Immunology 4

Question 1

How does T cell kill each other?

What disorder is this called?

Answer 1

Fas : FasL interaction - pathway

Autoimmune lymphoproliferative syndrome;
CHAI - CTLA4 haplo-insufficiency
LATAIE - LRBA deficiency - decreased CTLA4 expression

Question 2

Peripheral T cell tolerance mechanisms - 4 types?

Answer 2

1. CTLA4/PDL-1
2. Anergy ( Only signal 1 )
3. Clonal ignorance - ignore low antigen in privileged sites - brain/eye/testis
4. Treg cells

Question 3

T reg cells express what CD?

Answer 3

CD25

IL2R

Question 4

IL 17 stimulates what and important in pathogenesis of what disease?

Answer 4

IL17 stimulates keratinocytes

IL 17 - psoarisis

Question 5

Follicular helper T cells secretes what and the function?

Answer 5

IL21 - migrate to lymphoid follicles and help B cell do anything ( affinity maturation, class switching)

Question 6

Atopic dermatitis has elevated Ig what?

Answer 6

Ig E

Question 7

Mepolizumab is anti IL5 - so for what asthma?

Omalizumab is anti-IgE - so for what asthma?

Answer 7

Mepolizumab - refractory oesinophilic asthma

Omalizumab - allergic asthma ( IL4 = Ig E mediated)

Question 8

CD8 cells activated by what cells?

Answer 8

Dendritic cells

Question 9

Early phase asthma composed of?

Late phase asthma composed of?

Answer 9

Early - vasoactive mediators from mast cells

Late - influx of leucocytes esp. eosinophils ( steroid is good here)

Question 10

B cells - how it recognises Antigen?

Answer 10

SmIg

Question 11

HLA I expressed in what cells?

HLA II expressed in what cells?

Answer 11

HLA I = all cells (nucleated cells) except RBC

HLA II = specialised APC

Question 12

MHC I complex assembled where?

Answer 12

MHC I assembled in golgi

Question 13

How viruses survive by affecting the MHC I?

• HSV
• Adenovirus
• CMV

Answer 13

HSV = TAP inhibitor protein = Hinders transport of peptides onto MHC

Adenovirus = Anchors MHC in ER

CMV = Chances of binding MHC low - accelerate peptides out of MHC

Question 14

How cross presentation occurs for CD8 and CD4?

Answer 14

CD8 for EXTERNAL antigen when leaked into cytoplasm

CD4 for INTERNAL antigen when autophagy occurs - peptides is FOREIGN

Question 14

How cross presentation occurs for CD8 and CD4?

Answer 14

CD8 for EXTERNAL antigen when leaked into cytoplasm

CD4 for INTERNAL antigen when autophagy occurs - peptides is FOREIGN

Question 15

How HLA causes what transfusion disorder?

Answer 15

Platelet refractoriness

TRALI

Question 16

Contraindications for immunotherapy?

Answer 16

Malignancy
Autoimmune disease
Acute illness
Asthma + FEV1 < 70%
B-blockers

Question 17

Allergic rhinitis - gold standard test?

Food allergy - gold standard test?

Insect sting - gold standard test?

Anaphylaxis - good test?

Mastocytosis - good test?

Answer 17

Rhinitis = skin prick test = +ve if > 3mm at 15 minutes

food = Oral food challenge

Insect = intradermal test - high sensitivity

anaphylaxis = Serum tryptase levels

Mastocytosis = D816 kit in plasma and BM, serum tryptase > 20

Question 18

Can mast cell degranulation tells you IgE mediated or non-IgE mediated?

Answer 18

NO

Question 19

Penicillin has rare cross-sensitivity with cephalosporins - what drug?

Answer 19

1st and 2nd generation cephalosporins

cefaclor and cefalexin

Question 20

What drug-meds that HIV patient commonly has allergy to?

-for some reason-

Answer 20

Sulfonamides

Question 21

Chronic idiopathic urticaria - clinical features and tx?

Answer 21

Pruritic hive like lesions - last < 24 hours + intermittent for > 6 weeks

Treatment = Non-sedating anti Histamines H1

2nd line = Omalizumab ( anti IgE)

3rd line = cyclosporin

Question 22

Roles of steroids in SJS/TEN?

Answer 22

No, referral to burn unit

Question 23

Treatment of GPA/EPA/Anti-GBM disease/PAN - what’s the common treatment?

PLEX role in ANCA vasculitis?

Answer 23

Induction : Prednisolone and CYP

Maintenance : Prednisolone + RITUX - less relapse

PLEX NO ROLE unless hemoptysis/ lung hemorrhage

Question 24

Cryoglobulinemia vasculitis types and clinical features?

Answer 24

Type I - all Ig Monoclonal
Type II - all Ig Polyclonal
Type III - all Polyclonal + RF

Acral ischemia ( can be cold induced), Necrotic ulcers
MGUS + Hyper viscosity
Low C4

Question 25

Kawasaki disease treatment?

Answer 25

Aspirin

IVIG - reduces coronary artery aneurysms

Question 26

Risk factors of relapse in AAV? - anca a/w Vasculitis?

Answer 26

Young
PR3 - C anca
GPA
chronic nasal carriage of staph aureus

Question 27

Hyperacute rejection are what mediated?
Acute rejection are what mediated?
Chronic rejection are what mediated?

Answer 27

Hyperacute = Antibody mediated - IgM or antibodies to HLA proteins

Acute - DIRECT allo-recognition

Chronic - INDIRECT allo-recognition ( T cells react to self - but actually foreign HLA)

Question 28

Hyperacute rejection are what mediated?
Acute rejection are what mediated?
Chronic rejection are what mediated?

Answer 28

Hyperacute = Antibody mediated - IgM or antibodies to HLA proteins

Acute - DIRECT allo-recognition

Chronic - INDIRECT allo-recognition

Question 29

Hyperacute rejection are what mediated?
Acute rejection are what mediated?
Chronic rejection are what mediated?

Answer 29

Hyperacute = Antibody mediated - IgM or antibodies to HLA proteins

Acute - DIRECT allo-recognition ( Donor HLA antibodies)

Chronic - INDIRECT allo-recognition ( Processed donor proteins)

Question 30

What is Donor specific antibodies detection vs HLA cross matching?

Answer 30

DSA

• single antigen beads attach to specific HLA antigen OF PATIENT”S SERUM- then fluorescent dye come bind that beads
• then machine detects the light from fluorescent

Cross matching ( flow cytometry)

• DONOR LYMPOCYTES -throw into recipient serum
• if binding of recipient antibodies to DONOR LYMPHOCYTES = hyperacute rejection