Autoimmune Disease 2

Question 1

Autoantibodies are not always?

Answer 1

Pathogenic

Question 2

DiGeorge syndrome is due to?

Answer 2

Failur elf migration of 3rd and 4th branchial arches

Can cause thymocytes aphasia, congenital heart defects, cleft palate, absent parathyroid

Question 3

IPEX immune dysregulation polyendocrinopathy enteropathic x linked?

Answer 3

Rare x linked mutation FoxP3 gene

Can cause iBD

Question 4

HLA system is encoded on chromosome?

Answer 4

6

Question 5

HLA system classes?

Answer 5

1- A,B,C

2- DR, DP and DQ

Question 6

How many people are affected by coeliac disease?

Answer 6

1%

Question 7

Manifestations of cealic?

Answer 7

Anaemia, vitamin deficiency, weight loss, loose stool, poor growth in children

Question 8

What is coeliac disease?

Answer 8

Is autoimmune but triggered by exogenous antigen gluten

Question 9

What do you see in coeliac disease microscope?

Answer 9

Villus atrophy, crypt hyperplasia, and lymphocyte infiltration
HLA- DQ2 and DQ8- both or either

Question 10

What happens to gliadin?

Answer 10

Gut tissue transglutamine 2 enzyme to form gliadin peptide

HLA DQ2/8 present these peptides to T cells

Question 11

How many Europeans express HLA-DQ2/8?

Answer 11

30-50%

Question 12

Molecular mimicry?

Answer 12

Presentation of viral peptides or CD4 causes T cell activation
Viral peptide is similar to host derived peptide, T cell initiates inflammation

Question 13

Autoimmune haemolysis after mycoplasma pneumoniae?

Answer 13

Mycoplasma antigen has homozygous to I antigen on red blood cells
IgM antibody to mycoplasma may cause transient haemolysis

Question 14

Clinical onset of diabetes type 1 only happens when you have lost what percent of the pancreas?

Answer 14

90%

Question 15

HLA class II alleles and risk?

Answer 15

DR3 or DR4 risk is 6

DR3 and DR4 risk is 15

Question 16

Lupus seen mostly in?

Answer 16

Asian/ African descent, women

Question 17

What predisposes to lupus?

Answer 17

Deficiency C1q, C2 and. C4 because can’t clear immune complexes

Question 18

Pemphigus disease?

Answer 18

Thin walled Bullare on skin and mucus membranes- rupture easily
Target is the intracellular cement protein desmoglein 3 in superficial skin layers

Question 19

Plasmapheresis?

Answer 19

Antibody is causing disease, therefore removal e.g vasculitis

Question 20

Molecular mimicry?

Answer 20

Epitopes relevant to the pathogen are shared with host antigens

Question 21

Conditions for molecular mimicry?

Answer 21

Correct MHC molecule to present epitope

Correct T cell to recognise it

Question 22

What happens at molecular level in SLE?

Answer 22

Anti nuclear antibodies, apoptosis

Answer 23

Indirect immunoflourescence in blood

Solid phase immunoassay in blood

Direct immunofluorsence in tissues

Question 24

Drugs for immunomodulation?

Answer 24

Systemic corticosteroids

Small molecule immunosuppressive drugs, methotrexate

Question 25

Examples of molecular mimicry?

Answer 25

Autoimmune haemolysis after mycoplasma pneumoniae, homology to i antigen on rbc Rheumatic fever, streptococcal infection then affects joints heart skin and brain Protein 2C from coxsackie virus has homology with islet cell antigen glutamic acid decarboxylase

Question 26

Presentation of lupus?

Answer 26

``` Butterfly rash Photosensitivity Hives Serositis- pleurisy, pleural effusion, pericarditis Renal Nephritis Pulmonary fibrosis Joint pain autoimmune cytopenia ```

Question 27

SLE is most common in?

Answer 27

Women of reproductive age who are Asian and African descent

Question 28

What may be the cause of lupus?

Answer 28

Antinuclear antibodies, and division apparatus Immune complex disposition Disordered apoptosis Classical component deficiency 1,2,4

Question 29

Indirect immunoflorescence?

Answer 29

Glass slide with tissue Then patient serum with antibodies or not Then detection antibody with fluorescent marker, then look through microscope

Question 30

What happens in ELISA?

Answer 30

``` TgT solution Then samples with antibody Then anti igA antibody binding to igA Fc Convalenly linked to horse radish peroxidase Then trigger added ```

Question 31

Pemphigoid?

Answer 31

Antibody mediated disease Target is antigen at dermo-epidermal junction Thick walled Bullae

Question 32

Immunosuppressive drugs are?

Answer 32

Systemic corticosteroids Methotrexate Azathiprine Cyclosporine