Immunology of Autoimmune Disease

Question 1

monogenic disorder

Answer 1

single gene defect causes an autoimmune disease eg IPEX syndrome

Question 2

IPEX

Answer 2

characterised by overwhelming systemic autoimmunity

Question 3

symptoms of IPEX

Answer 3

severe infections, diarrhoea, eczema, very early onset insulin dependent diabetes mellitus

Question 4

when does IPEX present

Answer 4

early childhood

Question 5

what is the treatment for IPEX

Answer 5

cure: hematopoietic stem cell transplantation

supportive care: Is drugs plus total parenteral nutrition

Question 6

what is IPEX caused by

Answer 6

mutation in FOXP3 gene - essential for the development of regulatory T cells

Question 7

how is IPEX passed on

Answer 7

X linked

Question 8

describe central and peripheral tolerance mechanisms in normal people

Answer 8

central - removal of self reactive lymphocytes in primary lymphoid tissues

peripheral - inactivation of self reactive lymphocytes that escape central tolerance

Question 9

what are Tregs

Answer 9

regulatory T cells that modulate the immune system and prevent autoimmune diseases

Question 10

what happens to Tregs in IPEX

Answer 10

failure of peripheral tolerance due to defective regulatory T cells (Tregs)

Question 11

do Tregs modulate central or peripheral tolerance

Answer 11

peripheral

Question 12

what does mutations in FOXP3 gene cause

Answer 12

loss of function of regulatory T cells - uninhibited T cell activation

Question 13

what is the influence of HLA genes in autoimmune disease

Answer 13

1000s of variants of HLA genes - some variants are associated with inc risk of developing a specific autoimmune disease

Question 14

how do T cells recognise antigens

Answer 14

when they are presented by MHC(HLA) molecules

Question 15

what causes the sex differences in autoimmune diseases

Answer 15

different hormonal influences on lymphocyte function

alteration of the course of some autoimmune diseases during pregnancy

Question 16

molecular mimicry

Answer 16

similarities between foreign and self peptides are sufficient enough to result in the cross activation of autoreactive T or B cells by pathogen derived peptides - can contribute to autoimmune disease

Question 17

name 4 potential mechanisms for autoimmune disease

Answer 17

molecular mimicry
antigen sequestration
super antigens
unrelated bystander activation

Question 18

unrelated bystander activation

Answer 18

t and b cells just activated - dk why

Question 19

antigen sequestration

Answer 19

a sequestered antigen (one that is not recognised by the immune system) is released due to trauma etc

Question 20

what do superantigens cause

Answer 20

hyperresponsiveness eg TSST-1 in TSS

Question 21

what type of hypersensitivity reaction is SLE

Answer 21

III

Question 22

what type of hypersensitivity reaction is RA

Answer 22

IV

Question 23

what happens in glomerulonephritis associated with SLE

Answer 23

deposition of IgG and complement C3 in granular pattern

Question 24

what happens in glomerulonephritis associated with goodpastures

Answer 24

linear deposition of IgG along the glomerular basement membrane