Immunology in Medicine

Question 1

Types of vaccines

Answer 1

live “attenuated” (handicapped) viruses, killed viruses or bacteria, “subunit vaccines” - purified proteins

Question 2

Vaccination process

Answer 2

T and B cells recognise foreign antigens, are activated and produce antibodies

Question 3

Tolerance

Answer 3

mechanisms to prevent responses to self proteins - kill or control self-attacking T and B cells

Question 4

Autoimmunity

Answer 4

incomplete tolerance, T and B cells attack self molecules, involves genetic factors and environmental factors (infection)

Question 5

Types of autoimmune diseases

Answer 5

systemic, organ specific

Question 6

Systemic Lupus Erythematosus (SLE)

Answer 6

Antibodies form against many cell proteins. Form deposits of “immune complexes” in tissues.
Many tissues are damaged by antibody deposits - skin rashes, kidney failure, heart, joints.
Many and varied symptoms, including joint pain and “butterfly rash” on face.

Question 7

Type I Diabetes

Answer 7

(Insulin-dependent diabetes mellitus- IDDM):
Insulin producing cells in pancreas specifically destroyed by T cells
The T cells recognise a number of different “self” antigens including insulin
Loss of insulin production = loss of control of blood glucose levels
Treated with insulin injections or insulin pumps

Question 8

Rheumatoid Arthritis

Answer 8

Antibody, T cell activation, chronic inflammation
Attack on joints, swollen joint capsules
Bone erosion
Now treated with an antibody to block action of an inflammatory cytokine - TNFa

Question 9

Multiple sclerosis

Answer 9

Affects nerves of central nervous system
Problems with sensation, movement, vision
Myelin (fatty) sheath surrounding nerve axons is attacked, which disrupts transmission of nerve signals
T cell-mediated, + antibody involvement?

Question 10

Limitation of transplantation

Answer 10

Recognition of “non-self” molecules by the immune system

Question 11

Requirement for transplantation

Answer 11

donor and recipient must be well matched for “HLA” antigens, immunosuppressive therapy eg. Cyclosporin (patient becomes more susceptible to infections and cancer)

Question 12

Blood groups

Answer 12

A, AB, B, O - produce antibodies in plasma to the A and B antigens the cells don’t have

Question 13

Blood transfusion

Answer 13

immediate response to antigen mismatching

Question 14

ABO blood typing

Answer 14

red cells clump together if mixed with an antibody that recognises an A or B antigen on its surface

Question 15

Allergy

Answer 15

inappropriate immune response to food or environment, antigens=allergens

Question 16

Hygiene hypothesis

Answer 16

suggests our overly clean environment is not providing appropriate immune stimulation in early life

Question 17

Allergy steps

Answer 17

sensitisation to allergen - production of IgE - IgE binds to mast cells - histamine released (degranulation) - symptoms caused (severe=anaphylactic shock)

Question 18

Immunodeficiency disease causes

Answer 18

genetic, chemical/biological agent exposure, stress (lowers immune function, not disease)

Question 19

SCID

Answer 19

severe combined immunodeficiencies: affect both T and B cells, extreme susceptibility to all infections, typically die

Question 20

Primary immune deficiency

Answer 20

hereditary or acquired, immune deficiency the cause of the disease, low frequency eg. Antibody deficiency, phagocytic disorders, cell-mediated immunity deficiency, complement deficiency

Question 21

Secondary immune deficiency

Answer 21

immune deficiency the result of another cause or condition eg. Burns, leukaemia, chemotherapy, immunosuppressants, infections such a HIV

Question 22

AIDS

Answer 22

acquired immunodeficiency syndrome: HIV infects CD4 surface molecule - causes death of CD4 cells - leads to immunodeficiency (AIDS)