the 2 complement pathways

Question 30

What are the functions of different complements (C3a, C4a, C5a, C3b, C5-9)

Question 31

What are the types of hypersensitivity reactions

Answer 31

Type 1,2,3,4,5 (ACIDS)

Question 32

What is Type 1 hypersensitivity and what are the factors involved

Answer 32

Type 1- allergy/ anaphylaxis IgE antibodies bound to allergens/ antigens cause mast cells/ basophils to release mediators that give the symptoms of allergy

Question 33

What is Type 2 hypersensitivity and what are the factors involved

Answer 33

Type 2= cytotoxic cell mediated IgG and IgM involved Circulating antibodies interact with antigens on cell surfaces to cause cell death eg: rhesus incompatibility, haemolytic anaemia, ITP, transfusion reactions

Question 34

What is Type 3 hypersensitivity and what are the factors involved

Answer 34

Type3= Immune complex mediated IgG and IgM involved Antibody-antigen form complexes and cause inflammatory reactions where they land and activate COMPLEMENT cascades causing tissue destruction eg: SLE, RA, serum sickness, post-strep glumerulonephritis

Question 35

What is Type 4 hypersensitivity and what are the factors involved

Answer 35

Type 4= Delayed hypersensitivity T-cells involved Takes 2-3 days to develop eg: Tuberculin test, allergy tests, dermatitis, tissue/ organ transplant rejection

Question 36

What is Type 5 hypersensitivity and what are the factors involved

Answer 36

Type 5= Stimulating reactions Antibodies stimulate the receptors against which they act eg: myaesthenia gravis/ graves (TSH receptor antibodies cause prolonged secretion of thyroid hormones)

Question 37

Examples of phagocytic cells

Answer 37

neutrophils, monocytes, macrophages, kuppfer cells

Question 38

Eg of infective causes of Type 3/ immune complex disease

Answer 38

post-strep glomerulonephritis Hep B/C CMV Malaria

Question 39

What antibodies/ antigens (A/B) does someone with a blood group O have

Answer 39

AB antibodies (can only receive from O) No antigens (universal donor)

Question 40

What antibodies/ antigens (A/B) does someone with a blood group AB have

Answer 40

No Antibodies (universal recipient) AB antigens

Question 41

What antibodies/ antigens (A/B) does someone with a blood group A have

Answer 41

Group A: Antibodies-B Antigens- A Group B: Antibodies-A Antigens-B

Question 42

What are Kinins and some of their functions

Answer 42

Kinins are polypepides/ proteins/ enzymes Vasodilation increased vascular permeability attract phagocytes

Question 43

Which conditions show a high titre of: -ANCA -pANCA -AMA -anti-SMA + ANA + dsDNA -anti-EMA + ttG -anti-CCP -anti-Scl70

Answer 43

ANCA= vasculitis/ polyangitis/ UC pANCA= PSC AMA= PBC anti-SMA/ ANA/ dsDNA= SLE/ autoimmune hepatitis anti-EMA/ ttG= coeliacs anti-CCP= RA anti-SCL70- systemic scelroderma

Question 44

What are the effects of Thromboxane

Answer 44

vasoconstriction increased vascular permeability aggregation of platelets

Question 45

Timeframes and management of hyperacute rejection acute rejection

Answer 45

Hyper acute= mins-hrs [remove donor organ] accelerated acute= 2-4 days acute= 1week- 3months [corticosteroids] chronic= months-years [ciclosporin/ steroids]

Question 46

Cause and management of hereditary angio-oedema

Answer 46

Caused due to SERPING1 gene mutation causes reduced levels/ reduced function of C1 esterase inhibitor causes increased levels of bradykinin causes inflammation and increased vascular permeability= oedema

Question 47

What cells produce leukotrienes and what are the actions of leukotrienes

Answer 47

Mast cells Leukotrienes cause: vasoconstriction bronchoconstriction

Question 48

MOA of ciclosporin in immunosuppression

Question 49

What do the following hepatitis antigens/ antibodies indicate anti-HBs anti-HBc anti-HBe HBsAg HBcAg HBeAg IgG HBcAg IgM HBcAg

Answer 49

anti-HBs (surface)- immunity due to vaccine/ recovery from prev infection anti-HBc (core)- prev/ current infection anti-HBe (envelope)- persistent=chronic infection/ less infective HBsAg- acute infection HBcAg- acute infection HBeAg- highly infective IgG HBcAg- pev infection (G=gone) IgM HBcAg- acute infection (M= mantenaint)

Question 50

What are the mediators in the 2 phases of type 1 hypersensitivity response

Answer 50

Early phase: -histamine -prostaglandin D2 -leukotrienes C4, D4 -serotonin -proteases late phase: prostaglandins leukotrienes bradykinin

Question 51

What produces the mediators in the early and plate phases of a type 1 hypersensitivity reaction

Answer 51

early= mast cells late= mediators are products of metabolism of arachadonic acid

Question 52

Why should hydrocortisone be given following anaphylaxis

Answer 52

to prevent the late phase of type 1 hypersensitivity rxn (prevents formation of prostaglandins and leukotrienes)